Substitute Transformer?

Al Parker anchor at EC.RR.COM
Tue Nov 18 13:52:09 EST 2003

Hi Paul,
    Your post is by no means off topic, the old Super Pros are very
definitely boatanchors, and one main purpose of the list is to help us all
keep/get our treasures operating.
    You can figure the reqd current rating for the 5V windings directly
from the 5Z3 & 80 filament ratings.  The 6.3v line to the rcvr could be
figured similarly (but not as easily) by adding all the filament currents
of the tubes in the rcvr.
    For the hivoltage winding - I thought I had taken (and recorded)
measurements of the current of each last Spring while working on my
BC-779, but can't find them now, and don't see that they're noted in the
manual.  It's not a big amt, maybe 100-125 ma at the most, for the winding
that supplies the HV.  Note that the whole rcvr can be run with 5 ea. 45v
batteries supplying all the HV delivering 225 for the 270 & 385v lines,
and 90 for the 140v line, and another 45v bat for the bias line.  So,
actual voltages are not critical, tho' performance will be best at the
spec'd voltages.
    Total power draw for the whole rcvr is stated as 180w average, just
for a reference point.
    I'm a bit surprized you haven't found an original supply.  They are
out there, but shipping is pretty high, they're very heavy, 89 lbs, abt
the same as the rcvr.  They are very over-designed,  I'm sure you can do
with a much lighter xfmr.  Just for info, Al Klase has recently updated a
very good reference page on these rcvrs & p.s.'s:
There's also info on The Hammarlund Historian website:
there's a link there on the "service" page to my rebuild of the BC-779.
    (I have 3 Super Pro series rcvrs, but only 2 pwr supplies)
    I hope this helps.
Al, W8UT
New Bern, NC
BoatAnchors appreciated here

----- Original Message -----
From: <pjhend at>
Sent: Tuesday, November 18, 2003 12:21 PM
Subject: OT: Substitute Transformer?

Hi Folks,
Slightly off topic, but I am having a hard time locating a Power Supply
a Hammarlund Super Pro (series 200) receiver. I've decided to homebrew a
power supply for it if I can't locate one soon. But I cant't find out what
model transformer was used and what voltage-current ratings are needed for
the high voltage winding. There are 2 separate low voltage windings: 5v
the 5Z3 HV rectifier, 6.3v for the receiver tubes, and 5v(?) off a tap
the high voltage winding for the 80 rectifier tube supplying grid bias for
the set. I don't know the current requirements for these as well. Any help
you can give me would be appreciated. I know that AES has a number of
transformers that might work if I knew the correct requirements. Thanks
your help!

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