Home |
Search |
Today's Posts |
#5
![]() |
|||
|
|||
![]()
In article NrIpg.833$lv.144@fed1read12,
"Sal M. Onella" wrote: "ml" wrote in message ... hi If you buy a length of coax w/connectors on it , either a short jumper say 3ft or a run of say 100ft what is an easy way to test the coax as well as the quality of termination connector quality? accuracy is what i am looking for to ensure realibility at 1gig "Easy" and "accuracy" may not both come in the same package. Bob Bob is right but you could also do a swept VSWR. In my experience, it involves a device called a network analyzer, which sweeps across the band of interest through a directional coupler at the near end of the cable, into a dummy load at the far end. It automatically samples the reflected power and compares it to the forward power to produce the SWR more or less continuously. (I believe the sweeping is done incrementally, with steps so small it _appears_ continuous.) The resulting info is plotted or displayed as a graph with frequency left-to-right and VSWR up-and-down, with 1:1 being on the bottom. Some cable is sold as being "100%" sweep tested" to some upper limit. Last year I had a case of a Navy shipboard satcom uplink transmission line that failed its sweep test at one spot near the upper end of the frequency range ... around 8 GHz. We had to replace it. (AN/WSC-6, for those who know what that is.) We had the contractor "shoot" it three different times with different test equipment each time -- always the same. The new line was fine. Until then, I had never seen a defective cable that was quite so frequency sensitive! just wanted to thank everyone for the responce, i wish i had a network analyzer(wasnt that for pc's?) or an coax/ant analyzer however easy wasn't ment to mean common tools that a ham might have i want to buy some used coax to taking adv of price but i need to test it, tnx |
Thread Tools | Search this Thread |
Display Modes | |
|
|
![]() |
||||
Thread | Forum | |||
The "TRICK" to TV 'type' Coax Cable [Shielded] SWL Loop Antennas {RHF} | Antenna | |||
Shortwave random-wire antenna question | Shortwave | |||
WXHL DX test - update! | Shortwave | |||
Poor quality low + High TV channels? How much dB in Preamp? | Shortwave | |||
Response to "21st Century" Part One (Code Test) | Policy |