KL203P linear

[Robert Cook Sr]

I just checked system again using Peak on my pdc600 meter. I'm getting around 50 on dead key and around 85 watts on modulation, and SWR seems to back up a little while talking on it. Without leaner SWR is 1.1 and box jumps up to about 1.2.5 and then falls back a little while talking. I noticed box getting a little warm while talking to contact for first time using it. I keep under edge of driver's seat. I've read on forums that average is better than Peak power but meters seem to swing correctly on peak better than average. Should I have any worry about leaner working ok or not. My contact about 5-6 miles away on mobile said it sounded fine good & loud using power mike. Thanks for all help & suggestions here, I learn every day. by the way the voltage is 12.3 engine off and average v13.8 when engine running at idle, Nissan will go up to 14.5 volts if battery needs it and then drop back to 13.8 driving also I checked radio output engine running is 4 watts modulation These test were done using truck 102"whip not dummy load

 

[BJ radionut]

Output power
100 W MAX

For those of you who aren’t familiar with this amplifier, it’s a small amplifier (sub-compact would be the way to describe it) capable of around 100 watts on AM and 140-160 watts on SSB.

RM KL-203P MOSFET Linear Amplifier.

• 
  
  • DRIVE POWER: 0.5W – 10W (PEP MAX) while talking using AM.
  • 1 – 20W SSB input
  • Up to 100W AM/FM 200W SSB output
  • 13.8V DC
  • Switchable SSB Delay Relay

RM Italy KL203P CB Amplifier | CB Radio Magazine

 

[ForestRunner98]

@Mr Cook Sr...Maybe try to lower the radio’s DK even lower. 1w and see if that improves it. On the U980 you have to go into the inside of the radio so it’s not as easy as other radios. But if you have time, it’s worth a shot. You’re at 50w DK now so your definitely getting closer to the ideal ratio.

 

[Robert Cook Sr]

Thanks for info. I'm not too familiar with insides of these new radios. I can't look at board and know what each section does. Plus in 1973 when I went to school and haven't used my brains much in 50 years working with CB radios and they have gone from coil output to other means, maybe some helpful instructions would be nice, I have copy of specs for 203P here in front of me. Thanks for help

 

[144inBama]

Just got finished checking mine out....
Results:
SWR: 1:1.2
Cobra 29LTD Chrome @ 12 watts PEP
Engine off, battery @ 12.7 VDC = 100 watts PEP
Engine running battery @ 14.8 VDC = 150 watts PEP
Your numbers vs volts seem to be inline with my results.

 

[Bow]

If you check out my thread in the Export CB section, I have a lengthy discussion about this amp..

1.75w carrier drive is about the max you can push it with 100% modulation before you start clipping the peaks

Set the radio drive up so you have a Carrier of ~25w out of the amp, and leave it... that will gave you, when modulated, around 100-110W PEP

You won't gain anything on the RX end by pushing it harder, and might even keep you in the channel you are transmitting on...

 

[ForestRunner98]

Any updates OP???

 

[Robert Cook Sr]

If you buy a new Nissan Frontier. You'll find voltage drops to 11.6 at times then back up to 14.2 volts. Factory setting. So I installed a constant voltage box that maintains 13.8 Volts all the time. Nissan says saves gas????Check radio & now a KL503HD box and voltage stays at 13.8 volts all the time on both items. I gave Nissan service guy hell about computer turning off Alternator at times