[CQ-Contest] 160 Receiving Antennas

David Pruett k8cc at comcast.net
Fri Aug 31 01:28:30 EDT 2007

Duncan, Tom, et al:

As W8JI makes clear on his web site, the only real improvement in 
receiving capability on 160M results from DIRECTIVITY.  A short loaded 
vertical will be no better noise discrimination than a full-sized vertical.

Here at K8CC, the low loops as WC7S describes are very useful for high 
angle signals.  However, it is omnidirectional which goes against the 
W8JI tenet described in the previous paragraph.  This doesn't mean it's 
not a useful antenna, but it's not going to significantly improve your 
RX capability for DX signals.

I've built a homebrew version of the two loop (four direction) K9AY 
system (essentially a homebrew version of the ArraySolutions product) 
and found it to work exactly as advertised.  When you point the array at 
a station, they always got louder. Even the front/side seemed much more 
significant than the pattern plots would suggest.  However, the array is 
not all that directive - the only real directivity is the null straight 
off the back.  However, it IS a good null.  The first night I had the 
array running was in a CQ 160M contest a few years ago.  I decided to 
fire up on a freq to call CQ, asked QRL? three times then let loose, and 
aroused the wrath of some K9 who I could barely hear on the K9AY array.  
However, he was in the null, and when I switched the direction of the 
antenna he was S9!

I also have had an array of loaded short verticals in a four-square with 
1/4 wave spacing on each side.  This was before the DXEngineering 
switchbox became available, so I fed it with a ComTek transmit-style 
switchbox.  The array DID work - when VY2ZM was S7 here on the FT-1000D 
s-meter with the array switched NE, he was S0 (needle not moving) with 
the array SW.  However, it did not seem to help us hear the DX any 
better. I'm sure the array would have worked better fed with a 
DXEngineering switchbox.  It probably would also work better if I didn't 
have five other towers in my five-acre yard :-(



> Very timely thread....
> I will be doing CQWW SSB this year from a beachside location in EA6
> (Formentera island) and am still wondering what band to do, bearing in
> mind I will only have a few hours to set up shop before sundown. The
> bands I was weighing up were 40 and 80, the plan being to put our new
> "KISS" phased verticals through their paces. 
> In my troubled sleep last night I started mixing up my plans for a new
> 160m mobile antenna with the spiderpoles I plan to buy for another
> project, and came up with what looks like an oversized mobile antenna
> for 160m. In my imagination it consists of an 18m spiderpole with wire
> for a radiator, a loading coil about 6m from the base, and a cap hat
> just above the coil. It would sit on the beachfront with two or three
> resonant and elevated radials. The thing that appeals to me about the
> antenna is that it is only one antenna to erect instead of two for the
> phased verticals, and I don't have to lug a load of phasing lines and
> stubs along with me. (OK, I could do the phased vertical thing for 160
> too but I think that's maybe a bit OTT). 
> Now I am awake, I am trying to see the disadvantages of this system, but
> as I plough through the morning mail, all I see that Dale reckons a
> short loaded vertical would do good for RX too.... I also see that Alex
> K2BB is going vertical to the seaside too....
> Is there something I'm missing here or is this just maybe a good idea???
> And if it were to be a good idea, how might I go about calculating the
> coil I need to wind?
> 73 de Duncan EA5ON
> -----Original Message-----
> From: cq-contest-bounces at contesting.com
> [mailto:cq-contest-bounces at contesting.com] On Behalf Of Dale Putnam
> Sent: jueves, 30 de agosto de 2007 1:59
> To: Tom Taormina; cq-contest at contesting.com
> Subject: Re: [CQ-Contest] 160 Receiving Antennas
>   A short loaded vertical may turn some decent results too.
> Hope to see you on 160 this year!--... ...--Dale - WC7S in Wy
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