[Amps] More parasitic choke questions

[Jim Thomson]

Date: Wed, 28 Jul 2010 15:11:22 +0200
From: "DF3KV" <df3kv at 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 at contesting.com [mailto:amps-bounces at 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