Unknown Chatsworth, Burlington County LTR TRS

[Joseph11]

I've done some searching and found my radio stopped on 507.9875, hearing only bursts of silence about every 9 seconds or so. That brought me to think I am hearing an LTR system. Sure enough, I am. The system is registered to "POTTS, JAMES T" and is based out of Chatsworth, Burlington County. I thought that this was a business system untill I heard some of the users talking about going to CMC (Community Medical Center) and other hospitals. I'm logging the talkgroups and trying to ID them, this is what I have so far:

Unknown Chatsworth, Burlington County LTR TRS

Frequencies:

502.9125 LCN 01
506.4125
506.8875
507.9875
508.2625

Talkgroups:

101014 - Medics
101253 - CWID
102253 - CWID
104253 - unid (Only silence heard, so far)

If anyone knows more about this system, please post an update here.

 

[robbinsj2]

James Potts' licenses are for Mid State Communications. Note the mailing address on the license comes back the same as Mid State's. Their web site is at http://www.midstateradio.com/ . I was trying to sort out a bunch of his/their licenses in Mercer County, but took a little sabbatical from that while a few APCO systems come online.

When you get LTR TGIDs, the second and third digits are the LCN. For example, if you heard 101014 on 502.9125 then that LCN is 01. The 505, 509, 510, and 511 frequencies should be repeater inputs.

 

[pro92b]

For example, if you heard 101014 on 502.9125 then that LCN is 01.

Not necessarily. If the system is busy a user may not be transmitting on their home repeater. The CWID (talkgroup xxx253) is an accurate way to find the repeater number.

 

[Joseph11]

Thanks for your help on this. I removed the frequencies that I didn't hear the bursts of silence on and added the LCN's. Since I didn't hear the silence bursts on those other frequencies, it brought me to think that they were repeater inputs. If I am wrong, please correct me. It seems odd to have a two frequency trunked system, though.

 

[pro92b]

Single frequency LTR systems exist so a two frequency system is not unusual. Your system has at least three frequencies since you logged three xxx253 talkgroups. The idle burst may not be present on all channels so that is not a reliable way to tell how many channels are active. Most likely you have a five channel system. If all channels use CWID it will be easy to find the correct repeater numbers.

 

[Joseph11]

Single frequency LTR systems exist so a two frequency system is not unusual. Your system has at least three frequencies since you logged three xxx253 talkgroups. The idle burst may not be present on all channels so that is not a reliable way to tell how many channels are active. Most likely you have a five channel system. If all channels use CWID it will be easy to find the correct repeater numbers.

OK, I added 505.9125 back to the list. I heard some activity on it. So far it seems that it only has 3 channels. At twenty-six past the hour they CWID, I'll check the other frequencies for activity and log the TGID(s).

 

[Joseph11]

OK, there was a CWID only on 502.9125 at 3:26 PM ET. On 505.9125, there was some activity under TGID 101014, which tells me that it is LCN 01. That makes no sense as it shows the same for 502.9125.

 

[ericcarlson]

505.9125 is the input to the 502.9125 repeater.

I added the system to the RR database. You can submit updates here:
http://www.radioreference.com/modules.php?name=TRSDB&sid=3944

-Eric

 

[Joseph11]

505.9125 is the input to the 502.9125 repeater.

I added the system to the RR database. You can submit updates here:
http://www.radioreference.com/modules.php?name=TRSDB&sid=3944

-Eric

Thanks for the information. I'll see what else I can find out about this system. How did you figure out that was an input frequency?

 

[pro92b]

According to the FCC site the following are inputs: 505.9125, 509.4125, 509.8875, 510.9875, and 511.2625. Repeater frequencies are 502.9125, 506.4125, 506.8875, 507.9875, and 508.2625. Notice that the inputs are 3 MHz above the repeater frequencies. You should be monitoring only the repeater frequencies.

The presence of a talkgroup on a given frequency does not positively identify the repeater number (LCN) unless the rest of the frequencies in the system are idle.

 

[Joseph11]

According to the FCC site the following are inputs: 505.9125, 509.4125, 509.8875, 510.9875, and 511.2625. Repeater frequencies are 502.9125, 506.4125, 506.8875, 507.9875, and 508.2625. Notice that the inputs are 3 MHz above the repeater frequencies. You should be monitoring only the repeater frequencies.

The presence of a talkgroup on a given frequency does not positively identify the repeater number (LCN) unless the rest of the frequencies in the system are idle.

OK, Thank you.

 

[hulka]

What are they talking about on here? When I worked for Quality Medical Transport ~ 5 years ago they used a system that had a repeater in Chatsworth/Tabernacle area. Could be them possible. All there Rigs and Wheelchair coaches are in the 100 series.

 

[Joseph11]

What are they talking about on here? When I worked for Quality Medical Transport ~ 5 years ago they used a system that had a repeater in Chatsworth/Tabernacle area. Could be them possible. All there Rigs and Wheelchair coaches are in the 100 series.

I really can't understand a word they say, the audio level is low and the quality is too.

 

[EricCottrell]

505.9125 is the input to the 502.9125 repeater.

I added the system to the RR database. You can submit updates here:
http://www.radioreference.com/modules.php?name=TRSDB&sid=3944

-Eric

Thanks for the information. I'll see what else I can find out about this system. How did you figure out that was an input frequency?

Generally in the US (and maybe Canada):
VHF repeaters do not have a standard split between input and output frequencies but it is generally around 1 MHz or so. The closer the input frequency is to the output frequency the more fun the techs have keeping the repeater output from desensing the input. Hams on 146 MHz use a 0.6 MHz split due to repeaters originally only having a 1 MHz allocation and it can be difficult to get everything to work correctly.

Repeaters are more common on UHF and above frequencies.
UHF (450 - 470 MHz) Repeaters use a 5 MHz split with the repeater outputs in the 450 to 455 MHz and 460 to 465 MHz ranges.
UHF-T (470 - 512 MHz) Repeaters use a 3 MHz split. This is due to the band being allocated to areas in 6 MHz chucks. The lower 3 MHz are the repeater outputs so for the allocation of 506 to 512 MHz the outputs are 506 to 509 MHz and for the allocation of 500 to 506 MHz the outputs are 500 to 503 MHz.

73 Eric