Re: Antenna Tuner Toroid Turns?

---------

From: Leon Heller (leon@lfheller.demon.co.uk)
Date: Sat Jun 21 1997 - 11:28:47 EDT


In message <199706211455.KAA26362@marconi.concentric.net>,
tgordish@concentric.net writes
>QRP folk,
>
>I am building an antenna tuner so that I can use my 20m SST with my 30m
>dipole. This is a junk box project. I have a 1 1/4" toroid that I plan
>on using for a multi-tapped inductor, and a air variable capacitor with
>100 a uf value. Now the question is.... how many turns of what gauge
>wire should this toroid be wound with to make a good general purpose
>antenna antenna tuner?
>

The July issue of RADCOM has a 'T' Match AMU design using a tapped
toroidal winding. With a pair of 400 pF tuning capacitors (each is a
dual 200 pF unit connected in parallel), the T-130-2 toroid is tapped at
10, 12, 15, 17, 20, 23, 26, 29, 31, 33, and 35 turns, with 36 turns of
22 SWG wire (~.71 mm) in total. It covers the range 1.8 MHz to 30 MHz,
and is good for 5 W. A balun consisting of 12 bifilar turns of 26 SWG
wire (~0.45 mm) on an FT-50-43 ferrite toroid can be switched in and
out.

Leon

-- 
Leon Heller
Amateur radio callsign: G1HSM
Email: leon@lfheller.demon.co.uk http://www.lfheller.demon.co.uk
Tel: +44 (0) 118 947 1424 (home) +44 (0) 1344 385556 (work)


Search QRP-L Archives

[ QRP-L Archive | ]
[ 1993 | 1994 | 1995 | 1996 | 1997 | 1998 | 1999 | 2000 ]

---------

This archive was generated by hypermail 2b29 on Fri Jun 02 2000 - 11:33:54 EDT

kd4ab@kd4ab.org