[TowerTalk] Vertical comparison question

[Dan Schaaf]

For what it's worth :

I designed and built a multiband tower vertical for 40, 60, 80 and 160. Last 
night I worked VK9CZ Cocos Keeling, 11,000 miles on 40 CW.

It is 1/2 wavelength on 40,
1/4 wave on 60, 80 and 160

I use a matching network at the base for 40 and another for 160.
It has a 60 meter trap.

Total height is 59 ft. The trap inductance adds length for 80.

It is an insulated base tower.

I have a good 50 ohm match at the base due to the matching networks.

These networks are remotely switched from the shack.

But I will say that my HyGain AV-640 works like a charm. It does not have 
traps. It has loading coils with capacity hats above each coil. And a few 
stubs on the side for some other bands. The advantage of the 640 is that it 
is a 3/8 wave vertical which gives a lower angle of radiation than a 1/4 
wave vertical.
3/8 wave and 1/2 wave give pretty good low angle radiation. Then more than 
1/2 wave you start to get some other lobes, as I have been told.

Best Regards
Dan Schaaf
=================================
K3ZXL www.k3zxl.com
60 Meters www.60metersonline.net
=================================

-----Original Message----- 
From: n8de at thepoint.net
Sent: Saturday, April 06, 2013 7:07 AM
To: towertalk at contesting.com
Subject: Re: [TowerTalk] Vertical comparison question

Those who have heard my 80/40/WARC signals may be aware that I am
using an insulated tower vertical (photo on qrz.com).

This antenna on 40m is a 1/2-wave vertical.  Estimates of feedpoint
impedance are in the 2000 ohm range, but I feed it with 50-ohm coax.
There is also a 40m 1/4-wave vertical available for use on that band.
Both verticals have 60 1/4-wavelength radials spaced equally about
them. (on the ground).

Comparisons are interesting, depending on DX distance.

>From here in Michigan to the Caribbean, the 40m vertical seems a bit
better (one s-unit in most cases), but for JA and YB, the difference
is quite astounding!  While the 40m vertical 'hears' those areas quite
well, there is a 5 S-unit difference in favor of the 80m vertical!  My
concept of this difference is 'take-off angle'.

I have NO IDEA why it works so well with that 40:1 feedpoint SWR, but
I will never complain.

73
Don
N8DE

> On 4/5/2013 6:56 PM, John G. wrote:
>> How do the "radialless" verticals, like the R5, R7000, MA5V, Gap   ones, 
>> compare in performance to the standard 1/4 wave verticals   that are roof 
>> mounted with radials?  Does one tend to outperform   the other?  I am 
>> looking how each performs for DXing and longer   haul communications.
>>
>
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