Thread: Antenna Tuner
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Old December 14th 04, 06:45 PM
chuck
 
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Jack, I do think there's some confusion here. In cases where the balun
is a part of the tuner input, the tuner chassis is usually connected
directly to the transmitter chassis through the normal coax. You can
ground the tuner chassis to an external earth ground if you so wish.
Internally, the balanced output of the balun is connected to the "T"
components at the input side. The coil, of course is not at chassis rf
ground potential, but that is not relevant. It is, however, at DC ground
potential (via the balun winding). I don't see any additional lightning
issues associated with placing the balun at the tuner input.

73,
Chuck

wrote:
And yes you can stand-by-for-fireworks if you think lightning


protection

isn't an issue. Anyone that thinks "floating equipment chassis"


(isolated

from ground) is a good plan, lives in a place where lighting is


something

they watch only on the Discovery Channel.

73,
Jack




Jack
Let me assure you, my station is well grounded, Hi! I even have an
abnormal passion regarding grounds.
My remark was in regarding to a "floating" balanced antenna tuner,
which is not grounded anymore than is a balanced line fed doublet.
Certainly everything before the tuner is well grounded. I even have a
spark gap type lightning protector on the balanced feeds.
As far as the debate regarding baluns at the input or output, I would
be delighted to be convinced that it either does not matter, or is
better at the output..because it makes my life a lot simpler. Right
now I am using about 5 feet or so of LMR400 from my unbalanced tuner to
a Radio Works remote balun, terminated with 300 ohm transmitting
twinlead, feeding a 40 meter doublet. Works like gangbusters.
Jim