Green County p25 lsm

[sgtmatt]

I apologize if this question has been asked previously. But I was up in Green County with my sds went up through Monticello and New Glarus on 69. Didn't rely hear much off of my scanner but did hear traffic off of the scanner app. I may be possibly moving to the New Glarus area in the future. Is there anything special I need to do to recieve traffic. It may just have been bad location too. I also carry a Tait TP 9100 for ham radio repeaters. If there is anyone on here that could kill two birds with one stone for me that would be helpful. I am aware that the 9100 will do LSM, is there any particular settings I need to do in the software for it? I did notice a section where you set up the scan list where it says linear scan. Just was curious if that would help somehow. Thanks again.

 

[DVINTHEHOUSEMAN]

Green County is LSM on all of their P25 channels. All of the PS and LG repeater sites appear to have a tower near New Glarus so simulcast distortion shouldn't be much of a problem on your scanners, if at all, at least while in town.

As for help with the Tait, you would probably have to ask in the Tait forum. I don't know anything about them.

 

[autovon]

I was through there not too long ago and used a BCD325P2, which is not usually too great for LSM. Was fairly close to NG and picked up what I though was a normal amount of radio traffic. Didn’t notice I was missing any transmissions.

 

[sgtmatt]

Thanks guys. I was able to figure the Tait part of the issue up. I'll hopefully be taking possesion of the apartment next month so I'm kind of curious to see what I'll hear. Can anyone tell me what I can expect to here from any of the surrounding counties?

 

[DVINTHEHOUSEMAN]

You will probably be able to hear Lafayette county and Dane county, and you will likely get Iowa county bouncing off of your WISCOM site. You might also hear Dane county on WISCOM if you have too much distortion on Danecom. You're also likely to hear Monroe PD.

If you have a good antenna you could *maybe* pull in Rock, Jo Daviess, or Stephenson counties as well.

Not everything fun to listen to is public safety as well, there's a lot of area trunked systems and other frequencies that can be interesting (such as electric and tow companies, farms, repairmen, gravel pits, snow plows, etc.) There's also a GMRS repeater in Monroe that is fun to listen to sometimes.

 

[gormana99]

Green County is LSM on all of their P25 channels. All of the PS and LG repeater sites appear to have a tower near New Glarus so simulcast distortion shouldn't be much of a problem on your scanners, if at all, at least while in town.

As for help with the Tait, you would probably have to ask in the Tait forum. I don't know anything about them.

Help me out, what is LSM? I have been trying to get green county re-programed into my scanners, with out success.

 

[kayn1n32008]

Help me out, what is LSM? I have been trying to get green county re-programed into my scanners, with out success.

Linear Simulcast Modulation. It's a wave form used in Motorola simulcast cells.

 

[DVINTHEHOUSEMAN]

It's not just used in Motorola simulcast.

LSM is a way of improving coverage with less sites. LSM is Compatible Quadrature PSK (CQPSK) modulated, compared to Continuous 4-level FM (C4FM), which deviates the frequency instead of the phase like PSK. C4FM simulcasting is possible, but allows only for a slight delay in the received signals before becoming unreadable due to intersymbol interference or multipath (keep in mind P25 is 9600 bps). CQPSK is much less susceptible to intersymbol interference and it's labeled as compatible due to yielding the same deviation at symbol time as C4FM.

If you want to learn more about the actual modulation schema, the search button and Wikipedia is your friend as there are already multiple great posts on how each works.

 

[kayn1n32008]

It's not just used in Motorola simulcast.

LSM is a way of improving coverage with less sites. LSM is Compatible Quadrature PSK (CQPSK) modulated, compared to Continuous 4-level FM (C4FM), which deviates the frequency instead of the phase like PSK. C4FM simulcasting is possible, but allows only for a slight delay in the received signals before becoming unreadable due to intersymbol interference or multipath (keep in mind P25 is 9600 bps). CQPSK is much less susceptible to intersymbol interference and it's labeled as compatible due to yielding the same deviation at symbol time as C4FM.

If you want to learn more about the actual modulation schema, the search button and Wikipedia is your friend as there are already multiple great posts on how each works.

Harris uses WCQPSK for phase 1 simulcast and H-DQPSK for phase 2 simulcast

 

[sgtmatt]

Thanks guys. I was able to get my Tait question answered as well. I do alot of joy riding so I'm sure one way or the other I'll have some fun. When I was in Monroe I was able to get Starcom 21 no trouble at all and I thought I heard Rockford Fire faintly on the radio. I may have to get one of my antennas up on my car to get some better reception. The place I'm looking at is on a hill so that should mean at least something.

 

[gormana99]

I am just over the county line, I have not been able to receive Green County since the change. This may be the excuse I need to try another antenna project.

 

[DVINTHEHOUSEMAN]

I am just over the county line, I have not been able to receive Green County since the change. This may be the excuse I need to try another antenna project.

What receiver are you using? Green county's (or anybody's for that matter) simulcast setup doesn't play nice with anything but a receiver designed for simulcast, especially if your radio is hearing more than just one site. I am able to hear Green county's system fine in Jo Daviess county so with you being just over a county line you should hear at least a raw datastream just fine.

 

[sgtmatt]

I have the SDS1000 and a Tait TP 9100

 

[DVINTHEHOUSEMAN]

Thanks for drawing my attention back to this thread, I was driving past New Glarus with my PRO-96 and the signal was very strong and clear without distortion until I got out of town about a half mile.

As for the poster that commented that he couldn't hear it, I'm assuming he fixed his issue.