On 4/24/2013 9:37 AM, GARY HUBER wrote:
As I consider the materials required to replace my 30 year old tower, rotor,
antenna and cables, I have several like new runs on LDF4-50A terminated with
N-male which could run from my ground window (UHF female) to the top of my 53
foot tower (60 feet max LDF4-50A cable run) where a flexible low-loss 10 foot
jumper would terminate on a new BN-4000 and new TH-7 tribander. This
configuration would require the 60 feet max LDF4-50A cable run, two half inch
N female to UHF male adapters, one UHF double female and 10 feet of high
quality RG8 cable as the jumper to the BN-4000.
Several thoughts. My SteppIR is fed by 350 ft of 7/8-inch Heliax, and I
spent the bucks because it's a LONG run that I use all the way up to 6M
(do the arithmetic with the published loss data for coax and Heliax and
you'll see what I mean).
LDF4 is great stuff, but it's a waste of money for a short run on the HF
bands. Save it for your 2M or 432 MHz antennas, where it's low loss
matters a lot more.
As to adapters -- GOOD connectors and adapters cost money, but they do
NOT introduce measurable loss until you hit high UHF. It's the JUNK
connectors and adapters that are lossy. W3LPL recommends nothing but
Amphenol for coax, and I strongly agree with him, except that I will use
the old stuff I find at hamfests with MIL-spec numbers on them.
73, Jim K9YC
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