I purchased a cell phone booster for the cottage that came with an external yagi. Since its important to get the antenna as far away as possible from the indoor omni, the yagi has about 25 meters of relatively thin coax, smaller than RJ59, permanently connected on the antenna side and with an N-connector on the other. This solution never worked very well, in spite of any geometry I tried I always ended up with feedback on LTE. So I got a ZTE288 wifi router which has external SMAs and plugged it into the same antenna with an N->SMA adaptor. Presto, wifi calling, solid signal.

Now the question(s): The antenna is less than 5 meters from the router, so I assume I could get even better signal if I were to cut the cable down. But I know that getting a good connection on the cable is not trivial.

  1. should I even bother, or is the line loss not worth worrying about?
  2. is putting an SMA on as easy as, say, an F-connector on RG6?
  • 2
    $\begingroup$ Hello Maury, and welcome to this site! $\endgroup$ – Mike Waters Apr 16 at 15:25
  • 1
    $\begingroup$ Is your coax labeled with a model number or something? With that information, it would be possible to look up the loss predicted in 5m of coax. $\endgroup$ – user10489 Apr 19 at 2:01

F connectors are stupid simple to install, the ones I've seen are screw on and you're done. SMA is not going to be that easy.

I've seen solder on SMA, and crimp on SMA might exist, but both require some skill and tools. I've seen screw on BNC, but they require specific cable with a solid center conductor. Very likely your existing coax has a multi-strand center conductor and won't work with any screw on connector, even if an SMA one existed.

It's hard to say without knowing exactly what coax is involved how much loss you are getting from the extra length. There are some good low loss GHz rated skinny coax types.

  • $\begingroup$ Crimp SMA (or at least crimp jacket, solder center) does exist, Times makes them for 240 and 400 cable. I don't know about skinnier stuff. $\endgroup$ – hobbs - KC2G Apr 19 at 2:47
  • $\begingroup$ Ok it sounds like this is an answer. If I ever come across another yagi that has a SMA I'll buy that and the apropriate length of cable. But for now, working is working. $\endgroup$ – Maury Markowitz Apr 19 at 16:35
  • 1
    $\begingroup$ Anyways, before you can even buy a replacement connector, you'd need to know what kind of cable exactly you're dealing with (if it's a cable for indoors, might be RG-174/U), and from that knowledge you can infer the amount of loss you're getting. $\endgroup$ – Marcus Müller Apr 20 at 18:53
  • $\begingroup$ Good point. Different coax has different diameters and needs different connectors to fit. $\endgroup$ – user10489 Apr 21 at 1:04

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.