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Re: [Amps] potential suppressor...

To: "Amps Reflector" <amps@contesting.com>
Subject: Re: [Amps] potential suppressor...
From: "Roy Koeppe" <royanjoy@ncn.net>
Date: Mon, 21 Mar 2005 07:38:35 -0600
List-post: <mailto:amps@contesting.com>
Hi Tomm,

As Richard said, if you work only the lower bands, that resistor will
work fine. I have used several similiar resistors, up to 5 ohms, in
fact, with 4 or 5 turns on ceramic forms. Of course, you should still
use parallel film resistors just like with any other inductor. If you
can stomach the added bulk, you can parallel two of those 5 turn wire
wounds along with the film. Then 28 mHz should be okay. (Great minds).

73,   Roy   K6XK

Hello, Tomm -- L/R parasitic suppressor networks typically have roughly
the same reactive ohms at the anode's self-resonance as their resistive
ohms.   For example, a pair of 3-500Zs typically have an anode
resonance of c. 120MHz.  Thus, for a 100-ohm suppressor R, 140nH
(XL=100-ohms) would be roughly optimal.   For use with a 50-ohm
suppressor R, L-sup would be c. 70nH.
- note - In the above example, the 100-ohm suppressor would give more
VHF suppression, but it would run much hotter at 29MHz. Parasitic
suppressor design is basically a balancing act between adequate
reduction of VHF gain and a meltdown at 29MHz.
- cheers

On Mar 20, 2005, at 6:46 PM, Tomm Aldridge wrote:

> All,
>
> As part of my amp project I just received some Dale 1 Ohm, 25W ww
> resistors.  I was holding one in my hand admiring its chunkiness (yes,
> I
> am that strange)when I saw it was wound with 5T of flat strip.  This
> made me wonder if it was a nice lossy inductor,  It is, the inductance
> is .43uH as measured on my AADE L/C Meter IIB.  Could this be a ready
> made parasitic choke?  What do you think?
>
> Dale HL 0250Z1R000JJ is the P/N
>
> Cheers,
>
> Tomm, KD7QAE
> _______________________________________________








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