Date: Thu, 10 Oct 2019 08:35:48 +0700
From: Martin Sole <hs0zed@gmail.com>
To: amps@contesting.com
Subject: Re: [Amps] Tips For Winding a Plate Choke
<Carl,
<Did you notice any effect on 10MHz. When I put an Ameritron choke in my
<78, which I agree fits just fine, it was okay but went bang on 10Mhz.
<Had I the time then I would have investigated moving it to resonate
<somewhere else but in stock form mounted in the 78 I measured resonance
<at 10.5MHz, too close to 10.1MHz to work I think.
<As a more general question, where would be good to place a single choke
<for 160-10 9 band coverage, around 12 MHz?
<Martin, HS0ZED
## The RF parts / Ameritron choke resonates at 12.5 mhz.....and 27
mhz.
## There is no way to wind a single choke..with 200+ uh.... that
will only
have one resonance. They will always have two resonance points.
## 50 uh is fine for 80-10m amps. On paper, 100 uh should work
on 160-10m. But your typ 90 choke will resonate just above 15M.
A 100 uh choke will resonate just below 15M. Its tough to park
resonance points between ham bands.
## I think its only the usa that has a 200 watt limit on 10 mhz band.
750 watts out.... measured at the ant...here in Canada.
## IF u removed turns from the very top of the rf parts /
ameritron choke,
it would probably shift the 27 mhz resonance up higher....like 10m band.
It may or
may not shift the lower resonance point upwards.
Jim VE7RF
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