Heard from E Ohio - SysID: 4B1D

[mtindor]

I was scanning 406-420 today and found:

406.75 - cc
- SYSID 4B1D
- 90 khz tone
# 410 406.7500
# 418
# 474
# 498

I suppose I ought to be able to use the # above to determine what frequencies go next to them, but I don't know how.

It apears that when I hear transmissions on 406.75 I also hear them on 408.95. I also think that there may be a very short delay when I hear them on 408.95.

I am monitoring using both a handheld with stock antenna as well as a BCD996T using an external ant with some really pisspoor mini coax from 10 years ago with major infiltration by the elements and a 144/440 Cushcraft vertical. Signals are about the same (weak - no S-unit readings).

Just wondering if anybody has a clue as to where I might be hearing these transmisisons from considering I'm in East Ohio (just south of the WV/PA/OH border at about 1200 feet).

All I've managed to pick out thus far are a few little things such as:
"control to medical"
"blah blah duty officer"
"the A-side outer door needs opened"

Heard a mention of security.

It's interesting because I have looked up and found the usual bandplans for the 406-411 range and one of the frequencies that I can hear is in the second plan and one is in the third plan.

I figure likely it is going to be Pittsburgh area or downstate WV.

Not sure if it is fed or military based upon what I've heard so far.

Any ideas?

Mike

 

[trashman43]

do you have a Federal Prison close?

 

[jawhite2]

from E Ohio - SysID: 4B1D

There are Bureau of Prison facilities in Monongalia and Preston counties in WV. Perhaps you are hearing one of them.

 

[mtindor]

You guys might have called it just right. I think Preston is out, but Monongalia is definitely a possibility. I noticed on those same evenings I was able to pull in the WVIRS sites in Wheeling and Monongalia. So I think Monongalia is the likely site.

I'll post if I get more info.

Thanks guys.

- mike

 

[mtindor]

Still unknown where this system is - It's either in West Virginia (top/west portion) or in Pennsylvania (Allegheny Co area). Would be nice if somebody in Allegheny Co or down in West Virginia could try to scan these frequencies / this trunked system and see what it is. As noted previously, there is speculation that this is probably some BOP (bureau of prisons) system.

The first time I heard it the CC was on 406.75, and currently the CC is 406.95.

confirmed info:

SysID: 4B1D
base: unknown
offset: 25 khz

# 410 406.75 cc
# 418 406.95 cc
# 474 408.35
# 498 408.95

There may be more frequencies associated. I had heard talking on 408.95 on numerous occasions and I had heard talking on 406.95 on numerous occasions. Then I started hearing the CC on 406.75 or 406.95 - once I got clean enough signal and a CC to monitor, I saw 410 (decimel) show up as the channel number for frequency 406.75 and 418 decimel show up as channel number for frequency 406.95 in unitrunker. Additionally Unitrunker showed two other channel numbers after traffic was sent to those channels - 474 and 498.

I originally didn't know the offset and had to figure that out. Since I heard chatter or CC on three different frequencies in the past I made the assumption that they were all part of the same system (since they also had the same relative signal strength). Figuring that they were all part of the same system, it was time to figure the offset.

410 to 418 is 8 channel increments
418 to 474 is 56 channel increments
474 to 498 is 24 channel increments

#410 406.75 + (8*.025) = 406.95
#418 406.95 + (56*.025) = 408.35
#474 408.35 + (24*.025) = 408.95
#498 408.95

I referenced http://www.freqofnature.com/information0001.html to get a clue on figuring out offsets.

I initially figured it as if 50 khz channel spacing was being used and quickly found out that using 50 khz offset would result in not all of my heard frequencies aligning with the channel numbers. Then switched to figuring on 25 khz steps and that was it.

Now I just need to figure out the base frequency (unless by chance 406.75 is the base frequency) and get my new LP up outside so that I can reliably monitor this system.

Mike

 

[freqhopping]

Can't you just program the control channels into a new Motorola UHF system, set it to control channel only and let the scanner do the rest. Works for me in determining base, offset and step. After the scanner has tracked it, that information will show up in the band plan settings.

 

[mtindor]

Can't you just program the control channels into a new Motorola UHF system, set it to control channel only and let the scanner do the rest. Works for me in determining base, offset and step. After the scanner has tracked it, that information will show up in the band plan settings.

Beats me. Do you do that with the 396 as well? The fact is that if i fire up unitrunker and then sit on the Control Channel and it doesn't show up the frequencies automatically, then it isn't being given those frequencies. The offset isn't _standard_ offset - I think that's the deal. I don't think your scanner will determine the channels if the offset is not the standard offset. And Federal trunked systems typically are non-standard offset. I dont know if 25 khz is a 'standard' offset for that band or not.

After reading more what you said above, I'm curious where you find the information about base/offset/step if you do what you said. Lets say I create a new trunked Moto system, put the one active CC in it, set it to CC-only. Then, are you saying it would automatically populate something in the scanner with the other frequencies ? If so I've never seen that before and have no experience with it.

To be honest though, I'd prefer to document all frequencies - not just put in a CC and let it go - simply because not enough info is known about this system yet (how many frequencies in total, which frequencies are used as CCs - because at least two are but maybe more are). So I have to know all of the frequencies. If I simply wanted to listen to it, that's one thing - I don't have to know everything about the system to listen to it, but I hav to know everything about the system to document it.

Oh - I forgot to mention that i can't _reliably_ listen to the CC - it's not strong enough the vast majority of the time. So the scanner would miss a ton of traffic (if there were a ton of traffic) if it was set to CC-only and just monitoring the CC to have it switch to the active audio channel. This way I can listen to them conventionally in the meantime - I can often hear/make out what is being said when they talk even though the signal isn't strong enough for decoding of the CC.

Mike

 

[freqhopping]

I'm using a 396T. When I programmed several federal and DOD 400mhz Motorola systems in my area I just programmed the control channel(s) and run it in search mode if I don't know any TGs. Afterwards if I go to 'Edit Sys Option', 'Edit Band Plan', it shows 'Band Plan 1', 'Band Plan 2', and 'Band Plan 3' to choose from. Select one of those and it will display the base freq. Press 'Enter' and it will then show the step, press it again and it displays the offset. Most recently I was at Patuxent Naval Air Station to get a SYSID for the 380mhz system there. I didn't know any freq data for the 400mhz system there. I scanned the 406-420 range and found the control channel. Programmed a new system and let it run. Now my scanner has band plan info of 406.0/50.0khz/380.

For programming purposes, I'm not concerned with what freqs are used. As the system searches I just write down what I see being used.

The same works with the new 380-390mhz systems. I wouldn't have a clue about finding that info for these systems. For example, on one system this is what was automatically populated in the settings.

0:851.00625/6.25
1:762.00625/6.25
2:380.00000/12.5
3:------------/----
4:------------/----
5:------------/----
6:------------/----
7:------------/----
8:------------/----
9:------------/----
A:------------/----
B:------------/----
C:------------/----
D:------------/----
E:------------/----
F:------------/----

 

[csvff78]

Its not in Allegheny County. I don't hear it here at all.

Frank K3FSS

 

[mtindor]

That helps me out a lot - I appreciate the info. Sure is a lot easier than what I was doing!

Mike

I'm using a 396T. When I programmed several federal and DOD 400mhz Motorola systems in my area I just programmed the control channel(s) and run it in search mode if I don't know any TGs. Afterwards if I go to 'Edit Sys Option', 'Edit Band Plan', it shows 'Band Plan 1', 'Band Plan 2', and 'Band Plan 3' to choose from. Select one of those and it will display the base freq. Press 'Enter' and it will then show the step, press it again and it displays the offset. Most recently I was at Patuxent Naval Air Station to get a SYSID for the 380mhz system there. I didn't know any freq data for the 400mhz system there. I scanned the 406-420 range and found the control channel. Programmed a new system and let it run. Now my scanner has band plan info of 406.0/50.0khz/380.

For programming purposes, I'm not concerned with what freqs are used. As the system searches I just write down what I see being used.

The same works with the new 380-390mhz systems. I wouldn't have a clue about finding that info for these systems. For example, on one system this is what was automatically populated in the settings.

0:851.00625/6.25
1:762.00625/6.25
2:380.00000/12.5
3:------------/----
4:------------/----
5:------------/----
6:------------/----
7:------------/----
8:------------/----
9:------------/----
A:------------/----
B:------------/----
C:------------/----
D:------------/----
E:------------/----
F:------------/----

 

[mtindor]

Its not in Allegheny County. I don't hear it here at all.

Frank K3FSS

Thanks Frank, appreciate you looking into it. Then I think its gotta be downstate WV or over in Columbiana Co - Elkton.

- mike

 

[mtindor]

Ok, actually the scanner uses a default bandplan based upon what is programmed into it. In this case, I stuck it on that frequency (with beam in hand, pointing north so as to get a reliable sig). It did show up as band plan base 406.00, offset 380, 50 khz. I don't know what the offset is all about (I'll have to read up on that again), but the 50 khz spacing is not appropriate for this system - it is specifically 12.5 and would have to be adjusted. If you were to your scanner to the CC of this system it would not properly track it by default.

The signal is definitely North of me - so its going to be Columbiana County (Elkton) or something up Youngstown way.

Incidentally, found another CC to another system while pointing north.

SysID: CA17
#587 408.25 cc

So now I"m really getting antsy to get this antenna up outside.

Mike

 

[freqhopping]

Camp Dawson WV ANG training center Kingwood, WV ?

 

[mtindor]

Camp Dawson WV ANG training center Kingwood, WV ?

Hmm, could be. Kingwood is pretty far from Steubenville Ohio area though. I wouldn't anticipate that a system like that would be up on any major hills or at a very high elevation, and it'd need to be in order to cross all the mountain tops to get to me.

I'll be goin down river a ways this week, so i'll take the scanner with me and see if I have better luck with it on a hill down in Belmont Co.

M

 

[freqhopping]

Its not in Allegheny County. I don't hear it here at all.

Frank K3FSS

Where in the county are you? Near the airport?

I was thinking the Air Force units at Pittsburgh airport are a possibility. 400mhz systems are common with the Air Force.
The Federal Correctional Institution in Elkton, OH is another possibility.

 

[csvff78]

I'm in the South Hills. I can pick up the current VHF- Highband freqs used by them. I can pickup the UHF stuff used by Greater Pittsburgh airport as well. It certainly is possible that it is at the airport. I am a bit deaf when it comes to the west, but I should be able to pick up something there. I'll put it in the mobile radio and see if I can pick it up while driving around. I haven't seen a reply of anyone hearing it on the Tramalist group yet, so it may be no joy here.
A good bit of the military TRS systems are popping up in the 380-400 range lately. So, I would lean towards Elkton as the user.

Frank K3FSS

 

[mtindor]

Hmm, I never think to scan 380-400 - I'll have to give that a try. I'm not federal or military monitoring expert or afficionado, probably because I'm not in a big city where there is likely to be much Fed traffic to monitor. I must admit though that I'm becoming more interested in it since not many people talk about what they hear.

Mike

 

[Yokoshibu]

if your that far south it wont be cleveland / nasa

 

[mtindor]

if your that far south it wont be cleveland / nasa

Agreed, not at those frequencies. But interestingly enough I can pick up a lot of stark/summit/cuyahoga/lorain co VHF stuff from down here.

Mike

 

[WayneH]

I'm using a 396T. When I programmed several federal and DOD 400mhz Motorola systems in my area I just programmed the control channel(s) and run it in search mode if I don't know any TGs.

You're talking about P25 Trunking which is different than the standard Motorola trunking. These systems are standard 3600 baud Motorola systems. So it won't work for him. He has to manually calculate it.

I don't know what the offset is all about (I'll have to read up on that again), but the 50 khz spacing is not appropriate for this system - it is specifically 12.5 and would have to be adjusted.

The offset is the channel id that the base freq is assigned. Those decimal values with the freqs you've been listing are the channel ids. Btw, the assignments for this system are 406/380/25.0KHz