[AMPS] good, bad, ugly

Dick Byrd n4uq@mindspring.com
Tue, 25 Mar 1997 21:43:52 -0500


Reading all the comments about which amps are junk and which ones can run
all night long, etc. inspires me to comment.  

I have a sack full of burned up Alpha parts in my Lab-shack.  They melt down
just like any other manufacturers' if they are abused.

The two Alphas I have right now belong to a big-time dxer who's photo, I
understand, is on the cover of a recent issue of a popular ham magazine.
The little 76 three holer has two shorted tubes.  When the overload circuit
became a nuisance, they defeated the circuit.  When the fuses blew, they put
bigger fuses in.  When the fuse holders caught fire, they removed them and
twisted the wires together.  When the 160 toroid melted down, they finally
gave up.  I didn't ask but they were probably running RTTY.  They were in a
foreign country and fixing the amp wasn't an option.

The 8877 Alpha single holer has a cooked tube, the spare is even worse.  The
fuses (30 amp instead of the specified 20A!) have been so hot they melted
into the fuse holders.  One of the two air variable load caps is fused
together....It's history.

Bottom line here is, you can burn up anything.

The newer Alphas are even less bullet-proof than the older ones.  If it
weren't for all the protection circuitry in the 87A, there would be more of
them melted down...the guys can't figure out how to defeat all the
complicated overload circuits.  The reason you don't hear more complaints
about them is the factory's very generous warranty policy.

I suggest to all RTTY users to adjust the transceivers' output to at least
half that of the key-down level.  If you tune your amplifier using 100 watts
of carrier, turn it down to 50 watts and readjust the load control.
Put your hand over the vent every few minutes...if it feels warmer than when
you are rag-chewing on SSB or CW, turn it down some more.  These things
aren't broadcast rigs.  And if they were, most of us could never own one.

I operate a pair of 20KW key down transmitters at my work...24 hours a day,
seven days a week, 365.25 days a years.  You can hardly think for all the
noise!  It takes alot of air to remove all that heat.

I've been to hamfests and seen inside those Ameritron rigs.  I don't see
that much difference between them and the Colorado kilowatts.


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