Sanyo RP-8880 repair?

[Derundurel]

The 2sc930 transistors are indeed a problem.

Q303 2sc930d gain measured at 31.
Q302 2sc930e gain measured at 34.
Q305 2sc930d gain measured at 33.

"D" parts should be 60-120 and "E" 100-200. That's quite a bit of gain lost overall! All three were replaced with SS9018G (gain measured at about 90). The set works and does seem more sensitive, but I need to re-align it a bit and measure it properly. I am aware that Q302 should really have more gain still, but I have the SS9018G parts to hand and can settle for this slight loss.

Lessons learned so far: 2sc930 transistors lose a lot of gain over time. Ceramic resonators drift more than you might expect, so re-alignment is necessary if you have an old set.

 

[Gregory]

Sanyo RP 8800 update I put my receiver in the cupboard and forgot all about it so only a few days ago I thought wouldn't it be nice to switch it on again and listen to some medium wave DX anyway found out the shortwave bands don't work again.

So I got the service manual out again the FM, LW, MW, MB, bands all worked fine but shortwave completely dead. I again checked all the shortwave section transistors all working it turned out to be the second mixer Q111 the oscillator needed adjustment I turned CT19 trimmer until I could hear an increase in background hiss I don't have any fancy test equipment, once the hiss was heard I knew that the 10.7Mhz was mixing and converting it to the 455Khz I.F, a little tune of the main frequency dial and the radio burst into life. While doing the adjustment I had clipped a long wire antenna into the back panel external antenna and earth connections.

Originally I replaced this transistor Q111 with a 2N2222A it works fine as an oscillator as the original transistors in this receiver lose gain over time I changed a few transistors that where suspect any way radio is fully working on all bands now.

 

[Gregory]

Below photos of the radio and the shortwave section showing location of trimmer CT19

 

[Derundurel]

I made some notes and posted about this here: http://www.tech-cave.co.uk/2020/10/sanyo-rp-8880-receiver.html I hope it helps somebody who might be trying to get one of these receivers working.

 

[erererere]

胡歌

 

[cabralcr]

Hello everybody!
I ended up purchasing an RP 8880 ASIA version and it has the same problem reported here, I managed to bring the FM, LW, AM and MB part to life, but SW was still completely dead.

The solution to get things back to life was to replace all the 2sd930d, 2sd930e and 2ks49 transistors, when installing the new ones, measuring the gain of all.

I would like to know what instruments are needed to align this equipment because the service manual does not mention them.

Thank you in advance for your help so far. Grateful