Montgomery County PSSM Program update

[Mr_Boh]

Probably a staffing issue. They are still hiring:

Communications Specialist,Montgomery County Police Department , Montgomery County, MD

www.montgomerycountymd.gov

 

[maus92]

I’m listening to 7V2 on a G5 in eastern Montgomery and northern PG today- sounds ok in this area.

 

[maus92]

I do detect a background hum, but since the G5 speaker is so small, it's really not too noticeable / overpowering - but it's there.

 

[Chris52]

Thanks...yeah, that's my feed. I'm getting the same quality on all my radios here in JeffCo. It sounds to me the carrier and signal are fine. The problem seems to be what's being fed to the transmitters is over-modulated causing major distortion. I don't see how the tones are even effective to set off a pager with that distortion. Dispatch audio seems to be talking over the alert tones as well.

The signal on both (154.160) and (150.995) are not fine in my opinion and I’ve ask many of folks who can only receive the VHF side of things and the consensus is 1. Its too scratchy or 2. They can’t even receive neither at all. However we all can agree for the ones who do receive it that there’s plenty of distortion. Hopefully this is just a working progress thing and it will be ironed out soon. (We hope)

 

[W3DMV]

Signal report:
Location:Gettysburg, Pa (Downtown)
Receiver: SDS200
Antenna: Larson 150-450-800 Mobile antenna sitting on
a indoor tri-pod (Street level living room)
Signal: Excellent -60/-70dbm (Site 2)
Decode: Very good..

 

[jeffkraussws]

The signal on both (154.160) and (150.995) are not fine in my opinion and I’ve ask many of folks who can only receive the VHF side of things and the consensus is 1. Its too scratchy or 2. They can’t even receive neither at all. However we all can agree for the ones who do receive it that there’s plenty of distortion. Hopefully this is just a working progress thing and it will be ironed out soon. (We hope)

I live in the Rockville area. The VHF transmissions sound to me like there is RF interference. I don't know whether I'm receiving signals that are simulcasted from several towers, or spurious emissions from some electrical appliance or fluorescent fixture, or an IF image from some other transmitter, or something else.

 

[maus92]

I live in the Rockville area. The VHF transmissions sound to me like there is RF interference. I don't know whether I'm receiving signals that are simulcasted from several towers, or spurious emissions from some electrical appliance or fluorescent fixture, or an IF image from some other transmitter, or something else.

I believe the VHF FTO is simulcast now. In the pre-800 MHz days, the fire side dispatchers could key up the nearest site to the stations being dispatched, but usually they used the Rockville or Shady Grove site (I think I'm remembering this correctly.) In Anne Arundel County, the FTO / dispatch channel used to be transmitted on one big fat site - aka high power / high elevation. The service contour reached into southern Pennsylvania. They have since moved to a multi-site system with lower power transmitters, although I'm not sure if it's simulcast. It does sound better than Montgomery's FTO channel, but it's not flawless.

 

[atlong]

Prior to the Phase II cutover, the signal on 154.1600 would be intermittent, probably because of what Maus92 said (keying up the nearest site). Now, it sounds like it's a solid carrier on all transmissions from my QTH up here in Jefferson County, WV. I do get the loud background hum and incredibly over-modified audio, but I have a gut feeling this poor quality is temporary until the new system is fully cut-over and the P16 system is turned off. These VHF channels sound to me like they're being fed from another radio with an impedance mismatch from an audio patch cable or input/output ports. Also, audio transmissions never had the data burst/squawk, which is why I'm thinking the audio is coming from another radio for now and not a direct feed from a console.

 

[maus92]

It also could be a problem in the D-A conversion chain.

 

[dpm797]

I believe the VHF FTO is simulcast now. In the pre-800 MHz days, the fire side dispatchers could key up the nearest site to the stations being dispatched, but usually they used the Rockville or Shady Grove site (I think I'm remembering this correctly.) In Anne Arundel County, the FTO / dispatch channel used to be transmitted on one big fat site - aka high power / high elevation. The service contour reached into southern Pennsylvania. They have since moved to a multi-site system with lower power transmitters, although I'm not sure if it's simulcast. It does sound better than Montgomery's FTO channel, but it's not flawless.

Anne Arundel County's FTO is simulcast.

 

[Bjc123]

I have noticed it has been dramatically clearer for me recently. This weekend it was not great but its getting much better.

 

[Chris52]

I’ve been listening all day and it seems the audio is clearer (at times) as well as the signal but still nothing from 150.995. I hope that will come in at some point here. Perhaps that too is being worked on or will be worked on.

 

[bradam2001]

I work for the county, I have a friend that works for TMC and he showed his radio they got Monday. Looks like the APX 900 radio. I Didn't have my glasses on.

 

[dtscho]

The P16 system has been deprecated, based on submissions from two reliable sources. If someone in range of the P25 system could get a full list of frequencies now in use, I'd be happy to add those to the database. Thanks.

Dave

 

[dmi]

I tried listening to both 7V2 - 154.16 (TSQ 156.7) and 7V1 - 150.995 (TSQ 210.7) and tried switching between FM and NFM. Receiver is in Bethesda, MD

It seems to me that they are transmitting in FM -- when I switched to NFM the received audio had a hiss on it. When I switched back to FM, audio sounded more "normal".

I don't have an SDR setup so I can't say for certain even though both RR and the FCC listings show NFM emission designator.

I also agree that the received signal strength is much worse than what they'd been using before the system changes.

Has anyone analyzed the signal on an SDR and can post if it's FM or NFM?


Jay

 

[villlythekid]

Is anyone else having issues with Openmhz? I'm just getting a bunch of blank even after refreshing several times.

 

[gesucks]

I am surprised no one has gotten or posted any of the Sheriff talkgroups yet

 

[allen5565]

Is anyone else having issues with Openmhz? I'm just getting a bunch of blank even after refreshing several times.View attachment 100376

Yes. You have to mess with it for a bit, toggling between the groups and talkgroups filters and the "results" page. It eventually settles down, but it has been wonky since the switchover.

 

[maus92]

The P16 system has been deprecated, based on submissions from two reliable sources. If someone in range of the P25 system could get a full list of frequencies now in use, I'd be happy to add those to the database. Thanks.

Dave

I'm working in Baltimore tomorrow, but maybe this weekend.

 

[allen5565]

Yes. You have to mess with it for a bit, toggling between the groups and talkgroups filters and the "results" page. It eventually settles down, but it has been wonky since the switchover.

I forgot to mention that the Open MHz website behaves itself much better when accessed on my iPhone's Safari browser than it does from my Google laptop. On the phone there is no difference at all from the site's earlier operation, except for the new system's sometimes "broadcasting underwater" audio quality.