-
You can now help support WorldwideDX when you shop on Amazon at no additional cost to you! Simply follow this Shop on Amazon link first and a portion of any purchase is sent to WorldwideDX to help with site costs.
NEED NPC-RC MOD FOR TRC-465
- Thread starter 15minigrass
- Start date
Uniden PC-122 Upgrade/Troubleshooting Service Section How-To Manual
I've done all mods he described, my PC122 is still alive
Mike
I've done all mods he described, my PC122 is still alive
Mike
OK Mike - thanks again!
Sooo . . . the mod can be placed at two different points at one end of this modification. One end of the mod can go between the 'gain cell' (resistor/ capacitor) or at the end of it. It is left open - as an option depending on which one sounds better. Any idea of which one would be considered best - in your opinion?
Would making R187 a variable resistor make this mod adjustable - so to check the net effect on a scope for a finer tune?
Sooo . . . the mod can be placed at two different points at one end of this modification. One end of the mod can go between the 'gain cell' (resistor/ capacitor) or at the end of it. It is left open - as an option depending on which one sounds better. Any idea of which one would be considered best - in your opinion?
Would making R187 a variable resistor make this mod adjustable - so to check the net effect on a scope for a finer tune?
I did that paralel to C169 - as on EPT boards. Looked better on scope. Slight diffrence when listened on another radio.
Only diffrence is, that I used 100ohm resistor. Of course you can use variable, but 100ohm is just what we need. Higher resistance, less NPC efect. If went below 100ohm, it becomes distorted, so 100ohm for me was a sweet spot
To do it complete there is a need to remove AM limiter (r153 in TRC) and put 13.8V to final as in EPT-xxxx based radios. Than adjust AM power and modulation level to get nice, clean signal on the scope. The way I do it is to put variable resistor inside the radio between mic socket and mainboard to adjust maximum input modulation level, so user can't overdrive and power is set around 2W carrier. It works perfect.
Mike
Only diffrence is, that I used 100ohm resistor. Of course you can use variable, but 100ohm is just what we need. Higher resistance, less NPC efect. If went below 100ohm, it becomes distorted, so 100ohm for me was a sweet spot
To do it complete there is a need to remove AM limiter (r153 in TRC) and put 13.8V to final as in EPT-xxxx based radios. Than adjust AM power and modulation level to get nice, clean signal on the scope. The way I do it is to put variable resistor inside the radio between mic socket and mainboard to adjust maximum input modulation level, so user can't overdrive and power is set around 2W carrier. It works perfect.
Mike
I did that paralel to C169 - as on EPT boards. Looked better on scope. Slight diffrence when listened on another radio.
Only diffrence is, that I used 100ohm resistor. Of course you can use variable, but 100ohm is just what we need. Higher resistance, less NPC efect. If went below 100ohm, it becomes distorted, so 100ohm for me was a sweet spot
To do it complete there is a need to remove AM limiter (r153 in TRC) and put 13.8V to final as in EPT-xxxx based radios. Than adjust AM power and modulation level to get nice, clean signal on the scope. The way I do it is to put variable resistor inside the radio between mic socket and mainboard to adjust maximum input modulation level, so user can't overdrive and power is set around 2W carrier. It works perfect.
Mike
Can you snap som,e pix of the mod spit???
Even if do the mod as described in that diagram on the first page; you will still need to remove the AM limiter, and volt the final transistor. Oh yeah; and put a variable pot on the incoming mic wire in the mic preamp. Then adjust that pot with a scope for best waveform shape. Not exactly easy to do right. And if done wrong; it will sound like crap. Be real careful!
I know some will poo poo on removing the limiter (i dont care myself if i do) but i did in my 465 and i NPC RC modded the radio and it works well..
I have done the NPC MOD on one of my 465 that I sold a long time ago and forgot whrer I got it from either from Defpomʻs site or somewhere else. I had it DK around 1.5 watts and it would swing 12+. All I did was add a diode and resistor.
Thanx guys. Too complicated to do that Mod. Maybe Yanking the limiter would be my best bet but I also run SSB too so contemplating on it.
Mahalo james.....
IS this the same mod?
FROM DEFPOM!!!!
SuperSwing Mod for the TRC 453, TRC 465 and Uniden PC122
1. Remove Q27 (located UNDER mic socket)
2. Change the 10k resistor between mic white audio wire and collector of Q27 to 1k ohm.
3. Change the 10k resistor at base of Q26 and disc capacitor from collector of Q27 to 1k ohm.
YOU WILL NOT SEE A BIG INCREASE IN WATTAGE BUT THE MIC AMPLIFICATION WILL BE IMPROVED AND/OR LOUDER.
4. Do the retuning for your maximun forward gain.
5. Now you could try and adjust the final bias and driver bias (@ left rear of radio) along with the the AMC and SSB/AM power tweeks. The VR's have their functions printed right on the board.
This was sent to me by DJ Weber
FROM DEFPOM!!!!
SuperSwing Mod for the TRC 453, TRC 465 and Uniden PC122
1. Remove Q27 (located UNDER mic socket)
2. Change the 10k resistor between mic white audio wire and collector of Q27 to 1k ohm.
3. Change the 10k resistor at base of Q26 and disc capacitor from collector of Q27 to 1k ohm.
YOU WILL NOT SEE A BIG INCREASE IN WATTAGE BUT THE MIC AMPLIFICATION WILL BE IMPROVED AND/OR LOUDER.
4. Do the retuning for your maximun forward gain.
5. Now you could try and adjust the final bias and driver bias (@ left rear of radio) along with the the AMC and SSB/AM power tweeks. The VR's have their functions printed right on the board.
This was sent to me by DJ Weber
Bump!
I have a TRC-465 back home in Georgia and was wondering what would I need to do to run this radio with an Amp? Can I set the DK my self? If there some involved work I'd rather send it off to someone who knows this radio.
Just looking to set it up for an Amp, not really mod it all out.. Unless there are some easy mods to do to it, but wont kill reliability.
I have a TRC-465 back home in Georgia and was wondering what would I need to do to run this radio with an Amp? Can I set the DK my self? If there some involved work I'd rather send it off to someone who knows this radio.
Just looking to set it up for an Amp, not really mod it all out.. Unless there are some easy mods to do to it, but wont kill reliability.
- No one is chatting at the moment.
-
-
dxBot:63Sprint has left the room.
-
dxBot:kennyjames 0151 has left the room.
-
-