Jay is correct. A 25 foot length of LDF4 (1/2" Anrdew) would be good and have about 0.4 db loss. It's also pretty good for felxability. I just picked Andrew since I had that spec sheet handy. Other brands would also be good.
Most adpaters will be in the 0.2 db loss area at 450 MHz. Obviously minimize the number, but don't worry about one or two. Dwayne Kincaid WD8OYG > Just go get some 1/2 suplerflex and call it good. > > Willis M. Hagler wrote: > > > > > > Hello All, > > > > I am putting up a UHF repeater in Seattle and have a question > > regarding feedline losses. The repeater site is on top of a > > building and the distance from where the repeater/duplexer will be > > located is less than 25 feet of coax distance away from the antenna > > mount. > > > > Of course I would like to reduce the system losses as much as possible > > so I'm willing to pay for ~25 feet of 7/8" Heliax. However my > > question is more about the loss experienced with inter-series > > connectors in the feedline. > > > > The 7/8" Heliax is not very friendly to bend and route into the > > cabinet for direct connection to the duplexer, so every repeater I've > > seen has a short chunk of something more friendly like RG-214 going > > from the duplexer, through the cabinet, and then joins to the Heliax > > with some kind of N-male/N-male adapter. > > > > What kind of signal loss occurs through such an adapter at 442mhz? On > > such a short run am I losing more signal through a Male/Male adapter, > > such that I just may be better off running a single segment of RG- 214 > > the entire 25 feet? > > > > As far as I can tell, 25 feet of RG-214 would be about 1.28 dB of > > loss, while 25 feet of LDF5-50a Heliax would be as low as 0.2 dB, but > > if a single Male/Male adapter causes anything close to 1 dB of loss > > than it seems like a wash to me... > > > > Thanks for any advice. > > > > 73 and Merry Christmas to everyone. > > > > Mark Hagler > > W7WMH Seattle > > -- > Jay Urish W5GM > ARRL Life Member Denton County ARRL VEC > N5ERS VP/Trustee > > Monitoring 444.850 PL-88.5 >
