[Heath] Concerning the SB-200 and tubes...

[Allen Jones]

Several different HF amps have been retrofitted using the Russian GI7BT triode.  A Google search will result is dozens of examples.  They are cheap, I have bought them on eBay and had them shipped from Ukraine for about $30 each.  The plate dissipation is 350W and they work real well in the 2000 - 2500V range.  Filament voltage is 12.6 so a new filament transformer will be needed in many cases.  I am using one of these tubes on 6M and get 500W out on peaks with 30W of drive and 2400V on the plate.

Allen, W9DZ   



>________________________________
> From: Kenneth G. Gordon <kgordon2006 at frontier.com>
>To: Heath at puck.nether.net 
>Sent: Sunday, May 18, 2014 12:27 PM
>Subject: [Heath] Concerning the SB-200 and tubes...
>
>
>In the meantime, and previous to this delightful news from RF Parts Co, I 
>had, in desperation, decided to modify at least one of my SB-200s to a pair of 
>4CX250Bs, since those tubes are practically ubiquitous on eBay and can be 
>bought,
 NIB, for very little money. I now have almost a dozen of those, all of 
>which have, so far, tested good.
>
>
>
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