Subject: Re: [TowerTalk] Looking for a good small coax for 160, 75 and 40
> My thought are what freq. are you operation on ? Also how much loss are
> you
As the subject line says, 160, 75, and 40.
The dielectric is thick enough, but there might be two problems. One would
be arcing across the end of the dielectric so trimming the foil back to give
plenty of space in the connectorshould help. The other potential problem is
the power handeling capability of the small center conductor.
> willing to have ? Yes there are alternatives to LMR-400 and you can look
> at
> options, but you need to answer your needs first other than weight etc.
400 is relatively light compared to the older coax cables being Copper
plated aluminum center conductor and foild with single braid covering, but
it's stil heavy and it's also stiff. As the slop-ers are near 95 feet on
the top end that leaves a lot of coax hanging down and over to the tower.
This is quite a bit of wind load and that stuff can really swing around. in
50 to 70 MPH gusts. Also in spring and fall, ice is quite common. The LMR
and CNT 240 are strong enough, but only testing will tell if it'll stand up
to the power and voltage. On 75 the SWR will probably get as high as 3:1
while on 40 I doubt it makes 2:1.
73
Roger (K8RI)
>
> On Jan 31, 2008 3:17 AM, K8RI <K8RI-on-TowerTalk@tm.net> wrote:
>
>> I have some LMR 240 as well as CNT-240 which works quite well. Running
>> the
>> legal limit on these bands is right at the limits for these cables, but
>> they
>> are light and work well for dipoles as well as half wave slopers. OTOH
>> I'd
>> like something more flexible like RG8-X, but RG-8X has relatively poor
>> shielding. OTOH it might work quite well for these installations. And
>> 8X
>> is *inexpensive*
>>
>> I'll be using crimp connectors and flooded heat shrink for good
>> mechanical,
>> waterproof connections. I'm just tryin to get away from the weight of
>> the
>> RG8 and LMR 400 cables for these antennas.
>>
>> Any thoughts?
>>
>> Roger (K8RI)
>>
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