Rich,
Seems that issue is not that effective resistivity of nichrome increases
with decreasing frequency - I don't think anybody is arguing that. What
is evident is that the effective series resistance of the nichrome suppressor
is higher than conventional suppressor at low frequencies. From what I
can see, this seems to be the basic tradeoff between the nichrome suppressors
and the conventional suppressors. If I am recalling the test data correctly,
the nichrome suppressor has higher losses at moderate VHF frequencies
(50 to 100 MHz) - a good thing, at the expense of higher losses in the HF
frequency range (a bad thing). As the frequency increases further the
the two suppressors start to converge as the inductive reactance of the
nichrome suppressor starts to dominate over the resistance of the wire.
No rocket science here.
Mike, W4EF...................................
----- Original Message -----
From: "measures" <2@vc.net>
To: "AMPS" <amps@contesting.com>
Sent: Saturday, October 14, 2000 12:14 AM
Subject: Re: [AMPS] a sticky issue.
>
> >At 08:01 PM 10/13/00 -0700, you wrote:
> >>
> >>According to Wes, the copper-wire suppressor had an Rp of 166-ohms at
> >>100MHz and the resistance-wire suppressor had an Rp of 101-ohms. More Rp
> >>means more gain. Are you arguing the opposite, Bill?
> >
> >Rich- I am NOT arguing either way, which may surprise you- You are missing
> >the point- your problem is that you misstate other peoples arguments-
> >exaggerate their position, and make ALL debate into a personal attack.
> >Your reference to others as "lapdogs" is a case in point- THat was uncalled
> >for,
>
> During the grate debate, Tom's faithful lapdogs attacked my 1/1994 QST
> article, The Nearly Perfect Amplifier and stated that a rheostat simply
> will not work for adjusting filament potential (sic).
>
> >and made several people upset. some of the ones most upset were people
> >who dont like Tom , either.
> >
> >>
> >>Do you believe that the RF resistance of nichome wire increases as
> >>frequency decreases?
> >
> >Rich- I KNOW that the resistance of Nichrome wire changes with frequency.
>
> ok
>
> >What I don't know is just where (what frequency range) , and how much it
> >changes. I only know that at very low frequencies, it is higher that it is
> >at very high frequencies.
>
> The resistance of all conductors increases as frequency increases. As
> frequency increases, skin depth decreases, and conductivity decreases.
> This is why 10m tank inductors need more copper than 80m tank inductors.
> // In Wes' measurements, the resistance of the nichrome inductor - with
> no parallel resistor - changes from 15-ohms at 10 MHz to 45-ohms at
> 200MHz. Rauch's assertion that nichrome is different than all other
> conductors is a laugher.
>
> >Again- this has NOTHING to do with the problem. You keep interjecting this
> >into posts on other subjects as if it was a sever indictment and a MAJOR
> >error.
>
> It undoubtedly is.
>
> > You have taken this out of context, with mystifying results to all
> >newcomers,
>
> How do you know what all newcomers think?
>
> cheers, Bill.
>
> - Rich..., 805.386.3734, www.vcnet.com/measures.
> end
>
>
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