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Vintage Radio (domestic) Domestic vintage radio (wireless) receivers only. |
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14th Apr 2021, 9:28 am | #21 |
Heptode
Join Date: Jan 2003
Location: Tewkesbury, Gloucestershire, UK.
Posts: 693
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Re: Bush VHF61 FM band dead.
You could use the E88CC. This has gold plated pins, thus greatly improving the dynamic warmth and sonic soundstage transparency.....
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Keith Yates - G3XGW VMARS & BVWS member http://www.tibblestone.com/oldradios/Old_Radios.htm |
14th Apr 2021, 10:45 am | #22 |
Moderator
Join Date: Mar 2012
Location: Fife, Scotland, UK.
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Re: Bush VHF61 FM band dead.
Rats! I'd held off mentioning that one. But mainly used in mil spec equipment for brass band marching music. So its application is limited.
David
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Can't afford the volcanic island yet, but the plans for my monorail and the goons' uniforms are done |
14th Apr 2021, 2:36 pm | #23 | |
Octode
Join Date: Dec 2003
Location: Leeds, West Yorkshire, UK.
Posts: 1,592
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Re: Bush VHF61 FM band dead.
Quote:
Cheers Mike |
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15th Apr 2021, 1:09 pm | #24 |
Dekatron
Join Date: Nov 2009
Location: Lincolnshire, UK.
Posts: 5,000
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Re: Bush VHF61 FM band dead.
The ECC88 valve worked just fine. The tuning drift on warm up that these sets have was exactly the same with this valve as with the ECC85 and I remember the valve being the possible cause of this was ruled out in a previous discussion sometime last year - after all, these valves don't drift in the Grundig sets.
I was going to try a couple of the other valve types mentioned that are apparently pin compatible (haven't checked myself yet) but fluorescent light failure in the loft when I went to look for them had be swapping tubes only to find that it was the actual fitting. This ended up with me removing the fitting itself and having to hold a replacement up in the apex of the roof with one hand while trying to locate the screws holding it in place with the other, so I'd had enough of the loft for the day after that little episode! To the OP - if you haven't done so already (I can't remember whether you have without going back over the thread), then try replacing BOTH the ECC85 and the ECH81 with known good ones, perhaps from another working set. If there's still no FM then you'll have to start some serious fault finding. |
15th Apr 2021, 1:16 pm | #25 |
Dekatron
Join Date: Nov 2009
Location: Lincolnshire, UK.
Posts: 5,000
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Re: Bush VHF61 FM band dead.
Thanks David. You're more technical explanation is better than my 'HT across it until it sparks' method, which wouldn't have proved the heater cathode insulation limit, so very useful to know - and certainly worth doing a bit of the latter that you mention.
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15th Apr 2021, 2:07 pm | #26 |
Octode
Join Date: Dec 2003
Location: Leeds, West Yorkshire, UK.
Posts: 1,592
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Re: Bush VHF61 FM band dead.
Hi everyone.
Good news, the Bush VHF61 now works on F.M! I found a good ECC85 valve in a box in the garage. Job well done! Cheers Mike |
19th Apr 2021, 2:34 pm | #27 |
Octode
Join Date: Dec 2003
Location: Leeds, West Yorkshire, UK.
Posts: 1,592
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Re: Bush VHF61 FM band dead.
I have been reliably informed that the ECC81 conversion does work, so it is another possibility for people to carry out when good ECC85 valves are scarce.
At least I have been able to procure a good ECC85 to complete my job. Cheers Mike |