AA County - 154.34/TG48 Comparison

[TinEar]

I've noticed this a couple of times, most recently last evening during the double shooting in Glen Burnie (Freetown). When Trooper helos respond to a fire department call they generally can also be heard on the old 154.34 mHz freq in addition to Talkgroup 48 (when they use "B") on the trunked system. However, at times, there are transmissions on 154.34 that are not on TG48. Last evening I heard several transmissions from Fire Alarm to Trooper that were only on 154.34 but Trooper's response was on both places. Why would they do that? Is it just a mistake? It obviously means that Trooper is monitoring both TG48 and the 154.34 frequency but I can't understand why they would do that. Any of you fire department guys have a clue about this?

Speaking of AA County comms...Have you noticed that many times the first word or first syllable of a word when someone starts speaking is cut off? I've always assumed the operator started speaking before fully keying the mic. Not so. If you monitor both the talkgroup and the frequency in a conventional mode on a different radio, you only hear the cut off word on the trunked system. It's all there while monitoring the frequency in conventional mode. There is something about the trunked system that requires a longer wait before starting to speak. I haven't really checked this on other systems than AA County but I'd be interested to know if this is common to all trunked systems or just here on Anne Arundel's system.

 

[tolley]

First, regarding the cutoff. Most trunked systems have a small delay when the PTT button is pressed. A small beep occurs and lets you know you have connected to the radio system. This takes about one second. In conventional mode you do not have to do this since there are no repeaters to communicate with. All of the MSP helos have a conventional radio equipped that cannot talk directly to any 800mhz radio system without the use of a crosspatch. We have this same problem in Dorchester with the troopers. We have a Johnson Multinet system but it basically works the same as any other 800 radio system. They (the Trooper Helos) don't realize that when they key up in conventional mode that they have to wait about one second before talking so their message is not truncated due to this delay. I have always wondered why MSP won't go on ebay and buy about 15-20 Johnson LTR/Conventional 800 MHZ radios and program them with the NPSPAC channels for the Helos so they could talk directly to any 800 mhz system in the States of MD, VA, and DE? Right now you can pick up these radios for about $25.00 each on EBAY and they can be programmed for conventional 800 mhz communications. This would save the taxpayers a ton of money and most importantly cut down on the delay in communications between multiple agencies which in turn saves peoples lives!!!


Regarding the transmissions by Fire Alarm not heard on TG 048: This is similar to Dorchester where we communicate on 46.40 with our troopers. Dorchester Central's 800 system is not hot linked to the lowband 46.40 channel because it would probably cause a loud squeal having both radios on at the same time. In the field you usually monitor either the conventional or 800 system but not both for this same reason. So if central wants to contact the fireground/ems personnel they would have to use the 800 system and not the conventional system. If they want to contact the trooper they would have to use the conventional channels. I would venture to say this applies to AA Co as well just based on what you stated earlier. Hope this helps.

Brian Tolley

 

[TinEar]

Yes, your explanation makes perfect sense Brian but still leaves me guessing about a couple of the aspects of what is happening in both instances I described above.

First the 154.34/TG48 thing: What you said makes a good point and your suggestion for improving the system makes an even better point. I could understand what I heard based on your explanation if it was a constant situation but it isn't/wasn't. Only "some" of the transmissions to Trooper from Fire Alarm (FA) were exclusively on 154.34. For instance, FA would say something to Trooper and be heard only on 154.34, the response from Trooper was heard on both 154.34 and TG48 and the next sentence from FA was also heard on both 154.34 and TG48. So even within the same conversation, some FA transmissions were only on 154.34 and some were both places. That's why I was thinking something was going wrong with the system rather than being a method of operation. Obviously, Trooper doesn't care that he's hearing FA in one place or the other as long as he hears him.

The cut off transmission thing: Again, your explanation makes perfect sense and I knew about the PTT slight wait but why would that not also apply to listening to the frequency in a conventional mode rather than trunked mode? Isn't the transmission still going through the trunked system and through the repeater before I can hear it on the frequency?

One more little story from that shooting situation last evening: As a gunman put his gun to his own head and was about to blow his head off, the officer on the scene, in a very serious tone, told the dispatcher that the guy was about to go 10-7. You don't want to laugh at such a serious happening, but I just couldn't help myself. Sometimes, cops at tragic events are unintentionally funny without realizing it just because they use their own lingo to describe events unfolding in front of them. I'm still laughing as I think about it.

 

[ericcarlson]

Only "some" of the transmissions to Trooper from Fire Alarm (FA) were exclusively on 154.34. For instance, FA would say something to Trooper and be heard only on 154.34, the response from Trooper was heard on both 154.34 and TG48 and the next sentence from FA was also heard on both 154.34 and TG48. So even within the same conversation, some FA transmissions were only on 154.34 and some were both places.

My guess is that the dispatcher has the ability to only transmit on the VHF frequency as opposed to talking on the TRS talkgroup (which is in turn patched with VHF).

-Eric

 

[mfn250]

Ok here is the deal.. Fire alarm can key up on any 1 channel or on multiple channels at the sametime, so alot of times they talk to the trooper on 154.34 and dont click on the 800mhz icon. As for which channel they link with 154.34 it all has to do with what channel the operation is on.

So if there is a 9 rescue box on echo and they request MSP they will crosspatch 154.34 to echo. But if e21 is on a 2 box for a medical call (lets say a fall) they will most likely patch on Bravo. Now if bravo is busy with alot of traffic they will have the ops. switch to charlie.

So 154.34 can be patched to any tac channel the operator wants... and dispatch can talk to just the tropper or everyone on that the tac channel and the tropper at the sametime.

 

[gesucks]

About radios in helo. first you can not put just any old radio in a helo they must be FAA approved. some helos have motorola astro spectra's in them (Eagle). there is some APCO-25 radio for helos out there but they run about 20,000$. that is why they dont just buy a radio off ebay. plus the other problem is that dorch. is the only place in the tri state area on a Johnson system. Every one is one motorola systems and a few on edacs

 

[TinEar]

Thanks mfn250. That fully explains what I was seeing and explains why sometimes Fire Alarm is just on 154.34 and other times on 154.34 plus the trunked TAC channel they're working on. Multiple scanners necessary once again.

Does Fire Alarm monitor systems other than Anne Arundel? Several times when Fire Alarm is transmitting, you can hear comms in the background even though no other fire talkgroup is active at the time. I've often wondered if they monitor surrounding counties.

 

[Llwellyn]

I've wondered that myself, TinEar...

The ones that puzzle me the most though are when I'm listening to Alpha on simplex (154.01), and they're toning out a box and giving the info... and you can hear another set of tones and a dispatch in the background. They're our tones for sure, and the audio is always too faint to tell, like whoever it is is way across the room from the console.

I thought they only dispatched one call at a time, since there's only one dispatch channel and theoretically whoever is toning the second box should be stepping on the first one, and it's not happening.

I've also had it, where it's not the 1A dispatcher where I can hear it in the background, but one of the guys doing the TAC channels... I'll have my 785 scanning everything but 1A and one of my Pro's on simplex, and I'll hear tones in the background of the TAC chatter but no call is going out over Alpha.

 

[NINN27]

ok, here we go...

many times, FA will put out tones on a tac channel to get every responders attention... for example...

lets say north arundel hospital goes on re-route (which happens almost every day). FA will put tones on 1B to let all medic units know that north arundel is on re-route.

however, you are right... FA will dispatch 2 calls at once (which btw... drives me nuts if im at the firehouse and i near 6 tones thinking its a fire only to find out its 2 diff calls).

as for monitoring other systems... i dont think so (never actually benn INSIDE FA), but i can confidently say that if you are hearing transmissions in the background with no other activity on tac channels... they are probably talking on 10O (mutual aid channel). either that or some county is asking another county for assistance on mutual aid channel.

any more questions? mfn and myself will be happy to answer

 

[TinEar]

Thanks NINN27. Now I'm going to have to listen real carefully to what is going on in the background when I'm listening to Fire Alarm. It could very well be Mutual Aid, however, it takes place so often that I don't think there could be that much activity on Mutual Aid. Perhaps so. Since I already listen to four scanners simultaneously (sometimes five), I've gotten pretty good at separating voices that are all talking at once and concentrating on the one that catches my attention. But this is going to take more than my nickname implies.

By the way, that shooting from a couple of days ago that I mentioned above finally made the Baltimore Sun this morning. They're a day late and a dollar short as usual. (It's in the Anne Arundel section so might not be in all versions of the Sun.)

There is also a story about Carroll County adding more sheriff deputies to the force because of growth in the county. They've split the coverage into North and South Districts with four quadrants in each District (but does not say how many posts are in each quadrant.) Of course there was no discussion about new talkgroups and how they'll be split up so we'll have to figure that part out on our own.

[Edit]: Just heard something on the scanner (AA County) that leads to another question: What is the function of Air Wagon 1 and where is he stationed? Just heard him responding to the scene of a building fire.

 

[NINN27]

in regards to air wagon 1... im pretty sure hes stationed at 23 (jones station). i could be wrong though

 

[mfn250]

Air Wagon 1- Is a day work air main... job. but is put on any 2nd alarm or bigger (does not mean it always goes) It is the cascade truck, and comes out of the wharehouse during the day and whoevers home at night..

 

[TinEar]

Had the same situation yesterday where AA Fire was working on TG80 with Trooper. There were transmissions on 154.34 that were not on TG80. So, if you're anal and need to hear "everything," you've got to monitor both frequencies.

The same situation exists for Mutual Aid on 154.28 and 10O on the AA system. There are some transmissions on 154.28 not heard on 10O and some on 10O not heard on 154.28.

Does everyone know that on AA 10O you hear other than just AA County's Mutual Aid transmissions? I had to prove that yesterday to someone that strongly believed only AA and whomever they were talking with could be heard there and it got me wondering if perhaps others don't know that.

I did some search on the 153/154 fire frequencies the past couple of nights and learned that Blades DE comes in loud and clear on 154.40. They finally gave their morse callsign and I was able to identify it. So, where is Blades and why does it have so much fire traffic? It's a simulcast, by the way, of a digital net from the audio qualities. I was also hearing Cumberland County VA on 154.43 which does not show as their frequency in this database. They identified themselves by voice many times. I also heard some others on frequencies that used to be in this area before trunking such as 154.22(Howard) and 154.175(AA) but haven't been able to identify the new users yet. It reminded me of how much fun scanning used to be before special and expensive equipment was necessary.

 

[ericcarlson]

I did some search on the 153/154 fire frequencies the past couple of nights and learned that Blades DE comes in loud and clear on 154.40. They finally gave their morse callsign and I was able to identify it. So, where is Blades and why does it have so much fire traffic? It's a simulcast, by the way, of a digital net from the audio qualities.

Many of the VFDs in Delaware have VHF or UHF simulcasts of their county's dispatch talkgroup on the state's digital trunked system.

-Eric

 

[TinEar]

Thanks Eric. That explains why an unheard of town could have so much traffic on their frequency. It's the whole county rather than just Blades. That's kind of interesting to be able to hear one entire county out of the three in Delaware by monitoring one small town. Now I just need to find a couple more to have the entire state - assuming they can be heard from here.

 

[NINN27]

although ive known this for awhile... 10O is patched to 154.280... which is a NATIONAL mutual aid frequency... so of course your going to hear other counties if your monitoring that talkgroup... i have heard as far north as bucks co on it and as far south as alexandria (both with good reception). just a little thought for you all...