[1000mp] RE: AMPS

[lhlousek]

Some very interesting info so far.

How does Eimac tube nomenclature work?  Does the 4CX or 3CX indicate the type and the following digits the size?  Do all
3CX tubes have thoriated tungsten filaments and hence are more robust?

I presume estimable amps like the Alpha 99, ACOM 2000, 1000, and Ten-Tec Titan II using the excoriated 4CX tubes would
have quick acting grid current protection schemes. The Alpha 87A, and of course the AL1500, 1200 and 800H use 3CX
tubes.  What about the Svetlana GU48B and GU78 used by Emtron? I understand the GU74 is equivalent to a 4CX type.  And
then there's the pair of lovely glass enveloped 3-500s in the Ten-Tec Centurion and QRO HF-2000.  They sure are pretty
but not quite QRO.

One thing I consider very important is good CW QSK.  What I've heard is that vacuum relays are quite fast enough and
robust (if a little noisy) whereas PIN diode switching, although faster (and silent) is not worth it's relative frailty.
What has been the experience with these and with the Ameritron PIN diode QSK accessory?

Anyway; however convenient (and operator error proof) the 87A or 2000 may be, for my purposes, I'd eschew the
microprocessors and turn the knobs myself which would be more in keeping with the troglodytic thermionic character of
tube technology.  And, although solid state amps may be technically advanced with all the attendant benefits, they are
rather cold (figuratively) and inscrutable.  Don't get me wrong.  I'm not anti-technology and am not attributing any
metaphysical character to tubes.  It's just that there's a certain level of nostalgic atavism that I associate with ham
radio and that I would like to maintain. I say "certain level" because I'm not quite wistful enough to put in the effort
and live with limitations of a boat anchors.

Lou W7DZN