ARRL

Register Account

Login Help

Forum Home - Rules - Help - Login - Forgot Password
Members can access, post and reply to the forums below. Before you do, please first read the RULES.

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

Super Moderator

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

Back to Top

EXPLORE ARRL

Instragram     Facebook     Twitter     YouTube     LinkedIn