> How do these developments relate to the Heath SB-1000? Are any
> modifications required to the cooling?
The SB1000 was a clone of the AL80A. The original AL80 was
designed in Twinsburg Ohio by other people who eventually had
It is totally different than the AL80A.
Prime Instruments owned all the original parts and tooling for both
Amp Supply and Ameritron but the original "designs" were by Amp
Supply and Prime ordered, stocked and owned the parts and
tooling. When the relation$hip fell apart Prime kept the Ameritron
stuff to "$ettle up".
When I looked at the AL80 with the owner of Prime, we decided to
recall all amplifiers and rebuild them at Prime's expense. All the
AL80's we could find were called in, gutted down to the bare
chassis, and rebuilt with proper tank Q, proper input circuits, better
tube-to-cabinet top spacing, new airflow, new metering, the 2 watt
carbon resistors across the electrolytics that dissipated 2.3 watts
were removed and replaced with components rated for the job, 270
volt rated resistors across the diodes were removed, the QSK
system that was a piece of coax from output to input was removed,
wiring was converted from point to point to a harness system,
unreliable surplus purchased parts were scrapped, filament voltage
was set at 5 volts instead of 5.8, meter shunt protection was
added, the bandswitch was changed, ALC was changed, the relay
wiring changed, and even the front panel transmit light was
changed to a light that actually worked instead of a surplus light
that had no spring in the contact of the holder.
It probably cost Prime about $300-500 each in 1982 dollars to
rebuild the amplifiers, not to mention the ten's of thousands of
dollars of rejected parts that were scrapped or sold as surplus.
I was very pleased that John Moran W8IOB agreed to this program,
since he was never paid for the amps or even most of the parts. He
was one of the most honest people I have ever met in my life.
John passed away last year, and not a mention was made in QST.
John was key to Raytheon, Bud Radio, and others. John worked on
the first radars designed for WW II, and made many quiet
contributions to amateur radio. He founded Actron Electronics,
they made virtually all of the electronics test equipment for Sears,
Snap-On Tools, and many other companies. John's companies
turned out many millions of meters and panel instruments for
automotive and other applications, and virtually every meter used in
popular battery chargers as well as the first transistorized ignition
73, Tom W8JI
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