[Hallicrafters] how to power up old radio with variac

[Greg Mijal]

I wonder if this radio is old enough to not have any electrolytics in it? 
Some 40's stuff doesn't.  They're all oils and bathtubs (some sets, mostly 
transmitters). No electrolytics? Just turn it on and test.
If it does and you really want to experiment I think all afternoon on the 
variac would give them a chance to reform themselves.  Take your available 
afternoon time, say 5 hours then divide up the variac into 10 little 
increases until you hit 100% of the variac.  The inital start up will be 
slow because you have to reach a minimum voltage before the tube rectifier 
starts doing it's thing.  Just shoot for 20 vdc at the start, wherever that 
is on the variac setting. Something else you should do is put a 60 w light 
bulb in series with the ac into the set.  If there is a short on the primary 
side the bulb will glow brightly.  If things look good, short the bulb out 
or remove it because it is hogging some power from the set.
I have had some many fun afternoons cheating Sprague out their money that I 
built a fixture with a 6A variac, bulb and breakers on a plywood board. It 
works great and I can toss it in the corner until the next victim shows up.
All in all, I would replace the power supply electrolytics (if that's what 
they really are) at a minimum before turning anything on.  This is a real 
oldie man!
73's and good luck
Greg
WA7LYO
Kinston NC
----- Original Message ----- 
From: <chandlerh2 at aol.com>
To: <hallicrafters at mailman.qth.net>
Sent: Wednesday, June 06, 2007 12:11 PM
Subject: [Hallicrafters] how to power up old radio with variac


> hello to alll . most of my hallicrafter radios were in working order or 
> close
> to it when i aquired them .
> i just found a rather unusual radio it is a wells-gardner rao3 at least 
> that
> is what i think it is the plates on top have been removed except for the 
> one
> that says accepted by the navy 1944.there also is a mounting base the 
> radio
> sits on with a navy tag on it that has a part number and says a unit of 
> model rao
> 3.i cant seem to find any info on it .
> this radio weighs a ton and is in untouched condition inside and out still
> has all of the US navy tubes in it to also  the huge coax plug in the back 
> with
> about 2 feet of cable on it .evrything looks factory origional on the 
> chassis
> has all paper wax caps in it . how long should i let it sit on variac when
> powering upto see if everthing is working .
> thanks to all who reply .
> steve
>
>
>
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