Hi All, I use LMR600U for a flex loop on 2m, 70cm and 23cm. On the higher
frequency bands the TX power amplifier and RX converters are located at the
antenna so only a run of LMR240 is used for the 144 MHz i.f. flex loop.
There is always a good sized bundle of various cables and the entire
bundle is wrapped with a couple of layers of vinyl tape to form a single large
loop. Then the bundle is attached to the tower on one end and the antenna on
the other end.
This wrap does a good job of protecting the LMR600U jacket so there have
been no jacket failures over a 10 or 15 year span.
Other operators use 1/2" Andrew Super Flex and that seems to work well.
I know of no issues with Bury Flex on the higher frequencies. It seems to
have similar loss to LMR400U and 9913F cables.
73,
Gerald K5GW
CEO Texas Towers
In a message dated 8/20/2013 8:41:04 A.M. Central Daylight Time,
K8RI-on-TowerTalk@tm.net writes:
On 8/20/2013 8:24 AM, Mike Reublin NF4L wrote:
> BuryFlex from Davis RF. Someone else is selling a cheaper version, but I
can't remember who.
I use a lot of Davis BuryFlex(TM), but I'd not recommend it on 1296. I
don't operate "up there" so I don't know what the going choice is, for
low loss, "relatively" flexible cable for rotator loops.
they may just use a multi turn coil, (coiled like a watch spring) of the
"big stuff". I'm sure we have at least one or two microwave and EME
operators on here that could give you "the straight dope" that know far
more about those frequencies and operation than I, which ain't much.
73 and good luck,
Roger (K8RI)
>
> 73,
> Mike NF4L
>
> On Aug 19, 2013, at 7:23 PM, Jay Kesterson <k0gu@verinet.com> wrote:
>
>>> You mention 600 UF. I've used a fair amount of it and found very
>>> poor life with the stuff. Poor resistance to UV and easily abraded
>>> if it rubs against something like the tower top in a rotator loop.
>> Yes I know LMR-###-UF is not very good outdoors. I'm using one
>> of the other vendors LMR-400-UF (sort of) equivalent with a better
>> jacket in places where I can use 400. I'm not aware of a generic
>> LMR-600-UF with a better jacket. Is there one available? 1500w at
>> 432 MHz and loss at 1296 MHz creates some problems with small cables
>> like 400. Unless there is something else available, Superflex has
>> it's problems also, I'll put something over the jacket to help with
>> the uV and abrasion and replace as needed.
>>
>> 73, Jay K0GU
>>
>>
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