Bush VTR103. Quiet VHF problem - UK Vintage Radio Repair and Restoration Discussion Forum

mark pirate · 7th Jun 2008, 2:22 pm

Hi all, have just got a bush vtr103, It is working loud & clear on mw/lw but about half the volume on vhf & seems to be a bit 'deaf'.
I have been through the pots & wavechange switch as they were all noisy.
Could it be a problem with the notorious af11x transistors? or something else?
any suggestions welcomed, also it maybe worth noting, when i got the set,
someone had hooked up an old sinclair zx power supply to it, this was measured at 12.65v so may have overrun the set for sometime

Cheers
Mark

howard · 7th Jun 2008, 3:24 pm

Hello Mark,

It might not be a problem, Bush VTR103s are noticably quieter on VHF than MW/LW.

Howard

mark pirate · 7th Jun 2008, 3:43 pm

Thanks for that, Howard, 1 problem down

1 to go! the radio seems to deaf to use at the moment, even connecting to an outside aerial does'nt improve matters much, i wonder if the problem lies in the tuning unit

howard · 7th Jun 2008, 4:16 pm

Hello Mark,

There's an AF114, and an AF115, in the FM module which expired in one of my VTR103s, see this thread where Ron Bryan replaced them both.

https://www.vintage-radio.net/forum/...d.php?p=152494

Howard

mark pirate · 7th Jun 2008, 7:48 pm

Hi Howard, thanks for the link, i wish mine looked that good

Mine certainly looks well used

but for £3 what do you expect

Again, i only bought this for a doner set (speaker, tuning knob,etc)
but i think as it works & i only have 1 other vtr103, i will break up a non-working tr82 to fix up this one

Cheers
Mark

paulsherwin · 7th Jun 2008, 8:29 pm

It's admittedly a bit of a generalisation, but most domestic FM transistor sets from the Ge era aren't especially sensitive. They only reached what we now think of as normal sensitivity with the arrival of Si transistors in the late 60s.

Paul

Hybrid tellies · 7th Jun 2008, 9:54 pm

As Paul says most early 60's VHF portables are the same, ie quieter on VHF compared with the more lively performance on the AM bands. This is most certainly the case with my old GEC G817, which has just recently died on me.

Steve_P · 7th Jun 2008, 10:04 pm

TR1 through to TR5 are AF11x series.

First, see that 10.7MHz VHF IF gets out OK and on frequency. Check Caps in the area, and transistor voltages. If the IF is OK, then I would suspect R10 and C16, C9 and the decoupling components C4 and C8.

Also, check CD2, CD3 and C42.

Cheers,

Steve P.

Hybrid tellies · 8th Jun 2008, 9:27 pm

Cheers Steve, when I get some spare time I will take a look at it and put a write up on this forum. It does sound rather good perhaps not as good as the Bush VTR103 and certainly is not as iconic image wise. I would say that it is possibly easier to work on than the Bush but I can't as the GEC uses double sided print.

Mullard · 9th Jun 2008, 3:18 pm

I have a couple of VTR103s and although slightly quieter on VHF than MF, they are not significantly so. As for sensitivity, they are reasonabvly good and being only mono, don't need too strong a signal to give good reception. I would check the AF transistors, but if this does not fix the problem, loook at the alignment.

John

7th Jun 2008, 2:22 pm	#1
mark pirate Dekatron Join Date: Mar 2008 Location: Worthing, West Sussex, UK Posts: 5,185	Bush VTR103. Quiet VHF problem Hi all, have just got a bush vtr103, It is working loud & clear on mw/lw but about half the volume on vhf & seems to be a bit 'deaf'. I have been through the pots & wavechange switch as they were all noisy. Could it be a problem with the notorious af11x transistors? or something else? any suggestions welcomed, also it maybe worth noting, when i got the set, someone had hooked up an old sinclair zx power supply to it, this was measured at 12.65v so may have overrun the set for sometime Cheers Mark

7th Jun 2008, 3:24 pm	#2
howard Nonode Join Date: May 2005 Location: Godalming, Surrey, UK. Posts: 2,593	Re: Bush VTR103. Quiet VHF problem Hello Mark, It might not be a problem, Bush VTR103s are noticably quieter on VHF than MW/LW. Howard

7th Jun 2008, 3:43 pm	#3
mark pirate Dekatron Join Date: Mar 2008 Location: Worthing, West Sussex, UK Posts: 5,185	Re: Bush VTR103. Quiet VHF problem Thanks for that, Howard, 1 problem down 1 to go! the radio seems to deaf to use at the moment, even connecting to an outside aerial does'nt improve matters much, i wonder if the problem lies in the tuning unit

7th Jun 2008, 4:16 pm	#4
howard Nonode Join Date: May 2005 Location: Godalming, Surrey, UK. Posts: 2,593	Re: Bush VTR103. Quiet VHF problem Hello Mark, There's an AF114, and an AF115, in the FM module which expired in one of my VTR103s, see this thread where Ron Bryan replaced them both. https://www.vintage-radio.net/forum/...d.php?p=152494 Howard

7th Jun 2008, 7:48 pm	#5
mark pirate Dekatron Join Date: Mar 2008 Location: Worthing, West Sussex, UK Posts: 5,185	Re: Bush VTR103. Quiet VHF problem Hi Howard, thanks for the link, i wish mine looked that good Mine certainly looks well used but for £3 what do you expect Again, i only bought this for a doner set (speaker, tuning knob,etc) but i think as it works & i only have 1 other vtr103, i will break up a non-working tr82 to fix up this one Cheers Mark

7th Jun 2008, 8:29 pm	#6
paulsherwin Moderator Join Date: Jun 2003 Location: Oxford, UK Posts: 27,943	Re: Bush VTR103. Quiet VHF problem It's admittedly a bit of a generalisation, but most domestic FM transistor sets from the Ge era aren't especially sensitive. They only reached what we now think of as normal sensitivity with the arrival of Si transistors in the late 60s. Paul

7th Jun 2008, 9:54 pm	#7
Hybrid tellies Nonode Join Date: Jan 2004 Location: 1966-1976 Coverack in Cornwall and Helston Cornwall. 1976-present Bristol/Bath area. Posts: 2,965	Re: Bush VTR103. Quiet VHF problem As Paul says most early 60's VHF portables are the same, ie quieter on VHF compared with the more lively performance on the AM bands. This is most certainly the case with my old GEC G817, which has just recently died on me. __________________ Simon BVWS member

7th Jun 2008, 10:04 pm	#8
Steve_P Dekatron Join Date: Sep 2003 Location: Bolton, Greater Manchester, UK. Posts: 6,644	Re: Bush VTR103. Quiet VHF problem TR1 through to TR5 are AF11x series. First, see that 10.7MHz VHF IF gets out OK and on frequency. Check Caps in the area, and transistor voltages. If the IF is OK, then I would suspect R10 and C16, C9 and the decoupling components C4 and C8. Also, check CD2, CD3 and C42. Cheers, Steve P. __________________ If we've always had it, why is the Car Boot open? You're not sneaking another Old TV in are you...?

8th Jun 2008, 9:27 pm	#9
Hybrid tellies Nonode Join Date: Jan 2004 Location: 1966-1976 Coverack in Cornwall and Helston Cornwall. 1976-present Bristol/Bath area. Posts: 2,965	Re: Bush VTR103. Quiet VHF problem Cheers Steve, when I get some spare time I will take a look at it and put a write up on this forum. It does sound rather good perhaps not as good as the Bush VTR103 and certainly is not as iconic image wise. I would say that it is possibly easier to work on than the Bush but I can't as the GEC uses double sided print. __________________ Simon BVWS member

9th Jun 2008, 3:18 pm	#10
Mullard Pentode Join Date: Jul 2007 Location: Clophill, Bedfordshire, UK. Posts: 127	Re: Bush VTR103. Quiet VHF problem I have a couple of VTR103s and although slightly quieter on VHF than MF, they are not significantly so. As for sensitivity, they are reasonabvly good and being only mono, don't need too strong a signal to give good reception. I would check the AF transistors, but if this does not fix the problem, loook at the alignment. John