Bush VTR103 radio

[lol30375]

Hi all
I am a beginner to this & have only a little experience in radio restoration, so this is going to be my first real project which I hope you can help me with. I have a Bush VTR103 radio which has been in the loft for about 20 years. I put a battery in it & it came on very faint, but came on loud when I poked about with the transistors. There are 3 AF117 metal can transistors & I have read on here how they can short out. My question is what would be the best direct replacement? & where could I buy some from? Also are the terminals marked as I would not want to solder them in incorrectly. Thanks in advance & sorry if I sound a bit dim but any advice will be gratefully received.
regards lol375

[Simon Gittins]

This picture of the AF117 leads is from Newnes - Radio Repair Questions and AnswersLes Lawry-Johns, Newnes Technical Books 1979


Cutting the screen lead is always worth a try.



Putting "tin whiskers" into the search box at the top of the page will give lots of threads with possible solutions such as https://www.vintage-radio.net/forum/...ad.php?t=76440

[Graham G3ZVT]

Havn't we been here before with its MW/LW brother

https://www.vintage-radio.net/forum/...d.php?t=101727

If you follow Simons link, you may well find that some scientists at NASA did research into tin-whisker growth using AF11x samples provided by the administrator/owner of this forum. How cool is that?

[lol30375]

thanks simon
nice information
regards laurie

[lol30375]

hi all
managed to find a transistor from another set & its working fine now but only on vhf i have no mw or lw cant remember if mw was working before switch is clean & works ok any help where to start looking appreciated.
regards laurie

[crackle]

Try the advice Simon gave you and cut the screen lead.

Mike

[tim.norris]

I`ve never had much luck cutting the screen leads , though have had problems with poor wave change switch contacts on these , exercise caution when cleaning as they aren`t the most robust design . the three accessible transistors can be swopped for the later AF12x types but these are becoming very expensive, i have fitted the russian germanium gt322b types with no problems apart from the fact that the legs are much shorter and much more difficult to fit and they also have a different pin out ,it would probably be easier to zap the existing transistors to temporarily kill the tin whiskers , member "Radiocruncher "has some good videos on youtube showing how its done. there are also a couple of transistors in the vhf tuner a AF114 and a AF115 i have only ever swopped these with the corresponding AF12X versions as they are a pain to get to , if vhf is working ok i would probably leave these alone. They are not the best performers on vhf but still useable . Is yours the earlier tan version or the later blue rexine ? if you need any i have quite a few spares for this model apart from aerials ! hope this helps , regards, Tim

[tim.norris]

Forgot to add , i usually swop out the yellow and red "plessey" electrolytic capacitors for modern equivelents ,as they dry out over time . If your pedantic for the ones that are visible you can hollow them out and hide new ones inside !usually these are the only capacitors that need replacing. Also take a look at Robert darwent`s website ,loads of info on the different Bush models in this iconic case , www.wavesintheair.co.uk , Bush Mb60/Tr82 series ,regards, Tim.

[lol30375]

thank you tim for that great advice its really appriciated & the link to that great site plenty of good info there,if i do need any spares i will give you a shout ,my vhf set is the tan & cream model
regards laurie

[lol30375]

Hi all
another problem has developed when a new battery was put on it works ok for 10 seconds then the volume decreases & fades away to nothing & radio is dead untill i switch off then on again & it does exactly the same again like its losing all its power,any help appriciated.
laurie

['LIVEWIRE?']

Something, possibly a leaky electrolytic capacitor or faulty output transistor,, is obviously drawing excessive current, so normal fault-finding techniques should identify the culprit(s). As to cutting the screens of AF11x transistors-personally i never bother, but regard them as 'replace on sight. In recent times I've used Russian Transistors (GT322, IIRC) to replace AF11x types. I haven't checked lately, but these are usually available on eBay for around £1 or less each.

[lol30375]

all plessey caps changed with modern type fitted inside now & its working really well & looks as it should & great sound thanks for all advice laurie