Strange simulcast/rebroadcast in Groton NL area

[BabaDude77]

Other night I was searching around and found a strange simulcast or rebroadcast of Groton Fire Alarm on 464.4625 (GFA is normally vhf) and it seemed to only have the transmit side from mobile units(heard Groton ambulance and mystic River and some PQ bridge units but only on the mobile side not the dispatch side) the FCC has this freq licensed to Pfizer. I tried the + /- 5 that normal UHF repeaters run and no traffic on either side. Anyone know what this ?

 

[ecps92]

PL/DPL ???
Could it be PFizer ?

FCC Callsign WPPG877 (PFIZER INC)

FCC Callsign WPPG877 (PFIZER INC)

www.radioreference.com

Other night I was searching around and found a strange simulcast or rebroadcast of Groton Fire Alarm on 464.4625 (GFA is normally vhf) and it seemed to only have the transmit side from mobile units(heard Groton ambulance and mystic River and some PQ bridge units but only on the mobile side not the dispatch side) the FCC has this freq licensed to Pfizer. I tried the + /- 5 that normal UHF repeaters run and no traffic on either side. Anyone know what this ?

 

[BabaDude77]

I wasn’t using a PL or DPL but yes the freq is licensed to Pfizer I just found it strange they would be rebroadcasting one side of fire alarms traffic and none of the usual operations of Pfizer. Pfizer FD does have their own frequency But this frequency is not their listed fire or Groton fire alarms frequency because GFA transmits on VHF.

 

[62Truck]

How does the dispatcher transmit on the VHF frequency? Does the dispatch center use it as a repeater, or as a base? Maybe what you're hearing is an image of the input frequencies when the mobiles are transmitting?

 

[ecps92]

Some of the Larger Plants [General Dynamics, etc] not specifically talking about NL/Groton area, do patch into their own networks [Trunk, LTR etc] the local PD/FD/EMS for situational awareness and interop.

Just a WAG, on this one, since Pfizer is licensed. See what PL/DPL or None is being sent, could be a legacy LTR... been awhile since I hit NL for RF Searches

I wasn’t using a PL or DPL but yes the freq is licensed to Pfizer I just found it strange they would be rebroadcasting one side of fire alarms traffic and none of the usual operations of Pfizer. Pfizer FD does have their own frequency But this frequency is not their listed fire or Groton fire alarms frequency because GFA transmits on VHF.

 

[BabaDude77]

How does the dispatcher transmit on the VHF frequency? Does the dispatch center use it as a repeater, or as a base? Maybe what you're hearing is an image of the input frequencies when the mobiles are transmitting?

But why would it be on UHF when GFA dispatch is VHF also GFA dispatch is simplex (same input and output) I’ll have to try to find a PL or DPL on it

 

[BabaDude77]

Some of the Larger Plants [General Dynamics, etc] not specifically talking about NL/Groton area, do patch into their own networks [Trunk, LTR etc] the local PD/FD/EMS for situational awareness and interop.

Just a WAG, on this one, since Pfizer is licensed. See what PL/DPL or None is being sent, could be a legacy LTR... been awhile since I hit NL for RF Searches

That’s a good point but why would it just be one sided ?

 

[nhfdcadet]

just a guess, could it be that pfizer has a cross patch set up so that their (presumably) UHF fire brigade can operate with groton's vhf units should there be an incident? And good possibility that the reason you werent hearing anything from pfizer was because there was not an incident going on?

 

[62Truck]

That’s a good point but why would it just be one sided ?

I'm not familiar with that area,

I see that there are 3 frequencies for Groton Fire, Dispatch, Command East, and Command West. Command East, and West look like they are repeaters. on the UHF frequency you post above, are you hearing traffic from Command, East or West? How does GFA operate on those frequencies? Mobile units are obviously using the repeater input frequencies. Does the dispatcher transmit on the repeater input, or on the output of the repeater like a base station? If the dispatcher is transmitting on the output like a basestaton, it could explain why you're only earing mobile units, the UHF frequency in question might pop up on your scanner as an image for the VHF input frequency for the repeater.

 

[62Truck]

just a guess, could it be that pfizer has a cross patch set up so that their (presumably) UHF fire brigade can operate with groton's vhf units should there be an incident? And good possibility that the reason you werent hearing anything from pfizer was because there was not an incident going on?

From what I understand from his post, he is hearing the mobile side, not the dispatcher side.

 

[ecps92]

[Assumptions here] maybe they programmed it for the input [VHF] only not thinking listen to the Repeater ?

Good find, now to determine if a Conventional UHF or an LTR [see what you get for a PL/DPL or the LTR Channel info] next time they talk.

That’s a good point but why would it just be one sided ?

 

[BabaDude77]

From what I understand from his post, he is hearing the mobile side, not the dispatcher side.

Yes just the mobile side. The only repeater channels are the command channels the FG are simplex along with the dispatch channel and all are vhf. Units and departments are dispatched on dispatch and then move to one of those tac channels depending on the location of the call. Pfizer has their own fire department and they operate and dispatch themselves on UHF. I tried the traditional repeater split of +5 and -5 just haven’t heard anything on them.

 

[sefrischling]

It is Pfizer Public Safety. This has happened before where their public safety channel ends up patching in GFA and leaving it open. This typically only happens when they are operating mutual aid, such as their ambulance G900 (is it D900 now?) operating off campus or their foam uniting operating on a call off campus.

 

[ecps92]

So to close this out, if Pfizer an LTR, DMR or conventional system and if conventional PL/DPL or if LTR/DMR [channels] ?

It is Pfizer Public Safety. This has happened before where their public safety channel ends up patching in GFA and leaving it open. This typically only happens when they are operating mutual aid, such as their ambulance G900 (is it D900 now?) operating off campus or their foam uniting operating on a call off campus.

 

[BabaDude77]

It is Pfizer Public Safety. This has happened before where their public safety channel ends up patching in GFA and leaving it open. This typically only happens when they are operating mutual aid, such as their ambulance G900 (is it D900 now?) operating off campus or their foam uniting operating on a call off campus.

Thanks for the info makes sense now. Any idea why I was only hearing one side though ?

 

[900mhz]

One thought...not sure if Groton uses a mobile repeater for apparatus, it is possible Pfizer was retransmitting RF coming off of a Groton FD/EMS mobile repeater, there is your answer.

 

[nhfdcadet]

Thanks for the info makes sense now. Any idea why I was only hearing one side though ?

just venturing a guess, could be that the crosspatch is set up with equipment that receives on the repeater input so when theyre operating at pfizer, it will receive the portables without them having to go through the city system.

 

[bmeehan282]

Dial in the 469.4625 as well, i'll bet it's a mobile repeater (PAC RT or PL) at Pfizer.

 

[sefrischling]

I believe you are likely only hearing one side of the conversation on 464.4625 because it is a mobile repeater frequency. I could be wrong, but I recall that being the mobile repeater.

 

[BabaDude77]

Was able to find a PL of 186.2