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Re: [Amps] grid resonance

To: "Tom W8JI" <w8ji@w8ji.com>
Subject: Re: [Amps] grid resonance
From: R L Measures <r@somis.org>
Date: Wed, 9 Aug 2006 01:52:49 -0700
List-post: <mailto:amps@contesting.com>
On Aug 8, 2006, at 10:01 AM, Tom W8JI wrote:

>> If you have some data which either proves or debunks the
>> usefulness of
>> nichrome, let's hear it, but please no implied insults.
>
>
> N7WS measured a nichrome suppressor and a regular suppressor
> and found no difference at all behavior at VHF.
> I've done the same.

Mr. Rauch --- At 100MHz, N7WS' measurements  showed that the parallel- 
equivalent resistance (Rp) of a  suppressor constructed from Ni-Cr  
wire is 103-ohms, and the Rp of a similar suppressor constructed from  
copper wire is 167-ohms.
http://www.somis.org/Rp-comp.html
Since VHF-Rp is proportional to VHF amplification, would more be  
better in an HF amplifier?
>
> Nichrome causes the greatest Q change at the lowest
> frequency, and has the least effect at the highest
> frequency.

All other metals seem to have the opposite characteristic with  
alternating current.

At 50MHz, measurements with a Boonton Q-meter indicate that a copper- 
wire inductor has 5.5x more Q than a similar inductor made from  
nickel-chromium wire.


>
> 73 Tom
>
>

R L MEASURES, AG6K. 805-386-3734
r@somis.org



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