Folks My sincere apologies for asking a question which perhaps has already been covered from all angles and grounds and in all accents.. To avoid jamming the forum with an old boring subject any advice based on your practical experience directly to my email would be appreciated.
What would be the most easy and practical implementation for detuning a wire Inverted L TX antenna for 160m? Going to VK9L this September, and having second thoughts regarding my antennas for 160m. Having tried K9AY (tried at different locations), beverages (tried at different locations), and a random wire loop I have failed to launch effective RX antenna in my earlier 2010 VK9LL operation. Some photos here http://www.qrz.lt/foto/main.php?g2_view=core:ShowItem&g2_itemId=3793&g2_GALLERYSID=c559c77c61a755e36a005a520b857dc1 Since most of RX antenna experiments have been done at night, in extremely adverse weather condx, there was little thinking behind what I was doing, as I had to concentrate on keep my pants dry.. None of RX antennas tried demonstrated much (if any) directivity at all. So I ended up using wire Inv L TX antenna for RX. When I now think over it, my TX antenna in all RX antenna location scenarios was some 50m - 100m away from RX antenna, and there is also electrical fence around the perimeter of the whole paddock, which was always some 10m or even less from RX antenna.. Q1) Would a simple relay disconnecting the vertical wire at the TX antenna feedpoint be good for detuning TX antenna? (I am using a piece of wire attached to 18m Spidermast for the vertical section) and another piece of horizontal on the top. Q2) Are there any practical solutions for detuning TX antenna by using some circuitry at the shack end instead? Q3) What in practice could be done about the impact of the electrical fence? (other then moving RX antenna as far away as possible/ and considering using a shielded coax loop / or Waller Flag to 'null' the fence out?) The fundamental problem is - I could move the RX antenna back to the main yard to be away from the fence, but it will then be picking up all the house electrical noises and be close to Telstra ground satellite/ VHF mobile radio base station. Some of the challenges represented by VK9L is that the overall baggage allowance is 14kg so building a full size WF is not an option. Having tried a coax shielded loop at my backyard in Sydney city i am quite happy, but it has 2 nulls, and nulling the ground satellite station will null W6.. Enough questions for now.. Many thanks in advance for sharing your practical experience Tomas VK2CCC _________________ Topband Reflector
