[Collins] Replacement chokes and Transformers for the 516F-2 and 30L-1

[Bill Abate]

Hi,

About two years ago I started a project to provide replacement
transformers and chokes for the 516F-2 power supply.  Despite the
typical nay-sayers it was very successful.  Over 100 hundred
transformers and chokes were shipped.  Since then I have gotten periodic
inquiries asking if I could supply more.  I usually respond that to make
one or two of something is cost prohibitive.  But now I see it's been a
few years and maybe there is enough new interest.  I doubt if we could
match what happened a few years ago but the price could be comparable
with a decent response.

Enough of a preamble.  Here is what you could buy if we get enough
interest.  The replacement transformer for the 5126F-2 would be as
follows: The transformer laminations will be 3" thick X 5 1/4" wide X 4
3/8" high, as original.  The mounting holes will be 4 1/2" X 4 1/8" c-c
as original.  The transformer will have end bells, as original.

The electrical specifications will be a little different.  The primary
will be tapped for 115, 120 and 125 VAC (not 115/230).  That should
cover every part of the country!  (No more variacs or buck/boost
transformers).  The filament winding will be 6.3 VAC @ 11 amps. The HV
secondaries will be 1920 VCT @ .275 amp and 720 VCT @ .25 amp.  The
current specs are for the KWM-2A plus a little extra.  The high voltage
secondaries were based on my 516F-2 RE unloaded transformer
measurements.  I then deducted 60 volts from the measured voltage to
center tap because I'm eliminating the 5R4, and 50 volts for eliminating
the 5U4.  My tube manual claims those are the voltage drops for those
rectifiers.  Since we will be using diodes, I eliminated both 5 volt
secondaries.  I think this is the way Collins would have designed it
today.

I expect the cost today to be about $120 plus S&H.  Maybe less if we get
a decent number interested.  Peter Dahl wants $235 the last time I
checked.  I just want to mention the disclaimer that you would be buying
from the manufacturer, not me.  I am not making anything out of this and
don't want to.  If there is a problem with your shipment, contact the
manufacturer.  That is between the two of you.  I'll help, if I can, but
that is it.  This is not a business for me.  I can't see marking up the
cost for the handful of hours of my time that this will take.  But I'm
not going to possibly get entangled in something that I did not create
nor profit from.

The Chokes will have the original inductance of 8H and 1H, each at 350
ma. which is a little beefier.  Coincidentally I recently had to replace
one of the 8H chokes in my 516F-2.  It fit like a glove.  The no load
voltage came down from 1400 volts to about 900 volts, as it should.  My
KMW-2A is very happy again!  The 8H chokes come with end bells but only
the upper choke uses both.  I simply removed one end bell.  You have to
reuse the original mounting hardware as it is special.

I expect the cost for the 8H choke to be about $30 plus S&H and the 1H
to cost about $17 plus S&H.  Again these are bolt-in replacements.  No
drilling holes or hammering needed.

Now for a new twist.  Is anyone interested in a replacement transformer
for the 30L-1?  I don't think the failure rate is that high but let me
know if you want me to pursue this.

Please email me direct if you are interested in buying the transformer
and/or chokes.  I'll put a list together and see if another production
run would be feasible.

73,

Bill, K3PGB