The Astron power supplies use the 723 linear voltage regulator IC. It’s very
durable, and there are millions of linear power supplies operating with that
chip.
One of the problems with the Astron’s is they used the data sheet from TI about
the 723, then removed every single part that they could yet still have the
circuit operate. It’s under designed.
And like Stuart said, the first thing to go in the regulator IC, especially
during electrical storms with the supply plugged in and turned on.
Another ‘under design’ in the Astron supplies is the continued habit of the
designer to use one of the emitter balancing resistors as the shunt for the
current meter. The resistor needs to be there, so, they use it for a dual
purpose. Because of this design, the current meter is far from accurate.
Instead of using a full wave bridge, they use, as Stuart said, only two diodes
in a bridge block. It must be cheaper that way instead of using two stud mount
diodes.
They also have a tendency to use two bridge rectifiers in parallel in their
high current supplies.
But with all the lumps and bumps, they are rather robust, many of them operate
for decades without fail.
yet, with that being said, I’d think hard about putting on in repeater service
when it takes a 4X4 two hours to climb to the hill top to the repeater site.
Google ‘repeater builder’ and you’ll find tons of information on making these
supplies more robust, more reliable, and safer.
I have a Astron SS-30 that had been on for 18 years none stop. It failed last
spring, the PWM chip when out. Replaced the chip and all the high zoot
capacitors and I expect another 18+ years from it.
I do leave my power supply on all the time. No matter how much it storms and
how many lightening strikes are taking place. It’s built to take it— 36 6-volt
220 amp/hr batteries run the shack
Mike Bryce WB8VGE
prosolar@sssnet.com
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