MAERTZ, A REID wrote:
>I have a M^2 22 element circularly polarized yagi (2mcp22) with a 4:1
>SWR on it as measured with the MFJ-259B. It should be about 1.4:1 at
>max. I've triple checked everything I did in assembly and it all checks
>out well. I have replaced the feedline, isolated the antenna from any
>potential undesired interacting structures, etc. but the SWR remains
>high with a small dip at the expected resonant frequency.
>
>In considering the MFJ-259B as possibly giving false reading at this
>frequency (even though it's rated for that freq), I'm wondering if
>that's a problem anyone else has encountered with this test instrument.
>I'm reluctant to get another SWR meter just to test this theory out,
You don't need another meter - just a good, small dummy load.
How accurately does the meter indicate a good 50 ohm load, at 144MHz and
at lower frequencies?
My guess would be that the meter isn't too far out, but that you
genuinely have a problem with the antenna.
> but
>can't find anything else wrong with the antenna itself although I
>haven't checked the phasing harness or other antenna hardware.
So in fact you haven't checked everything, nowhere near. Look for
whiskers of braid wire, solder bridges, or bad solder joints that have
cracked and become open-circuits.
73 from Ian G3SEK Editor, 'The VHF/UHF DX Book'
'In Practice' columnist for RadCom (RSGB)
http://www.ifwtech.demon.co.uk/g3sek
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