[HamWAN PSDR] New sector antennas tested

[Bart Kus]

Ran 3 new sector antennas through their paces:

  *
    ITelite Sector 50018H
    <https://www.hamwan.org/t/tiki-index.php?page=ITelite+Sector+50018H&structure=HamWAN>
  *
    RF Elements SECM5120
    <https://www.hamwan.org/t/tiki-index.php?page=RF+Elements+SECM5120&structure=HamWAN>
  *
    Teletronics 15-704
    <https://www.hamwan.org/t/tiki-index.php?page=Teletronics+15-704&structure=HamWAN>


The results are underwhelming.  The ITelite was looking very good on FR 
and absolute gain, but then it totally fell apart on the radiation 
pattern.  The RF elements has very poor gain @ the upper ham 
frequencies.  The radiation pattern of this antenna is quite good 
though, if only we were using it lower down.  The Teletronics has pretty 
low gain @ the upper ham frequencies, but more importantly, the 
radiation pattern is just broken.  Almost a -20dB null @ 320 degrees.

I've updated the Antenna Shootout 
<https://www.hamwan.org/t/tiki-index.php?page=Antenna+Shootout&structure=HamWAN> 
page to add the results of these 3 new antennas.  Had to normalize them 
to the 100m range standard levels.  I also re-measured many of the other 
sector antennas on the 8m range and normalized their results to 100m 
range equivalents.  Things are measuring mostly consistently.  The 
largest delta is the 16dBi Ubiquiti sector, which lost 2dB of gain in 
the re-test.  I re-ran the radiation pattern on it as well, since I 
noticed the peak gain involved adding a bit of up-tilt to compensate for 
the built-in electrical downtilt.  The new radiation pattern is not so bad.

So far the best sector is looking like that Laird I originally bought.  
Need to rig up vertical plane radiation pattern measurement 
capabilities.  A narrow vertical beamwidth can kill a decent 
horizontally behaving sector.  Unidirectional antennas are so much 
easier to deal with!

--Bart

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