[TowerTalk] Outdoor Coax Issue

[Tim N9PUZ]

Richards wrote:
> OK... I have been trying to follow the detailed discussion on
> various brands and models of all weather, bury-able coax...
> But it is new to me and all the information is swimming in my
> brain in a big swirling vortex.
> 
> So... is there any reason I should not use LMR-400-DB in my
> back yard?  I am going to run about 50 feet of it underground
> to a new big vertical with one of those DX-Engineering radial
> plates... but it must traverse through a low area used for
> yard drainage, and it can get rather wet with occasional standing
> water (like when the snow melts in spring, the soil gets rather
> saturated for extended periods.)

If I remember correctly your vertical may end up being a temporary 
antenna until a tower can be installed next year, correct?

For what it's worth about 6 years ago I put up a Gap Titan DX in the 
back yard with a similar plan. There were no control cables, etc. to 
consider so I laid a single run of Bury-Flex on top of very closely 
mowed grass and "stapled" it to the ground with scraps of 12 ga. solid 
wire formed into a "U" shape.

It took just a few weeks the following Spring before you could not 
find the coax without digging through the thatch. I've driven over it 
with my truck occasionally and a good sized Kubota tractor every week 
for a few years now.

I haven't done any extensive study but as a practical test I made a 
simple measurement a couple months ago. (No sunspots = boredom!) If a 
put a dummy load and a watt meter out at the antenna connection and 
put 10 Watts in I read about 8.5 Watts at the antenna end of things. 
The measurement was made on 30 Meters for no particular reason. I 
don't have high grade test equipment and did not think to make the 
same measurement when it was newly installed but I think things are 
still in good shape. According to an online calculator the loss for 
120 ft of this coax should be 1.63 Watts.

Your mileage may vary, as they say.

Tim, N9PUZ