New project: 217 MHz system for VT Transco utility

Scanning information and discussion for the state of Vermont.
Post Reply
User avatar
bfrederi
Posts: 221
Joined: 29 Mar 2012 15:06
Location: Burlington, MA

New project: 217 MHz system for VT Transco utility

Post by bfrederi »

For a few years a couple of 217 MHz signals have tripped my Close Call whenever I go through mid-state Vermont on I-89. After getting home this weekend and doing a little research & FCC DB digging, I have started to put together the info below.

I believe the two frequencies I caught are MPT 1327 control channels for the high-voltage electric transmission system administered by Vermont Transco LLC. Because I was driving, I didn't log exact locations for the hits. All can say is that they occur somewhere along the Washington County stretch of I-89 between Montpelier and Richmond. The FCC licenses for these licenses are extremely vague about specific transmitter frequencies and locations.

There's a lot more research to do, so I want to put the topic up here for discussion. I note that Eric C. posted a typically informative overview of AMTS on RR back in 2004, and there are some utility pages here on SNE for Eversource in MA and CT which cover some 217 MHz utility channels. So, if anybody with expertise can help validate or fill-in the following, please have at it. We need to identify just about everything: channels/LCNs, site numbers, specific locations, usage, etc.

I'll be better prepared to try to snag some of this when I next drive up there in a few weeks. [Mike: will you be strictly on the Rt 7 corridor or will you be mid-state also?]

B.


Code: Select all

Vermont Transco LLC

Home Page: https://www.vermonttransco.com/
FCC FRN: 	0018268649

WQKC621
WRAN228

MPT1327 (?)


Site: (1)  --  ?, Washington County
====================================
Frequency	Channel		Use	
217.0600	?		CC (?) 



Site: (2)  --  ?, Washington County
====================================
Frequency	Channel		Use
217.1200	?		CC (?)  
                          
Bruce, KA1FGY
Burlington, MA
wb1hbu
Posts: 1064
Joined: 08 Oct 2005 21:38
Location: Lynn, Essex Co.

Re: New project: 217 MHz system for VT Transco utility

Post by wb1hbu »

Hello,

Those leases tend to be based on market area so not very helpful for locations.

I found a map of New England Electrical Transmission lines. It should be helpful if they own all the HV Transmission lines in VT. The +/- DC line from Quebec only connects to Sandy Pond in MA. As you can see there is a line in the Berlin to Barre area.
https://www.iso-ne.com/static-assets/do ... anning.pdf

73 Eric
wb1hbu
Posts: 1064
Joined: 08 Oct 2005 21:38
Location: Lynn, Essex Co.

Re: New project: 217 MHz system for VT Transco utility

Post by wb1hbu »

Hello,

I dug into this more and came up with some interesting information. The Vermont Transco system is statewide and other Vermont utilities are on the system. Vermont Transco was tasked with building the base stations throughout the state. The system was constructed in 2012 and various upgrades have occurred since. AVL using GPS is on the system. There is mentioned of a digital trunked radio system, so it might not be MPT-1327.

It appears Gould Electronics UK is supplying equipment for Vermont Electric Power Company. It looks like the Tait TP9300 series as it covers the frequency range. The radios can do analog FM, full MPT-1327, DMR Tier 2, and DMR Tier 3.

This is a neat map of VT service territories and transmission lines.
https://vtpsd.maps.arcgis.com/apps/weba ... d98aa895fc

73 Eric
User avatar
bfrederi
Posts: 221
Joined: 29 Mar 2012 15:06
Location: Burlington, MA

Re: New project: 217 MHz system for VT Transco utility

Post by bfrederi »

Thanks Eric. Good info.

I assumed MPT-1327 just by the sound, plus the fact that Eversource uses it. I'm certainly ready to be proven wrong.

There is another a good map in PDF on the Transco site:

https://www.velco.com/assets/documents/ ... p_8X11.pdf

Have a great Fourth.

Bruce
Bruce, KA1FGY
Burlington, MA
wb1hbu
Posts: 1064
Joined: 08 Oct 2005 21:38
Location: Lynn, Essex Co.

Re: New project: 217 MHz system for VT Transco utility

Post by wb1hbu »

Hello,

Here is a 2012 Map of the sites
2012SiteMap.png
2012SiteMap.png (475.63 KiB) Viewed 207 times
These are additions and possible changes to the sites mentioned in later years:
Chester (town tower)
W. Rupert (general store)
Rockingham
Putney
Huntington
White River
Londonderry
E. Corinth
Orwell
Topsham
Royalton

73 Eric
User avatar
bfrederi
Posts: 221
Joined: 29 Mar 2012 15:06
Location: Burlington, MA

Re: New project: 217 MHz system for VT Transco utility

Post by bfrederi »

Eric, do you know the significance of the "half moon" orientations on that map? Transmitter directionality? If so, Brownell 6 and Irish 3 are likely the sites that are setting off Close Call. Although they are just outside the bounds my of estimated Montpelier-Richmond stretch, they seem like the most likely candidates.
Bruce, KA1FGY
Burlington, MA
CG
Forums and Wiki Moderator
Posts: 1400
Joined: 29 Aug 2005 15:46
Location: Granby, CT

Re: New project: 217 MHz system for VT Transco utility

Post by CG »

I wouldn't be surprised if they try to get a common system that can work all over their service area. Tait makes multimode radios that can do MPT1327 and DMR Tier 2 (conventional) and Tier 3 (trunking)
Eversource in Western MA runs MPT1327 on 217MHz with lower power sites, perhaps 10 or 15 watts I think. I had logged 32 Sites (but not confirmed locations)
Eversource in CT is still in the process of bringing online a 45 site Tait DMR Tier III 217MHz system for power and gas (unsure if Aquarion Water will end up on it)

chris
User avatar
bfrederi
Posts: 221
Joined: 29 Mar 2012 15:06
Location: Burlington, MA

Re: New project: 217 MHz system for VT Transco utility

Post by bfrederi »

We were up in Vermont last week where I spent quite a bit of time documenting what I could about this system. I used SDR# to identify likely targets and nail down their center frequencies, and used Unitrunker V2 to decode the control channels.

NOTES:

1. This is definitely an MPT1327 system.

2. This system is very large and has dozens of sites across the state. I've only started to scratch the surface.

3. I never managed to capture any voice traffic. That may be due to my less-than-perfect knowledge of Unitrunker functionality, or my temporary QTH may simply have not been able to hear the voice channels.

4. Most of my time was spent at a static location in Franklin County, but on my trip home I pulled over at nearly every rest stop along I-89 to make a 10 minute survey of the sites receivable at each location.

5. The 1 MHz slice where most of these transmitters are located (217 - 218 MHz) is a great target for an Airspy R2/SDR# setup. I had my laptop in the passenger seat and glanced at the waterfall periodically on my way home. It was impressive to watch the number of control channels that would pop up and then fade away as I proceeded southbound. I saw some other channels that looked like they might be voice, but was never in a position to pull over and investigate them.

6. I could never figure out the channel spacing--I had to manually click on the center of a signal in SDR# to ensure that I could provide an accurate enough frequency to Unitrunker to decode. These almost never turned out to be nice round numbers that would neatly snap to a 12.5 KHz spacing. (And my Airspy is rock solid with no drift and no error correction needed.)

7. While most control channels fell between 217 - 218 MHz, I logged one at 220.xxx. I didn't have the time to further explore 220 - 221 for additional transmitters. (Actually, several frequencies exceed the 217.5000 upper limit specified in the two Transco licenses referenced in the original post.)

8. The Unitrunker properties tab logged the same values for all systems/sites:

mpt1327
duration 2
polarity normal
sync c4d7
ttl 0


SUMMARY:

1.

Freq: 217.3562
============
Zone 5049, Site 20553
------------------------------
Heard from: Saint Albans
Signal strength: good

Peers
--------
Site, LCN (also referred to as "Remote, Control" elsewhere in the UI)
20577, 54
20489, 9
20929, 77
20617, 65
20913, 25
20961, 1


2.
Freq.: 217.956
===========
Zone 51c1, Site 20929
-----------------------------
Heard from: Saint Albans
Signal strength:good

Peers
--------
Site, LCN
20529, 41
20617, 65
29577, 54
20913, 25
20921, 81
20489, 9
20929, 80

source/target/action
002-0605, 002-8185, join
001-1808, 001-8185, join
001-1460, 001-8189, join
001-1808, 001-8189, join

groups:
001-8185
001-6140 voice, 14 hits
001-8189
002-8185
006-8185
006-8189

users
002-0605
006-0640
002-0612
001-1460
001-1802
001-1402
001-1807
001-1808
001-1499
001-4609


3.
Freq: 217.6687
============
Zone 5061, site 20577
------------------------------
Heard from: Saint Albans
Signal: very strong


Peers
--------
Site, LCN
20921, 81
20529, 41
20489, 9
20929, 29
20617, 65
20553, 29


source, target, action
001-1403 001-8189, join
001-1402 001-8189, join
001-1807 001-8189, join
001-1808 001-8189, join
001-1420 001-8189, join
001-1807 001-8189, join
001-1462 001-8189, join
001-1403 001-8189, join


4.
Freq: 220.2561 (note outside of FCC authorization)
=============
Zone 51B9, Site 20921
---------------
Heard from Saint Albans
Strength: fair

Peers
--------
Site, LCN
20745, 21
20529, 41
20497, 9
21761, 5
20577, 54


5.
Freq: 217.581
Heard from Saint Albans
Strength: weak

Too weak to decode.




6.
Freq: 217.5058
============
Zone 5031, site 20529
---------------------
Heard from: I-89 Exit 18, Georgia, VT
Strength: very strong

Peers
---------
Site, LCN
20881, 25
21761, 5
20641, 65
20625, 47
20577, 53
20921, 81



7.
Freq: 217.06
===========
Zone 5029, Site 20521
------------------------------
Heard from: I-89S Rest stop, Waterbury
Strength: very strong

Peers
---------
Site, LCN
20505, 59
20745, 21
20497, 9
20881, 25
20529, 41
20609, 33

calls
006-0208 to 006-6921. service: Ana (?)




8.
Freq: 217.8805
==============
Zone 5111 , Site 20753
----------------------------
Heard from: I-89S rest area, Randolph, VT
Strong

Peers
-------
Site, LCN
20593, 17
20673, 10
20889, 33
20713. 25
20641, 65
20761, 60


9.
Freq: 217.4533
============
Zone 5149, Site 20809
------------------------------
Heard from Wendys parking lot, Lebanon, NH
Strength: fair

Peers
---------
Site, LCN
20721 81
20673 10
20665 43
20593 17
20753 71
20513 33
Bruce, KA1FGY
Burlington, MA
CG
Forums and Wiki Moderator
Posts: 1400
Joined: 29 Aug 2005 15:46
Location: Granby, CT

Re: New project: 217 MHz system for VT Transco utility

Post by CG »

Many years ago, I drove all over Western MA mapping out the MPT1327 system that then Western MA Electric (Northeast Utilities) built out. I documented 32+ sites before I got tired of lots of driving and sitting. They use 217-217.5 and some 220 as well. They use 4 frequencies per site and were set in a pattern. For example, Ch 6 is the CC of a site near me in Granville MA. The Voice Channels are 16, 26, 36

If I recall, there was an option in UniTrunker to use HEX or DEC which eliminates the mix that you are showing. For example, Zone 5049, Site 20553... 5049 hex = 20553 decimal

There is likely a band plan for the 2 ranges of frequencies. I would suggest:
Base 217.00625 - Ch 1 (OR) 217.00000 - Ch 1
Step .0125 (12.5Khz)

1 217.00625 217.00000
2 217.01875 217.01250
3 217.03125 217.02500
4 217.04375 217.03750
5 217.05625 217.05000
6 217.06875 217.06250
7 217.08125 217.07500
8 217.09375 217.08750
9 217.10625 217.10000
10 217.11875 217.11250
11 217.13125 217.12500
12 217.14375 217.13750
13 217.15625 217.15000
14 217.16875 217.16250
15 217.18125 217.17500
16 217.19375 217.18750
17 217.20625 217.20000
18 217.21875 217.21250
19 217.23125 217.22500
20 217.24375 217.23750
21 217.25625 217.25000
22 217.26875 217.26250
23 217.28125 217.27500
24 217.29375 217.28750
25 217.30625 217.30000
26 217.31875 217.31250
27 217.33125 217.32500
28 217.34375 217.33750
29 217.35625 217.35000
30 217.36875 217.36250
31 217.38125 217.37500
32 217.39375 217.38750
33 217.40625 217.40000
34 217.41875 217.41250
35 217.43125 217.42500
36 217.44375 217.43750
37 217.45625 217.45000
38 217.46875 217.46250
39 217.48125 217.47500
40 217.49375 217.48750
41 217.50625 217.50000
42 217.51875 217.51250
43 217.53125 217.52500
44 217.54375 217.53750
45 217.55625 217.55000
46 217.56875 217.56250
47 217.58125 217.57500
48 217.59375 217.58750
49 217.60625 217.60000
50 217.61875 217.61250
51 217.63125 217.62500
52 217.64375 217.63750
53 217.65625 217.65000
54 217.66875 217.66250
55 217.68125 217.67500
56 217.69375 217.68750
57 217.70625 217.70000
58 217.71875 217.71250
59 217.73125 217.72500
60 217.74375 217.73750
61 217.75625 217.75000
62 217.76875 217.76250
63 217.78125 217.77500
64 217.79375 217.78750
65 217.80625 217.80000
66 217.81875 217.81250
67 217.83125 217.82500
68 217.84375 217.83750
69 217.85625 217.85000
70 217.86875 217.86250
71 217.88125 217.87500
72 217.89375 217.88750
73 217.90625 217.90000
74 217.91875 217.91250
75 217.93125 217.92500
76 217.94375 217.93750
77 217.95625 217.95000
78 217.96875 217.96250
79 217.98125 217.97500
80 217.99375 217.98750
User avatar
bfrederi
Posts: 221
Joined: 29 Mar 2012 15:06
Location: Burlington, MA

Re: New project: 217 MHz system for VT Transco utility

Post by bfrederi »

Thanks CG. :beer:

It never occurred to me that the Zone/Site results were redundant values with different labels & formats. I was wondering why I never saw multiple sites under the same zone.

Will need to look closer at your suggested band plan, and also compare the results you came up with for W. Mass. Electric. Good stuff.

I was driving solo on the trip back. Next time I'm going to ask my wife to drive while I nerd out in the passenger seat.
Bruce, KA1FGY
Burlington, MA
CG
Forums and Wiki Moderator
Posts: 1400
Joined: 29 Aug 2005 15:46
Location: Granby, CT

Re: New project: 217 MHz system for VT Transco utility

Post by CG »

I also meant to add that the best decoding seemed to be at the lower part of each signal spike.
Post Reply