HFU HF Underground
Technical Topics => Equipment => Topic started by: IQ_imbalance on July 19, 2018, 2129 UTC
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I'm going to have to run something like 100'-120' ft of coax to get my LOG antenna connected to my radio room. Anyone have favorite versions of coax beyond RG-8/U, LMR-400/DMR-400, RG-6/U, and/or favorite vendors? It's for HF <15Mhz RECEIVE ONLY, direct (shallow) burial.
Thanks,
RF
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I use RG-6 TV coax now exclusively. It's easy to get, cheap, and for receive applications works great. I just ran two runs about 150+ ft each to the two new (south and south-south-west) beverages.
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I use Davis RF's Bury Flex direct in the ground running close to 100' back to my 4 Square for the last 10 years with no problems.
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RG-6... it's cheap, readily available, low loss, and easy to work with. Use it around here for just about everything.
Costs less than .10/ft and have even scored it for free. The gel filled stuff is for direct bury but is more expensive and messy to work with.
IHMO, for hobby use, the general purpose cable will be fine in the ground as long as the outer jacket isn't damaged.
Just slit the turf and stick it in the ground an inch or two.
However, always call the utility cable locator before digging.
For example, the phone and cable guys use the same shallow technique...
you don't want to hit anything.
Also, be aware if there are underground lawn sprinklers those pipes and wires can be very shallow buried.
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Thanks all. Will hit the internets and shop around this evening. Right now my radio is by the front door w/coax sneaking in through the screen door. Not a permanent installation.....
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I agree with RG6. If you have a lot of critters around, the direct bury cable with the gel does not seem to be as appetizing to them. I have 5 runs of 200 feet in place, and no cable has failed yet.
I have used environmentally sealed connectors (such as Snap N Seal) for a number of years without failure outdoors. These require a stripper and crimper, but these can generally be found at a reasonably cheap price.
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For receive only I have been using a good quality RG6 cable. Common, inexpensive and the compression connectors are easy and quick to install.
However, to throw a twist (pun intended) into the discussion, I have also been using outdoor or direct burial rated CAT5 or CAT6 network cable. This cable is 4 twisted pairs of about 24 AWG with an impedance of around 100 ohms. Simple matching transformers on either end to convert from unbalanced 50 ohm (or whatever you might require) to the balanced 100 ohm cable and then back again.
Common and inexpensive, the only challenge perhaps are the matching transformers.
cheers, Graham near Ottawa Canada
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For cat 5 baluns you can always salvage a ready made one from any old nic card.
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Network cable is an interesting option. My crossed parallel loop uses the LZ1AQ amplifier, and it uses a run of shielded CAT5. One pair is the return signal, another is power, and the other wires are used for control signals - you have some control over how the four loops are fed to the amplifier.