Topband: WWROF Webinar - High Performance RX Antennas for a Small Lot

Grant Saviers grants2 at
Sat Mar 5 20:21:23 EST 2016

Great presentation!  It inspires a question about detuning a vertical:

The goal is to reduce noise and any pattern distortion in my receive 4 
sq (DXEng) which is about 200' from my transmit vertical.

My 160m transmit antenna is a 75' vertical T with 8x 125' radials 8-10' 
above ground.  I've positioned the radials a bit asymmetrical to 
maximize separation to the 4sq.  I can detune the antenna to a 2.3Mhz 
resonance with a 300pf series capacitor.  Is that sufficient or do I 
need to do something to the radials?   Is there a better way to detune it?

The 4sq shows excellent directivity on 80m, 5+ S units on a 756PIII.  
With a 70' baseline I expect less directivity on 160m but not nada which 
seemed the case in the SSB contest last week.

Grant KZ1W

On 3/5/2016 5:15 AM, Ken Claerbout wrote:
> Thanks to JC N4IS for his excellent presentation on lowband RX 
> antennas and
> to WWROF for their continued sponsorship of the Webinar programs. We had
> almost 500 people register for this event!  The recorded Webinar along 
> with
> a copy of JC's slides has been posted to:
> 73
> Ken K4ZW
> _________________
> Topband Reflector Archives -

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