[TowerTalk] Matching 75 ohm hardline for 3 bands

[Maurizio Panicara]

Assuming matched antennas and raliziong that also reflected power will be
attenuated, expecially at 440 MHz.
Extra losses because of an 1:1.5 SWR produced by a 75 OHm cable use are
neglegible and much less than with an intrinsecal lossier 50 Ohm cable.
Unless the cable lenght isn't exactly a quarter wave or an odd multiple, the
SWR will stay 1:1.5 (or less) whose fact is within solid state PA
requirements.
I'd simply use the 75 OHm coax, eventually trimming out a bad lenght with an
RG11 (RG59) tail.

73,
Mauri I4JMY




----- Original Message -----
From: "Michael Foerster" <mike.foerster@home.com>
To: <towertalk@contesting.com>
Sent: Saturday, March 31, 2001 7:02 AM
Subject: [TowerTalk] Matching 75 ohm hardline for 3 bands


> Is there a solution for matching 75 ohm hard-line to a triband antenna?
>
> I have a 6 meter, 2 meter and 440 antenna on my tower with 100 ft of 9913
> feeding it.   At 440, it's probably about 6 dB loss.   I would like to
> replace the bulk of the line with 75 ohm hard-line.  I know that you can
> match the impedance with tuned matching stubs, but that's difficult to do
> with 3 different bands at once...
>
> Any suggestions?
>
> Mike
>   W0IH
>
>