small valves

Allison ajp166 at bellatlantic.net
Fri Apr 22 19:25:22 CDT 2005


>
>Subject: Re: small valves
>   From: ard at p850ug1.demon.co.uk (Tony Duell)
>   Date: Sat, 23 Apr 2005 00:32:48 +0100 (BST)
>     To: cctalk at classiccmp.org
>
>I have a UK battery/mains radio that uses valves throughout (even the PSU 
>rectifier) and directly heated valves in the signal stages. The filaments 
>are in series (carefulyl ordered to get suitable cathode bias voltages), 
>for a total of 7.5V. The batteries were a 7.5V LT and 90V Ht pair. On 
>mains, there is a mains transformer, the output of which is full-wave 
>rectified (EZ40 IIRC). That provides the HT (B+) directly, and the 
>filament supply (A+?) via dropping resistor.
>

I have an RCA AM broadcast Battery/mains radio that I still use.  
Works well. The multivoltage battery though bad supplied the 
authentic looking cover for a box I'd made using uses NiCds 
to run a switchmode supply to provide the A,B and C voltages 
required.  Runs for hours on that too.


Allison
Kb1gmx



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