[Boatanchors] FW: Tube source

[mac]

Bob,

Antique Electronic Supply <http://www.tubesandmore.com/> currently has  
25AV5GA's listed at $5.05 each.

The 25AV5 TV tube works well as a substitute for the 6000.  Same pin- 
out as
the 6000 but don't just plug it straight in because the plate
current will be too high.  The screen circuit must be modified by  
replacing
R120 (the original screen dropping resistor) with a  15K 10W  unit and  
adding
a 25K ww pot to ground.  The screen is then fed from the arm on the  
pot which
can be mounted on a bracket behind the front panel.  Adjusting the pot  
for 25 - 30
ma driver plate current gives 10-12 ma drive to the 4-400 on all bands.

I modified my Basic as above several years ago when 6000s were very  
hard to
find, and have been using it regularly with the original 25AV5GA in  
place ever
since.

Dennis D. W7QHO
Glendale, CA



On Jul 5, 2010, at 6:46 AM, Bob Peters wrote:

> Does anyone out there have a 6000 tube or as I understand a 25av5 or  
> 25au5
> are subs... I have a buddy not on the list looking for one...T3 Osc  
> not
> Oscillating...
>
> Thanks
>
> Very Best 73's
> Bob Peters
> W1PE
>
> ARRL, QCWA, AM FOREVER
>
> Money is only temporary, Radio is forever
>> From The Old Dog
>
>
>
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