Hellacious UHF Intermod In Tampa

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It sounds like a Motorola control wiping out UHF at times. With the Icom ID-880H scanning in the car, it frequently stops on 450-460 MHz frequencies with a loud blaring control channel noise.

It happens most often in downtown, but it seems to be everywhere. Anyone else in the area have the same problem? Is this a matter of hammy rigs not rejecting intermod well versus commercial gear, or do we have a real interference problem in Tampa?
 

jhal94

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Could you record it possibly? There shouldn't be any control channels in that range for a moto system. Could be an image from duke energy or pinellas.
 
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Sometimes the control channel sound will suddenly stop after a few seconds of hearing it after the radio pauses from scanning. I'm wondering if there is something else transmitting intermittently that causes a heterodyne or something.
 

ecps92

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What specific Freq's.
you might be hearing DMR (MotoTRBO) users in the 450-470 band

It sounds like a Motorola control wiping out UHF at times. With the Icom ID-880H scanning in the car, it frequently stops on 450-460 MHz frequencies with a loud blaring control channel noise.

It happens most often in downtown, but it seems to be everywhere. Anyone else in the area have the same problem? Is this a matter of hammy rigs not rejecting intermod well versus commercial gear, or do we have a real interference problem in Tampa?
 

TampaTyron

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It is Mototrbo systems you are hearing. We have several connect plus sites in the area. Also, there are many capacity plus systems in use. Further, there are even several linked capacity plus sites in operation. Even more.... there are a couple of NXDN or whatever its called Kenwood multisite dmr trunking in operation. Dig up a program called dmrdecode. Acquire a trbo radio and programming gear...... it is a big world out there. TT

PS I work for a large, low profile radio shop.
 
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That explains a lot and thanks for the post. How long has all this DMR NXDN stuff been up in Tampa? It's causing havoc. I'm wondering if commercial rigs do a better job rejecting all the intermod than hammy rigs.

So it's both trunked and digital? What's the control channel and is it a standard Motorola control channel that scanners can track?
 

jhal94

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That explains a lot and thanks for the post. How long has all this DMR NXDN stuff been up in Tampa? It's causing havoc. I'm wondering if commercial rigs do a better job rejecting all the intermod than hammy rigs.

So it's both trunked and digital? What's the control channel and is it a standard Motorola control channel that scanners can track?
I've never had an issue with the XTS2500 I carry around for Ham Use and business monitoring (my PRO163 wont shut up however), try setting up a bandpass filter on your radio.

No you cannot trunktrack it with a scanner unless you use special software such as unitrunker and DSD, or DMRdecode. Capacity plus is a Motorola proprietary trunking format for Mototrbo. It's like Digital LTR.
 
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TampaTyron

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Most commercial radios have better filtering to keep the trbo and other signals out of their receivers. We have had issues with Trbo triggering DPL protected chennels (basically DPL or DCTSS falsing). Many systems that I work on locally are trunked, but the majority of trbo is conventional in the sense that all users are always on that one repeater. Many do not know that a conventional trbo repeater is essentially a Community Repeater with millions of valid talkgroups. FYI, I also spen a good bit of time tracking down unauthorized users and interference. TT
 

ecps92

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So it is NOT intermod, but actually TRBO/DMR on the freq you are stopped on .

Many Companies have gone DMR from Analog in the based frew years.


That explains a lot and thanks for the post. How long has all this DMR NXDN stuff been up in Tampa? It's causing havoc. I'm wondering if commercial rigs do a better job rejecting all the intermod than hammy rigs.

So it's both trunked and digital? What's the control channel and is it a standard Motorola control channel that scanners can track?
 

N4CYA

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I know a few hospitals around the Tampa who are using MotoTRBO as their talk radios St. Joesph security and Mofitt Cancer Center & Research Institute security as well.
 
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