[Collins] PM-2 Xfmr upgrade - Its ready!

[wabate]

Sorry for the long delay in finishing this project.  I let work 
interfere with ham radio!  But the good news is that the upgraded 
transformer is finished testing and ready for manufacture.

For those that missed or have forgotten the original email, I wanted to 
use a PM-2 power supply with my 2A but I was concerned about its 
intermittent B+ rating (Collins description, not mine).  Another concern 
was that the power supply was designed for 110VAC operation.  If you 
check the supply voltages, they will be higher than spec.  The only 
significant problem I found was with filament voltage.  On my stock 
supply with 120VAC input I had 6.8VAC volts under load!

In 40 years or so since the original design, wire and insulation has 
improved dramatically.  The wire now used has a rating of 150 C and the 
insulation is rated cat 130 C!  The other improvement was in lamination 
efficiency.  The result was a transformer with the same size and 
voltages that I operated at full load for 3 hours continuous.  The power 
supply, with the new transformer installed, and under lock key had a 
filament voltage of 6.3VAC and DC voltages of 280VDC and 796VDC.

I eliminated the 110/220VAC dual primary because I thought it had 
limited appeal and because it the allowed me to tap the primary.  The 
primary now has taps for 115VAC, 120VAC and 125VAC.  Now we can 
compensate for the higher line voltages that exist today.  I also 
eliminated the 400 HZ capability.

So what's the bottom line?  Well initially I got a price of $125 plus 
S&H.  After all the refinements and based on the initial interest 
expressed, the price is now $128 but that INCLUDES S&H.  So the price 
came down.  S&H is limited to CONUS.  Others can request S&H charges for 
outside CONUS.  Please note that this is a one time production run.  I 
will not be stocking transformers for future sales.  To get one you must 
order one (or more) now.  This is a hobby for me, not a business.  If it 
were, I would be marking up the price.  The price is just what I am 
being charged.

To see the transformer and my upgraded PM-2 please go to:

http://mysite.verizon.net/wabate/pm-2.htm

You in effect have a 516F-2 in a PM-2 package.  Those who expressed an 
earlier interest are being emailed direct.  Whoever wants one, please 
email me direct.

73,

Bill, K3PGB