Bwi 154.100

[18-3box]

okay, its back, but not for long. i am in the 18-3 in AA county and i am getting it loud and clear. why would it be gone for like 2 months and just comes back 100% clear, like the good old days; early 2005. alright it'll be gone tomorrow, like it has done so about 12 times since it vanished, but it is back.

 

[ka3jjz]

Why it really disappears is not known, but it's been hinted at before; it's very likely that someone forgets to open up the patch between the trunked system and 154.1; and we can expect more outages as the new BWI TRS is constructed. 73s Mike

 

[18-3box]

do you think it will come back after the BWI TRS construction project is completed?

 

[TinEar]

Just to be clear on the problem....when the 154.1 freq "disappears" it does not go away. It simply becomes extremely weak but it's still there and still able to be heard if you're close enough to BWI. The question is whether they cut their transmitting power when it gets weak or are doing something with their antenna.

 

[18-3box]

yeah, it is coming in right now (still is, i am still hearing transmissions over the radio on 154.1) as clear as i heard it when i was at bwi yesterday. i am guessing that it will eventually return to the same thing it was before.

 

[dpm797]

Hint.....154.100 is NOT patched.....it is Simulcasted at the dispatch consoul. If it were a PATCH you would here both the dispatcher and Field Units. Notice you only here dispatch. The dispatcher must have the TRS talk group and The 154.100 multiselected at thier consoul to be able to transmit on both systems. AA and Balt Co. Dispatch are Patched and multiselected. 154.100 is kept around at the airport for the Motorola Minitor pagers that the staff use and opening up the base set in the fire station. That way they do not have to listen to all the radio traffic on a portable radio. I am still checking to see what happens when it disapears. I think they do go to low power so it can only be heard at the airport/or is the dispatcher not multiselecting like they are supposed to. It they are not transmitting on it then the pager system is not opening when units at BWI get a call.

 

[ka3jjz]

Dumb question - what is a 'multiselect', and how is it different from a standard patch? It sounds to me, seeing as the talkgroup and 154.1 must be tied together, that it constitutes a patch.

73s Mike

 

[dpm797]

patch goes two ways........both filed units on 800 TRS would be heard on on both the TRS talk group and the VHF freq.........at BWI only the dispatcher is heard.......therefore they are only use it to "talk out" from the dispatch center.....this is for the fire tones for station alerting and minitor pagers........multiselect you can transmit on more than one talk group or frequency at the same time or seperately......therfore they are not patched like AA and Balt Co. In those counties you hear both the dispatcher and filed units on the VHF freq talk goes both ways not one way

 

[dpm797]

if someone were to transmit from a mobile or portable radio on 154.100 it would not go over 4A BWI Dispatch. If a mobile or portable transmits on 4A it does not go over 154.100 Only when the dispatch center transmits is when you here 154.100. If someone were to transmit on 154.010 Anne Arundel Dispatch then it would go over 1A on the TRS and when someone transmits on 1A it goes over 154.010. Hope this clears things up

 

[ocguard]

A multi-select is just what it says - the dispatcher selects multiple CCMs (channels or talkgroups) on their console, therefore, when the dispatcher transmits, they transmit on all channels and talkgroups they've selected. Imagine if you pick up two portables on different channels, key them both up, and talk into both of them. This is essentially what multi-selecting is.

Patching is when two channels are linked together, we'll say for example, channel 1 and channel 3 are patched together. Everyone monitoring channel 1 hears everything on channel 3, and visa versa.

Counties with a TRS that use a conventional channel for paging and dispatching will often have their TRS dispatch talkgroup and their paging channel "patched and multi-selected." The multi-select is so that the dispatcher transmits on both channels, and the patch is so that radios monitoring the paging channel can also hear field units transmitting on the TRS. Often times, such as in AA and Baltimore Cos, the recieve function on the paging radio is disabled, so there will be nothing heard over the TRS from the paging channel, even though they sre patched together.

 

[dpm797]

In Anne Arundel the recieve is NOT disabled........that is so when can patch them and have the MSP troopers talk to the units on scene. Normally the MSP helo TRPs do not use 154.010.......they just come up on 154.340. We have "recieve function and transmitt function on 154.010, 154.340, 154.280, and 154.295. we can also patch all to our 800 TRS. I do not know baltimore county does it. We do not keep 154.295 patched to any talk group on a regular basis........154.340 gets mainly patched to Bravo, Charlie, and Echo. The REASON for the patch is so the radio Transmission on the VHF channels CAN be heard on the TRS. So our units can communicate with units that do not have our TRS but have the ability to use the VHF (most notibly) MSP Helos. 154.010 is always patched to Alpha. 154.280 is patched on 10-oscar about 90% of time. The dispatch center has the ability to enable or disable any patches at any time. We keep 10-Oscar patched to 154.280 so if needed any field unit can come up and talk directly to the surrounding juristdictions dispatch centers and not "disturb" them on that juristdiction's TRS. Therefore the "recieve" function is not disabled. At BWI it is not patched, it is only Multiselected. I HOPE this clears things up for Anne Arundel County. I can not speak for Baltimore County. I beleive Queen Annes is set up like Anne Arundel on thier VHF Hi band freqs.

 

[dpm797]

also If my memery serves me correctly.....BWI 154.100 was "patched" to the old Anne Arundel TRS. If I remember correctly you could hear both the dispatcher and the field units on 154.100 even though the field units were on the TRS I believe TG 60272. If I remeber correctly. It was not unitl Anne Arundel switched to this new 800 TRS and the TG ids changed that it was no longer patched. Also about that same time Caroline County came up on a TRS system and got liscenced on 154.100 as thier Dispatch Freq for station alerting and minitor pagers. BWIs liscence had expired and the FCC gave the freq to Caroline for them to use so they would not be on low band for minitor pagers and station alerting. I wounder if that is why both jurisdiction do not have them patched to the TRS

 

[dpm797]

anyone get a chance to hear the testing BWI was doing on 154.100 today. Driving in my vehicle today here around Chestertown it was coming in very strong. 1st time I have heard them when I have been on this side of Bay Bridge in a while.

 

[ka3jjz]

You sure it was BWI? Caroline county uses that freq as well, and I can easily hear that when the conditions are right. The last couple of mornings have been very good for tropo skip, with a couple of 70cm. repeaters coming thru from as far north as southern NJ - and this on an Austin spectra and a 245 in my car. 73s Mike

 

[18-3box]

yeah, bwi was testing their alert tones yesterday. just a thought: when i was in pennsylvania, i was getting the Gibson Island Police Channel loud and clear. the only reason was because a really strong storm was passing over. my cousin, who has something to do with radio frequencies, etc.(works for the gov't) and he was right next to me saying that they get frequencies from other states when storms pass over. (just a thought maybe- that's the only reason i can think he/she would get bwi's dispatch. there could be other reasons though.

 

[troymail]

The fact that Caroline County also uses the same frequency is almost certainly why BWI keeps the power output low. They really only need to reach the loop around BWI (maybe 2-3 miles at most). Those times when it seems stronger is probably just one of those things (weather effects, etc.).

 

[dpm797]

Actually it was BWI I heard.....I used to live In Anne Arundel until about a year ago. Listened to them for years. I work for Anne Arundel County. PS---the power maybe low but the assuption that it only needs to be in the 2-3 mile loop is not correct. The Cheif, Division Chiefs, and Fire Marshals have Minitor pagers and get alerted when they are at HOME. Therfore it has be strong enough to alert thier pagers when they are off duty and not at the airport.

 

[dpm797]

I remember when Caroline County 1st started testing on 154.100. I still lived in Millersville. For those of you who dont know Caroline County and BWI sound distintly different. I can tell which one it is as soon as they key up......each have different back round noise and the dispatchers articulate differently. So its easy to figure out which jurisdiction it is. I do not have a scanner that is tone code capable yet. Planning on getting one this year though

 

[troymail]

Actually it was BWI I heard.....I used to live In Anne Arundel until about a year ago. Listened to them for years. I work for Anne Arundel County. PS---the power maybe low but the assuption that it only needs to be in the 2-3 mile loop is not correct. The Cheif, Division Chiefs, and Fire Marshals have Minitor pagers and get alerted when they are at HOME. Therfore it has be strong enough to alert thier pagers when they are off duty and not at the airport.

I doubt that. I really doubt that the off-duty, off-site chiefs monitor a BWI pager given that their tone alert is exactly the same for every call regardless of type... I'd suspect it is more likely that they are on a callback procedure - cell phone, home phone, etc. Hell, I have a pager for my volunteer station, I live in the first due area but I don't keep it on all of the time because I'm not interested in getting woken up at all hours for a "sick person", etc. I'm sure the off duty, off-site officers don't want to get woken up everytime a flight is coming in with a person experiencing chest pain.... It's unlikely any of them are coming back unless a plane goes down near the airport -- and that doesn't happen very often (thank god)l.