The 200' run is Cable TV hardline (1/2") 75 Ohm, that's where the UnUn would go (maybe).
Jerry Moore Cell: 803-431-1870 -----Original Message----- From: Victor Rosenthal 4X6GP <k2vco....@gmail.com> Sent: Tuesday, March 31, 2020 1:58 PM To: elecraft@mailman.qth.net; ae...@carolinaheli.com Subject: Re: [Elecraft] 75ohm Impedance question K3S and Antenna side. I don't think you need a unun because the additional loss due to SWR running RG/6 at 2:1 is only 0.381 dB, and the unun itself would certainly have some loss. But the loss in 200' of RG/6 even at 1:1 is about 2.9 dB! That is almost half your power. RG/8 would have only 1.9 dB loss, and with a probable SWR of about 1.5:1 you would have a total loss of 2.2 dB. Even better would be Belden 9913 or similar coax, which would give you a total loss of 1.6 dB. All these facts and more are available at <https://www.qsl.net/co8tw/Coax_Calculator.htm> 73, Victor, 4X6GP Rehovot, Israel Formerly K2VCO CWops no. 5 http://www.qsl.net/k2vco/ On 31/03/2020 19:39, ae...@carolinaheli.com wrote: > I'm about to pull the trigger on a Hustler 6BTV (6-Band, 80, 40, 30, > 20, 15, > 10 meters). It will be temporarily installed (with radials) about 200' > away from my house. I'd like to run CATV "hardline" but I'm not sure > how to get a > 2:1 UnUn with a wide enough bandwidth on the antenna side (the > impedance with 60ish radials should be in the 35ohm range). In > addition I believe I will be ok on the RIG side to just connect RG6 > (75ohm) to the hardline and direct to the rig since my K3S can match > the impedance. Is this essentially correct and is there a better way > to do this? I'm trying to minimize losses for the distance run and still have > a decent transmitted signal. > Thanks in advance. > Yeah, I should know this stuff but I can't know everything 100%. > > 73 es > De AE4PB > .. > > > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Elecraft@mailman.qth.net > > This list hosted by: http://www.qsl.net Please help support this email > list: http://www.qsl.net/donate.html Message delivered to > k2vco....@gmail.com > ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
