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[TowerTalk] Perplexing Antenna Problem

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Subject: [TowerTalk] Perplexing Antenna Problem
From: "Bernard(wtrone)" <>
Date: Sat, 28 Aug 2004 14:40:19 -0500
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    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!


                Bernard, WA4OEJ

See:  for "Self Supporting Towers", "Wireless Weather 
Stations", and lot's more.  Call Toll Free, 1-800-333-9041 with any questions 
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