On 8/6/2012 8:17 PM, Steve Jones wrote:
> I'd do the same, except I'd use homemade true open-wire line (not ladder
> line), much lower loss than coax. With the relays at the antennas.
Open wire in the shack is out of the question because of radiation and
running multiple stations. I was set up for SO2R, but the goal is two
stations in the shop and one in the house running QRO. That makes open
wire from the shack and switching more than a little complicated,
particularly with two towers, plus a multiband vertical for a total of
roughly 12 antennas.
The amps are tuned into dummy loads using the matching networks are
tuned using antenna analyzers and the VNA. Then the rig is switched to
the antenna with the input to the analyzers and VNA being shorted out.
All coax in the shop runs in two runs of 2" EMT. Runs to the big tower
are in 3" underground conduit.
73
Roger (K8RI)
>
> 73,
>
> Steve
> N6SJ
>
> ----- Original Message -----
> From: "K1TTT" <K1TTT@ARRL.NET>
> To: <towertalk@contesting.com>
> Sent: Monday, August 06, 2012 2:40 PM
> Subject: Re: [TowerTalk] Looking for thoughts
>
>
>> I would use a decent low loss coax, a remote relay box, and keep the tuner
>> in the shack.
>>
>> David Robbins K1TTT
>> e-mail: mailto:k1ttt@arrl.net
>> web: http://wiki.k1ttt.net
>> AR-Cluster node: 145.69MHz or telnet://k1ttt.net
>>
>>
>> -----Original Message-----
>> From: K8RI [mailto:K8RI-on-TowerTalk@tm.net]
>> Sent: Monday, August 06, 2012 20:49
>> To: towertalk@contesting.com
>> 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)
>>
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