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CPI CP2000 AM modulation limiter modification

Posted: Wed Feb 08, 2017 11:55 pm
by Goldfinger
CPI CP 2000 AM modulation limiter modification.
This mod got me from 80% mod (tops) to 110-115%
4 more watts PEP as well.
Communications Power, mod limiter, clip, cut, diode

make R232 higher in value.
cpi2000 R232-1.jpg
cpi2000 R232-1.jpg (66.25 KiB) Viewed 938 times


R232 is at the top in this shot, above the red line (resistors in series)

cpi2000 R232-3.jpg
cpi2000 R232-3.jpg (155.11 KiB) Viewed 938 times


I've wanted to figure this out for years. The board/soldering is very fragile on these radio's. I used solder braid and a small 25 watt iron.
Lifted one end of R232 (2200 ohm) and added another 2.2K, 1/2 watt in series with R232 as seen in the right of the third and top of the second. This gave a total of 4.4K.
I tried adding a 4.7K first but it went overmod and got choppy, so I lowered it to 2.2K. It was at %150 and was peaking past 20 watts though... lol :roll:

Re: CPI CP2000 AM modulation limiter modification

Posted: Mon Feb 20, 2017 11:38 pm
by Goldfinger
Google
Bing
bump

Re: CPI CP2000 AM modulation limiter modification

Posted: Wed Mar 01, 2017 4:29 pm
by Goldfinger
....and yes, I'll admit that I had a pink towel on my bench that day. :roll:

Re: CPI CP2000 AM modulation limiter modification

Posted: Thu Mar 02, 2017 6:48 am
by grasshopper
Haha, I didn't even notice the towel til you said something. I had to look again to find it, lol. :D

Re: CPI CP2000 AM modulation limiter modification

Posted: Sat Sep 23, 2017 2:45 am
by a365
To much bleach on a blue towel :roll: