Bill Turner <dezrat@outlook.com> wrote:
> I can think of several ways where transistors are superior to tubes:
> 1. When not abused, transistors are far more reliable than tubes.
My SB-220 still has Eimac tubes in it. I suspect they are the 40 year-old
originals, though I cannot prove it. Tubes should last a very long time in
routine amateur service.
It will be interesting to see how long my 811's last; they been used off and
for over six months without any change in performance. Ask me again in a
couple of years. When they do go, I can spend a few bucks and change them
simply by plugging and unplugging them in sockets. Can you change the
transistors on the heat sinks in the sold state amps as easily?
> 2. Safer. A 50 VDC supply is essentially harmless. 3 kV will kill you
> instantly.
Can't argue with that.
> 3. No expensive filament transformer needed.
Instead, you need an expensive auto-tuner and protection circuitry, whereas a
tube radio is fine with a manual transmatch. I use an ATR-30, which will tune
just about anything.
> 4. A 1500 watt transistor is cheaper than a 1500 watt tube.
Fairly meaningless given the expected lifetime of both (very long). What
matters is up-front cost and ease of replacement when needed.
> 5. No warm up time.
The warm up time of my 811 and 3-500Z amps is essentially zero.
> 6. The amps you mentioned are not rated at 100% duty cycle at 1500 watts of
> carrier (RTTY, FM, etc.) The PowerGenius XL is (ICAS).
As I and others said, if this amp were capable of 100% duty cycle CCS (not
ICAS), the additional cost would make more sense.
A $7K amp is at least $3K more expensive than a comparable tube amp. It's hard
to see where any of the above would justify the extra $3K.
73,
Cathy
N5WVR
_______________________________________________
Amps mailing list
Amps@contesting.com
http://lists.contesting.com/mailman/listinfo/amps
|