I posted the following message on the Yahoo SteppIR board and thought that
I might also get some ideas on this board.
I have an interesting problem for all of you antenna experts out there. If
you have been reading this thread (Yahoo SteppIR board), you know that I have
been having problems with my new SteppIR 3 element beam. I was able to borrow
a MFJ-259B this morning and made a relatively extensive set of measurement,
which taken as a whole, just do not make sense.
In summary (2 measurements on 20, 1 on 17, 2 on 15, 1 on 12 and 2 on
10M for each series of readings):
1. Set of measurements using the MFJ with a 20" length of coax to
the SteppIR. Measured from 20-10M SWRs of from 1.5:1 to 1:1 (also have the R
and X measurements but won't go into those just yet).
2. Set of measurements using the MFJ in the shack using the full
length of cable to the SteppIR. Measured from 20-10M SWRs of from 1.4:1 to 1:1.
3. Using MFJ to measure Coax Loss from 20-10M showed 1.3 to 1.6 dB.
Probably about 135 ft of cable.
4. Put the cable in the shack directly on the antenna connector of
a Daiwa NS-660PA SWR and Power Meter, and the SWR is 5:1 from 20-10M. The
reading on the TenTec Orion is high VSWR. Take the PL-259 off the SteppIR and
put it on a 50 ohm dummy load and the SWR is a flat 1:1 across 20-10M both on
the Daiwa and Orion.
5. Tried varying the "tune" power of the Orion from about 1 watt to
50 watts. No difference.
6. Tried taking the Daiwa out of the circuit. No difference.
Orion still reads high VSWR.
7. Swapped out a complete set of coax cables to insure nothing was
common. No difference.
Anyone out there in radio land have any ideas? I am going to talk to Jim
on Monday, but this is really a STRANGE set of data. I am a bit perplexed with
what I am seeing!
73,
Bernard, WA4OEJ
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See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather
Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
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