[TenTec] Zepp?

Sat Sep 13 17:00:28 EDT 2014

My first thought is one should be using a 1:1 balun which would be a current 
balun and not a 4:1 voltage balun.  The described antenna would likely have 
a feed point Z of about 75 ohms, based on length and height.  Feeding with a 
non resonant feed line the impedance would appear similar at the 
transmitter/tuner end.

Based on your description the impedance seen by the tuner is some 18 ohms. 
Fact is known, a tuner a very low Z load presents higher tuner loss.  I also 
suggest a common mode choke between the tuner and the balun.

73
Bob, K4TAX

----- Original Message ----- 
From: "Don Jones" <ko7i at comcast.net>
To: "Discussion of Ten-Tec Equipment" <tentec at contesting.com>
Sent: Saturday, September 13, 2014 9:12 AM
Subject: Re: [TenTec] Zepp?

>I am using a 34 ft doublet / zepp for 20M and above. I feed it with 100ft 
>of #16 420 ladder line that can be purchased from radio works. I am using a 
>4:1 DX Engineering 10kW-pk rated balun.
> The antenna is 34 ft high and works pretty good. I am happy with my 
> shortened zepp.
> One strange misbehavior I have found that my MFJ 929 auto tuner lockup if 
> placed near the 4:1 balun (i.e. using a 2 ft jumper of RG213). requiring 
> power to be cycled to regain its brain.
> With a 12 ft length of  RG213 (about a 1/4 wave long @ 20M) between the 
> remotely mounted tuner and balun, it works fine up to 28.3MHz.  I have not 
> grounded the case of the balun yet, going to try that next.
> The auto tuner is installed inside a spare 50 cal ammo can I had kicking 
> around to protect it from the elements. Come to think of it, a EMI gasket 
> vendor dropped off some rubberized EMI Gaskets at my lab, I think I will 
> install some of that stuff and see if that solves my problem.
>
> 73, Don KO7i
>
>
> On 9/10/2014 8:59 AM, Joel Hallas wrote:
>> That's what I mean by "at the bottom," at the bottom of the feed line 
>> rather
>> than at the top where the antenna is. The SWR is not improved, but the 
>> loss
>> is reduced.
>>
>> Regards, Joel Hallas, W1ZR
>> Westport, CT
>>
>>
>> -----Original Message-----
>> From: TenTec [mailto:tentec-bounces at contesting.com] On Behalf Of Paul 
>> Gates
>> via TenTec
>> Sent: Wednesday, September 10, 2014 11:29 AM
>> To: Discussion of Ten-Tec Equipment
>> Subject: Re: [TenTec] Zepp?
>>
>> I do not know what you mean by putting Balun at bottom? I place my balun
>> between the openline and the tuner. 130 ft attenna then the SWR is 1:1 on
>> all bands.
>>
>> Paul Gates KW4BD
>>
>>
>> On Wednesday, September 10, 2014 10:46 AM, Joel Hallas
>> <jrhallas at optonline.net> wrote:
>>
>>>
>>> Gents,
>>>
>>> This is an interesting antenna idea, and I did a quick EZNEC/TLW look
>>> on the
>>> 5 major HF bands. Unfortunately, the SWR ranges from a low of 5:1 (80
>>> and 10
>>> meters) to 11:1 on 40. 100 feet of RG-213 will have a loss of more than
>>> 2 dB on all bands, except about 1 dB on 80.
>>>
>>> An alternative, and what I am using here, is to feed the 130 foot cf
>>> antenna with lower loss window line and a balun at the bottom, with a
>>> short length of coax to a tuner. Window line is lighter (less sag),
>>> cheaper and has less loss than coax.
>>>
>>> The same discussion about names could take place in the window line
>>> realm <g>!
>>>
>>> Regards, Joel Hallas, W1ZR
>>> Westport, CT
>>>
>>>
>>> -----Original Message-----
>>> From: TenTec [mailto:tentec-bounces at contesting.com] On Behalf Of John F.
>>> Sent: Wednesday, September 10, 2014 10:16 AM
>>> To: tentec at contesting.com; Jim Allen
>>> Subject: [TenTec] Zepp?
>>>
>>> Jim,
>>> I like the sound of Zepp better than dipole.  Actually it's probably a
>>> matter of semantics, and I'm not going to argue how many angels will
>>> fit on the head of a pin! ;>)  There is a reason I called it a zepp,
>>> and I think it was in the 95 or 98 Handbook.  Terms many have changed by
>> now.
>>> I actually think it's a dipole only on 80 meters, and technically a
>>> doublet on the other bands!  Ooops, I did it!
>>>
>>> 73,
>>> John, K4AVX
>>>
>>> Yes the balun, I think is a 9 to one.  It will load and put out a
>>> signal on all bands except 160 meters.  Trying to work out an inverted
>>> L again on that band - tricky.
>>>
>>>
>>>> Message: 3
>>>> Date: Tue, 9 Sep 2014 15:46:59 -0500
>>>> From: Jim Allen<jim.allen at longhornband.net>
>>>> To: Discussion of Ten-Tec Equipment<tentec at contesting.com>
>>>> Subject: Re: [TenTec] Eagle Tuner
>>>> Message-ID:
>>>> 
>>>> <CAO5v6iLk96Oi-DVfpCPLpO35MphtsfoFD7K4MUvGOP9wPokQEw at mail.gmail.com>
>>>> Content-Type: text/plain; charset=UTF-8
>>>>
>>>> What makes a 130' center fed dipole a Zepp?
>>>>
>>>> 73 de W6OGC  Jim Allen
>>>>
>>>> On Tue, Sep 9, 2014 at 3:44 PM, Rick - DJ0IP / NJ0IP<Rick at dj0ip.de>
>>> wrote:
>>>>> That is an excellent setup, John.  Nice choice.
>>>>>
>>>>> I'm a friend of that antenna too and have used it most of the time
>>>>> for the past 50 years.
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