|
Vintage Amateur and Military Radio Amateur/military receivers and transmitters, morse, and any other related vintage comms equipment. |
|
Thread Tools |
15th Jun 2022, 1:36 pm | #1 |
Tetrode
Join Date: Jan 2018
Location: Stockholm, Sweden
Posts: 78
|
Plessey PR155 Audio output problem
Hi Guys
I have got my hands on a very nice Plessey PR155, however it has a problem with Audio output. The radio has 2 Audio amplifiers in Module 9: One is feeding the internal speaker and the headphones (board A)and the other (board B) is feeding the line outputs inkl an external 600 Ω speaker. At first I had problems with both A and B but A was solved by replacing capacitor C1 on board A. The problem with B remains - i.e. very low output. have checked all capacitors which were OK, At the input to B is a variable potentiometer RV1 and adjusting it will change the output slightly. Is anyone familiar with the Plessey PR155 and able to give a hint of what the problem may be? Any advise will be appreciated. 73 Jan / SM5MRQ |