• 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.

RM Italy KL-300/P Tips and Traps

ButtFuzz

Anti-BS Advocate ● WO0WOO ● Reverend Doctor
Aug 11, 2005
587
418
173
Sunny Salem, VA
robco.ath.cx
Video about the 300P RM amplifier.
Have a look for ideas before you chuck it in the garbage.

Disclaimer:
I am not a linear expert.
Your mileage may vary.
Linear Power Amplifiers, particularly those using Thermionic Valves, have extremely high voltage inside that will probably kill you if given the chance.



Short Version:
1. Life middle leg of TR3 to disable pre-amp / pre-amp relay
2. Make sure pins 1-2 are jumpered (old models) or PA section will not work.
3. NO MORE than 5 watts input.
 
Last edited:

Nicely done. I have repaired so many of the KL amplifiers and they were all killed by being OVER DRIVEN!
There is also a modification to convert the "Class C" amps to "B" or "AB". They sound much better on SSB after the modification.
 
  • Like
Reactions: ButtFuzz
Nicely done. I have repaired so many of the KL amplifiers and they were all killed by being OVER DRIVEN!
There is also a modification to convert the "Class C" amps to "B" or "AB". They sound much better on SSB after the modification.

Thank you!

I have seen the excellent work done to properly bias these amps on these forums, and this place has been an invaluable learning tool. Hasn't hurt that I've made a few friends along the way, either.
 

dxChat
Help Users
  • No one is chatting at the moment.
  • dxBot:
    Tucker442 has left the room.
  • @ BJ radionut:
    LIVE 10:00 AM EST :cool:
  • @ Charles Edwards:
    I'm looking for factory settings 1 through 59 for a AT 5555 n2 or AT500 M2 I only wrote down half the values feel like a idiot I need help will be appreciated