Topband: Suggestions for a tower?

[mikefurrey at att.net]

I think I would hang a delta loop off of that tower. It would be very 
slightly squashed. You would not have to worry about matching the tower or 
installing a radial system. Through in about a db of gain too.

73, Mike WA5POK

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From: "Ashton Lee" <Ashton.R.Lee at hotmail.com>
Sent: Wednesday, April 23, 2014 11:51 PM
To: "Jon Zaimes AA1K" <jz73 at verizon.net>
Cc: "Jaan Jürgenson" <swejaan at gmail.com>; <topband at contesting.com>
Subject: Re: Topband: Suggestions for a tower?

> Or an easy and fairly good approach is to set up a sloper off the tower. 
> The sloper acts as an inverted vertical ( inverted verticals work better 
> than ground fed ones) and uses the grounded tower as its ground. Basically 
> you run your feed line to the top of the tower, run the hot core to a wire 
> slanted down and away from the tower and connect the ground to the tower. 
> I ended up with the best match using a 130 foot wire and feeding through a 
> 4:1 unun. Slopers are a bit tricky as each installation requires some 
> trial and error. But they work darn well.
>
> Also, while you will get some counter argument, setting up an inverted V 
> off the tower top will work very well too. That may have a higher angle of 
> radiation but will be very easy to tune to a 50 ohm match.
>
>
>
>
> On Apr 23, 2014, at 5:19 PM, Jon Zaimes AA1K <jz73 at verizon.net> wrote:
>
>> Jaan,
>>
>> Before replacing the guys, you might consider trying a gamma match at the 
>> bottom end of one of the top guy wires to load the tower and guys as-is. 
>> I did something similar on a sailboat for 80 meters (gamma matching the 
>> rigging on a 35-foot-high mast)  and it worked OK.
>>
>> 73/Jon AA1K
>>
>>
>> On 4/23/2014 8:15 AM, Jaan Jürgenson wrote:
>>> Hello low banders.
>>>
>>> My name is Jaan and I have been reading all kinds of interesting things
>>> regarding propagation, antennas and other topics here on this reflector. 
>>> I
>>> hope to receive some valuable comments, recflections and also hands on
>>> experience on my question.
>>>
>>> Last winter I became active on 160 and found it very exciting with
>>> propagation and activity on this band. What I would like to ask is what
>>> would You propose for antenna?
>>>
>>> Background:
>>> I have a tower that is 137ft. or 42m tall. It is triangular 1ft 10inches 
>>> or
>>> 40cm wide. The tower is guy wired at three levels with non-isolated 
>>> wire.
>>> The foundation is a concrete slab on on rocky ground.
>>> The surroundings is quite flat and conductivity is perhaps not the best.
>>> About 1/2 mile away I have the Baltic Ocean in almost 360 degrees.
>>>
>>> My question is what options do I have to build a good TX antenna out of
>>> this? What can I do? On RX side I will use separate antennas.
>>> I could think of isolating the guy wires or replace them for 
>>> non-conductive
>>> type. I'm not sure if it possible to isolate the base today. Shunt fed 
>>> the
>>> tower, use it as a folded monopole? Or should I just use the tower as a
>>> support for a L-antenna?
>>>
>>> 73 de Jaan, SM0OEK
>>> _________________
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>>>
>>
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>
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