Repairing/splicing antenna coax

[kadetklapp]

I have an old VHF magnetic antenna laying around here that I would like to use for temporary installs (in my wrecker). However, somehow the coax got cut and it's about half as long as it should be, making it pretty much unusuable for most mobile applications. It doesn't appear to be a real high-quality piece, but rather than buy a new one, I am wondering if it's possible to properly splice the dead end to some fresh RG 58. This antenna would be used on a VHF commercial unit, like I said, for temporary installs.

 

[zz0468]

You can splice it, but how far are you willing to lower your standards? A carefully done splice will have measurable (if not noticeable) impairment at VHF. A bad slice may be so lossy that it's unusable. You can be cheap, and you can be picky. But not at the same time.

BTW, one doesn't generally "properly" splice RG-58. One replaces it. The closest thing to "properly" is to install connectors on the end and use a barrel adapter.

 

[kadetklapp]

That's what I thought. I may use adapters on it in lieu of throwing it in the trash. We will see. Thanks for the info.

 

[SCPD]

I understand that you're using it to transmit? As you know the radio needs to be as close to a 50 Ohm impedance as possible. If the antenna system wasn't matched right to begin with you'll compound the problem as the splice will create an impedance "bump". The more R.F. power output from the transmitter will cause more reflected R.F. power back to the radio. The more R.F. reflected back to the radio will possibly cause it to reduce power output and/or damage the R.F. final transistor. ZZ0468 is right, if the connectors aren't soldered/installed correctly you might as well not have done it to begin with. If you can afford it just buy another antenna/coax assembly, it would be cheaper than a visit to the local radio service center for a radio repair