Mike:
The impedance should be about 150 ohms (balanced). And if I recall
what I was taught years ago, there's really no significant
penalty to be paid by just connecting the two lines together...
esp. if the part which is made from LOW-LOSS coax is relatively
short, say, 100' or less.
Tom Hammond N0SS
>What is the impedance of the two 75 ohm cables in parallel? Is
it close to 450 ohms so that you just hook it up directly to the
end of a long run of 450 ohm open wire feeder?????
>
>Thanks, Mike, N7ML.
>
>Tom Hammond wrote:
>
>> K2AV wrote:
>>
>> >From: Jerry Morris - W5MS-W5KUF-Corpus Christi Amateur Radio Club To:
James
>> >Subject: Re: [TowerTalk] Bringing Ladder Line into the house ??
>> >
>> >>connect 2 -75 ohm cables together side by side......connect shield
>> >>together at both ends.....
>> >>use center conductor for each side of ladder line.....do not ground
>> >>shield......been using this system on all 6 antennas......w5kuf
>>
>> >Curious as to why you don't ground the shields. Grounding the shields was
>> >the only way I could get rid of some florescent lamp noise. It changed the
>> >tuner settings just a smidge.
>>
>> In this month's (May) issue of QST, on page 53, they show using coax
>> for parallel conductor line and they show the shields tied together
>> at both ends but only the TX END of the shields grounded to TX or
>> tuner ground.
>>
>> 73 - Tom Hammond N0SS
>>
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>
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