Cell Towers and Scanner Reception

[TechnoDave]

Has anyone else noticed a problem with receiving digital traffic while in the vicinity of a cellphone tower? There is one particular area during my daily commute that has two cell towers in close proximity. When driving through that area all digital traffic goes to "turkey talk". When Im outside the area everything works fine again.
Anybody else noticed anything like this?

 

[DickH]

Anybody else noticed anything like this?

Where have you been for the last 15 or so years? That's the reason for re-banding.

 

[TechnoDave]

Well, it obviously didnt solve the problem.

 

[troymail]

Nope. Not for scanners it hasn't.

 

[tampabaynews]

Ongoing issue for me when mobile. There's one tower on a large highway I pass through that's unusually low to the ground and I lose all 800mhz reception for a half mile or so.

 

[zz0468]

Well, it obviously didnt solve the problem.

A scanner is going to desense in the presence of any strong RF field, not just cellular, and not just something near the frequencies you happen to be listening to. Rebanding will help on cases of public safety grade radios, but it won't be a cure-all.

I have seen and measured cases on interference from A and B band cellular to NPSPAC and non-NPSPASC 800 MHz radios, and rebanding has absolutely no impact on those cell sites.

 

[james1095]

I would expect the transmission from the cell tower is swamping the front end of whatever you're listening with. I used to live a short distance from several powerful FM broadcast towers and I would pick up those stations in multiple places across the dial on most radios and not much else would come in until I got further away.

 

[stlouisx50]

I always notice this , around my residence. A tower is less than a mile away and it blocks some signals that are further out as well as scrambles signals which are local.

What is the maximum distance away from a cell tower which allows for uninterrupted listening?

 

[mitaux8030]

What is the maximum distance away from a cell tower which allows for uninterrupted listening?

Thats a bit like asking how far away from a bomb do you need to be when it goes off to be safe. The answer is: it depends.

There's lots of variables: how powerful the cell transmitter is, what sort of gain & pattern do the cell antennae have, where are you in relation to the antenna pattern, what is between you and the tower, what sort of scanner you're using and how susceptible it is to overload, what sort of antenna your scanner is using etc etc etc - even down to how many people might be using the cell tower at that instant.

Assuming very worst case in all respects - lets say 10 miles.

 

[stlouisx50]

Thats a bit like asking how far away from a bomb do you need to be when it goes off to be safe. The answer is: it depends.

There's lots of variables: how powerful the cell transmitter is, what sort of gain & pattern do the cell antennae have, where are you in relation to the antenna pattern, what is between you and the tower, what sort of scanner you're using and how susceptible it is to overload, what sort of antenna your scanner is using etc etc etc - even down to how many people might be using the cell tower at that instant.

Assuming very worst case in all respects - lets say 10 miles.

Good point & ouch!

Just FYI using my PRO-106 and the 800mhz antenna from radio shack. I can get too much overload from about a half mile of where I am to totally knock out signals while around MO-DD and I-64. That tower is harsh. The tower near I-64 and Just west of K is a little less strong to me.

The other thing to consider with what you said is the frequency output being used at the time as well. Great reply.

 

[Thayne]

I have driven to within 50 feet of a cell site with 3 carriers on it, with a 197 scanner and a P7200 Ma/Com; the scanner will not hear the denver system at all within the 50 feet, (especially with the NMO on the truck) but the 7100 still works right next to it with a stock rubber duckie with little degradation. Of course the panel antennas on that sight are pointed nearly straight out. Scanners just have crappier front ends---

 

[K4APR]

My day job is with NASA and I'm doing some looking into this very subject. With Verizon LTE now at the 700 MHz range, I'm wondering what kind of impact that will have on the 700 MHz PS and 800 MHz PS ranges.