>
>Especially if you're only looking for 1500watts of CW, why not 4CX250B's? 4
>of them, 2kV at an amp or so, and you're there. You should be able to pick
>them up reasonably cheaply with sockets. Over here, I'd reckon to get
>sockets and 4 tubes for under $150. You could probably get away with 3 of
>them if you pushed the HV to 2500v. According to my book, they are rated at
>1500v in plate modulated service, which gives a peak plate voltage (crest of
>modulation, crest of RF waveform of around 4500 to 5000 volts,
? indeed, or even a few hundreds of volts more.
> so pushing them to 2400 or 2500volts in CW should be OK.
? providing one does not send A-0/NØN
>And if you really are CW only,
>you don't need anything too fancy by way of screen grid supply.
>
>Do you really need instant on?
>
? No one needs instant on if they put an IR motion detector in the radio
room which switches on the cathode-heaters at the first sign of life.
>The big advantage of 3-500Zs to my mind is that the blower requirements are
>such that it's likely to be reasonably quiet.
>
? provided that one copies the split-chassis cooling method used in the
SB-220. Air system sockets require a noisy centrifugal blower.
>
- later, Peter
Rich...
R. L. Measures, 805-386-3734, AG6K, www.vcnet.com/measures
--
FAQ on WWW: http://www.contesting.com/ampfaq.html
Submissions: amps@contesting.com
Administrative requests: amps-REQUEST@contesting.com
Problems: owner-amps@contesting.com
Search: http://www.contesting.com/km9p/search.htm
|