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From: dmt@ptsfa.UUCP
Newsgroups: sci.electronics
Subject: vari-loopstick
Message-ID: <3220@ptsfa.UUCP>
Date: Thu, 9-Jul-87 18:56:39 EDT
Article-I.D.: ptsfa.3220
Posted: Thu Jul  9 18:56:39 1987
Date-Received: Sun, 12-Jul-87 02:36:26 EDT
Organization: Pacific * Bell, San Ramon, CA
Lines: 43

A few weeks ago someone requested information about a vari-loopstick
needed for a home-built transmitter. The schematic specified a Lafayette
Radio part number.

I let the article expire and don't know the name of the person who asked
for the information so I must ask the indulgence of the rest of you. Sorry.

Vari-loopstick antennas were popular in the 1950's for small "pocket-sized"
radios. I built my first one in a plastic pie container using a Popular
Electronics article from late 1954.

As the name implies, a vari-loopstick is a variable inductance loopstick
antenna. They usually have fairly high inductance and most were tapped
at the 600 ohm point.

Lafayette Radio stopped advertising in Radio Electronics in Sept 1976 and
in Popular Electronics in Nov 1976 so I assume that they have gone out
of business. They closed their store in downtown San Francisco about the
same time. The last address I have for them is:

	Lafayette Radio Electronics
	111 Jericho Turnpike
	Syosset, L. I. NY 11791

J. W. Miller still sells Sub Miniature Antenna Loops in two inductance ranges:

	Part No.	Inductance
	2002		40 - 300 uH
	2007		150 - 1000 uH

They cost about $13.00 each. Both are tapped but the catalog doesn't say
what the tap impedance is.

These things are hard to find but any good electronics parts store that
carries Miller coils should be able to order them.

Oh, the size is about 1/2 inch diameter by 2 1/5 inches long.
They are slug tuned using a brass screw and mount in a 1/4 inch hole.

I hope this helps.

-- 
Dave Turner	415/542-1299	{ihnp4,lll-crg,qantel,pyramid}!ptsfa!dmt