Poor cell signal in new flat. Cellphone repeater question.

August 19, 2012 1:53 AM

Poor cell signal in new flat. Cellphone repeater question.

I'm about to move into a basement apartment in a converted hospital (basement on one side, ground floor on the other - it's on a hill) and I've discovered I have no signal in the apartment except for the window at the rear - which isn't ideal.

I've looked at some cellphone repeaters, such as this one, which is designed for exactly the situation I'm in.

I can position the antenna on the exterior higher up (discussed and approved by the building owner).

But the company selling them seems to be charging a lot for the coax lead for the antenna. Is it just regular coax that would be used for a tv antenna??

posted by lemonfridge to Technology (10 answers total)

Best answer: No, it's 50 ohm cable. This is the same impedance that amateur radio equipment uses, so you should be able to use any amateur radio co-ax. (Or any co-ax advertised as being 50 ohms.) It uses N-type connectors. You can either fit them yourself or buy pre-fitted cable.
posted by Mwongozi at 6:14 AM on August 19, 2012

(Just for reference, TV antenna cable is 75 ohms.)
posted by Mwongozi at 6:15 AM on August 19, 2012

You can ask (and pay) for femtocell from your carrier if you have good internet access.
posted by zeikka at 6:28 AM on August 19, 2012

I recently put in a zBoost Metro repeater. It was around $150 on Amazon, and came with a long coax lead. I don't know if the frequency bands are correct for you, but you might have a look.
posted by snuffleupagus at 7:47 AM on August 19, 2012

Lead line losses increase with frequency (chart [PDF]), and cell phone frequencies are up in the microwave range. You'll need the expensive cable, otherwise most of the signal you've paid to amplify will be lost.
posted by scruss at 8:15 AM on August 19, 2012 [2 favorites]

What carrier do you have? AT&T gave parents a femtocell at no charge because their house didn't get reception.
posted by The Dutchman at 8:34 AM on August 19, 2012

Thirding the femtocell. I used to live in a home where it was literally the only option.

Be forewarned about the femtocell, however...if your internet is not good, it's a real problem. The house I used it in had spotty internet drops on occasion, so the result was that calls would drop, I would miss calls, texts would randomly arrive hours later, or there would be audio issues where either party might disappear for 10-15 seconds. It was infuriating. So make sure you have good internet, or the best you can afford.

I have AT&T, so I don't know about other carriers. The femtocell was free, but we could only have 5 numbers use it, and they had to be added online via our account.
posted by nevercalm at 10:24 AM on August 19, 2012

Response by poster: Great advice! Will look for some cheaper 50ohm coax. Do they make the "window" sections at 50ohm (the flat wire designed to pass through windows)?

I'm on O2 in the uk. I've messages them asking for advice and they are getting back to me. I'm hoping they have a 100% legit solution, as what I'm looking at is not 100% legal.
posted by lemonfridge at 3:38 PM on August 19, 2012

Like scruss said, the cheap cable isn't going to do much for you, especially at 2100 MHz. About how long would this cable be? The longer the cable, the more signal loss you'll get.

Also, a "flat" cable segment will not work, unless it's only flat because it's a square with a cross-section the same as the coax diameter.
posted by Juffo-Wup at 4:19 PM on August 19, 2012

You can get flat 50 Ω cable, but it's not rated for microwave use.
posted by scruss at 7:22 PM on August 19, 2012