I normally do not need a resistor at all.
Either, because a parasitic suppressor is not found necessary, or
my usual way of blocking parasitics by loading a one turn loop with a
ferrite toroid.
On some tubes I need to wind a small three turn loop and insert a piece of
ferrite rod.
73
Peter
-----Original Message-----
From: amps-bounces@contesting.com [mailto:amps-bounces@contesting.com] On
Behalf Of Jim Thomson
Sent: Mittwoch, 28. Juli 2010 17:34
To: amps@contesting.com
Subject: [Amps] More parasitic choke questions
Date: Wed, 28 Jul 2010 15:11:22 +0200
From: "DF3KV" <df3kv@t-online.de>
Subject: Re: [Amps] More parasitic choke questions
Why is that impossible?
On HF the resistor is almost shorted out by the inductor.
The power absorbed will be less then 0.5% of the desired HF with a typical
amp.
73
Peter
### .5% of 1500w = 7.5 watts CCS..which is a bunch. Forget the HF
power absorbed
by the resistor. The poor resistor is already being cooked by the thermal
heat from
the hot anode anyway ! I noticed the 10 x 1 meg 2 watt CARBON HV
multiplier
resistor's on one of my old B+ supplies from the 70's had all risen in
value by
34% ! And that 34% rise was only after 3 yrs. I recently checked
carbons that
I bought new, back in the 70's..still in their wrapper.. and most of em are
way on the
high side..and were never used.
## Ok... how does one install the cap that's used to negate the XL of the
MOX
resistor ? Do u wire the cap in series with the resistor.. then parallel
the entire
mess with the coil ? . The Drake L4B uses wide cu strap.... no 12 ga
wire used.
## I used one, real small globar in my hb 3-500z amps from the 70's.
The GS35-B
doesn't require a suppressor on 6m. The YC-156 doesn't require a suppressor
an any band,
and neither does the 3CX-3000A7 or 3CX-6000A7.
## to reduce the plate load Z on the upper bands of a HF amp.. I typ
install a
.6 uh coil [ 1/4" -3/8" tubing] between plate block caps and input to
tune cap. This
does not appear to promote instability.
Jim VE7RF
-----Original Message-----
From: amps-bounces@contesting.com [mailto:amps-bounces@contesting.com] On
Behalf Of Bill, W6WRT
> Of course the main L should be very low
>loss and the complete suppressor should not absorb any of the desired HF
>power.
REPLY:
Not absorb "any" of the desired HF power?
That is impossible and Carl should know better than to make such a
statement
Bill, W6WRT
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