[TowerTalk] 6ØØ Ohm Line, and Entry Panel

[Mark - AA6DX]

As to 600 ohm systems .. I seem to recall that the usual 3 wire line used in
broadcast studios, etc. , was about 150 ohms, or so.  In the days before the
ubiquitous op-amp, impedance matching was not as tolerant as these days, but
MUCH better to feed a higher impedance rather than a lower.  Too low, and
the circuit, of course, saw it pretty much as a short....with the ensuing
problems.   A tad bit high could be readily compensated via output gain,
with less effect on the delivered signal.  Do I have this right, or is old
age taking a toll?  Anyway, replaced a lot of haywire setups in old tyme
small market stations ... lamp cord just did not cut it!
     Inna meantime .. as I type I am wirelessless, but re-roofing is
finished, and house remodel is in full swing.  Have had a metal 12 x 18"
metal plate made for for shack entry, am designing the feed-thrus, and
antennas will start going up soon.  I have save the recent articles on coax
entry, etc.. and will dig the archives for more .. but might be asking for
some ideas/suggestions/wisdom as I progress.   I plan to use automotive
connectors for the rotator control lines. Since I have a relatively large
plate, I am going to add extra connectors, and of different types .. UHF, N,
TNC, F, Wire, etc...
Now to figure out how I want to have the one 4ØØ ohm lead I will be using
feed through that  .. or, perhaps another spot .. the house is stucco .. One
fortunate thing, the feed plate will be less than 6 feet from the shack's
console!  (Fancy name for desk) ..   And, I have a 12' ground rod to drive
just below the plate.  I intend to ground the plate itself to that, and
therefore the feedthrough devices will be offer coax, etc. grounding at that
point.  The main electrical ground is less than six feet further down the
outside wall, and I intend to tie into that as well.  There will be a new
electric service installed, and all new wiring, throughout the house, with a
separate breaker for the shack, as well as 2 23ØV outlets for amps, etc...
Any and all thoughts on what to do with this NEW setup appreciated.  Hey ..
no more knob and tube in the attic!  Wheee!
Mark  AA6DX   CN7Ø


~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
A flashlight is a case for holding dead batteries.