[ARC5] BC-454-B Power

[MICHAEL BITTNER]

Not wanting to poke around the underneath to trace the wiring, Instead I measured the cold filament resistance of each tube (not exactly the same for each one) and then did the math for all of these 12-Volt tube filaments in parallel.  It came out to 2 Ohms down to 4 decimal places as I had originally measured at the dynamotor terminals.   So this puppy has either been converted for 12-Volt power (very workmanlike job) or was originally built that way.  Was there ever a factory-built 12-Volt version of the BC-464-B?  Mike, W6MAB 

> On July 19, 2021 at 1:58 AM Brian Clarke <brianclarke01 at optusnet.com.au> wrote:
> 
> 
>     Not such a good idea, Ken.
> 
>      
> 
>     This idea of substituting 6 V tubes really only works if all the heaters are in parallel. 6SK7, 6K8, 6SR7 all require 6.3 V @ 0.3 A. The 6V6 heater requires 0.45 A.
> 
>      
> 
>     Further, the 6V6 is not a good match for anode load; a far better match, and available in metal with the same pin-outs as the 12A6 and 6V6, is the 6F6, anode load 7 k Ohm , but heater current 0.7 A.
> 
>      
> 
>     73 de Brian, VK2GCE
> 
>      
> 
>     From: arc5-bounces at mailman.qth.net [mailto:arc5-bounces at mailman.qth.net] On Behalf Of Kenneth G. Gordon
>     Sent: Monday, 19 July 2021 2:24 PM
>     To: 'MICHAEL BITTNER'; arc5 at mailman.qth.net; Robert P. Meadows
>     Subject: Re: [ARC5] BC-454-B Power
> 
>      
> 
>     On 18 Jul 2021 at 21:16, Robert P. Meadows wrote:
> 
>      
> 
>     > How about checking the wiring against a proper schematic.  Then you will
> 
>     > know.  First check the tubes.  A quick change to 12v filaments is to install
> 
>     > 6 v filament tubes…   Not hard R
> 
>      
> 
>     Use a 6V6 in the 12A6 socket. Base diagrams are identical: 8AC
> 
>      
> 
>     Ken W7EKB
> 



-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.qth.net/pipermail/arc5/attachments/20210719/345885ac/attachment-0001.html>