[600MRG] Linear Line Strecher for Tuning

[Paul Signorelli]

I am using a new fine tuning system for my final antenna coil.

A Linear Line Stretcher.

It is an old Telescopic Whip from and old FM radio.


I set my antenna coil resonance to a slightly higher than desired frequency tap

and then stretch for lowest SWR.

It is hung upside down so the moisture doesn't get inside.

Mark it for temperature variations.

I go down about 1 kHz/5 inches.


I also tried adding a 0.0015 MFD, 1KV,  mica capacitor across the top 2  -  4 turns of the coil.

I connected the antenna to the nearest high frequency tap (476 kHz) and then connected the capacitor across 3 turns of the coil that it brought down to 473 kHz.

Just changing the capacitor tap allows me to vernier across the band.

1 turn on my coil changes the antenna resonance 5 kHz so I need a vernier.

 If I could get all the way around the coil I could just add a tap to the other side but it is not easily accessible because of the insulating cover.

This works well too.

Paul    w0rw