Larry,my initial thought was to urethane clear coat .125 in. copper tubing
and wind enough turns around paralled ferrite rods to get what I need...I
planned to isolate the filament trans anyway,so added chokes in the primary
may be effective in eliminating filament hum/modulation..PWD makes a nice
high current choke too( for around 300.00 or so)...Jim K7RDX..
----- Original Message -----
From: "Larry Carman" <lncarman@swbell.net>
To: <amps@contesting.com>
Sent: Wednesday, January 03, 2007 5:11 AM
Subject: Re: [Amps] Ferrite Rod
> Jim,
> Forgot to mention this but you might consider floating the filament
> transformer. I've never tried the approach myself but have heard others
that
> have had good results with it. It's pretty easy to isolate the filament
> transformer from the chassis and use much smaller chokes in the primary
> leads and no choke at all in secondary. Chokes in the primary would only
be
> passing about 1.6 amps or so. The capacitance between the transformer and
> chassis would have to be calculating in with the input tuning network.
> Larry N5BIP
>
> -----Original Message-----
> From: k7rdx [mailto:k7rdx@charter.net]
> Sent: Tuesday, January 02, 2007 11:15 AM
> To: Larry Carman
> Subject: Re: [Amps] Ferrite Rod
>
> Nice point Larry, I am thinking for my 8171 with 75 amps filament current
to
> parallel two 30 amp filament chokes and since they will be getting the
> initial blast of 800cfm, do you think this will work? I`m laying out
> components now and having metal cut&bent for the rf deck. I found a new
> Peter Dahl filament trans a w9 had made&didn`t use. Still looking for a
> trans to do 7500vdc/3 amps...I may do initial testing with the ps in my
> yc-156 amp...Have a great New Year,73, Jim K7RDX..
> ----- Original Message -----
> From: "Larry Carman" <lncarman@swbell.net>
> To: <amps@contesting.com>
> Sent: Tuesday, January 02, 2007 7:32 AM
> Subject: Re: [Amps] Ferrite Rod
>
>
> >
> > I used the .5 X 4 rods material type 33 with #10 enamel wire wound to
the
> > ends in a 3cx3000a7 amp and it works on 3.75 MHz just fine. It sits in
> from
> > of a fan in the lower deck compartment. At 51.5 amps I figured it needed
> > some cooling. Been running for years. I bought it from Amidon at
> > http://www.amidoncorp.com/aai_ferriterods.htm . They are probably pretty
> > pricey these days.
> > Regards,
> > Larry N5BIP
> >
> > -----Original Message-----
> > From: amps-bounces@contesting.com [mailto:amps-bounces@contesting.com]
On
> > Behalf Of Ed Stallman
> > Sent: Tuesday, January 02, 2007 8:29 AM
> > To: amps@contesting.com
> > Subject: [Amps] Ferrite Rod
> >
> > Who has or sells Ferrite Rod? I'm looking for 3/8 OD , not sure how
long
> > to wind a Filament choke!
> >
> > Thanks Ed N5BLZ
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> >
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