Pro 97 - ratty reception - atypical ?

Status
Not open for further replies.

avflyguy

Member
Joined
May 7, 2009
Messages
46
Location
Plano, TX
My pro 97 has been a really good workhorse over the last year or so, but now it seems the primary channels I listen to now have a lot really ratty com / static, sometimes to the point of not being able to hardly hear it.

I use both a rubber duck 800mhz for mobile and around the house and home outdoor antenna while fixed and can't tell much difference between the two. There are a couple of areas around the house that are not that ratty or if I change position or go upstairs and say lay it flat instead of sitting up it will get slightly better.

Could this just be a weather phenomenon? Some times it is crystal clear, but of late, more scratchy than clear. Used to be 80% clear, 20% not. Now seems just the opposite. 80% not, 20% OK

Also wonder if turning on attenuation would help any? Could it be interferrence from cell towers? As I get closer to the broadcast site, it clears up really nice.

Got me stumped!
 

n5ims

Member
Joined
Jul 25, 2004
Messages
3,821
What system are you trying to listen to? Several systems around Plano TX are simulcast systems and my Pro-95 has similar issues at times. What is happening is the scanner is picking up several towers and the mixing of the signals is causing the noise. At times the attenuate function helps since these are generally strong system. You may very well be getting too much signal, as strange as this may sound.
 

gmclam

Member
Premium Subscriber
Joined
Sep 15, 2006
Messages
5,750
Location
Fair Oaks, CA
I use both a rubber duck 800mhz for mobile and around the house and home outdoor antenna while fixed and can't tell much difference between the two.
It sounds like you constantly switch between antennas, like I do. A common problem with these scanners is either a worn out antenna connector, or a loose wire inside the scanner. I've repaired a few of them. Often there is a break in the wire from the connector to the PCB that is to slight you can't detect it with a naked eye, but a meter will show it as open.

Could this just be a weather phenomenon? Some times it is crystal clear, but of late, more scratchy than clear. Used to be 80% clear, 20% not. Now seems just the opposite. 80% not, 20% OK
Certainly there are a number of factors that could be at work here. Are you sure you are receiving the same tower/frequency/etc? I have a couple of different NOAA sites in my normal receive range, and I use them to benchmark receive issues. While they are not immune to problems, they provide a good reference. Are all signals "ratty", or do some still work as well as they always have?

Also wonder if turning on attenuation would help any? Could it be interferrence from cell towers? As I get closer to the broadcast site, it clears up really nice.
This is another reason many of us run multiple scanners. If more than one scanner is not receiving well, we can assume it is the broadcast. When one stops working and the others work fine, we can start pointing fingers.

Make sure the attenuator is not on for the channels you are having trouble with. Certainly you could try the attenuator either way, but my gut says you won't pick up anything with it on, unless under a tower. Yes cell phone and other towers can degrade reception, but I would not think that would be a 24/7 scenario.
 

avflyguy

Member
Joined
May 7, 2009
Messages
46
Location
Plano, TX
It sounds like you constantly switch between antennas, like I do. A common problem with these scanners is either a worn out antenna connector, or a loose wire inside the scanner. I've repaired a few of them. Often there is a break in the wire from the connector to the PCB that is to slight you can't detect it with a naked eye, but a meter will show it as open.
This certainly would seem a FIRST item to check.. Makes good sense and YES, I do switch a LOT between the mobile and base antenna -and the bnc connector comes right off of some really stiff RG8 to the scanner so...yeah - I suppose it could have something loose or broke. How to I see inside to check and/or fix if broken?


Certainly there are a number of factors that could be at work here. Are you sure you are receiving the same tower/frequency/etc? I have a couple of different NOAA sites in my normal receive range, and I use them to benchmark receive issues. While they are not immune to problems, they provide a good reference. Are all signals "ratty", or do some still work as well as they always have?
Not much is changed in terms of what I listen to. Same system - I primarily listen to Addision Fire (office is on ADS airport) and City of Parker, Lucas VFD which comes off the Plano trunked system. From the office (on 9th floor) reception is far better than down lower in elevation, but even it has it's times where even ADS traffic is ratty. So, no realy comparison from office location. From home,(down lower) surrounded by comptuers and TV's that is where most of the really annoying changes are occuring. Used to be mostly clear on the duck or ext. Now it's 50/50 on the ext and the duck is just about worthless (but used to be pretty good)

This is another reason many of us run multiple scanners. If more than one scanner is not receiving well, we can assume it is the broadcast. When one stops working and the others work fine, we can start pointing fingers.

Make sure the attenuator is not on for the channels you are having trouble with. Certainly you could try the attenuator either way, but my gut says you won't pick up anything with it on, unless under a tower. Yes cell phone and other towers can degrade reception, but I would not think that would be a 24/7 scenario.
I've got a really old analog simplex RS PRO 2020 ( RigPix Database - RadioShack/Realistic - Pro-2020 ) home scanner that used to pick up DFR just fine. Now I can't hear anything. A few months back there was a 7 alarm fire less than 3/4 mile from the house, and I didn't hear anything on FG - ext ant - nothing. Every now an then got a garbled scratchy partial transmission from the command van. That scanner used to pick up DFR crystal clear too and still does on many other freq's (mostly aviation what I listen to 118 - 137mhz).

????????????
 

N8IAA

Member
Joined
Dec 19, 2002
Messages
7,051
Location
Fortunately, GA
the bnc connector comes right off of some really stiff RG8 to the scanner so...yeah - I suppose it could have something loose or broke. How to I see inside to check and/or fix if broken?

First, get a short coax connection between the RG8 and the scanner. Way to much for the scanner to handle. To check if the connection between the BNC connector and the board inside the radio is broken, or, in need of repair, you need to open the back of the scanner. Take out the battery pack, and take out the screws. Be careful not to lose them. There is a short copper wire that goes between the center conductor of the BNC and it is soldered to the board. Check to see if it is broken anywhere. A good way to do this is if you have a volt/ohmmeter that has setting for continuous. Put one lead on the BNC center connector, the other on the board where it is soldered. If you hear a continuous signal or the meter shows a really low reading, it is not the wire. My best guess is that you wore out the BNC connector over the years of connecting the different cables to it (especially the RG8). The easiest way to test this is to put a small duck antenna on and wiggle it. If the reception changes, it is time to change the BNC connector. Find someone who is comfortable in doing this, so you don't mess up the radio:D Oh, and just is the DFR that you are monitoring??
HTH,
Larry
 

avflyguy

Member
Joined
May 7, 2009
Messages
46
Location
Plano, TX
I'll let you know what I find. Am competent to trouble shoot this but feeling less likely this is the problem. The ducky wiggling around doesn't seem to make any difference. I already did the shorty pig-tale patch from the RG8 down to RG58 for some more flex while on ext antenna.. no difference one way or the other.

I think what is happening is interference from somewhere, but nothing of any significance has changed in the house over the last year. And why won't my Pro 2020 pick up Dallas Fire Rescue any more? (won't do it very good on the Pro97 either FWIW!


RR Live feed picks it up pretty good...
 

N8IAA

Member
Joined
Dec 19, 2002
Messages
7,051
Location
Fortunately, GA
I think what is happening is interference from somewhere, but nothing of any significance has changed in the house over the last year. And why won't my Pro 2020 pick up Dallas Fire Rescue any more? (won't do it very good on the Pro97 either FWIW! RR Live feed picks it up pretty good...
I would find out what radio the feed provider is using, and where it is located. Are they conventional frequencies, or, trunked. Have they gone to a narrow band radio system. If you have been reading, the narrow band transmitters are not as loud or easy to hear on an older radio with the wide filter in it. A lot can be making the difference in receiving the signal.
Larry
 

N8IAA

Member
Joined
Dec 19, 2002
Messages
7,051
Location
Fortunately, GA
Go to the RR database. Click on Texas, click on Dallas county. Scroll down to Dallas Fire. I think your answer is right at the beginning of the frequencies. Once at the scene, they go to a SIMPLEX frequency so as not to interfere with normal operations on the repeater. Only way to hear is to be right on scene with the FD. That, or, install a 450Mhz beam on the roof to try and pull in the signal. Try asking in the Texas forum. I'm sure they will give you better answers.
Larry
 

gmclam

Member
Premium Subscriber
Joined
Sep 15, 2006
Messages
5,750
Location
Fair Oaks, CA
One scanner I looked at, you could not see the break even under a magnifier very easily. I used an ohm meter to verify the open. Don't forget the connector could be worn and need replacing as well.

For those who constantly change antennas, consider getting a BNC to BNC adapter. They do make them, although hard to find. It would stay on the scanner. Then you'll wear out the adapter and not the scanner. Replace the adapter when it wears out.
 
Status
Not open for further replies.
Top