> In solid state broadcast transmitters, there is always APC (automatic
> power
> control).
It's possible for the ALC mechanism in our amps to manage that much to the
same degree as commercial automatic power control. Its just a matter of
applying the right algorithim to the ALC bus. I suspect Elecraft uses an
ALC algorithm in its 500W amp that's much the same as the one in their K3
which has excellent transient and long-term power management time constants.
> The Harris MW-1...now there's a transmitter I'd like to forget...
Not for me. Once it was upgraded to the MW-1A, it was nearly trouble-free
at WLBK between 1980 and 1983, the year I graduated from NIU.
> The obvious solution here is liquid cooling.
Yes, but how is that implemented at low cost and low maintenance to the end
user?
> High volume/low velocity only works when you have a suitably large surface
> area of heatsink. Heatsinks aren't cheap, and, if the goal is to maintain
> a
> small form factor, you have design criteria that are mutually exclusive.
And that gets back to cabinet volume which I think is more the issue in
relation to heatsink cost.
> However, modern SS manufacturers are usually very responsible
> when it comes to putting out EOL (end of life) notices for devices well in
> advance. That doesn't seem to be the case with hollow state.
But the EOL notice does little to help a guy if no other semi manufactures
step up to the plate.
> Be very wary of buying SS RF devices from overseas.
Amen to that. I no longer purchase SS devices from anyone other than a
known supplier like Mouser, Allied, Newark, etc. It dawned on me last year
when I purchased what i believed were ultra-low-noise Toshiba transistors
for an audio amp circuit. I purchased a dozen or so from an on-line Asian
vendor then realized that without curve-tracing and noise testing, how do I
know that they are not just a re-labeled 2N3904 types?
Paul, W9AC
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