[TowerTalk] SO2R or Multiop Contesting without interference

Jim Thomson jim.thom at telus.net
Wed May 30 13:36:54 EDT 2018

From: Timothy Coker <n6win at yahoo.com>
To: Towertalk Reflector <towertalk at contesting.com>
Subject: [TowerTalk] SO2R or Multiop Contesting without interference

<Is anyone out there operating high power SO2R or Multi-Op without interstation interference (besides being on or very near a harmonic)? 

<I read reviews of various antennas, new filters, etc of having non-existant issues. However, in my limited experience it seems that tribanders will have these issues even with the latest high power triplexors and band pass filters. Even problems will arise at multi-<tower stations with monoband yagi stacks and/or different direction facing yagi's.
<Has anyone got the ability to say that they are trouble free on their various band combinations?
<For instance, at home I have lots of interference when receiving on 15m and while transmitting on 20m. Same goes when receiving on 20m and transmitting on 40m. For me, it can be both direction and/or antenna limited depending on what band combination <and which tribander that I take out of the stack. 

<I'm curious about the true confessions that other operators have about what they are dealing with when transmitting on multiple bands at once? Have some of the stations got this under control? If so is it mainly the big property owning stations with many towers <or have guys on 1-2 tower setups quelled this also?
<Tim / N6WIN.

##  back in the 80s,  at  VE7ZZZ  MM,   one tower used for  each band  for  40, 20,  15, 10m.   Only 1 yagi  on top of each tower.  NO filters  used anywhere.   Zero issues with  up to 4 x stations running at once.  And for the most part, HB linears
used on all bands..except  160m...where a small  TL-922  was used.    But this was on SSB,  so  harmonic issues  are not as prevalent as on CW.   40-20-15-10 m  during the day...and  160-80-40-20 m  at night.   They were on 20 acres out by the lake.
No commercial AC  power was available, so a diesel generator was used  to run the entire mess.   Nearest home that did have commercial AC power was a half mile away..and only that one home.   You could hear a pin drop  on every band.  If there was
any hint of interstation interference, we would have been able to hear it asap..and we did not.   Towers  ranged from right next to main building to  150-225 ft away from the main building, and well spaced between  towers.  Relatively simple setup. HB linears stayed at the permanent building, and the xcvrs were brought from home for each ssb  contest.   Start installing multiple yagis for different bands on the same tower, then all bets are off..and in have to go the band pass filters between xcvr  and amp, or high power  band pass filters  between  amp and ant. 

Jim  VE7RF      

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