digital scanners and cell towers

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crshuler

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I was wondering if living near a cell tower would affect how well a digital scanners receives. It doesn't seem to affect my analog scanners at all. TIA
 

N4JNW

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Nah...

Cell phone's and Digital public safety transmissions are on complete different frequencies.

Most digital public safety frequencies are 400 or 800 mhz. Modern cell phones are up in the 1100 range I belive..
 
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N_Jay

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KG4LJF said:
Nah...

Cell phone's and Digital public safety transmissions are on complete different frequencies.

Most digital public safety frequencies are 400 or 800 mhz. Modern cell phones are up in the 1100 range I belive..

I "believe" that most (all) cell phone are at the upper end of 800.
PCS phones (minor difference) are at 1900, Nextel (looking a lot like a cell tower) will be in the middle of 800, separated from public safety, but today are throughout the lower 2/3 of 800 mixed with public safety.

I also "believe" that cell towers in general can create a lot of wide-band noise that can desense a receiver, but that depends a lot of the particulars of the situation.
 

car2back

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I imagine you might get some intermod on anything in the 800 band too near a tower; but if your not getting any trouble on analog, you shouldn't with digital either.
 

N4JNW

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N_Jay said:
I "believe" that most (all) cell phone are at the upper end of 800.
PCS phones (minor difference) are at 1900, Nextel (looking a lot like a cell tower) will be in the middle of 800, separated from public safety, but today are throughout the lower 2/3 of 800 mixed with public safety.

I also "believe" that cell towers in general can create a lot of wide-band noise that can desense a receiver, but that depends a lot of the particulars of the situation.

Not the first time I've eaten crow... LOL..
 

Thayne

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My experience has been that of course scanners a less selective than a real radio; but when you are within about 2 blocks of any cell or Nextell site a scanner will degrade easily.

last week I was by I-25 and Logan st in Denver and I had the 2096 on at the same time as a jaguar on the same talkgroup and the 2096 was completely useless but it did stay on the group. The jaguar was still legible but noisy. I assume that around sunken highway areas such as this, the cellular panel antennas are angled lower to give better coverage on the sunken roadway, but of course this would blast the surrounding elevation with stronger RF.
If a news media type wants to hear any trunked system well while driving on major highways in an urban area, they better get a real radio with transmit disabled--I have heard so much *****ing lately about both Uniden and GRE digital scanners.
 

kb2vxa

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The proof is in the pudding, you never know until you try. Never mind the misinformation, celular or other, every tower is vertical real estate loaded with antennas for everything from soup to nuts. Then just because you don't have an intermod problem with some frequencies (analog) doesn't say a thing about others (digital). Note the qualifying parenths, analog and digital per se have nothing to do with frequencies. I just wrote it that way in keeping with the format of your post and not to confuse you by departing from it.
 

gcgrotz

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I work on PCS (1900 MHz) base stations, usually co-located with 800 MHz cellular and Nextel. I havent noticed any problem on the '396T while scanning the local TRS P25 stuff. That may be because it is scanning the control channel and you don't hear anything unless it is sent out by the CC. I will have to watch and see if I notice any de-sense. I know from experience that a busy (if you cand find one anymore) 800 MHz analog site with 15-20 calls up with each discrete channel pushing 100w ERP can generate a lot of intermod and will raise the noise floor.

Digital, or at least CDMA that I'm familiar with, not so much because CDMA may be only one or two (or in a big city 4-6) wideband (1.25 MHz) carriers with 100-200 watts ERP tops. Many of my sites only run about 2 watts out of the TX but the directional antennas have pretty high gain at these freqs.
 

DickH

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Thayne said:
... I had the 2096 on at the same time as a jaguar on the same talkgroup and the 2096 was completely useless but it did stay on the group. The jaguar was still legible but noisy. .
What is a Jaguar? Isn't it a foreign car?
 

ButchGone

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RE: digital scanner/cell towers

Jaguar refers to a specific model of a M/A Com radio.
For what it's worth, I have noticed with a 296d that being close to a cell tower can cause scanner to pick up noise, and on a few occasions to the point where the 296 does not trunk track for a moment. However, when in digital mode listeing to a 3600 baud trunked system on 800MHz, cell towers do not seem to bother my reception. I had always heard digital can be tougher to hear on scanners because of interferance, but those systems dont' seem effected. Anyone know why?
There are also some cell sites that don't even bother the 296 at all, while others hammer it to death. I assume the bad ones are Nextel?
BG..
 
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