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doesn't make sense to me

did you watch the video when the radio it's set at either 1/2 or 1 watt ???
this not an amp issue a bird meter issue it's a radio issue again at that power lever the modulation starts falling off but not at higher lever why critical because that happens to be the set power to run the solid-state 200


So it works ok without the amp?
What is the input SWR on the Amp?
What I am asking, if you put a SWR meter behind the radio and in front of the amp, turn amp on , key up, adjust set point, read SWR going into the amp.
Is it high?

73
Jeff
 
here is an updated ok been the same mod is on my 2000 while in the 1/2 watt dead key same issue now just for shit's and giggle i cut r131 problem solve r131 is causing it to act like that at very low power and now modulation does not fall out. the question is how do i fix it so i can still have r131 intact
 
the question is how do i fix it so i can still have r131 intact

Again,
  • R127 - Lower it to 1K,
  • R166 - Raise it to 10K
  • R165 - Lower it to 1K
IF you do just one, make it R127...

IF you can do all three you won't have the "fall-out" or fade away you'd get from Limiter staying on too long.
 
ok will try today and report back remember i did r127 only and there was no change


Again,
  • R127 - Lower it to 1K,
  • R166 - Raise it to 10K
  • R165 - Lower it to 1K
IF you do just one, make it R127...

IF you can do all three you won't have the "fall-out" or fade away you'd get from Limiter staying on too long.
 
ok did as you wrote turn the radio on with no modulation at all so i started back words 1 resister at a time put R 127 back. while r165 is 1k and r166 is 10k now i got modulation back with a little improvement compared to my complain for some reason r127 no doing it for me


Again,
  • R127 - Lower it to 1K,
  • R166 - Raise it to 10K
  • R165 - Lower it to 1K
IF you do just one, make it R127...

IF you can do all three you won't have the "fall-out" or fade away you'd get from Limiter staying on too long.
 
Boy, you do have some pieces of work...

Screamers, well, if that is what you want, R131 might need to be removed, but warn your neighbors first - but the R131 limiter really?

As said earlier, R131 changing it, won't do much, you have to take on and reduce the power going into the AMC circuit the Input that goes to the Limiter amp...that's thru those resistors and their divider design.

R127 and R166, R165 vales were chosen so the original STOCK design would be within FCC limits - R127 simply trims output of one (AMC) to help with ALC on the other input - all inputs are "terminated" in some fashion to help meet the levels so the switchover - when the power is being produced in the other side, isn't killing the other section

When R127 is/goes too low, it won't help on ALC either - so you'll have to look at R166 and R165. for your AM....

Really swinging RWOB mods - you trim R165 to a low of a value as 560 ohms, and R127 - to same value as R165 (balances) and you're going to have to run the Mic Dynamike control ride it, if you're on SSB mode so you can even use an amp without killing it.

A quick ADD...

You're ALC is still on when you disable AMC by removing R131 - Adjusting R127 without AMC even being enabled - and you still have fallbacks or FADE?
  • - then ALC will need more work to handle your swings.
 
thanks, andy been r165 and r166 did make it a diff I'll let it be for now

Boy, you do have some pieces of work...

Screamers, well, if that is what you want, R131 might need to be removed, but warn your neighbors first - but the R131 limiter really?

As said earlier, R131 changing it, won't do much, you have to take on and reduce the power going into the AMC circuit the Input that goes to the Limiter amp...that's thru those resistors and their divider design.

R127 and R166, R165 vales were chosen so the original STOCK design would be within FCC limits - R127 simply trims output of one (AMC) to help with ALC on the other input - all inputs are "terminated" in some fashion to help meet the levels so the switchover - when the power is being produced in the other side, isn't killing the other section

When R127 is/goes too low, it won't help on ALC either - so you'll have to look at R166 and R165. for your AM....

Really swinging RWOB mods - you trim R165 to a low of a value as 560 ohms, and R127 - to same value as R165 (balances) and you're going to have to run the Mic Dynamike control ride it, if you're on SSB mode so you can even use an amp without killing it.
 
Last edited:
SIX-SHOOTER i have a separate pep meter and besides that not the problem
if you watch the video at that low power level when listening to the audio on another radio you can hear the audio falling off but never at a higher level

I have the same meter that you use for PEP but I use the Three Autek WM-1 meters for most everything except my 6 meter antenna where I use a WELZ SP-600 with a K4DPK PEP Kit in it so I can monitor the ICOm PW-1 amplifier on 6 meters.All of my meters read PEP even for VHF/UHF just in case it's needed.I have no need of a wattmeter that reads just Average power.

SIX-SHOOTER
 
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thanks for taking the time on this but again my main complaint if you watch the video on my 148 when the dead key of 1/2 watt or 1 watt as soon as I started talking the watts would start dropping off again only at that low power level for variable power I'm using the rf gain knob but on the 2000 i'm using the SWR calibrate knob I've gotten good clean audio on the 2000 barefoot or with the amp on 148 i'm still trying to find the power leak thanks again for taking time for a better undestanding

Quick analysis/description of this mod.




~Cheers~
 
I would suspect a bad capacitor, has the radio been fully recapped? My 2000 GTL was fully recapped 4 years ago, and it is in constant service, it doesn't sit unused. Even though the mod was not designed to be ran at 1/2W to 1W deadkey, your audio should not fade or fall out, so I would suspect a faulty capacitor.


~Cheers~
 
well for shits and giggles i tried a different variable pot and it's not doing it anymore shit does happen and your keyword =Even though the mod was not designed to be run at 1/2W to 1W dead key, point taken thanks once again

I would suspect a bad capacitor, has the radio been fully recapped? My 2000 GTL was fully recapped 4 years ago, and it is in constant service, it doesn't sit unused. Even though the mod was not designed to be ran at 1/2W to 1W deadkey, your audio should not fade or fall out, so I would suspect a faulty capacitor.


~Cheers~
 
When a radio is tuned for ONE Specific frequency, all the effort goes into that one frequency...

You said you tuned to 1000hz



So any sort of audio CLOSE to that freqoency of tone, will also pass thru easier than the LOWER tones or, in reality, any range of tones above and below that "tone tune" will not pass as well.

The simple Cobra 29 is set up to pass more voice than whistle, not saying it can't be done, your radio proves this, but the tone you're trying to pass thru is not your true voice range.

View attachment 44949
I mean, come on!
Whistle is closer to a tone and
an over modulated one at that!​

Many people would open up the radios' band pass to make it more Hi-Fi - Wi-Fi on 11 meters,.

But the effort of using the whistle for a swing in a tune up of 1,000Hz tone is pushing the upper limits of the radios own BUILT-IN band pass...

Besides, you have a Big Huge CHOKE called a Modulator you gotta push all the colors thru...tends to kinda limit the whole effort of making it pass - when you tune for one side of the spectrum and forget there's' a whole bunch more that makes up your voice - and all for a silly little meter called a BIRD that you feel is more important to watch swing, than to pay attention to the actual conversation and saying "Hello".

The idea of the Modulator is to change your Audio voice component into a range of frequency as a power to be mixed in with 27MHz and call it AM.

The choices of Capacitor value used (say 330uF to as much as 1,000uF) and the Modulators' number of winds themselves, limit your ability to pass everything - it's "pre-set" for a range of vocal tones, not just whistle.

So you're limited right from the start, and why some people use Galaxy's AM Regulation method to pass more audio - also at a price - so it's a give and take.

Please, don't focus so much on Bird watts, they get you into trouble every time - focus more on sounding good to others, that's where the money is, or at least you should throw your $$$ it in that direction - people hearing a good sounding radio makes your voice, your thoughts, get heard, and understood, not a whistle.

.
Wow.....thanks Andy! You got rid of my headache better than aspirin!! I was gonna try to explain that but....well....you know.......;-)
 

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