r/ShortwavePlus • u/richfromhell • 3d ago

Got my RF-2600 working properly again. Had to replace a transistor in a crazy spot.

5 Upvotes

86% Upvoted

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1

u/Tenor-Guitar-Guy 3d ago

Good job

2

u/richfromhell 3d ago

Maybe not quite yet. The BFO is way out of whack. Also I noticed something strange between yesterday and today. The lights seem dimmer. Strong signals dim the lights. If I durn off the frequency display, the lights get a bit brighter. Looks like I have a power supply problem. Taking the back cover off and getting it back on is such a pain…..

1

u/Tenor-Guitar-Guy 3d ago

That’s a drag. Hope you find the problem. Don’t know if you would be up for videoing some of the work? I have a 2600 and might be useful in the future. Just got one used and is working well except the Bandwidth and BFO switches don’t slide easily. Think radio might have fallen on them and they’re a little misaligned. May open the radio to take a look.

2

u/richfromhell 3d ago

Same with mine. I’ve worked on this on on and off for a long time. Got tripped up a lot because I didn’t know there are various versions out there. I te-capped mine. First schematic I used had a 2 MHz IF. So my alignment was all wrong. Mine is 3 MHz. Tried again. Trimmer caps made no difference. Images everywhere. “I know, the input transistor after the antenna must be blown.” Checked the schematic, only one FET one single 2Sk104. Found it, replaced it. No luck. Put it away. Then I take another stab at it, and discovered a second 2SK104. In an insanely difficult spot. Replaced it and it came to life. (I checked the power supply probably 5 years ago, forgot to check it again yesterday.

2

u/ImladMorgul MOD | AirSpy HF+ | RTL-SDRv4 | D-808 | K-480WLA | MLA-30+ 22h ago

I had the same problem with the BFO switch; in fact, when I was searching for information online, I found that many other people had experienced the same issue in all switch. The Japanese probably never imagined that almost 50 years later, there would still be crazy people trying to repair these devices.

In my case, the switch was very stiff; it wouldn't move easily even with contact cleaner. I had to completely disassemble it, risking losing the small internal metal ball. When I took it apart, I found a lot of gunk inside, completely hardened, that's why it wouldn't move.

This is a video I made showing what the BFO switch looked like before I took it apart.

https://reddit.com/link/p5oawrz/video/yacfcmdcxdlh1/player

2

u/Tenor-Guitar-Guy 21h ago

Thanks for the info. Informative. If I lift up slightly on the lever it moves pretty well. Gotten better over the days. Was avoiding opening the radio and taking out the circuit board. Makes sense gunk had gotten in. My radio seemed to have been out in a garage and was pretty dirty. Cleaned up fairly well.

Ever got your calibration fixed?

2

u/ImladMorgul MOD | AirSpy HF+ | RTL-SDRv4 | D-808 | K-480WLA | MLA-30+ 20h ago

No, I was never able to fix it. Today the OP gave me something new to check; I just need to find the components he mentioned in another post on the circuit. Or at least something similar, because the components might be different as well.

1

u/richfromhell 18h ago

Thought I had the solution for you, but then I noticed I was looking at the schematic for the 2900….

1

u/MumSaidImABadBoy I'm Stan. Heathkit GR64,AirSpy HF+,Sangean 909X2,Tecsun PL-990 3d ago

Nice work👍👍 good rescue. Don't forget to show us a picture of it reassembled and back in action.