-
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.
NPC RC modification mod
- Thread starter Happy_Hamer
- Start date
Mike posted:
"If you do not disable AM limiter, you do not get how npc-rc works."
Mike
if you disable the am "limiter" then you don't understand how "automatic modulation control" actually works.
"If you do not disable AM limiter, you do not get how npc-rc works."
Mike
if you disable the am "limiter" then you don't understand how "automatic modulation control" actually works.
Pinch the Terrier?
Oh, you meant Carrier...
Oh, you meant Carrier...
Guess we need to somehow tie, NPC-RC, to the secret behind, Cleaner is Meaner, and crack some cold beers before admitting the crowd.
.
Bump
This was on a 2995dx that I owned a while back.
Is this the NPC mod? It looks like a 100ohm resistor with a diode (not sure of the diode value).
This was on a 2995dx that I owned a while back.
Is this the NPC mod? It looks like a 100ohm resistor with a diode (not sure of the diode value).
Eldorado, if you have a scope, can you tell us what the negative peaks look like with this mod?
I believe that it will show them not even achieving 90%.
LC
I believe that it will show them not even achieving 90%.
LC
@loosecannon
I sold that radio back in December so I don't have it anymore. It was a good talking radio and I got many unsolicited compliments on how strong the audio was when I had it in service.
Anyways, as with all the radios I own I pulled off the covers to see the goodies and to take pictures. I assumed it was the NPC mod at that time but hadn't asked until I ran across the photo today.
I've thought about trying it with the 2950dx6 that I still have so another reason I was asking.
It appears to be a 100 ohm smd resistor but the diode I have no idea what it is. The 2950dx6 has a very similar board so if I can decode the diode in the photo I'll give it a shot and report back.
By the way, that work in the photo was done by Brian at Trucks CB on the 2995dxcf
the diode is a regular old 1N4148 or similar.
Ive done this mod to a few new style 2995s and found that any resistor value wouldn't allow the negative peaks to reach near 100%.
i ended up just using the diode alone.
however, i do not clip any limiters when i do this mod. Trucks may have additional things done/removed.
LC
Ive done this mod to a few new style 2995s and found that any resistor value wouldn't allow the negative peaks to reach near 100%.
i ended up just using the diode alone.
however, i do not clip any limiters when i do this mod. Trucks may have additional things done/removed.
LC
Thanks for the info on the diode. I had looked over the component side of the board really well and couldn't find anything swapped and all limiter were also intact. Unless I missed something, that was all he had done to it. The 2995 dxcf did have some strong audio.
Wow so 18 pages defeats you? I can see that if you did not know what it is.
NPC stands for negative peak compression and the RC stands for reduced carrier. Quick and dirty it is designed to let you get your peak modulation above 100% with out the negative portion pinching. So 120%, 150%, 200%, 300% modulation with out the negatives pinching so no box cars. The RC or reduced carrier is for example having a 1/4 watt dead key but when you modulate the radio it swings to 20 watts for example at 200% modulation.
NPC stands for negative peak compression and the RC stands for reduced carrier. Quick and dirty it is designed to let you get your peak modulation above 100% with out the negative portion pinching. So 120%, 150%, 200%, 300% modulation with out the negatives pinching so no box cars. The RC or reduced carrier is for example having a 1/4 watt dead key but when you modulate the radio it swings to 20 watts for example at 200% modulation.