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Re: [TowerTalk] Fw: Looking for thoughts

To: Gene Fuller <>, "" <>
Subject: Re: [TowerTalk] Fw: Looking for thoughts
From: Rod Greene <>
Reply-to: Rod Greene <>
Date: Tue, 7 Aug 2012 10:20:27 -0700 (PDT)
List-post: <">>
Good morning all,

Thought I would throw in my setup FYI. I have an approximately 50' tower with a 
little tribander (A3S) and 40m dipole (KLM single el) on top. I have installed 
three slopers from the top spaced fairly equally around the tower. They are 
each approx. 72' long and are angled at (again approx) 45 deg. to the tower. I 
also have an SGC-230 auto tuner at the tower top then a DX-Engineering remote 
switch to select one of the three. That way I can use the slopers on all bands 
and auto tune as needed. I get some pattern on 20m and up. It works pretty well 
as a second/backup antenna to the others. 


 From: Gene Fuller <>
Sent: Tuesday, August 7, 2012 10:49 AM
Subject: [TowerTalk] Fw:  Looking for thoughts
I sent this to Roger a couple of days ago,but judging from the other 
replies, I'll forward to the group.
Gene / W2LU

----- Original Message ----- 
From: "Gene Fuller" <>
To: "K8RI" <>
Sent: Monday, August 06, 2012 11:28 PM
Subject: Re: [TowerTalk] Looking for thoughts

> Hi Roger -
> Sounds like a good project. I have three 160 quarterwave slopers which 
> also act somewhat as 80 meter reflectors for my 80 meter bent vertical 
> dipole array. I use SPST relays to connect one sloper at a time to an 
> RG-213 cable which goes to the base of the 100 foot tower. At the base I 
> have a simple L network which matches the RG-213 to  a  200 foot cable TV 
> 75 ohm burial cable back to the station. Being on 160 there isn't too much 
> SWR loss in the cable down the tower and it is relatively convenient to 
> come up with an L network which results in an easy cable to work with back 
> at the station.
> Points which led me to this:
> 1. Relatively small loss, at moderate SWR,  in the RG-213 at 1.8 MHz. 
> Selected the sloper length as good for an 80 meter reflector, not minimum 
> SWR on 160.
> 2. Relative ease of applying and maintaining a  matching network at the 
> base of the tower.
> 3. I had all of the material on hand. Maybe  only 3 or 4 db "F/B" between 
> the three slopers on 160, but I love the idea of 3 KW ERP vs 1.5 KW.  Guys 
> who settle for a single sloper because "there's only 4 or 5 db F/B are 
> failing to appreciate the relative gain aspect of the configuration.
> Good luck with your endeavors.
> Gene / W2LU
> ----- Original Message ----- 
> From: "K8RI" <>
> To: <>
> Sent: Monday, August 06, 2012 4:49 PM
> Subject: [TowerTalk] Looking for thoughts
>> I'm thinking of mounting a tuner up on the tower to feed the 160 half
>> sloper (single wire) as well as the 75 meter fan dipole and 40 meter
>> sloping dipole with ladder line, so I'll need to add a few relays to
>> switch antennas.
>> This can be a simple manual tuner, remotely driven with air variables
>> and a switched inductor, or vacuum variable and a rotary inductor, or
>> even one of the MFJ 998RT auto tuners. If I build it, I'd much prefer a
>> tuner that handles single and parallel wire without using a balun
>> Unfortunately the 998RT only has a single wire and coax output. I can
>> work around that and *apparently*, or at least some think it'd handle
>> all the way up to 2500 PEP.
>> Of course there is the problem with lightning and remote tuners mounted
>> at or near the top of the tower.  Grounding relays could be added.
>> 73
>> Roger (K8RI)
>> _______________________________________________
>> _______________________________________________
>> TowerTalk mailing list


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