[Amps] Source for plate xfrmer

Jim Thomson jim.thom at telus.net
Wed Feb 15 06:15:28 PST 2012


Date: Mon, 13 Feb 2012 13:35:38 -0500 (EST)
From: "Steve Bookout" <steve at dx4win.com>
Subject: [Amps] Source for plate xfrmer

Hello all,

Where do you look for a new HV plate transformer these days?  

I understand Peter Dahl is no longer around.

I'm looking for 3000 VAC secondary @ 1+ amp CCS.  

TIA

73 de Steve, NR4M

##  harbach makes and carries the dahl line of xfmr's. 
A 3 kva CCS  xfmr will weigh 46 lbs.   The next one up from
that is the 68 lber.[ then the 86/127/168/253/441]
 My 46 lb'er is 27 ohms across the  2750 vac sec.

## My 253 lb dahl is 3.46 ohms across the 3 kvac sec.  And 6 ohms
across the 5200 vac sec.   How much $$  do you want to spend ?? 
The bigger they are, the cheaper they get. 

##  If you want superb dynamic B+  regulation, get the biggest xmfr you can
afford, then use BIG ga wire back to the main 200A panel..like 6 ga min. I use
6-8-10 ga  wire on these small supplies... and  1-0  and 2 ga on the big supplies. 

##  Then use some BIG caps.  A string of 2500uf @ 450 vdc lytics will 
result in superb regulation. I have  caseloads of em if you require any..cheap.
2"  diam x  4" long.  14 oz. 10A CCS ripple current rating.  .013 ohm ESR. 
Do it right, and you will be lucky if you can see the B+ meter even flinch. Beware,
the  PSUD software assumes a steady state load and not a dynamic load. 
No need for chokes, resonant chokes or CT plate xfmrs, that's  all steam engine
technology.  Big caps with low esr and a big xfmr, also with low esr and big ga wire
= zero ripple  at 120 hz...and all harmonics.  The  real no load B+ is what the B+  is
when sucking normal idle current. On ssb/cw, it won't drop much below that point. 
Your pep output  will be a lot higher too. 

Later... Jim  VE7RF 


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