No surprise and if you think about it, both ColPrk and Rockville overlap around I95/495 area and or when a major incident
is taking place on the boarder between 2 MSP barracks its easier to patch them together so they can work together or due to personal shortage
that would be a logical patch between both those barracks tho that would cover a large part of the NCR area .
is taking place on the boarder between 2 MSP barracks its easier to patch them together so they can work together or due to personal shortage
that would be a logical patch between both those barracks tho that would cover a large part of the NCR area .
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The regional EMRCs can patch any unit to any receiving hospital over a variety of Med channels, both conventional and talkgroups. This includes the helicopter channels, 7AIRMED, HELIMED1, and 47.66, to name a few. The regional EMRCs can cross-patch between each other. Here are some screen shots of our legacy patching system that we wrote 34 years ago and we are soon to replace with an updated system.
For those who wonder, we have 44.74, 7AG60, and SYSCOM TG patched together at all times for situational awareness of all medivac aircraft. The 44.74 uses a JPS SNV-12 for voting and transmitter steering. 7AG60 is voted but manually steered since Motorola does not support transmitter steering.....
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Chris52
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Could you explain how 7AG60 works and is it something I should replace 44.74 with ? Thank you
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Chris52
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Thank you, so I’m assuming the is just a simplex frequency and isn’t something that is repeater based and will only hear something if it’s really close and wouldn’t hear SYSCOM all the time ?
It only shows type M(obile) and I never receive it from south central PA, so you may be right.
I have heard the Helimed on the 1st system a couple of times while monitoring the montgomery site with my portable. One time it was Trooper 7 enroute to Trooper 1 HQ for fuel then off to Philly PA for training then I was able to catch it 6hrs later coming back from PA to Trooper 1 for fuel then on to southern MD to go home.
Chris52
Member
That sounds like SYSCOM. Helimed would have PT. info being reported to the receiving hospital they are flying too.
Yes I know but I Found that interesting they were using Helimed instead of SYSCOM
There are several voted ground stations scattered throughout the state, and mobile radios in the aircraft. The EMRC / SYSCOM communicators can determine which ground station has the best receive quality and use that site to transmit to the aircraft. What would be interesting is monitoring the input (mobile transmit) frequency 800.631250 to see if it is used for duplex or if 7AG60 is used in simplex mode. For clarity purposes, 7AG60 is not part of the FIRST TRS.
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No it is not. It is part of the USA NIFOG frequencies and it us used for a helo to make contact with a ground unit that is setting up the LZ
So everyone is clear, Maryland is coordinated to use the following 7AG channels: SYSCOM uses 7AG60 (769.63126/799.63125) for command and control; EMRC uses 7AG68 (770.63125/800.63125) for "Helimed" consults; and 7AG88D (774.61875/804.61875) for LZ ops. "D" in this context implies simplex mode. In my post 6432, I used the mobile freq for 7AG68 and related it to 7AG60 - sorry for the error.
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Looking at some more data, 7AG78 (773.11875/803.11875) is coordinated in STMC for EMRC use, probably consults. 7AG58 (769.13125/799.13125) is coordinated in Washington County for EMRC. 7AG80 (773.61875/803.61875) is coordinated for EMRC in Baltimore City.
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Channel expansions are planned for the simulcast sites in Anne Arundel, Calvert, Charles, Cecil, Caroline, Carroll, Dorchester, Harford, Howard, Kent, Montgomery, PG, QA, Talbot, Washington and Worcester counties. Some of the channel holds have been coordinated for some time, but in Anne Arundel and Howard counties, expansion channel allocations were doubled from two to four. Montgomery and PG counties also have four channel allocations. The recently approved DC site has 10 channels reserved. Interestingly, the Cecilton ASR has one channel designated as "silent" which may mean it is only used when necessary for coordination reasons / potential interference mitigation.
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7AG60 was developed to be utilized by helicopters that no longer have lowband capability and don't qualify to be on the Maryland FiRST radio system, such as commercial helicopters. 7AG60 and 7AGMED are part of independent six site voted systems with manual transmitter site selection. Originally this was planned to be the channel that replaced 44.74 but with proper programming, the MSP helicopters are able to leverage the Maryland FiRST trunked radio system's talkgroups (SYSCOM and HELIMED1 TGs). It is anticipated, that use of 44.74 will go away once the Maryland State Police have replaced their non-Phase 2 compliant radios, which was funded this last legislative session, and once 44.74 no longer becomes needed. Keep in mind that the MSP medivac program extends 30 miles outside of Maryland's borders so a lot depends on if 44.74 is still needed to reach these areas.
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The receive signal from all 6 sites are voted and only the manually selected site would be transmitted on. The base stations are not simplex.
Chris52
Member
Thanks, I added it in, let’s see what I’ll hear from the Frederick area
