Montgomery 700 MHZ (not AFRN)

I have already given this to a member via private message.

This morning I was using my PSR-800 in search mode listening to the 790-799 area. I picked up noise similar to a control channel on 792.7625. I locked it in and stayed there for a couple of hours. I finally heard clear speech on that frequency. It DPS Hqs reading back tag information.

I have heard that Montgomery County & City area is moving from the EDACS system to a Harris P25 system. Does anyone know the frequencies for the new system? It's obvious DPS is on this frequency and simulcasting on it. I confirmed the simulcast by having DPS Hqs on a separate radio and monitoring 792.7625 at the same time.

Clear voice is heard about 2 times an hour, with squelch noise & beeping during most on the hits on the PSR-800 that remains locked on that frequency.

Thanks.

It is probably an image. If you are hearing the input to a trunked or conventional repeater check 30 MHz lower (762.7625) to see if you hear the repeater output. 762 MHz is ouside of the narrowband part of the 700 MHz public safety band so it is probably an image of something between 851-866 MHz.

Thanks. I tried to go down 30mhz, but the PSR-800 cannot go that low...764.000 is the bottom of that area.

If this is an image of the local EDACS system would it be clear voice if the original EDACS is using ProVoice, which the 800 cannot decode?

qslmark said:

If this is an image of the local EDACS system would it be clear voice if the original EDACS is using ProVoice, which the 800 cannot decode?

Click to expand...

You would not hear ProVoice digital transmissions but you would hear analog transmissions if any of the talkgroups on that system were analog or mixed mode.

Are you sure you were hearing digital transmisions? The PD in my city is ProVoice encrypted on all their talkgroups but occasionally something goes wrong and you hear clear analog transmissions.

Have you checked the FCC database for new licenes or modifications to existing licenses for P25 in your area?

I have a 2nd PSR-800 and have put it on the local EDACS system; used to listen to it before it went ProVoice. It picks up the control channel and trunks as indicated by the "T" on the display, but not a sound as usual. Still getting stuff on that 792 frequency, but the EDACS is silent. The funny thing is the voice traffic on 792 is as clear and clean as the same traffic on the DPS VHF frequency. The majority of what is heard is still the squelch and beeping you hear on a trucked frequency when it messes up.

Yes, I looked in the ULS and didn't see anything new.

I'm sure one of the other members who live in the area will figure it out.

I found several 3 year old articles about Montgomery County replacing their EDACS system with Harris P25.
The new system is probably on the air now and they are switching over.
The new system is not in the radioreference database.
They are probably gradually converting the EDACS frequencies to P25.

Somebody that knows what they are doing will have to check all of the base frequencies on these licenses for P25 control channels:
KNNM675 (Montgomery Metro Communications Cooperative District) FCC Callsign Details
WPNQ888 (Montgomery Metro Communications Cooperative District) FCC Callsign Details

Also search 769-775 in 6.25 kHz steps and 851-861 MHz in 12.5 KHz steps for P25 control channels in case they are licensed to somebody else.

Then somebody will have to run control channel decoding software like Unitrunker or Pro96Com on the control channels that they find, collect all the WACN, SYSID, site numbers, site NACs and frequencies for each site and submit it to the database.

Then they will have to start identifying talkgroups.

I can't be of any more help.

You have been extremely helpful. I appreciate your time. I know more now than 6 hours ago.

Thanks.

qslmark said:

Still getting stuff on that 792 frequency, but the EDACS is silent. The funny thing is the voice traffic on 792 is as clear and clean as the same traffic on the DPS VHF frequency. The majority of what is heard is still the squelch and beeping you hear on a trucked frequency when it messes up.

Click to expand...

I didn't understand that part. I have no idea what you mean by squelch and beeping you hear on a trucked frequency when it messes up. Are you saying you are hearing analog transmissions that are the same as a VHF frequency or a trunked voice channel that occasionally has the same traffic as a VHF frequency when a certain talkgroup is on a certain voice channel?

If it is analog then you may be hearing intermod or images if the VHF transmitter is nearby and it may have nothing to do with any existing EDACS or new P25 system.

look ath the AFRN system thread. mention has been made of people hear tgs on there.

nd5y said:

I didn't understand that part. I have no idea what you mean by squelch and beeping you hear on a trucked frequency when it messes up. Are you saying you are hearing analog transmissions that are the same as a VHF frequency or a trunked voice channel that occasionally has the same traffic as a VHF frequency when a certain talkgroup is on a certain voice channel?

If it is analog then you may be hearing intermod or images if the VHF transmitter is nearby and it may have nothing to do with any existing EDACS or new P25 system.

Click to expand...

The best way to explain it...program one single EDACS frequency into a scanner and when that frequency has traffic you will hear what I have described. First will be a squelch sound, then beeps a second apart while the voice attempts to come through.

I can confirm this is the EDACS system and is as nd5y said probably an image, some of the groups on this system are in the clear so that is what you are hearing, the static then beeping is the provoice.