Roberts R300 Radio AF117 Transistors Chapter 1

[@daveinthailand]

Being a TV engineer back in the 80s I used a BnK tube rejuvinator across the AF117 and it worked evertime great video

[@stevehead365]

My experience with zapping AF117s and their ilk, is that you do lose a few, but it does retain the original appearance of the set if it works. I think with some, whiskers can remain between the base and emitter or collector. I have never found a solution for this. I put some in the freezer for about 4 months, in a vain attempt to disintegrate the whiskers. Didn't work, maybe the temperature wasn't low enough or maybe it would never work. Russian replacements work fine, if you just need to get it going. Maybe 30 volts and 470uF is optimal, who knows? Cheers, Steve.

[@SweeneyTTodd]

Thanks for watching and commenting Glad you said about putting AF's in the freezer I'd read that somewhere and was thinking of trying it but I won't bother now thanks Thanks for watching Best regards Shaun

[@raceingdemon6464]

Lovely Work Shaun I Dont Have a 60v DC Supply Either What I Do Is Get 7 PP9 Batteries From The Poundshop And Connect Them In Series To Get 63 Volts And Use a 470uf 100V Cap To Blow The Whiskers Off And Use a Bleeding Resistor Across The Cap To Discharge It Much Safer and Better For The Cap The R300 Is a Nice Set With a Bigger Speaker Than The R200 I Have a Lovely R500 as Well Your Getting The Hang Of This Whisker Thing Shaun he he Regards mike.

[@DJ_Cthulhu]

Hmmm, I might build a dedicated bit of kit for de-whiskering old transistors. 🤔

[@radiorobertakaandy5982]

Thanks for the thorough look at the transistors and replacements and zapping the old af117s shaun .sadly I still don't think I'm up to the challenge of doing it myself yet ....a few more videos of yours and other guys on you tube to watch yet such as codeeze,radiocruncer,george etc.oh and nice radio by the way .

[@zx8401ztv]

Superb job shawn, those pesky whiskers have been clobbered lol :-D I found nothing wrong with your methods, don't put yourself down, that's our job ha ha :-D joke. The sudden high current applied just blows the whisker like a fuse, they can grow back but it takes a while. If you ever need more current/voltage then connect two capacitors in series and charge each one with 30v, then you have 60 volts at more current. Think of the electrolitic as being a little battery with a very short life, in this application. If im being too simplistic, just tell me to sod off :-D

[@derricktaffman3887]

Ey up. Looks a nice set Shaun, are you going to fit the rushun transistors in there?

[@GeorgeChristofi]

Shaun Flashing on the internet..... What is the world coming to?

[@iceberg789]

ZAP !!

[@urbanodagrippino8433]

I working on a grundig model