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doesn't make sense to me
- Thread starter 1iwilly
- Start date
Well you really don't change R131, you change the LEVEL of signal it works with...
R131 and (See Graphic below inclusive R130) set a "gain" of the Mic limiter...so keep the 10K and the 1.5K where they are...
Locate R127 a 1M (Brown Black Blue) - change it's value to a lower, much lower value - like 1K or even 680 - 560 ohms...
The other side of TR26 looks at the AM Regulator - R166 and R165 - a simple divider - increase R166 to as high as 10K and REDUCE R165 to 1K - gives you a bigger window of drive for AMC...this affects the circuit you messed with earlier - R195 taps R166 and R165 - once you have R166 raised, and R165 lowered - you can leave the mess you were working with.
TR26 is on all the time, you tip the balance, scales or the waterfall effect - by changing the power available to flow across the Collector and Emitter - leave the Base alone, you can make the R131 and R130 (per graphic) equal - but that's not going to change much...The Diode forces AMC to work more towards Negative - the valve effect the Diode has, pertains to this.
Think of TR26 as a Common Base amplifier, then you can figure out the rest a lot easier by just fiddling, fixing the power flow thru TR26 by changing R127, R166 and R165 - leave the ALC alone to fend for itself...
R131 and (See Graphic below inclusive R130) set a "gain" of the Mic limiter...so keep the 10K and the 1.5K where they are...
- You may have a Diode to control the DIRECTION of power escaping the Base of TR26 while others are Pre-Set to ON Class A...R130 or VR12 (per model)
Locate R127 a 1M (Brown Black Blue) - change it's value to a lower, much lower value - like 1K or even 680 - 560 ohms...
The other side of TR26 looks at the AM Regulator - R166 and R165 - a simple divider - increase R166 to as high as 10K and REDUCE R165 to 1K - gives you a bigger window of drive for AMC...this affects the circuit you messed with earlier - R195 taps R166 and R165 - once you have R166 raised, and R165 lowered - you can leave the mess you were working with.
Giving away my secretes (AGAIN!)
Why keep R131? Well, you can remove it, but if you run an amp - you might want to keep the ability to limit the input swing so you don't blow up the amp - especially if you are segue-ing to using MOSFET's in the near future.
TR26 is on all the time, you tip the balance, scales or the waterfall effect - by changing the power available to flow across the Collector and Emitter - leave the Base alone, you can make the R131 and R130 (per graphic) equal - but that's not going to change much...The Diode forces AMC to work more towards Negative - the valve effect the Diode has, pertains to this.
Think of TR26 as a Common Base amplifier, then you can figure out the rest a lot easier by just fiddling, fixing the power flow thru TR26 by changing R127, R166 and R165 - leave the ALC alone to fend for itself...
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A whistle is Useless for testing since Nobody I have ever spoken with whistles to communicate.Even if the power was 10 times as much on a whistle it's useless for actual communications.A Voice Peak is a Far Better choice for ny modulated signal since it's what is used for communicating.I hear people whistle to tune an amplifier & they get upset when the amp will not put out the same output when they talk.It's quiet Funny to me.
SIX-SHOOTER
Many BIRD meters do have a PEP Reading Kit in them either from the factory or an aftermarket model so it's possible he has one of those but he did not say either way unless I missed it somewhere?
SIX-SHOOTER
Watching the vids he posted it's AVG, no peak kit.
73
Jeff
73
Jeff
audio shockwave yes bird is only for average for pep i use this meter
Attachments
Man, I need to pop in here and read the threads more often... Just been so busy.
Looks like someone tried to do my NPC/RC mod, with less than favorable results.
A few points to bring up...
This HAS to be done with an o'scope, a signal generator, and a spectrum analyzer. Not a power meter.
The AMC is not disabled, nor is it modified in my mod.
The AMC was not properly adjusted in this case.
It is not necessary to replace the C1419 with a TIP41C, but TIP41C's are cheap, and can run cooler.
R228 doesn't have to be changed, it can be left alone, but I've found that changing it to 1.5K yields a small improvement.
Changing or removing R131 is modifying the AMC circuit, and is a waste of time.
I'll get back to this when I have time.
~Cheers~
Looks like someone tried to do my NPC/RC mod, with less than favorable results.
A few points to bring up...
This HAS to be done with an o'scope, a signal generator, and a spectrum analyzer. Not a power meter.
The AMC is not disabled, nor is it modified in my mod.
The AMC was not properly adjusted in this case.
It is not necessary to replace the C1419 with a TIP41C, but TIP41C's are cheap, and can run cooler.
R228 doesn't have to be changed, it can be left alone, but I've found that changing it to 1.5K yields a small improvement.
Changing or removing R131 is modifying the AMC circuit, and is a waste of time.
I'll get back to this when I have time.
~Cheers~
( bang head on wall)
I Did not connect exit 13 with
Exit Thirteen
Oops
My bad
73
Jeff
I Did not connect exit 13 with
Exit Thirteen
Oops
My bad
73
Jeff
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
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
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hello exitthirteen if you read thru my remarks there is only one bug that it's only in the 1/2 to 1-watt range level yes the mod was done as you wrote it took it to a shop to be adjusted on a scope BUT keyword here it said set radio around 2 watts no problem
until when i run my 2 pills and the drive falls in the 1/2 watt or 1 watt and while talking local barefooted when i been told my audio is fading bring the dead key up and problem solve
until when i run my 2 pills and the drive falls in the 1/2 watt or 1 watt and while talking local barefooted when i been told my audio is fading bring the dead key up and problem solve
bird operation manual, 2016.
"like similar diode devices, the Bird 43 indicates the carrier component of
amplitude modulation, with very little response to side band components
added by modulation."
https://birdrf.com/~/media/Bird/Files/PDF/Manuals/920-43.ashx
"like similar diode devices, the Bird 43 indicates the carrier component of
amplitude modulation, with very little response to side band components
added by modulation."
https://birdrf.com/~/media/Bird/Files/PDF/Manuals/920-43.ashx
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