[AMPS] Re: 75 ohm cable

[km1h@juno.com]

I have had several requests for info, this is just an example which I
have blocked out the originator.


>Carl:
>
>I have been tempted to use 75 ohm 3/4" hardline for my long 6M run.  

I run 450'  of 3/4" to the 6M yagi on the 180' tower Barrie..seems to
work!  I have actually measured the loss and it was quite a bit under
specs which I found out are absolute worse case anyway.


>I
>have not because I read or heard that it wasn't the 75 to 50 ohm
>transition that caused problems, but that the connectors where the
>problem.


Yes they are 


>
>I have noticed that LMR-600 N male could be made to fit rather 
>easily,
>but have never tried it.
>
>What do you use for connectors on your 75 ohm harline?

There are several options. The cheapest is to get them from W8ZD or
others that offer CATV cable VHF/UHF adaptors. They are roughly $30 a
pair  ( for 3/4", almost all size cables supported) and convert to a 50
Ohm N Female which is included. On a particular VHF/UHF band they act as
xmsn line xfmrs. 
For HF-6M just buy the 432MHz setup which has virtually no xfmr affect
and use as is. Great adaptor, cheap, etc!


Home brew versions are possible but they almost all suffer from
reliability and/or VSWR problems....depending upon frequency.


73    Carl  KM1H
>

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