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Old November 5th 15, 05:47 AM posted to rec.radio.amateur.antenna
Jeff Liebermann[_2_] Jeff Liebermann[_2_] is offline
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First recorded activity by RadioBanter: Jun 2007
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Default How can I make a simple antenna trimmer?

On Thu, 5 Nov 2015 04:49:49 -0000 (UTC), sctvguy1
wrote:

On Wed, 04 Nov 2015 20:10:35 -0800, Jeff Liebermann wrote:

On Thu, 5 Nov 2015 02:28:05 -0000 (UTC), sctvguy1
wrote:

I have an old boatanchor, a Lafayette HE-10,


https://www.google.com/search?tbm=isch&q=lafayette+he-10
http://www.radiomuseum.org/r/lafayette_he_10he1.html
https://www.youtube.com/watch?v=Lk1dmQEsoIk
Made by Kenwood/Trio for Lafayette.

that takes a single wire antenna and a ground. I would like to make a
simple trimmer to optimize the 75 feet of random coated wire. The wire
is copper, Radio Shack.


I can't tell what it uses for an antenna input (50 ohms, 75 ohms, 300
ohms, broadband, narroband, tracking filters, whatever) so I can't offer
an antenna tuner design. Any idea what's behind the antenna connector?


It is just a simple old screw, made for a copper wire antenna, the radio
was made in the late 50's. I used to have one that I made out of a
variable capacitor and just tuned the knob to trim the antenna. I am now
64 and that was when I was in junior high school? Can I get a variable
capacitor for an old radio and connect the two ends?


I'm 67 and know the feeling. The lab that I patiently built up over
the last 40 years is now considered a test equipment museum.

Yes. Just a small 365pf(??) or lower value variable capacitor should
work. I wanted to see the circuitry so I could provide a better guess
at the capacitor value. Something like these:
http://www.ebay.com/sch/i.html?_nkw=365+pf+variable
Any old tube or xsistor radio should have one. Dig around at thrift
shops or ham flea markets for old radios and junk boxes.

Good luck and I'm amazed that such an old radio still works.



--
Jeff Liebermann
150 Felker St #D
http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558