[TowerTalk] 135 foot dipole, 300 ohm twinlead (more)

[Tom Rauch]

> hear it but dad can't.  It just started when I changed
antennas from the 129
> foot fed with coax to this 135 foot fed with 300 ohm
twin-lead.

That's a strong clue you have common mode feeder problems.

 I do have a
> ground wire going from the radio to a copper ground stake
outside my window.
> I also have a ground wire going from the 3rd wire ground
from my outlet to
> the outside ground stake.

You:

1.) have almost no RF ground. Not that you'd ever need one
with a good antenna feed system, but if you have an antenna
issue almost all RF would go into the power line.

2.) The power line safety ground could be grounded at a
single point in the shack to the shack ground. The ground
rod should be bonded to the power line entrance ground
outside the house with a low resistance conductor.

>The antenna tuner is grounded as is the radio.
> By default, one side of the antenna is grounded as per the
internal wiring
> of the tuner.

That should not be, if it is a direct ground and not through
a balun.

> The twin lead has a great electrical and mechanical
> connection to the dipole.  The wire is not shorted across
the back of the
> tuner.  The random wire/balanced line jumper is properly
connected and
> secure.

If the tuner has one connection to enable the balun and only
has two "wire" antenna posts, one that is used with or
without a balun, you have a voltage balun in the tuner.
That's a very poor balun.

I'd pull the balun out and rewire or rewind it.

73 Tom