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Re: [TenTec] New and Improved Terminology (NVIS origins)

To: "Discussion of Ten-Tec Equipment" <tentec@contesting.com>
Subject: Re: [TenTec] New and Improved Terminology (NVIS origins)
From: "Denton" <denton@oregontrail.net>
Reply-to: Discussion of Ten-Tec Equipment <tentec@contesting.com>
Date: Wed, 5 Jan 2011 10:23:55 -0800
List-post: <tentec@contesting.com">mailto:tentec@contesting.com>
I used to run a 40 ft vertical dipole, fed with 400 ohm ladderline with a 
Johnson Matchbox on the station end....and can pretty much concur what Rick 
has said.
the only reason it came down is cause we had a bedroom/bath addition built 
over my "vertical experimental antenna field".

----- Original Message ----- 
From: "Rick - NJ0IP / DJ0IP" <Rick@DJ0IP.de>
To: <geraldj@weather.net>; "'Discussion of Ten-Tec Equipment'" 
Sent: Wednesday, January 05, 2011 8:58 AM
Subject: Re: [TenTec] New and Improved Terminology (NVIS origins)

> Jerry, let me throw two things at you:
> 1. I think a horizontal loop is a pretty good radiator, straight up.
> 2. The vertical dipole antenna I've described has been in use here for
> nearly 20 years, at 3 different home QTH's and countless portable
> operations.  On 80m where one would think it is too short to work, I found
> that I was always just as loud working stateside, JA, or VK, etc. on the
> short vertical dipole, as I was on my full size horizontal dipole which 
> was
> only 40 ft. up.  Nobody on this earth can convince me I'm wrong because I
> have a logbook full of QSOs to prove it. (don't forget, I was in Germany)
> So, if someone tells me they can't get on 80m because they have no room, I
> just say humbug!
> You can get a good fiberglass pole, 40 ft long, for about $120 from
> companies like Spiderbeam.
> You can get 100 ft. of openwire (300 ohm or 450 ohm) for probably $35.
> Add 40 ft. of copper wire and you have a good 80m antenna (well 80 thru 
> 10m
> antenna).
> While living in Oklahoma (until last week), I used a bigger version.
> Using a 60 ft. Spiderbeam pole, I built my vertical dipole with 30' per
> side.
> On 80m in CQWW CW with about 800w, I was able to work every dx station 
> that
> came up on the DX cluster, be it in Africa, or anywhere else, with just 
> one
> or two calls.
> As I said, people highly underestimate how well these antennas work.
> L.B. Cebik W4RNL (SK) didn't.  He too was a fan of the vertical dipole.
> Actually, the main reason it works so well is because most people use
> antennas on 80m which are worse!  Hi
> I agree, you should have good success with a vertical mounted on the metal
> building.
> I've always wanted to try that but never had the building.
> 73
> Rick
> -----Original Message-----
> From: tentec-bounces@contesting.com [mailto:tentec-bounces@contesting.com]
> On Behalf Of Dr. Gerald N. Johnson
> Sent: Wednesday, January 05, 2011 11:00 AM
> To: tentec@contesting.com
> Subject: Re: [TenTec] New and Improved Terminology (NVIS origins)
> On 1/5/2011 4:42 AM, Rick - NJ0IP / DJ0IP wrote:
>> Ken,
>> I don't know if the low angle efficiency falls off faster than the high
>> angle radiation.
>> I can't remember ever reading that, but I have probably only read "a drop
> in
>> the bucket" of all there is.
> Because of extended ground losses, no antenna has strong radiation
> exactly at the horizon. It can try but that RF gets absorbed.
>> I do know that I changed my attitude about verticals since reading Rudy's
>> papers.
>> I also know that there is no reason to ever use a vertical with
> inefficient
>> ground.
>> Instead I use a vertical dipole, 30 to 40 ft. overall length, fed in the
>> middle with openwire, and matched with a matchbox inside the shack.
>> No radials, yet still has fairly good efficiency.
> Good efficiency on 40 and higher bands, but rotten on 160 where a good
> center fed dipole would be 240 feet tall.
>> I can't imagine why people continue to go with the traditional design,
>> except for the case that they are willing to lay down a complex ground
>> system (or 4 elevated radials per band).
> I have a metal machine shed 48 x 56', I figure a trap vertical at the
> middle of all that metal won't need longer radials for the low bands to
> work decently. I've used a trap vertical on a 30' diameter steel grain
> bin with super results 40 through 10.
>> 73
>> Rick
> A poor ground plane contributes a poor (e.g. resistive) ground in series
> with the antenna and so while it improves the bandwidth (and often the
> impedance match), it hurts radiation efficiency. But it gets out better
> than no antenna at all.
> 73, Jerry, K0CQ
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