North Adams,Mass 911 dispatches blacking out calls in Greene County, N.Y.

[Mtnrider]

NORTH ADAMS,MASS -- Every week, emergency dispatchers in Greene County, N.Y., are cut off from radio communications with their first responders -- and the interference is coming from North Adams.




North Adams 911 dispatches blacking out calls in Greene County, N.Y. - North Adams Transcript

 

[Rudy3145]

It's called a PL

 

[jaspence]

North Adams

Even with CTCSS, there can still be harmful interference, assuming these are conventional frequencies.

 

[Thunderknight]

PL only masks the source. Receiver desense/capture remains the same.

 

[Mtnrider]

Conventional Freqs....PL is installed on Greene side....there climbing in the repeater when its active....mainly the High Hill site here in Greene....but has been known to reach the Hunter repeater

 

[W3DMV]

Would someone please list the frequency in question ?

 

[pro106import]

Would someone please list the frequency in question ?

Probably 159.255

 

[Bruce42]

What a Surprise........NOT

What a surprise! North Adams licensed their repeater output on the Greene County repeater input of 159.255 MHz. Another example of the "Flat Land" radio attitude that permeates the FCC and many other dim-witted people including "competitive coordinating bodies.". Greene County is on two hills, Mountain Road at 49 miles distant and Hunter Mountain at 70 miles. The first site is about 750 feet and the second is about 4040 feet (per Google Earth) [Greene County's license says only 945 meters. Hmmmm]

Along came the North Adams "consultants?" who decided to put that same frequency on a 2037 foot mountain FB2 only 49 and 70 miles distant. Since repeater input frequencies are NOT protected by the FCC rules, and do not jump right out during a search, many, many folks overlook (sometimes on purpose) the fact that someone's FX1 might just be transmitting to a hilltop repeater receiver. I have seen this over and over in CA where we have a few more mountains that the FCC or Easterners may realize. Using a little intelligence and analyzing the licenses should raise a flag. I have had a repeater input bombed out by a repeater output 160 miles away before. [Of course, they made it easy to find since they used the same PL so there was no mystery about what was happening.]

Looking at the Google profiles between North Adams' Western Summit site to Green County's hills there is almost no obstruction between the Hunter Mt. site and Western Summit. One ridge rises 200 feet into the path but on high band that is almost nothing. [Google, too, seems to use flat earth so that obstruction is probably a little higher. If it were just free space loss, even at 70 miles, North Adams would be putting about 80 microvolts into the Greene receiver. Should the ridge provide 20 dB of attenuation there would still be 8 microvolts which can knock out hand-helds easily on what may have previously been a clear channel.

So...... North Adams needs to pack up and turn off that frequency as they were the "Johnny-come-lately" on that channel. Maybe their consultant should foot the bill for the new channel selection and licensing and the reprogramming of all the radios!

Now did I get that all correct? It seems rather simple to me what happened here.

Bruce.....

Referenced WNMH370, WQRH308, Google Earth and several on-line calculators for path loss and dBm to microvolt calculators.

 

[BirkenVogt]

Around here everything between the marine and railroad bands is used for inputs (generally)...is this not the case in the rest of the country?

Not knowing the specifics of the rest of the lay of the land, could not the pair simply be reversed with the input high and the output low just like everybody else?

 

[izzyj4]

Bruce, though I agree with you that North Adams has to change, you can't lay the blame on them solely as only as I'm reading and interpreting your post correctly. You have to blame the frequency co-ordinator who did not do their homework right and applied for the license in the first place. They are the ones responsible to make sure that there was no interference problems as they were contracted too.

Hopefully North Adams can get a VHF High band frequency that is available.

 

[Bruce42]

Share the Blame

Izzy,

You are definitely correct about the responsibility of the coordinator. In the past, police frequencies were coordinated by APCO and fire frequencies by IMSA. In the case of APCO the coordination was done locally by the technical members who knew the terrain and would insist on testing before considering something like this. [This frequency used to be Forestry Conservatiion so it would have been a different group.]

However, this didn't make anyone rich so the wise Federal Government, through the FCC, turned coordination into a competitive nightmare with folks on the other side of the country "coordinating" frequencies. The local knowledge was thrown out the door by the profit motive of our government. As an example, when some group "coordinates" a frequency the other coordinators such as APCO only have a few days in which to concur or protest. It gets very futile and allows no time for good work. Besides, the faster the first group "approved" the frequency the higher their hourly rate. That too, does not provide incentive to do good work.

So, in spreading the blame fairly I would proceed in this order:

1: North Adams for not keeping or having competent radio people on their staff.
2. North Adams for using Enterprise Wireless Alliance 2013021501 17750 Creamery Road, Suite B10
Emmitsburg, MD 21727 to do their licensing.
3. Which ever coordinating body issued coordination PS20130500470
4. The FCC for destroying the coordination process to allow greed to be the motivation.

And onward. Sorry about jumping on my soapbox again but once again greed triumphs over logical behavior.

And the other chap spoke about reversing the pair which might be a good idea but all the same work has to be done to be sure to avoid the same problem all over again with a new victim. Low band and high band do not have specific repeater spacings and input/output relationships like UHF, 700 and 800 MHz because they were used before repeaters existed. Fortunately, when UHF and above came into use the FCC still had more engineers than lawyers and accountants and common sense prevailed to produce sensible planning rather than auctions.

All in all, people need to be more responsible for their actions and the cost of this little mess should be shared among several individuals/groups rather than just taking the money and saying "sorry," and letting North Adams foot the entire bill to do it all over again.

All that aside, I still enjoy public safety radio planning and implementation, having been involved on and off for about 57 years.

Regards, Bruce.....

 

[KB1VLA]

North Adams has already had to reprogram the PD repeater once, when it was first fired up the tx frequency was accidentally 159.225 instead of 159.255.

 

[W3DMV]

I see that Hagaman, NY has a 100 watt repeater in that frequency also. I Think that's about
50 miles NNW of your county. Does that operation also cause problems ? (KZG275)

 

[Mtnrider]

No...its confirmed its them.i spoke to some people in the know..They have called N Adams dispatch center and had them key up...and gees what do ya know.....been going on for some time.although i haven't heard the issue lately..was first heard on a scanner at around 1000 feet elev in eastern greene county....and i am pretty sure something at 725 feet at 100 watts wouldn't bother it being theres a few mountains in the way.....mainly the helderbergs...And the elevation is correct on the license......Its on the summit of Hunter Mtn Ski center Colonels Chair Mtn at 3100 feet (945 meters) Hunter Mountain is south of the transmitter hence the name on the license .And if you noticed North Adams did not use anyone but there radio vendor...The radio vendor picked whom to file the FCC app thru....

 

[W3DMV]

Thanks for the info.. Good luck

 

[Bruce42]

What a surprise

My Bad! I forgot to include the most usual suspect, the vendor. This despite my six years with Motorola where I saw how the motivation of the sales people had little to do with being correct, just getting that check. I used to have to clean up the messes the sales folks created and try and get the customer happy enough to write the final check for a real, working system like they had been promised.

And I am still puzzled by Greene County's license. WNMH370 shows the Hunter Mt. site at 42-10-37.3, 74-13-46.5 which places it at the summit of Hunter at 4046' (Google) or 4040' (USGS). Colonel's Chair is 1.65 miles due north of Hunter Mt. and IS at 3100 feet. I think the license is incorrect but I, personally, would not try to correct it for they might just end up having to reduce power output under the FCC "Safe Harbor" rules.

I once licensed a sheriff's repeater at 4400' on the same frequency as the other three repeaters but, because it was after a certain FCC set date, the license was limited to 12.5W ERP even though the other repeaters had about 350W ERP. We would only have interfered with ourselves. Certainly never gave us the canyon penetration we had hoped for when we selected the site.

But these are the little details that make it so much fun, right?

Bruce......................

 

[kc2smb]

Columbia County 911 output is the same as Saratoga County 911 VHF repeater input. 154.025. Different PL. Kicks the mobiles and portables off the air unless they are dead solid into the repeater. The dispatchers don't understand understand why the field unit just disappears. I also remember North Adams repeater Rx on 159.225 which is NYS DEC. It took a while for them to correct. Sounds like the tech folks over there don't pay attention to details

 

[kc2smb]

I meant North Adams repeater Tx

 

[Mtnrider]

Bruce 42 ....the license is not done in house....i wont bother to put the vendors name that did it....point being A LOT of the licenses up there are wrong mainly in wording yes some have wrong lat long mainly because there out of town and someone put "Hunter Mountain" on the paper work. If you do a FCC search 2 mile radius of said lat long....you'll notice a few variations .....again blame the vendors....some dont even have the correct town.....i can point you to a few that have wrong county.....for years a high profile paging company had a license in Ashland NY......Guess what theres 2 in New York State.....no it didnt belong in Greene County ....

 

[W1KNE]

This isn't the first time this sort of thing has happened around here.
In reverse, Greene County 911's EMS repeater (155.895) would frequently get into the Agawam, MA PD repeater input (On their old repeater pair).
Same thing with Columbia County PD, when they changed PL from 110.9 to 146.2, all of a sudden they could key up Woonsocket, RI's repeater with the same input/PL.