[amsat-bb] Re: Possible SWR problems with 70cm antenna

Roger Kolakowski rogerkola at aol.com
Wed Jun 4 05:01:27 PDT 2008

"... The way
> > the power out meter on my radio acts, it leads me to believe I may
> > have an SWR issue. Unfortunately I don't own or have access to an
> > SWR meter or anylyzer capable of working at 70Cm..."

You don't mention what rig you have but many of the modern transceivers have
High SWR protection circuits and will cut back on the power as evidenced by
the meter already in the rig in the presence of return power.

If you have a good dummyload, note the power meter reading directly into it.
It ahould be high on the scale.
Then compare it to your antenna meter reading. If it drops down it's time to
start isolating parts of the antenna system using the same method.

Watch your coaxial jumpers. Your connecters as previously noted, and one
stab in the dark...check your power supply voltage to make sure you are
maintaining your 13.6 os so on transmit. RF into some power supplies drives
them funky.

Maybe you can borrow a meter from a club member or just rebuild the whole
shooting match. You already have all the parts. There is not much to those
antennas so I would assume, if you have a problem it is coax or matching
connections related.


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