[Hallicrafters] Hallicrafters HT-33A

[Glen Zook]

Unfortunately, good 8122 tubes are even more expensive than PL-172 or 8295 tubes.  However, the 8072 is the same tube as the 8122 except that it does not have the fins (it is designed for use in UHF transmitters where the cavity serves as the heat sink).  But, that is a thought because I have quite a number of both brand new and used 8072 tubes left over from my commercial two-way radio days.

It would not be that hard to fabricate a heat sink which could handle the heat.  I could use a couple of the used tubes to work things out and if they didn't put out quite enough power I could then go to a pair of new ones.  Definitely something to consider.

Glen, K9STH

Website:  http://k9sth.com


--- On Fri, 9/19/08, Charlie <pincon at erols.com> wrote:

From: Charlie <pincon at erols.com>

It would seem to me that a pair of grid driven 8122 tetrodes would be a good choice.  They're still made by Burle (Spelling?) Industries in PA and are currently in use in many medical applications.  It would take a little metal work but they use the same simple socket as the 8874's.  As for chimneys, some red silicon rubber sheet glued in a cylinder works fine. (It was good enough for Alpha)