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Components and Circuits For discussions about component types, alternatives and availability, circuit configurations and modifications etc. Discussions here should be of a general nature and not about specific sets. |
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19th Nov 2018, 2:45 pm | #1 |
Octode
Join Date: Dec 2003
Location: Leeds, West Yorkshire, UK.
Posts: 1,593
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Alternatives to 7R7 valves
Are there any unofficial but obtainable alternatives to the 7R7 valve other than the CV900 one? I was just thinking on the same lines that 10P13 = UL41 is a typical example of unofficial comparison, without modifying the base?
Any ideas? Cheers |
19th Nov 2018, 11:25 pm | #2 |
Dekatron
Join Date: Feb 2007
Location: Leominster, Herefordshire, UK.
Posts: 16,536
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Re: Alternatives to 7R7 valves
It looks a bit unique.....
Characteristics wise you might get away with an EBF80 in an adaptor. Or there's the 14R7/CV3937 with 12.6V heater There's a few offered on Ebay.
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24th Nov 2018, 11:18 pm | #3 |
Heptode
Join Date: Oct 2008
Location: Aalborg, Denmark
Posts: 903
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Re: Alternatives to 7R7 valves
If you need a NOS 7R7 you can buy one here for $3.- ex. P&P:
http://www.esrcvacuumtubes.com/vacuu..._7a4-11y9.html or here: http://www.abcvacuumtubes.com/vacuum..._7a4-11y9.html or here: http://www.thetubecenter.com/vacuumt..._7a4-11y9.html That doesn't seem a very high price for a NOS valve. I've done business with all companies in the past and allways been 100% satisfied. Actually it's one company marketed as 3 afaik. |
25th Nov 2018, 4:37 pm | #4 |
Dekatron
Join Date: Feb 2007
Location: Leominster, Herefordshire, UK.
Posts: 16,536
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Re: Alternatives to 7R7 valves
The valve prices are fine, but how much do they pile on for international postage?
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....__________ ....|____||__|__\_____ .=.| _---\__|__|_---_|. .........O..Chris....O |
25th Nov 2018, 5:56 pm | #5 |
Rest in Peace
Join Date: May 2003
Location: Harlaxton, Lincolnshire, UK.
Posts: 3,944
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Re: Alternatives to 7R7 valves
Equivalents listed in my G C Arnold book that you haven't mentioned:
7E7 and CV892. |
26th Nov 2018, 12:23 am | #6 |
Dekatron
Join Date: Feb 2007
Location: Leominster, Herefordshire, UK.
Posts: 16,536
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Re: Alternatives to 7R7 valves
If you compare the data for each in here:
https://frank.pocnet.net/other/Sylva...istics1945.pdf They're pin compatible but rather different in terms of the pentode characteristics. Probably rarer too.
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