[Hallicrafters] solid state device

[Barry H]

Very likely it has a couple of rectifiers potted in that octal tube base, but very unlikely there are any dropping resistors.  

These were sold way back as a pegboard item, some called a "Solid-Tube".  The line -- there were two or three mfr. names -- included other potted modules.  Many of them looked roughly like a half-sphere or egg shape and included simple circuits such as flashers, amplifiers, code practice oscillators, etc.  Those usually had 3 or 4 wires sticking out of the black epoxy or whatever it was. 

I recently came across a "solid-tube" like that in my junk pile.  Still had the plastic baggie, and the small instruction sheet folded up to the size of a postage stamp.  Also listed the rectifier tubes it replaced, such as the 5Y3, 5U4, etc.  and warned that the B+ would be higher with the plugin and should be checked and if necessary dropping resistors added.  So much for plug'n play - that's why I probably never used it.  The dropping resistor(s) needed vary according the specifics of the circuit as well as line voltage, and I guess the small tube base with potting would not allow sufficient cooling for the resistor anyway.  

Mixed bag -- typical buyer plugging one in but not checking the B+  might never have to replace a rectifier tube again, but possibly a few dozen other components would be stressed a bit.

Barry



-- "Ian" <ianwebb5 at comcast.net> wrote:
It's likely a plug-in solid state diode module.  They were common in the
1960s and 70s and widely available to plug in to replace a FW rectifier.

It is likely though that it does NOT contain dropping resistors though.

Take it out and measure between anodes and cathode with ohmmeter in both
directions and see what you find.

Ian, K6SDE


-----Original Message-----
From: hallicrafters-bounces at mailman.qth.net
[mailto:hallicrafters-bounces at mailman.qth.net] On Behalf Of Jack Schrader
Sent: Thursday, December 01, 2005 5:17 PM
To: Hallicrafters List
Subject: [Hallicrafters] solid state device

After a  closer examination of my sx101a I see what must be some kind of a
solid state device mounted where the 5y3 rectifier goes.. It looks like a
standard 8 pin tube base but it is made up of a solid base like material. It
is approx. 1" in dia. and maybe 7/8" high. It rectifies well and has an
output of about 285v on both plate pins and 371v on the heater pins.

Anyone know what this device is as there are no markings on it. I'm guessing
that it probably had a decal label on the flat top at one time.

Thanks Jack 

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