[Amps] HeathKit SB-220 Tank Circuit Inductance

[jim.thom jim.thom@telus.net]

Date: Fri, 12 May 2023 12:40:28 +0000 (UTC)
From: Bill Smith <ko4nrbs at yahoo.com>
To: "amps at contesting.com" <amps at contesting.com>
Subject: [Amps] HeathKit SB-220 Tank Circuit Inductance


<Has anyone measured the total?Tank Circuit inductance of the SB-220?? ?I
have read that it <needs to be doubled in order to use it for 160 meters.?
I used online Torrid Core calculators to <estimate it using the
recommendations in AG6K's article but 14 turns on a T-225-2 powdered iron
<core doesn't seem to be enough inductance.? Maybe I am missing
something.73 and thank <you,Bill KO4NR

##  You require  TWO of those T-225-2  cores.   And each core is 1" thick.
 With 2 x stacked, it should be 2" tall  x 2.25" diam.   Forget what the
wall thickness is on those cores.

##  one core is good for 750 watts pep / cw.   2 x cores are good for 1.5
kw.    3 x cores are used for RTTY.

##  you require  TWO of em, to convert a  SB-220 to 160m.

Jim   VE7RF