K2ENF audio processing, an update

 My suspicion turned out to be correct.
I've found in my experiments that the monitor function isn't as sensitive to ALC over-drive as the transmitter itself is. I've yet to check the schematic, but my operational observations suggest that the monitor taps into the audio that's fed to the modulator. So, in reality, one really has no way to determine where the "ragged edge" of ALC over-drive is. I managed to find that edge in playing with the local SDR's as was recommended to me about a week back, now, here on QRZ.

My results are not spot on what I was after but they're close.... and I'm finding busting pileups to be a lot easier as a result. My audio progress was confirmed to me just today when one of the stations I was working was live streaming on YouTube:

https://youtube.com/clip/UgkxJb4v8Ax6LSyDgmUAt_iLYHh-S3wdAQBG?si=dYkv7ypjH74dAzoT

I can't really hear what the transmitter is doing

I've written often enough about the audio system I'm using to drive the 991a. The object of the thing is the same as any processor... to raise the average power levels, and make maximum use of the available power in the transmitter.   I'm fairly close to what I want. I'm finding it much easier to bust pileups and make contacts.

Thing is, I'm not really satisfied with the  sound of the thing. After working with the external audio proc stack I'm using and experimenting with various settings over the last couple months, and combos of hardware, and the comments I sometimes get,  I'm becoming more convinced  of something I've suspected since I got this 991a:  That being, that the audio you get back through the monitor circuits (and into in my case, my headphones) is not what's on the air, but rather,  is tapped from the audio circuits before it goes to the transmitter.

I guess I should have expected this.
 

Look, for average use that setup is fine, but this isn't what most would consider average use. I'm aiming at a much higher average power level, on the order of 80 watts average for my 100 watt PEP signal, as oppose to the 25w average power we all get without any processing.  I'm actually getting that kind of increase,(and the respots I get suggest that the signal on their end s more more powerful)  but the amount of on air distortion is rather more than I'd like, and I think more than the average power levels I'm after should require.

It sounds good.... and I mean REALLY good, in my cans, but on air, there's more of a distortion component than I'd like, and since I'm not getting the actual transmitted audio in my headset, it's impossible to find that "crest of the wave" if you will.... that sweet spot where the system is giving what it can with what I consider to be acceptable distortion levels. 

Given the density of the audio I'm feeding the 991a, the on board processor and the ALC are both driven somewhat harder than they would be without the outboard proc, and so it makes it even trickier to set up, and even more imperative that you get what's actually on the air.  (As an aside, I've even tried running a clipper in mine after the agc/limiter, and then running with the 991 processor disabled. Still cant find the sweet spot because I can't hear what the transmitter is actually doing.)

I'm starting to think I should be using an SDR to monitor the actual on-air signal.. Trouble is, I'm unclear how to do that, since in most setups, the SDR is cut off while the rig is in transmit mode to protect the SDR from overload and burnout. I suppose that some resistance in the SDR's antenna line is called for... but that makes using the thing as a diversity receiver, as well as the transmit monitor a problem.

Obviously, this is going to require a custom solution.

10m contest

 Well, I watched (mostly from the sidelines) today as the first day of the 10m ARRL contest went by.  Don't misunderstand; I'm set up for some serious 10m work with my 991 and my IMAX. I've worked most of the world with this combo and with the audio  processor I've built up,  I certainly have no issues with busting through pileups. 

It's more that I simply don't have the time to invest. I'm looking forward tot he day when I can fully take part. I get the idea I won't be unheard.

This is Ham Radio

 

What was a special moment in your amateur radio career?

 Question posted at QRZ that I felt inspired to respond to.  I'll post in here; it may interest you and anyway, I don't want it getting lost to time.

Question was:

What was a special moment in your amateur radio career?

An excellent question with, I'm quite sure, a load of personal stories attached to it.

In my own case, my special moment came some 50 years before I was licensed for the Ham Bands.

I was out one summer afternoon, at about age 12, aimlessly riding my bike around my town. I happened to stop on top of a local hill, hoping for a cool breeze off the nearby lake.
When I got there, there was a car sitting in the parking lot of then local firehouse.Kind of battered, it had several antennas on it. He was chatting away on a mobile rig, which I now recognize as a Motorola low band unit with a modified control head.. I pulled up next to him and sat and listened intently to the conversation, since it didn't appear to be anything official. He looked over and smiled, and continued his chatting away.

After about 5 minutes or so, he asked me if I'd be interested in saying hello to his buddy on the other end. Being the curious lad I was, I lept at the chance. We chatted for a few minutes and concluded the (Apparently Simplex) contact.

It was Ham radio, of course. I've no idea who it was, what their respective call signs were, what their names were etc. Remember, this was 50 years ago.

But, as fate would have it, that memory stuck with me; I was hooked. And the truth is, I've always been on the air in some form or fashion for the 50 some odd years between then and now. I went through years of CB/SWLing, helped to build and operate a local FM broadcast station owned by the local school district, and because of that, went on to get my commercial ticket(s) Then I worked at several commercial broadcast stations both as air talent and as tech talent as well, eventually got my ham ticket a few years ago now. There was magic in the air for me in those days..... and you know what? There still is.

The lesson here is that you never know who you'll impress, whose life you will benefit. Even if the lives you come in contact with don't suddenly change direction, those impressions stay, and affect people in ways you might never realize. The intersection of lives is more than worthwhile. In my case, it made a life.

Real world rules for Ham Radio

 This will be a living document. As more rules occur to me, or are passed along, they will be added here.

 K2ENF Rules for Ham radio

1: Everything you do with your station affects everything else, both inside and outside your station.

2: After a few months of being a Ham you will realize that a drug addiction would probably have been cheaper.

3: CB operators will always be loathed by older hams, even though well over half of the hams of the last 20 years came from CB.

4: A non-conversational mode (say, FT8) will always be dumped on by operators whose radio conversations seem to revolve around their recent bout with (Insert a list of health issues you really don’t want to know about, here)


5:Tech of any sort appears totally unnecessary to those who don’t understand it.


6: Technology invariably moves many times faster than government (The FCC, the commerce Dept, your local zoning board...) is capable of.

7: Your list of friends will be centered around those similarly afflicted with the radio virus.

8:”That’s not Ham Radio” will forever be the battle cry of those resisting tech changes in Ham Radio.

9. Forget the amp. Concentrate on the sound. If you sound large, you are large.

10. RF is going to come out somewhere; and not always where you intend it to!

Yeah, it's like that....

 

What will the result of the elimination of the symbol rate be? Don't hold your breath.

 

Over at QRZ, K0IDT said: ↑

Well, US amateur radio got "bolstered", now what are hams going to do with it? I eagerly await the unique and innovative uses beyond the ones currently available
to amateurs on the HF spectrum or their smartphones. Maybe some software modem advances but usage will still be stuck where it is today, faster possibly but
not much else. Amateur SMS, texting and email is not an advancement of the radio art.

I've been chewing on this one for a while now, and I'm afraid that my response to the question will not please some.

I dare to suggest to you and the group that for several reasons, advancements in Ham radio tend to be rather slow. The hobby, in my observation, tends to be slow to adopt change. An extra step in that process is when there's been a regulatory roadblock.

Consider, as an example, that SSB came on the scene in 1933, but the ARRL didn't get into it (beyond the usual committees study of the mode) until 1947 when Byron Goodman started his QST column, “On the Air with Single Sideband”. And the first WAC/WAS awards in SSB went out in 1956. But we're still only talking about a few hundred stations with the ability. Despite this, the (rather heated) back and forth between the SSB crowd and the AM boys continued until well into the 1960's. In the end, the only thing that stopped those arguments was the then new argument over the value of "incentive licensing". ... which I note the old timers of today arguing FOR, while a goodly number of them were dead set against THAT change in the day.

So in the end, SSB took over 30 years to become really accepted.

Resistance to change. The pattern of this is well-established.
Other examples.... No code tickets. DIgi modes. I could give more, but you get the picture, I'm sure.

We're about to see it again, with this new regulation and the standards that will eventually come from it. What will those modes be? I suggest the ones who make that happen... the ones that will make that decision, will be the early adoptors and creators of modes that can be used in the new bandwidth.... with around half the ham radio population dragging their heels as they usually have historically.

So what will you and I get out of the new regs? I fear we won't live long enough to see what becomes of them.

Engaging with young folks, teaching Ham Radio

It's true, that are some  who will tell us that we really have no idea who Younger hams are and how to connect with them, and on that rather weak excuse, refuse to try.
 

Actually, however, I think we do know who we're dealing with.

We're talking about a group of folks who are technically adept to the point where they're the ones who get called to (As an example) solve computer issues that vex their grandparents repeatedly. A group of people who are used to the idea of carrying around more computing horsepower in their pockets than they had aboard the Lunar lander and know how to use it effectively. In the end we're talking about a group of people who scare the living poop out of their elders in terms of their tech ability, at least from a user standpoint.... and frankly, I can't help thinking this is the reason the Hams of today are reluctant to engage with the IPhone crowd.... or even more, the Android crowd. (Given the android is somewhat more accessible in it's internals.)

The trick is to get their curiosity peaked into finding out what's under the hood of radio, and learning about THAT.

Obligatory Warning: Once you get to that point, mixing the old and new technologies will be a natural thing for that crowd...That kind of melding of skillsets is going to be a natural for these folks. I speak from personal experience here, being someone who was a computer hobby type back in the 70's and once I left the broadcast industry, brought the skills of both fields to my Ham pursuits.

I wonder if that, too, isn't the cause of some reluctance on the part of today's hams to engage with tomorrow's. Look at the resistance to digi modes, etc. This new kind of Ham will bring changes with it that some are going to be unwilling to accept. But as Vince Gill sang:

"Just teach 'em what you know
and pass it on down...
Even though you built it
It's a young man's town."

Advantages of automatic logging?

 At the moment, my logs contain, 5793 QSO's of which, 4417 are confirmed. That comes out a hair over a 76% confirmation rate.  How is that confirmation figure so high after only a couple of years on the air?  Simple enough; Automation.

The vast majority of my contacts are either SSB or FT*.  Allowing for the slop in the numbers created by the smattering of other modes in my log,  that makes it that there are about 4900 contacts logged in either FT8 or FT4, or about 870 SSB loggings. 

I could dive into these numbers further, but it's clear to me there's a decided advantage in the digital modes in terms of logging new countries. Which in turn, suggests that the tendency is to log/ and confirm SSB QSO's less.

I'll dive into this more as times allow.

Tornado!!!

Technology and the personal connection

 My wife's gotten into playing the guitar lately, in a big way. She loves playing the thing. It does my heart good to see her dive into this thing with both feet.
But watching her go through this process, has got me to thinking about the physical relationship between music and those listening to it, and playing it.

There is an addicting quality I think, to playing music. And frankly years ago there was a similar quality to listening to music. There was a physical relationship in both cases.

Things have changed, however.
Consider the idea that with vinyl records and to a somewhat lesser extent with tape, there was a physical action going on and there was an interaction between the listener and the material being listened to. There's a record going around.

There's a tape in that machine that you can see being played. You had to put something there, you actually have possession and control of something that makes that sound. The equipment requires at least basic upkeep and a basic understanding to make those sounds. The maintenance and operations of such beasts is as much an art form as it is a science. There is a personal interaction at that level between you and the music.

With some more recent formats, say, CDs, and certainly with MP3s and streaming, there's nothing of the sort going on. There is no physical connection between the music being played and the listener. And it got me to thinking that maybe that's part of the reason why music hasn't been selling all that well lately. There's no holding it in your hand, no watching it being played. No technical expertise required to make all that happen on the listener end.

(Say what you will about the quality of MP3s, I will likely agree.... but frankly that's a discussion for another time.)

In the days of vinyl and whatnot there was a lot of listener input to the Hobby, if you will. That's no longer true.
I can't help but wonder if that isn't a major reason why sales of music has been dropping off, and why high-end stereo stores aren't doing well except for those engaging in sales of retro material and equipment..... The Resurgence of tape and vinyl.

Granted, the music isn't what it used to be either. For the most part it's been absolute crap for the last 20 years. But I'm starting to think that that's only half the issue. And the Resurgence of tape and of vinyl records for home use speaks loudly to me on that that point.

But but you know, about that as well, so much of today's music is being played on equipment and instruments that are as plug and play as the MP3 player.

Example:
It's certainly a lot more costly, less dependable, and certainly more fragile to carry a Hammond B3 /Leslie 147 combination around on the road with you everywhere you go. So, most people simply carry the synthesized equivalent. And it simply does not sound the same. Sorry, it just doesn't.

Another example would be Auto-Tune. Does anybody record vocals without it anymore? In listening to the radio these days, one has to wonder.

For that matter radio is another example of what I'm talking about here. Years ago every music station that you listened to had very little if any automation, or at the very least it was quite primitive and required a lot of user input. (An exception might be Drake Cherault, and their beautiful music systems.)
Back when top 40 radio was King, you had one or two folks on at all times who knew very very well how to run a manual live control board. Not only was there an art form to running the equipment but there was also an art form to making the sound. Every mix on the air was done live, you used Records & Tapes. There was "no holds barred" talent involved, there was a direct connection between the people on the air and the listener. I suggest that's one reason that Top40 music of the period remains popular to this day; there was a connection between the music and the listener that was aided by the relationship between the radio talent, and the listener.

Not so, anymore.

These days radio stations can run 24 hours a day without any human input at all. Every single element is pre-recorded, voice tracked, the mixdowns on-air between each element, are sloppy at best, the connection between the broadcaster and The listener is completely gone. And radio, is, as an industry, alas, is struggling, and wondering where their listeners went. Radio has become bland, impersonal, mechanized. And all of this before we come to AI running the show, which I assure you is coming and in a few cases is already here.

So again we come to the question... Have we succeeded in separating ourselves from our music by means of Technology?

(---

So runs the bit I wrote for general consumption a few years back and to the question I'll raise, here:

How does this trend i mention above, (possibly) affect Ham radio? Some of you will see where I'm going with this already, but let's spell it out:

I must wonder if the objections to the digi modes, the FT*'s etc, is not rooted in the same trends I note in the above piece. I must admit that it's possible, but if so, there's a lot of Ham ops mislabeling their objections, to the detriment of their own arguments.

If the comparison is true, (Obviously, I think it is) then the objection driving the complaints about digi modes, is the lack of human connection. And so anything that reduces that connection is labeled as "Not Ham Radio".

Yet, we are without question a technical hobby, a tech minded group of folks. Ham radio is placed in a rather unique position.... we're supposed to be on the cutting edge, at least if you take our charter seriously, which seems to suggest that the goals of maintaining that connection and being of the techie cutting edge, (At least at the current levels of technology) are mutually exclusive.
Is there a solution to this disconnect?

EmCon rears it's head again

 With the comment period 9n the fcc's new rules proposal for 60 m the arrl has responded with a call to amateurs to comment on the proposal with specific emphasis on the use of the band for public service and the experiences of individual hanlms in that context.

This response from the league goes directly to what I have been saying all along about the league using emergency communications as the wedge to drive governmental policy as regards ham radio. Not only operating privileges but a whole host of issues such as regulations on antennas global installations and so on.

Like it or not, Newington obviously feels that emergency communication is the best argument they have for defending any and all of amateur radio operation.

Iirc, one of the purposes of granting amateurs access to the 60-m band was the desire for interoperability between amateur stations and the United States military. I can't think of anything, personally, that would negatively affect that interoperability than lowering licensed power levels to the relative equipment of citizens Bank. Indeed in looking over this new proposal from the commission I can't imagine what got into their heads, and what the purpose of this new rulemaking is. Perhaps some of you have some insight on that point.

All of that said, I will repeat what I said a couple of months ago: The constant drumbeat from some amateurs that amateur radio is not an emergency service may technically be correct but in my view of the league in their efforts to protect what operating privileges we have.

Now, anyone who's read any of my stuff goes that I'm no fan of the league, but in this at least they are correct. If there is in fact a stronger argument to be placed before the FCC then the standard SHTF scenario, I've yet to hear it.

Bolstering amateur radio?

The FCC is trumpeting this today: 

We’re bolstering amateur radio. We will vote on a proposal to incentivize innovation and experimentation in the amateur radio bands by removing outdated restrictions and providing licensees with the flexibility to use modern digital emissions.

 I'm interested but not overly convinced.  Frankly, I've been writing about government for too many years to not be skeptical about ANYTHING they cough up, particularly when they sound like they're trying to promote something we're supposed to think is a good thing.

First, this vote will supposedly occur at an "Open Meeting" of the FCC. An Open Meeting just a dog and pony show; streamed these days on their website, wherein they read prepared statements.  That's it. And it needs to be remembered  that the commission has had these proposals floating around in their DC offices for over a decade, now, so nobody can accuse the FCC of a knee-jerk action, here.

Now, , you'll recall the conversations we've been having as regards the stock traders wanting HF access with high power and increased bandwidth. As I said at the time that proposal came up, it looks to me that the commission didn't expect the volume of howling from individual Hams to be quite so loud as it was.

With that in mind, it seems likely to me that this is the commission's version of "giveback". If commercial interests can run wider bandwidth, they reason, why should Hams be restricted? At least I suspect that is what they're trying to sell. The dog and pony nature of their open meetings doesn't lend itself to public comment, in any event. If they're bringing something up at this meeting, they've already hashed out what they're doing and how it'll be presented.

That said, I don't put much stock in the Chicken Littles wailing and gnashing of teeth over "the end of Ham radio" and more than I think FT8, SSB, or the break from spark gappers signaled the end of Ham radio.  Then again, I never have. 

Will the new rules be to our advantage? IDK, but it does seem to me that the commission will be reluctant to hand us any setbacks at this point. Yeah, I know....but understand me, here.

It's my take that they likely got clobbered to a level they didn't expect in the comment period for the SMC proposal, about how Ham radio was getting the axe from the commission. I'm certain, the league saw some of that thinking in their correspondence as well. (which would explain why folks like KE0OG took to his channel to address the issue with the message "Calm down". ) 

 

 How else, after all, to explain the loud trumpets surrounding the announcement of this proposal, about how they're "Bolstering amateur radio"? That kind of fanfare surrounding this announcement from the commission is fairly unique, in my experience.Why would they feel the need to promote things that way,except to counter that perception that the commission was working to eliminate Ham radio? I've been writing about government and the actions they take for too many years not to be skeptical, at least and in truth, cynical, thinking that In reality, there's no reason for it otherwise

 

As to what we WILL get...I doubt we're going to see (Lat's say) C4FM on HF outside of 10m, because (By Yeasu's description) that's using 12.5KHz generating the 9600 baud rate the mode uses. And frankly, I have my doubts that we'll see other digital modulation modes show up below 10m, (At least for passing voice) because even at the meager bandwidth C4FM uses,there's a practical consideration for the end user.... it still sounds like a bad MP3. Sorry, it just does. 

 

I've seen arguments going on over speculation that the commission was going to widen HF bandwidth limits to accommodate things like that. One can easily understand why they have (apparently) chosen not to significantly change those limits: Fear of running into this kind of creature. (Snicker) I mean, even a shallow reading of his reax to eSSB has me wondering if the prospect of digi sigs of 12khz (or, more) would have his family calling for an ambulance.

Let's bottom line this, at this: Doing away with symbol rate limits is a good idea, long past it's due. They've been sitting on this one since what, 2004, I think.  

 

However: 

 

At least in the near term, it's my read that there will be no significant changes to Ham radio on HF, either legally or practically. There are still physical limits on what we can cram into 3k of analog space and I don't see the average Ham having enough data processing horsepower on his desk to even partially overcome that limitation. Hell, I build my own computers, and I don't have such computing power available, either. In short any innovation in this area will first show up in the short bands.  

I'll be watching of course.

Emergency handling in the ham radio world

Had a conversation with Dave Jensen, W7DGJ the other day, in response to his recent article, Trials and Errors Issue #29: More Hero Hams -- the 1937 Ohio River Valley Flood

 I will suggest reading the article at the link before we go on.

Now, I know, there's been a lot of chatter about this over the last few years. I admit I take a different approach to the topic than many hams do. I tell Dave, in my response at QRZ:

A couple of things strike me about the editorial.

First the subject of regimentation of amateurs came up, regimentation of amateurs by government, the regimentation of response to emergency situations.

The editorial rightly states that emergencies are totally unpredictable. And, that's true.... Very obviously so. Indeed, in my opinion that's what makes them emergencies. Thereby, making a regimented response worse than useless in many if not most cases.

At the risk of sounding political, emergency planning by government is essentially impossible, thereby. Mind you, I'm not talking about one government or another, I'm talking about any government. Any government entity, any government individual attempting to plan such things except in the broadest of terms is destined for failure. And yet, they keep trying to do precisely that, in an apparent desire to maintain the power of control in their hands not in those of the volunteers. You know, the ones that are actually doing the work.

I suggest that the writings about this incident prove one thing that many people will wish they don't: training & regimentation is neither possible nor desirable in emergency situations and the people that are the most effective in those situations generally are simply doing what they can do, not necessarily what pre-planning by authorities, and regimentation has brought them to.

I suggest that a look at the volunteer fire companies around the country of 50 years ago versus what we have now, while perhaps not directly comparable, is instructive.

50 years ago most areas of the country had fire companies that were staffed by people who are completely volunteer. These days, as time has gone on fire companies have become professional organizations represented by unions in many cases.

The volunteer .... And with it, alas, the spirit of volunteerism, has essentially been erased under the weight of the attitude of "let the professionals do it".

As a result of this progression, many fire companies are left wanting for staff.

One could certainly argue that we are better protected by such a shift, at least in the more heavily populated areas because of the training and regimentation. (Well, at least government believes so...) But there are so many holes in those lines as to make that argument at least a bit more difficult.

Is this where amateur radio is headed as regards emergency response? And this brings us to our second point:

The league has been using emergency response ability as a lever, (one of several) as a means of justifying our operating privileges or frequencies and so on.

The negative effect on amateur radio of downplaying our emergency role is obvious and quite probably devastating, both from the standpoint of "let the professionals do it, it's not my job". (see also, "ham radio is not an emergency service", and the usual jibes about the "yellow jacket crowd".)

And thus needful things not getting done in a timely fashion in an emergency situation...

And also, from the standpoint of being able to maintain those operating privileges. Governments want some return for their investments. That's simply how things are these days. They need to know when time to regulate spectrum comes along, when questions of local zoning boards regulating antenna structures, of our ability and willingness to throw a shoulder where needed. Down playing that role, as I have seen happen so often here on the Zed, runs directly counter to that purpose.

 Dave responds, in part:

I love this line from that ARRL editorial, "The very greatness of our performance early this year now attracts many agencies who would like to commandeer, direct us, and so on. Let them understand that this service comes from us, of our own volition as free agents. We shall want to help them all as much as we can, but of our own accord and not by direction."

Friends, the message sent in that paragraph is the very essence of Americanism.

The message is that  it is the individuals, not the government, that makes us great.  Too often, those in government have either neglected or actively worked against that spirit. Does anyone suppose that editorial could have been written by the League today, much less be lauded by it's members?

. The message is that  it is the individuals, not the government  that makes us great.  Too often, those in government have either neglected or actively worked against that spirit.. Does anyone suppose that editorial could have been written by the League today, much less be lauded by it's members?

. The message is that  it is the individuals, not the government  that makes us great.  Too often, those in government have either neglected or actively worked against that spirit.. Does anyone suppose that editorial could have been written by the League today, much less be lauded by it's members?

. The message is that  it is the individuals, not the government  that makes us great.  Too often, those in government have either neglected or actively worked against that spirit.. Does anyone suppose that editorial could have been written by the League today, much less be lauded by it's members?

. The message is that  it is the individuals, not the government  that makes us great.  Too often, those in government have either neglected or actively worked against that spirit.. Does anyone suppose that editorial could have been written by the League today, much less be lauded by it's members?

the message sent in that paragraph is the very essence of Americanism. The message is that  it is the individuals, not the government  that makes us great.  Too often, those in government have either neglected or actively worked against that spirit.. Does anyone suppose that editorial could have been written by the League today, much less be lauded by it's membe

the message sent in that paragraph is the very essence of Americanism. The message is that  it is the individuals, not the government  that makes us great.  Too often, those in government have either neglected or actively worked against that spirit.. Does anyone suppose that editorial could have been written by the League today, much less be lauded by it's members?

More on the external processing at K2ENF

 Well, after running the external proc for a couple of weeks, now, I'm getting the hang of what this thing can do and what it shouldn't do. I must say I'm quite pleased with the reports I'm getting.

One of the things I've discovered, is the value of the expansion and noise gate ability. In fact I've come to think it's critical for a good signal.  To explain this, however, I've got to dive into the settings I'm using, and the working philosophy behind them.

Remember that the goal here is raising the average RF power levels by several DB without adding any undue distortion.  Understand what I mean, here. I'm not the audio purist in ham radio some operators are. I'm willing to deal with a bit of added distortion to a certain point, so long as I get the advantages of the increased audio level/RF level. 

So, here's a quick overview. 

1. Whatever mic I'm using. (Usually a Hiel pro-set 6 headset.)
   
2. Gemini mix console with EQ to bring things to line level
   
3. The Behringer Composer Pro-XL MDX2600 
4. Optimus 10 band EQ set to pass 100-3000Hz with a 3db push at ~2100Hz. 
5. Pyle breakout box with a pad to distribute the audio to a second console for recording conversations and to bring the audio back to microphone levels for the radio.
   

The 2600 Pro is a a broadband Noise Gate/ Compressor / Limiter/ De-esser  and is the star of this show.... It is a Stereo unit. but I'm not using it that way.  I have the two channels, left and right, running in series, each one running independently. . In other words, the audio comes out of the mixer and runs to the left channel as the first stage of level control.

This first stage (which if you like to think of it as such, is the left channel) is set up with a full-on noise gate which opens up at seeing anything on the inputs above about 15db down. This keeps stray noises from being broadcast and helps keep the radio's vox control in line.  Once it gets over that threshold, it goes directly to the compressor, with about a four to one ratio.... a slow attack and a slow release. The De-Esser is set fairly loose, only acting if it sees a very serious peak of higher frequency content. Remember, I'm trying to keep the audio bright with the input EQ leaning very heavy on 2100Hz, , but at the same time you need to keep it under some modicum of bandwidth control. So, the I have the De esser acting in peak mode, which over-rides the slower settings.

The second stage is the  right channel. I'm running the audio directly out of the left channel output to the right channel input, with the system set in "dual Mono" mode. The two channels' level controls operate independently, one from the other.  This "side", I have set as a pure peak limiter, with the rise and fall times set very fast indeed, including perhaps 8db worth of noise gating here. This helps provide a bit of definition between words.

This setup theoretically would allow me to run twice the compression... but that's not the purpose here.  Rather, doing it this way allows me to run two separate compression and expansion curves.... the first fairly slow AGC/Noise gate and the second very fast peak limiter/expander.

The purpose of the peak limiter is obvious.... it's maintaining very tight control over any peaks directed at the radio. With the expanders (noise gates) disabled, my peak to average ratio on my air is about 2 or three DB... no more. (If you're looking at a VU meter, that would be the difference between 80% and 100% Or if you like we're talking about less than a half an S-Unit of received signal between the room ambience and my voice.)  That would mean, absent the noise limiting, that I'd be picking up massive amounts of unwanted signal from the room. Echoes, fan noise, etc.  I also have employed the de-esser here as well, which seems to help in keeping the bandwidth inside the 2800 Hz wide skirt. (100-2900)

But here's the secret:  As long as my normal speech is above the threshold of the noise gates, the audio goes directly to as close to zero DB as no matter.  Below that level, the noise is unheard, as is the echo, my breathing, and so on.  No wasted watts, no clutter on the signal.  

I'm getting amazing reports and I am busting through pileups with little effort, even on those occasions I've run with with RF power levels reduced. From this, I learn two things; 

• With the power on full, I'm getting an average power I'd never be able to achieve without the external processor.
• Even at lower RF power settings, I'm being heard, apparently due to the distinctive nature of the audio. 

Both of these factors make a huge difference between my being heard or simply being buried in the noise. And, being heard is the whole point.

Interesting results with the IMAX2000

For about the last two years now, I've been running an IMAX2000  at about 35ft for working 6m-20m. This is one that was made before Solarcom bought them up. This version is 26ft tall whereas the more recent Solarcom version is made a bit smaller, at 24ft, so as to be able to ship the things more cheaply, at the cost of some performance. 

I should explain how I happened to get the thing. I've been running a local net on 10m for the past couple years, now. One weekend, we had a storm come through and wipe out the 40m end fed I'd been using.  Part of an old tree came down on it. I needed something in a hurry to allow me to run the net that night, and so I jumped at an offer made by a friend here locally for the IMAX for $30 bucks. I had only intended for it to get me out of the immediate troubles, never dreaming I'd be keeping it in the air as long as I have. I immediately started getting fabulous signal reports. (What the bleep are you running?)  It's a stone fact that a lot of the guys around the Rochester area started snapping up IMAX antennas once they heard me using this one.

Yeah, I know... A CB antenna?

Yep, and likely this older design is the best kept secret in Ham Radio. Indeed;  I'll tell you flatly, it's the best 10m omni antenna I've ever used. And well, my logs speak loudly to the validity of the design... with well over 5000 QSO's, all 50 states and 138 countries in those two years.

Here's the deal; At 10m it's a .64, which is as large as you can get in a vertical, without the pattern collapsing on itself, With 100w in on 10m from the 991a, and it's 5.2db Gain,  the numbers say I'm getting just shy of 400w ERPi, and somewhat less on the other bands. (350 if you subtract the losses of the LMR400 I'm feeding it with. ) I'm using 20ft worth of aluminum mast which I immagine provides aply counterpoise, which in turn keeps the radiation agles appropriately low for groundwave work and gives me an edge when DXing. I suppose the ground-plane kit would do even better but I've not managed to locate one, yet, and anyway, I'm unconvinced it wouldn't affect it's abilities outside it's designed bands.

In the process of the A/B comparison with the new tuner, I've left the antenna's tuned resonance point at around 27.800MHz, which allows me to run 15m, where the IMAX is a perfect half-wave, perfect match, no tuner needed, and still respectable gain.. 12m is also "no tuner", giving about a 1.7 match, though of course I use the internal tuner on the 991 to touch that up. On 17m and the bottom of 6m, I can handle also with the my Yaesu 991's internal tuner.   Past that, say, 20m, and 30m, an external tuner is required.

I had been using an MFJ 941b tuner until recently. The Inductance switch was giving out, however, (the shaft, where it intersects with the switch plate was loose... I gather this is a common problem.)  I decided it was time to upgrade, I managed to find a used MFJ Versatuner II (MFJ-969) at a local Ham Fest.

One of the first things I attended to with the new tuner was to put it through it's paces at the ends of the coverage the 941 had given me. The 941 was able to tune the IMAX to resonance at the transceiver on 20m with some effort, but no lower, and up to about 51 MHz on 6m, but no higher. Now, the antenna itself is also tunable to the extent of around 1MHz, but I left that alone for the purpose of keeping the comparison apples to apples. Besides, I didn't want to mess with the results I'm getting on 15m.

I found with the new VersaTuner that it would tune all the way down to 80m, but performance really starts falling off below 20m. 30m is marginally useful when the band is open, but the performance isn't really satisfactory. Even on 20m I reckon there's about a 6db loss in efficiency, so I can only imagine what it is down below that.

My assumption is that the loss of performance would be even steeper if I were not running very low loss  feed-line to it, given the amount of power absorption in, say, 8x when presented by a high actual SWR.

The amusing thing about this is the reaction I get from the folks on 20m when I tell them I'm running 100w into a CB antenna.

So, two conclusions: 

One: The IMAX stays where it is.
And two:The new tuner, aside from needing to clean up the inductor rollers a bit, was worth the $100 I paid.

End Fed Half wave in Half Square config....

 

The End Fed Half wave in Half Square config?

 

That's a mouthfull!

Essentially, I'd planned on doing an inverted L, It turns out that I would need a much more substantial guy wire system to make the fiberglass poles stable in the config I'd planned on using.

 

That problem was the first thing I noticed when I pulled the instruction manual out of the box containing the 46ft of fiberglass pole.

(Rats, here we go again.)

 

Then I remembered a vid that Peter Waters put up about a year ago.

 

Consider the drawing, below, courtesy of Peter himself.

 

 

 

What we have here is two vertical 1/4 wave antennas held in phase because there are two quarter waves of wire in the top section that feed from one side to the other. This results in about 3db worth of gain over a single quarter wave with appropriate ground plane. That gain comes off broadside to the antenna. In other words, you're standing right in the middle of one of two strong lobes as you look at the drawing. In my config, that means SW/NE.

 

That alone makes this thing attractive to my situation, given I can't go "up" as high as I'd like. I'm less than happy with only about 18ft worth of height. (understand.... the antenna ends are raised about the ground by a foot or so). I am thinking that the poles should eb reasonably good at the much lower height and wind load. At this height, the thing models to a radiation departure angle of about 18 or 19 degrees, in my modeling. Not the 5 degrees Callum likes, but not too bad.

 

One trouble is, it only works on 20m, if you're planning on running current fed, to get your usual 50ohm loading.

 

But there's one more bit of magic I'd not considered until going over Peter's vid again:...

Note the voltage feed point, on the one end, left side. Attaching there will give you about 2250 ohms, which of course is perfect for my 49:1 Un-Un.... and what you have here, effectively, is a half wave end fed for 40m, which will work on 40,20,15 and 10m and likely be close enough for the tuner to get me on about everything else.

 

Glad I got the VersaTuner at the Roc City Fest!!

 

So, this will be the way I go for the time being.

Comments as always invited.

The culture of Ham radio.... past vs present

 Every group, be it a group of family, friends, a group of professionals, a group of Hobbyists, whatever.... in fact, group you'd care to name, has it's own Culture. (mini-culture, microculture, whatever you'd like to call it.)  Each group has their own way of doing things, their own values, their own way of doing things, their own way of speaking, their own value structure, their own  stories, their own metaphors, and so on.

 Add to this, there are subsets of each grouping..... that have their own mini-culture within a mini-culture. 

Ham radio is no different in this regard than any other such grouping of people. 

The purpose of bringing all this up is an observation that a goodly amount of friction within Ham radio circles these days, is caused by a perceived slight by one sub-grouping within Ham radio to another. 

Consider a recent conversation on QRZ, wherein I posted the following Video:

 

 

Now, I happen to think the operators in question did a pretty fair job at what they were doing; passing info about the event. But of course there are those who disagree"

"I am sorry, Net Control was distracted."
"QSL"



This is why they won't even let us borrow the keys to the clown-car anymore.

 

And...

 

No real net control and they all run over a guy asking for help. I am sure if you tell them they will get all wrapped up in being offended. 

One of these two goes on from there:

My heartburn focuses on overview of the style, substance, and discipline (lack-of) by all stations concerned.

Net Control sets the tone. The situation for which this communications circuit was activated is a tornado--potentially a catastrophic situation with safety-of-life implications. Yes, we're Amateurs, not professionals--I get that. But the comment "Sorry, NCS was distracted" is superfluous and has no value to anyone. A skilled communicator transmits "SAY AGAIN"--that's all. No one knows or cares why a message was lost.

Likewise, sorry boys and girls, "QSL" on Amateur radio is no more appropriate than "10-4"--which I'll bet you all a small Dunkin' Donuts coffee 85% of you folks would go beserk over when you hear it. But--sorry--QSL to me sounds like 10-4 to you. Totally unprofessional and out-of-place. ROGER is the procedural word.

There were indeed all kinds of Amateur nets of every purpose, only several decades ago, where squared-away radio communications procedure was practiced, utilized, learned and advanced; everyone involved took justifiable pride in their proficiency & efficiency.
Emergency Management entities welcomed hams' help because many of us had listening skills and communications chops. Perception has now become reality. No one wants us anymore--for cause. This emergency situation voice network sounds like an ordinary Tuesday Breakfast Club at the Rome Point Cafe, only on VHF radio instead of the corner table for 6.

In any structured, disciplined critical endeavor--Emergency Medicine, Maritime, Aviation, Firefighting, Safety of Life radio communications-- the philosophy is "We train like we operate and we operate like we train." When things get stressful and overwhelming, as in a real-life bad situation, humans 'default to primacy'--under stress we get knocked-down to what's baseline and normal behavior. That's why a good communicator works
towards being effective every time, sounding like he or she should, every time. You can't just turn it on when it's mostly been off.

I wonder if this guy understand just how petty he sounds.  As I told him:

If he was in fact at the EOC it was probably intended to keep the government authorities more informed than they would have been from routine police and fire patrols. At the least, they apparently accomplished that.

The assessment on the idea of net control being distracted seems to me a trifle unfair. If he's at the EOC he has doubtless got information coming in from every direction, not just the radio that we're listening to.

I've been in police dispatchers quarters when major emergencies were happening. For example, when hurricane Agnes came through back in, what, 72? Getting data from multiple sources simultaneously is more than a difficult job.

 

I didn't bother to respond to the rest, mostly because I doubt he'd have understood my point if I did.

Where is this attitude coming from? He's defending his own mini-culture. What we're seeing here is a modification of the "Not Invented Here" syndrome we so often see. It's the same issue as some operators as regards Digital Modes.... FT8 for example.  I regard these complaints, these attitudes with annoyance mixed with some degree of amusement, in much the same way as I regard Socrates bemoaning the end of civilization:

"The children now love luxury; they have bad manners, contempt for authority; they show disrespect for elders and love chatter in place of exercise. Children are now tyrants, not the servants of their households. They no longer rise when elders enter the room. They contradict their parents, chatter before company, gobble up dainties at the table, cross their legs, and tyrannize their teachers."

First, the obvious comment is that Socrates' complaints to the side, Western civilization didn't end, it was EVOLVING, and was so even then. 

Second, let's now tie this in with my opening comments on this post: The complaint about quality of operators is not a technical thing. It is a social thing, a cultural thing. The complaint is not that traffic is not being handled, that messages and info aren't going out, and being understood and passed on to the appropriate authorities. It's that the traffic didn't sound the way he wanted it.

As I said, petty. It's the same self-righteous indignation directed at those running FT8 and getting their DXCC in six months instead of 40 years,   It's the same self-righteous indignation directed at"No Code Hams", ARES members, REACT members, Emcomm enthusiasts, and essentially anyone that doesn't fit their mold.

 Sing it with me, Children...."It's Not Ham Radio,

Except it is, regardless of his liking it or not. 

I'm of the firm belief that the attitudes we see here are harming Ham radio, not helping it. 

I close with the thought that as Paul Simon once wrote: " Orangutans are skeptical of changes in their cages". I hasten to add that the average age of ARRL members is 69.5.  Get the picture?

 

Two Meter Opening

 Openings on the 2m band are rare enough that when they happen, there are celebratory noises. Yesterday, the band was hot and now, today it's even hotter.  Here's a look at conditions today, based on APRS data:

That sea of red represents where signal paths are for the shorter bands, like 2m. And here's the list. These are made with FT8, 50w at 25 feet with a GP9 antenna, providing on the order of 400wERP:

And here's the activity for the previous three hours. Each dot and line represents a contact within the past three hours from when this is written.

From the memory file: Why I run FT8

 I wrote this a couple years back, while as a tech and before the short bands started opening up.  I thought to share this here. Since this was written, I've gotten all 50 states and 138 countries.

Yeah, OK, I know…. You’d rather be having an extended chat with your DX contacts. Well, sorry, but that’s not always going to happen. Particularly when you’re a tech, who is still learning code.



(And I swear, If I hear “That’s not ham radio” one more time….. )



On recognizing that my minimal setup (An FT-991 my home built desktop computer(s), and a handful of antennas, no amplifiers, etc) and a tech level license wasn’t going to get me much in the way of DX contacts on 10m…. which is the only place I can run any DX at all, really…. As I say, I’m still learning code yet. And so my digital and voice activities are limited to 10m.

So, what’s left? When 10m is open, I’m glad of it, and can occasionally get phone contacts. But for so much of the time, there’s a total dearth of any contacts at all…. At least on voice. There’s RTTY, of course, but in the last year I’ve only made one…. Count your nose, ONE contact via RTTY and that was by per-arrangement on one of the local 2m machines. PSK31? Apparently the bloom is off the rose for that one. I’ve yet to hear anyone running any PSK, Olivia, or for that matter any of the other modes offered by FLDIGI… and Lord knows I’ve tried.

So, that leaves Joe Taylor’s monster, FT-8. Particularly with the sunspots being questionable if they existed at all. We’re on the leading edge of the sunspot cycle as this is written, and so good DX isn’t east to get with the band closed.


And so it was… Closed, that is. I noted hardly any voice contacts over that period at all, despite wasting several hours calling CQ at or around 28.400, every time I sat down. And the more established DIGI stuff was pretty much the same. … But running Joe Taylor’s version of NBFSK, I’ve managed to rack up some rather impressive totals: At this writing, some 540 Qso's (247 confirmed) in 33 states and 23 countries. And I should also say in fairness to me, that I run a 10m net on 28.405 every Saturday night... (1930 eastern) and that's downright fun.

So, when you ask me why I like to run FT-8, that’s my answer. Do I like to rag chew? Certainly… when the opportunity presents itself. But I also like to experiment with Antennas (My IMAX2000 seems to work pretty well, my EFHW, somewhat less so) and I’m learning quite a bit about maximizing my 100w signal.

OK,Having a chance to chat with my DX contacts would be a decided plus. But in a choice between making DX contacts or not making them at all, which way do you figure I’ll go?


So til 10 opens and/or I manage to up my ticket...(in the works, now) you’ll hear me playing bagpipes pretty frequently.

 

A Hams plans are never really completed

 I've noted in the past, that when you're a Ham, you tend to stack projects that never get completed. I must admit this has always been a  character trait of mine, even before I got my ticket a few years ago. But these days, at least I have a reason, being home one day per week, usually. There simply isn't TIME to accomplish all the things I'd like to.

As an example, Antennas.

I've been trying to get to installing antennas in my back yard...(Garden for some of you) for a couple of years now, but something always seems to get in the way. I design a way to cover all the bands I'd like to cover, and the wife will decide she doesn't like guy wires, or that antennas are "ugly" and so new plans get made to satify that.. Or I get asked to work an additional day or two. Or the weather gets in the way. Even plans that sometimes don't work out, on those occasions when you do actually have the time. And each time, I end up starting over from line 1.

I've had a computer waiting for an OS installation for the last several months, now

I need to re-org my shack, the place is a disaster area, always teetering on self destruction.

Frustration seems a key element of this never ending story. 

Increasingly, however, I have begun to notice a different element in all of this; a desire to improve on the projects I've managed to complete, being never fully satisfied with stuff I've already done. Thus, my list of projects tends to grow exponentially. 

'"At last, I'm organized", he said. And then, he died.'

So goes the old saying, and I suppose it's true.  I get the idea that when it comes time for me to leave this world, I'll be disappointed because I didn't mange to get more of my project list done.

 

 

 

The Shortwave Modernization Coalition?

 

There's been an awful lot of talk the last week or two about a proposal for rule making (PRM)  that's currently before the FCC.

The request has been drawn up by a group which labels itself the "Shortwave Modernization Coalition." (SMC).

Apparently, this group is largely made up of Wall Street types, international Wall Street types in fact. 

They propose transferring data from our continent to theirs,  by way of a single transmitter as opposed to going through the internet, since it exhibits far less in the way of latency. The complaint being that that connection, that late latency that's been going through the internet has been costing these folks large amounts of money. Such is the state of our stock market these days the trades are going that quickly and the thing is in the estimation of the shortwave modernization coalition it's worth the money to invest in those systems, which certainly will not be cheap to erect, use or maintain.  They're talking about using 20KW TPO which is used with a directional antenna (why wouldn't they?) means quite a bit higher in ERP.

(Aside: It's been pointed out that this proposal if enacted, would create a serious and likely insurmountable advantage to the users of these systems. I point this out to show you the weight behind this proposal. But let's still with the technical and Ham radio related aspects, shall we?)

The SMC as I will call them, has been doing test operations since 2014 or so, using 10kw transmitters.. They point out in their PRM that nobody's complained about interference from their operations at the 10K level they've been playing with,  from from anybody else in the electrical neighborhood including maritime, aircraft, and for that matter amateurs and shortwave broadcasters and of course, Ham operators. 

(Aside:Further, I question what the added 3dB will give them, but, no matter for the moment on that part. )

I must admit that my initial reaction came from my technical side and was in effect "Well, that's interesting". But then the more practical side spoke up. As in, " Hold the phone!"

Without even looking at the proposal in detail, one question that pops out is bandwidth, another is harmonics, and with that kind of power, the issue becomes quite serious, in my view.

Let's face it ...if it has the proposal suggests their concern is getting messages through as fast as possible then the standard 300 quad rate isn't going to cut it anymore and at a power output of 20 kilowatts you can make a mess out of large portions of the HF spectrum in a real hurry, that go well beyond the primary frequency.

For their part, the FCC seems amenable to these ideas and has been pointing out for as long as I can remember that the HF spectrum is underutilized.  so I'm guessing that without a serious amount of pushback commission is going to be inclined to Grant the request and put forward an NPRM before the echo dies from the comment period.

But again, hold the phone, here. 

Before you get the wrong idea I do not believe that at least initially we're going to have problems with our proposed new neighbors. But I do believe the trend being signaled here is worth watching if we value our Ham radio future on HF

Large as the concern about problems radiating from this proposal, (sorry, couldn't resist) The FCC's attitude about this creates an even larger concern for me, when you look at the proposal and see where the money's coming from for it. Places like Ukraine, and Saudi Arabia to name a couple.Now, as traders begin to recognize the financial advantages of using systems like this, the rush for added transmitters and frequency space will skyrocket. Therein, in my view, lies the bigger issue. We're going to be drowning from these new, high power systems. I don't care how tightly they're filtered, there's bound to be problems for other users of these bands, including alas!, us.

 I mean, we're talking serious money here and I suspect that if this proposal becomes reality, we're going to start seeing large chunks of HF real estate being sold off with the money going into the FCC's wallet. Money they seem to think is desperately needed, if we observe the process by which large amounts of spectrum were sold off, the sales and the regs surrounding that sale,  rammed through like a bullet from a rail gun, for the cell phone companies.

With that kind of money involved the question becomes whether or not the ARRL (Who is, in all fairness, already reacting to the proposal) will be able to withstand the obvious desire for large growth in HF traffic.

Keep an eye on this thing. If you get some expertise to bring to the table in the way of comments for the commission, do so.

Addendum:

Tom, W9YW responds:

I have two minds on your posit,

. The first one is that we lived with short wave broadcasters around the world in HF for >100years. They were a fact of life. A few were coughing bad signals, but rarely did it cause a problem, even at >100KW of directed signal. Yes, that signal was AM and easy to shape the harmonic slope-- not high speed encrypted digital goo. But we lived with it. Part of the reason for the wide spectrum, I'm guessing, is that the new broadcasters want to prevent jamming, and also optimize their commercial goal-- quickly executed arbitrage that makes them revenue. That's understandable.

The other mind says that it will be random frequency, encrypted data, the kind that hams aren't allowed for both national security reasons, and assurance that other uses of the spectrum aside from the allocation aren't being used.

Their proposal lacks, and this is my other state of mind, a sufficient analysis of a highly sampled, nation-side scatter of what their signal actually looked like so that a FFT reception can be known. Meaning there aren't enough statistics nor boundaries to the signals used to vet that the transmissions won't harm other users of the spectrum to the fifth harmonic of the fundamental. Once it's allowed, the mode used over the bands allowed won't be easy to pull back or halt, and the squabbling will be huge and expensive because of the investments made. We also don't know how many concurrent signals might be used, by whom, and the boundaries of signal mode types. After revealing this, we know much more. Their data as proposed seems insufficient to me, and I have a lot of quality engineering background.

73 Tom W9YW

I can't disagree with your response, Tom.

Having just downloaded a copy of the PRM, I'll be examining it over the next few days. Obviously, (And as I think I indicated)  my comments were of the "first blush" variety.

Your comments bring up a few other thoughts and a clarification or two that perhaps we should explore.

I believe that once one leaves the realm of experimentation, which Ham radio certainly always qualifies as,   as has what the SMC has done so far, it's my belief that the commission should demand the same level of detail, and accept the same levels of public comment as we see in the world of commercial broadcasting. Certainly, this SMC project is a commercial operation, and should be directed to jump through the same hoops... including precise frequencies used, power levels, radiation patterns, testing for harmonic issues, and a standardized operational mode. So far as I'm aware, we've seen none of this.

More succinctly, I agree their data at least so far as I've yet seen, seems vague at least. Must be, nobody's directly commented on it, except to suggest increased bandwidth would be required for the kind of transfer speeds SMC is aiming at, and that seems a no-brainer right at the off.

That's troubling of itself, but further..... and here we get into the non-technical..... I'm made somewhat uneasy by the proposal that the signals be encrypted.

Your historical examples make your point well, and  like you, apparently, I have my doubts that at least in the first wave, we're going to have any serious interference issues.  Thing is, the argument fails to address the idea that they were, shall we say, open source. We knew what they were doing, were able to monitor their transmissions and so understood if harm was intended or not.  As Ham operators we can run any kind of protocol, so long as it is publicly documented. That minimal restriction was imposed for reasons of national security.... a wise precaution.

That's not, however, in what's being proposed here. We're talking about super-fast signals owned by foreign nationals in countries that have no always been friendly to us, and whom we have no guarantee, or even any indication, that they will be in future. (Smiling faces sometimes) 

 Yes, financial data, and I understand that point. Indeed, as I suggested in the OP, this proposal if enacted, would create a serious and likely insurmountable financial advantage to the users of these systems. That of itself may very well impact national security. We're talking about vast money, here, and that kind of money rises to the level of national security in terms of financial impact here in the 'states.

But can we trust that other data, of even more of a national security problem, isn't going to be buried in the data streams? That seems a security red flag at least, but as I suggested in my OP, I was trying to keep my comments (mostly) to the technical issues presented we as Hams by this proposal should it ever be adopted. At the same time, I'm unsure I trust anyone anyone at all, to monitor such things to ensure national security. Taking a chance either way in my view.

The commission appears to be looking at this from a purely technical POV as is their wont. And from a purely technical standpoint, the proposal seems fairly harmless in the short term, as I've suggested. But there seems more at stake here than that, and I wonder if more than just the commission will be involved here.

Audio processing at K2ENF

 Well, it took a while, but I've got the external audio processor running correctly.  There's still some tweaking to do, but it's mostly there. I've made some mods to the original design for a bit of simplicity and because of newer hardware now in the shack.

So, here's the path:

Whatever mic I'm using, going to a Gemini GEM-05USB mix console. This brings the level up to common line level, but it also has an EQ in it, which eliminates the need for the EQ I had designed into this stack. 

Then, we have a Behringer Composer Pro-XL (MDX2600) This is a noise gate / compressor/ limiter/ De-esser, This keeps a much hotter input level to the radio, on average, and takes away the heavy lifting from the ALC. The result is a nice dense audio, without the overshoots the ALC is frankly too slow to respond to. (I'll expand on this thought, shortly)

And of course the 991 has an internal EQ as well, so for the moment I'm not running a second EQ on the output of the 2600, though I may tinker with that later on.  The EQ's are set up mostly for bandpass, but also for a little punch.  

Aside: With the two EQ's one on the 2600 input and one on the output, 'm quite sure I'm getting some weird phasing within the band-pass, but not enough to worry about since most of that's being swallowed up in the phase shifting the 2600 is inducing... nobody's going to notice. And, anyway, there's some advantages to phase scramble, in terms of filling the RF envelope. 

 Here's why: The human voice is notoriously asymmetrical. If you look at most folks voices on a scope,you'll notice that the voice tends to swing either more to the positive side or more to the negative. This asymmetry is hugely inefficient when you're talking about maximizing a signal, particularly AM or SSB where the audio IS the power.  With most voices, you leave 25 to 30% of the RF envelope unfilled by audio.A bit of phase scramble over the width of the bandpass tends to counter that. tends to counter that.

Why would an AGC cause phase changes? There are very few phase stable AGC's, in my experience. Ask any broadcast engineer who has dealt with multi-band processing about that.
 

The result of all of this is quite encouraging... I'm seeing higher average power, on the order of a couple dB, and I'm also noting my bandwidth consumption has gone down somewhat, even with the higher amount of audio on air... to the point where I'm now easily within the 2800 hz bandwidth I've been shooting for, whereas before I was seeing ALC overshoots getting out from under the skirt, particularly when I was "getting on it. " Now, no such problems. I've said it before and I'll say it again... the ALC in most transceivers simply isn't up to the drill of maintaining max audio without getting nasty side effects.  I expect the de-esser on the 2600 is helping there, as well.

Next, now that the basic framework is laid out and working well...

I'm considering a DF4ZS RF speech processor. to be placed at the output of the 2600. It's essentially an RF Clipper.. For those who don't know what an RF clipper is, it's basically a transmitter receiver combination.What happens is, line audio is fed to the transmitter side and the audio is run to saturation level of the internal (AM) carrier..  The receiver portion detects the processed audio, and converts it back out to line level, which in my case would be fed directly to the 991a. 

Here's a nice techie explanation of the concepts involved. It explains that AF clipper does work, but has serious limitations.  Tom Kneitel, K2AES, (SK) wrote an article years ago on these topics that alas, now, I can't locate. He called the RF Clipper the "Poor man's linear", and he was right.

. Those beasts are very effective, but rather touchy once you venture outside of their level "sweet spot". Now that the 2600 is in place and working well I should have no trouble with keeping level in the sweet spot of the clipper.  I figure it'll add perhaps 5db worth of talk power.

(Yeah, they advertise up to 9db.... but I figure some of that ground has already been achieved by the stack as I've already described to you, and a bit cleaner, since the clipper only uses clipping as it's gain reduction, the 2600 doesn't. I won't need to drive the clipper nearly as hard for the same result. No danger of over driving the clipper with my current setup. .)

Why go through all of this?

For starters, consider the FCC's RF exposure paperwork, (Which the ARRL linked here) which suggests that conversational SSB has a 20% duty cycle. Supposedly heavy processing brings that up to 50%. In other words, even with the (rather lame) procs in most HF transceivers, the proc adds another 30w of average power in a 100w setup, better than doubling the power and raising the signal on the received end, what, about half an S unit?

Trouble is, as I've already suggested,  pushing most of the procs on even today's HF radios that hard for that rather modest gain, you'll end up taking more bandwidth than most consider wise. The problem is that ALC is used for most of the heavy lifting, and as implemented in even modern day transmitters, it's simply not up to the drill. The ALC lets a fair amount of signal peaks slip by it which results in audio clipping. Drive the ALC hard enough to get a 50% (Or more) duty cycle, and you'll be clipping the bleep out of your audio.... and the filtering following the ALC is, if it exists at all, is simply not up to the drill of keeping your signal "in bounds" under those conditions. That's without even mentioning the other artifacts caused by such a setup.

Consider Collins and the work they did years ago.Example, "Single-Sideband Systems and Circuits by W E Sabin and E O Schoenike", ( ISBN 0-07-054407-7)

(I gather they were working for Collins at the time of publication.)

As dated as that work is, most transceivers, even to this day, do not employ their advice on design and implementation of processing. In short, there's a LOT of room for improvement. And of course with technology improving rather a lot since those days... (including better output filters) the improvements in performance can (and, I think should) be even larger. In short, your signal is not nearly as efficient and clean as it could be.

I suggest reading the work of Leif Asbrink, SM5BSZ for some background. I found this article, particularly interesting.

Asbrink makes mention of that same book in his article, by the way. It, too, is a little dated but since so little has changed in audio proc design on HAM transcivers since then, it's still valid. One of the big points made in this article is that only about 2 or 3 db of ALC action is required for their to be undesirable out of passband products. Again, ALC overshoots. The reason is most ALC's simply are not fast enough to prevent overshoots and thereby clipping which results in splatter given the weak passband filtering is most radios, even today. You simply cannot get the best, most dense audio signal out with that setup. (and by the way, I know of blessedly few HAMs who run only 2-3 db of ALC as a rule.)

Understand me; Part of the object of adding external processing, particularly peak limiting, is to eliminate those overshoots, by removing them before the ALC even gets involved, which in turn allows for "filling the envelope" more fully without the problems ALC overshoots cause, thus allowing for a more effective signal for a given power level.

(I should, I suppose, note that SDR  radios with their digital bandpass filtering (IC7300, FT991, etc) have a tendency to handle such overshoots a bit better than units made even 20 years ago. Still, why allow such overshoots at all?)

And yes, I've heard it before.... SSB has a horrible S/N ratio, you're never going to get broadcast quality audio from that setup, etc. The. thing is that idea ignores that with decent processing at (or in front of) the transmitter, one can attain a much higher S/N ratio. Even doing what Sabin and Schoenike suggested 35 years ago adds 3db to the S/N ratio, or a half an S unit on average.... and that's without any serious compressing, peak limiting and so on, before the audio even gets to the radio. With that combo, with that external processing, I see no reason the average power couldn't be much higher, while still maintaining intelligibility.

That last word... intelligibility.... is critical to understanding what I'm about, here. I'm not in pursuit of broadcast quality audio. For openers, that's flat out impossible in a 3KC bandwidth and it's also counter productive to the goal of maximizing weak signal intelligibility.

What I'm about with my audio experimenting is making the most of available RF power while adding as few undesirable artifacts as possible, which in turn makes the difference between making the contact and being buried in the noise level.

So far, it's working.

73, K2ENF

 

Update:

 As of 8/6/23

I'm pleased with the progress I've been making. I've had a few comments that it tends to sound a bit harsh when in full cry, but it's now made the difference in making the contact or making noise several times. It does add some significant average power, but at this point I'm approaching diminishing returns. 

I must say that this is the first time I've been somewhat disappointed in the documentation surrounding the 991. I would have assumed that the internal audio processor used some kind of audio clipper as well as the internal compressor and ALC. Trouble is, I'm not seeing any clipping on any but the strongest peaks, which for the most part the external processor I'm using eliminates. A little clipping, perhaps up to 3dB or so would be desirable as a wave shaper, and watching the waveform I'm not seeing it on the 991's output.  That wave shaping is the only thing my audio lacks....

The other issue is that once the average audio power being applied to the radio goes up, by means of the external proc, the internal compression reacts too harshly. I'm seeing 15dB or so worth of compression  on the internal compressor, which would be a serious issue were it not for the noise gate I'm running on the input.... all you'd be hearing is background noise.  

I've tried turning the output of the stack down, and even cut the radio's mike gain to near nothing. But, while that lowers the amount of internal compression applied, while still giving a nicely dense audio signal,  it produces an actual loss of audio in the RF envelope less watts to the antenna.  

 Frankly, I wish there was a way to adjust the parameters of the compression in the radio.  Instead it's a sort of black box I can't access. So far, the working solution has been a rather strong setting on the noise gate on the external proc. This cures the issue of the internal compressor riding on the noise level during voice pauses, but the level ends up being a little jumpy as a result, precisely what I've been trying to avoid using this system in the first place.

It's all a learning process, but as I say I'm pleased with the gains I'm making so far. 

Addendum: 9/16/23
Well, I got rid of a lot of the crud I had been chasing. While I had thought it was the 991's clipper, it turned out to be a grounding issue with the mix console. All set now, however. Getting good reports.