[Elecraft] T1 Remote Tuning and Power Supply

[David Cutter]

Jim

I like the idea of a battery operated remote tuner and a simple relay 
change-over to provide a top-loaded vertical.  I'm often bothered by 
connecting the antenna feeder into a 1:1 balun and then to the tuner.  I've 
read that the very large impedance mis-match can lead to large losses in the 
balun on some frequencies, though you might not *feel* it with low power. 
With a self-powered little tuner, it would be easy to raise it off the 
ground a little and connect the ladder line feeder directly to the tuner; 
then coil some thin coax through a ferrite toroid to make a choke (see Jim 
Brown's excellent articles - K9YC) for connection to your RG213.  This 
should also result in less noise pick up on receive.  Some folks add a 
further choke at the shack end to further reduce received noise.

David
G3UNA


> I've been running my T1 remote out under my 88ft dipole which is just 
> short
> of 50ft in the air at the midpoint. The ends are a bit higher. The T1 is
> down at the ground under a plastic container and connected to the 
> windowline
> via a Elecraft 1:1 balun. I remote control it via the circuit on my 
> website
> www.jtmiller.com . I find it gets a 1:1 match on 80-6 meters. It is
> connected to my K3 about 60ft away via RG213.
>
> Obviously the pattern is a bit of a daisy above 20M and is mostly a cloud
> warmer at 80M and below. But that's just what this length dipole does
> independent of match.
>
> I've lately been using the windowline as a vertical with the 88ft as a
> capacity hat on 80-160 and found it works quite well. The T1 is very happy
> matching that on 80M and gets to about 2:1 on 160. I use my K3 internal
> tuner to remove the remaining mismatch on 160 to ensure proper power meter
> readings. The loss due to this level of SWR on 160 with RG213 is
> meaningless.
>
> When used in this vertical configuration the two ends of the windowline 
> are
> tied together to one terminal of the tuner and the other side connects to 
> 8
> 60ft buried radials.
>
> 73
>
> Jim ab3cv