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Old July 20th 03, 08:37 PM
Roy Lewallen
 
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Unfortunately, there's no easy way to determine what fraction of your
radio's power is getting radiated. Just about the only practical way
short of modeling or an antenna test range is to compare your antenna to
another antenna with known gain and efficiency, and even this can be
difficult to do with any accuracy. "Slinky" antennas are pretty
inefficient, so even if your tuner isn't losing much power, the antenna
itself is probably turning a good portion of it into heat.

The good news is that the antenna isn't likely to be less efficient on
60 meters than on 40. So if you're making QSOs on 40, you should be able
to do the same on 60. Just keep that twinlead dry if you want most of
your power to get to the antenna.

Roy Lewallen, W7EL

Ken wrote:
My field rig is an FT-817, with MFJ-971 tuner. Antenna is a 40M
extended double zepp Slinky with 30 ft of 300 ohm twinlead.

On 60M, I easily tune SWR down to 1.0. Power shows a full 5 watts on
FM when I test.

Am I radiating almost everything the radio is putting out? Or could I
still be having big losses in the tuner? How can I test it?

Ken KC2JDY


Ken
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