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SWR Meters for low power VHF use

Aug 20th 2013, 22:36

KC1ABR

Joined: Aug 10th 2013, 17:04
Total Topics: 0
Total Posts: 0
I was wondering if anyone has had success with an SWR meter using a VHF 5W handheld radio as the source? I want to do some work with a portable 3 element Yagi antenna hooked up to my Yaesu VX-170.

On all of the many product reviews I've read, meters tend to be very inaccurate at less than 20 watts.

Any ideas on what product I could use to assess how the radio/antenna system responds to changes would be much appreciated.

Thanks,
Dave

KC1ABR
Aug 20th 2013, 23:23

W1VT

Joined: Apr 4th 1998, 00:00
Total Topics: 0
Total Posts: 0

Instead of using an SWR meter, you might consider using a return loss bridge with a diode detector and a voltmeter.

Apr 1996 - QST (Pg. 76)
LF/MF/HF/VHF Return-Loss Bridge
(Hints and Kinks)
Author: Lau, Zack, KH6CP/1
http://p1k.arrl.org/pubs_archive/95022

Sep 1997 - QST (Pg. 34)
Build a Return Loss Bridge
Author: Ford, Jim, N6JF
http://p1k.arrl.org/pubs_archive/93787

If you need a rlb that can handle more power at VHF, I'd suggest experiment with metal oxide resistors--perhaps using two 100 ohm 1 watt resistors in parallel to make two watt resistors that have a resistance close to 50 ohms.

Zack Lau W1VT
ARRL Senior Lab Engineer

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