Date: Sun, 2 Nov 2025 17:40:39 +0100
From: <dj7ww@t-online.de>
To: <ah7i@gatech.edu>, <amps@contesting.com>
Subject: Re: [Amps] 12 KW CCS ON 160-15M....USING THE 3CX-6000A7.....
PART 35
>I never used electrolytic capacitors in my HV power supplies, only metal
>paper and never insane high capacitance values which will provide nothing.
>If there was any benefit from doing so, I guess the commercial
manufacturers
>did like Jim.
>My single phase Gates with 4CX3000A is using 12?F + 4H choke input and is
>specified with noise being 56dB down from full output.
>My R&S SK1 single phase transmitter with RS1072C is using a CLC power
supply
>with 9? capacitors and two 4H chokes in series, noise is down more than
55dB
>by specification.
>I use 2?F with my 3-phase power supply, 16?F with a single phase one.
>73
>Peter
Higher C values provide for superb dynamic regulation. I'm 250' from the
50 kva pole pig, so it's a 500' loop....and all aluminum wire. Over here,
we get way too much V drop from the 240 line, like 8-10 volts..when sucking
close to 100 amps on peaks.
There is no 3 phase available for residential use.
Oil caps and chokes are almost non existent these days. Shipping costs on
heavy oil caps and chokes is prohibitive. I was lucky to get a recent
vintage 4 H @ 3 amps Dahl choke. 127 lbs.....and was across town.
On that older 6700 vdc supply I built years ago, it used 4 x 47 uf @ 4.5
kv CDE oil caps in series-parallel for 47 uf @ 9 kv. Each steel cased
oil cap was 12" tall x 8" wide x 4" thick....and weighed 30 lbs..... or 120
lbs for all 4 of em.
I modelled ur single phase CLC supply with it's 9 uf-4H-4H-9 uf config,
and it sez the 100 hz ripple is down 55 db.
However on your single phase gates, with it's 12 uf + 4 H choke, it
does not come up with -56 db. Without a cap after the 4H choke, there
is no LP filtering. The PSUD-2 software won't model a choke by itself,
just a LC network, so to 'fool' the software, I used a very low value of
C. I believe it's a valid result.
Once I get my latest C-L-C filter finished, ( which has a vac relay
across the choke), I will also try it with and without the 2nd cap in
there, to simulate a C-L-C and also a plane C-L then measure the
difference.
Jim VE7RF
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