California Forest Service Wiki Changes

Status
Not open for further replies.

SCPD

QRT
Joined
Feb 24, 2001
Messages
0
Location
Virginia
Several years ago I learned that a lot of frequency changes in the federal VHF 162-174 band were going to take place due to direction contained in the 2005 (or thereabouts) National Telecommunications and Information Redbook, which is the manual of regulations covering federal government use of radio frequencies. The 2005 edition made huge changes in federal frequency use and was issued at the time narrowbanding became mandatory for federal agencies, some 8 years prior to the requirement that state and local agencies had to do so also.

The direction included changes in how frequencies are used in the 162-174 MHz and 406-420 MHz bands. In each band three ranges of frequencies were prescribed. One for repeater output or downlink frequency use, one for simplex use and one for repeater input or uplink frequencies. In the UHF band the lower frequencies are allocated for repeater output/downlink use, the middle frequencies for simplex use and the upper frequencies for repeater input/uplink use. The allocation required that the separation between the output/input frequencies be exactly 9 MHz. The reverse is the case in of VHF. The upper frequencies are allocated for repeater output/downlink uses and the lower for repeater input/uplink uses.

A split between the two is not specified as VHF has been in use longer (mid to late 1950's) resulting in a more disorganized and disjointed situation for existing frequency assignments. Most frequency assignments were not made based on a specified split that applied to the entire band, so an effort to establish one is not possible, unless a difficult and highly disruptive frequency coordination and reassignment effort is made. A further complication exists as some 25 kHz spaced frequency assignments had been made based on 12.5 kHz spacing. For example 166.4875 was assigned to the BLM in California in the 1980's, which is halfway between 166.4750 and 166.5000 and appears to be a narrowband frequency, however specifications allowed a signal up to 25 kHz wide at the time.

Up to now, most of the effort to bring radio systems into compliance with the Redbook direction has been directed to the UHF band. Narrowbanding required new equipment and systems were built to comply with the new allocation. Most hobbyists who listen to federal VHF systems did not notice the changes because such systems often use UHF for linking only.

Now federal agencies are beginning the process of complying with the NTIA direction by making sure that simplex, input and output frequency use falls in the proper ranges. I thought the process would have been as easy as exchanging inputs for outputs, etc., however one or both of the existing frequencies would often fall into the simplex only range, thus requiring new assignments. Sometimes using a frequency for the output of a repeater brought up interference issues with other agencies. The result is something that may appear to be rather random and without logic, but this is not the case.

During my hospitalization (5 weeks) a relatively new source of mine shared sent me a document that shows the frequency changes the Forest Service in California (USFS Region 5 or Pacific Southwest Region) is going to make between 2015-2017. Some changes were made just after the Labor Day holiday this year and others are scheduled for 2017. I've revised the California National Forests wiki page channel plans to show all the changes shown in the document. Upcoming changes are shown in a separate table apart from the existing system table. Most of the changes will occur in 2016, either in the spring or fall. As the changes occur and people confirm they have been made, I will revise the original tables to reflect them.

Unfortunately, these changes are coinciding with the installation of a new, far more secure server that NIFC has set up for all radio system information. Old web addresses that have provided us with updates in the last few years will no longer yield any information. This makes our hobby that much tougher. For a retiree like myself, who wants to keep some connection to my former profession, career and agency; being able to listen to natural resource and fire agency radio traffic is important. It is becoming increasingly difficult for retirees to maintain this connection.

I have some access to information for federal agencies in California, but none for the rest of the country. Keeping the database accurate and current for all the other states is going to be very difficult.


OPTIONAL INFORMATION

It has taken me several hours to write this post. Pain, pain medication and being confined to bed most of the time has taken its toll on my cognitive functioning. The accident, one minor and two major surgeries, 5 weeks in a hospital located 180 miles from home, the severe nature of the lower back pain (I had a compression fracture in one vertebra) and the hard work of physical therapy have been rough. I face many months of hard physical therapy in the recovery process and expect that it's going to be an equal amount of time for my brain to recover. Please accept my apologies for my less than clear writing and for not answering PM's during this time. My intellect, just like my mobility, is going to be limited in the coming months.
 

QDP2012

Member
Joined
Feb 8, 2012
Messages
1,921
Get Well Soon

Welcome back ExSmokey,

Congrat's on the continuing recovery -- it sounds like it's going in the right direction. I hope you enjoyed Thanksgiving. May God bless you with continued healing and enjoyable holidays with family and friends.

Get well soon,

PS: Thanks for the Wiki updates.
 

Kirk

DB Admin
Database Admin
Joined
Dec 19, 2002
Messages
784
I was sad to hear of your accident. Wishing you well and hoping for a speedy recovery.

73
 

silverspy

Member
Joined
Jan 30, 2003
Messages
253
Location
Portland,Oregon
Just a couple quick questions, and I don't mean to sound like I'm repeating myself in the second. As far as the Modoc NF is concerned, did the Modoc ever actually change their "Admin" Net or did it stay the same? The reason I'm asking is, the Database reflects the original "Admin" net pairs and the Wiki shows an entirely new pair, just a minor discrepancy I've noticed. So, my second question is, are there any situations that are known by anyone, where an exception(s) could be granted by the NTIA, barring any interference to adjacent Forests/agencies/zones, where an exception (s) could be granted to the stated "range" rules, based on some "grandfathered" clause, like the frequencies being recently obtained, etc? Thanks again, just trying to get as much clarification as possible.
 

SCPD

QRT
Joined
Feb 24, 2001
Messages
0
Location
Virginia
DB Updated with the Wiki changes.

Thanks for doing this. My energy level is a bit on the low side and a database submission of this size is probably a little to much for me right now.

I'm going to go back over the information again with a fine toothed comb to check for any errors. When I compare the database to the NTIA Redbook direction I find that many of the changes do not accomplish compliance with that direction. I wonder if I somehow made some errors in transcribing the data onto the wiki page. My brain is in and out foggy much of the time.
 

SCPD

QRT
Joined
Feb 24, 2001
Messages
0
Location
Virginia
I will continue my attempt to work through this fog I'm in. I reread the section of the Redbook concerning the use of the fed's 162-174 MHz band. I thought I understood how the three frequency ranges are to be used in determining simplex and repeater pair assignments. Then this clause jumped out of the page:

"5f. An agency may use any of their allotted frequencies in the range 166.5-169.5 MHz and any of the5fir allotted frequencies in the ranges 162.0500-166.4875 MHz and 169.5125-173.9875 MHz to make up a single channel pair if the requesting agency believes it to be more effective use of the spectrum and if it complies, in part, to the provisions of paragraph 5.a."

I wonder why the ranges were so well defined in Clause 5a and then so muddied by this Clause 5f. It is going to be impossible to know if existing frequency pairs are in compliance or not, just on the face of it.

The recently completed changes to all the nets on the Klamath NF illustrate this very well. Every net repeater pair follows the direction shown in Clause 5a, with the exception of the Black Net. The repeater input frequency of 168.7750 lies in the simplex use range (166.5000 - 169.5000). Something in the vague direction of Clause 5f is at play here, but what determines this to b;e a more efficient use of the spectrum? It would seem simple to comply with the ranges of Clause 5a as narrowbanding doubled the number of frequencies in each range and finding a frequency to use in each range fairly easy. But, we are only looking at the skin of the apple and not the flesh inside.
 

silverspy

Member
Joined
Jan 30, 2003
Messages
253
Location
Portland,Oregon
I don't know if this helps, but I hoped that you may at least find it interesting. I know that, theoretically, on the other side, that this move would satisfy 5A requirements, but not on the Klamath side, which I also find to be interesting. After going through my paperwork, I noted that the "old" input to the Black Net 168.175, also was previously used on the Central part of the Fremont-Winema as a repeater output,for two repeaters, this has since been changed. So, my question is, why was 168.175 completely eliminated on the Klamath and Fremont-Winema and 168.775 shifted around and ultimately kept on the Klamath? Both frequencies are technically in the "simplex" range by 5A, but yet, one was shifted and kept, the other eliminated. Interesting. Thanks for the info and your continued thoughts on the matter,
Bill

F.Y.I. 168.175 was not one of the frequencies "originally" assigned to the Fremont-Winema, twenty five or more years ago, it was added, as far as I know, as part of an additional pair, when the configuration of the forest radio system was changed to a pattern of two repeaters being assigned to a pair, with a total of six frequencies and 12 repeaters. Now they still have the same number of repeaters, but things have been shifted around, so that there are two frequencies, out of the six in the forest, that each have only one repeater assigned to them.
 

SCPD

QRT
Joined
Feb 24, 2001
Messages
0
Location
Virginia
I don't know if this helps, but I hoped that you may at least find it interesting. I know that, theoretically, on the other side, that this move would satisfy 5A requirements, but not on the Klamath side, which I also find to be interesting. After going through my paperwork, I noted that the "old" input to the Black Net 168.175, also was previously used on the Central part of the Fremont-Winema as a repeater output,for two repeaters, this has since been changed. So, my question is, why was 168.175 completely eliminated on the Klamath and Fremont-Winema and 168.775 shifted around and ultimately kept on the Klamath? Both frequencies are technically in the "simplex" range by 5A, but yet, one was shifted and kept, the other eliminated. Interesting. Thanks for the info and your continued thoughts on the matter,
Bill

F.Y.I. 168.175 was not one of the frequencies "originally" assigned to the Fremont-Winema, twenty five or more years ago, it was added, as far as I know, as part of an additional pair, when the configuration of the forest radio system was changed to a pattern of two repeaters being assigned to a pair, with a total of six frequencies and 12 repeaters. Now they still have the same number of repeaters, but things have been shifted around, so that there are two frequencies, out of the six in the forest, that each have only one repeater assigned to them.

Now you are overthinking! We don't have enough information to say why frequency assignments and changes are made. While it is true that knowing why these changes are made might help us figure out upcoming changes or to figure the frequencies in use now in other areas of the coutnry, there are far too many variables to be able to establish a cause and effect relationship.

I think I've listed what some of the variables might be. They can be as site specific as the way an electronic site reacts to RF power on a particular frequency. Transmitting on 169.1750 may cause harmonic RF emissions on the guy wire of a nearby TV transmitter, thus bringing interference to a cab company's 450 MHz repeater input. If 169.8375 is used in its place the guy wire no longer causes this effect. Do we really care why 168.1750 wasn't used? Do we care why 169.1750 is paired with another frequency for input 95% of the time in other parts of the country and in the case of the Dingleberry National Forest the frequencies are paired in a different manner? Do we really care why the guy wire is producing harmonic interference if just changing to 169.8375 makes it go away and it is the only interference issue at the site occurs when 169.1750 is transmitted? No, we don't need to know why, we just want to know frequencies are assigned and what they are used for.
 
Last edited:

Norman

Member
Joined
Dec 19, 2002
Messages
327
Location
N CA
Speaking of WIKI changes, I just heard MNF on their service net T1 164.125 (that's what he said, I never caught the tone). Never heard that before.
WIKI says that's the input to be implemented in Fall of 2017. Only one bar or so, so that could be correct.
Of course, I did not have the output programmed (do now).

Glad to hear that you are out of that place Fred.
 

Norman

Member
Joined
Dec 19, 2002
Messages
327
Location
N CA
No, no way. Dispatcher mentioned MNF several times. ENF also has a service net on same freq.
I'll stay tuned.
 

Norman

Member
Joined
Dec 19, 2002
Messages
327
Location
N CA
Just heard multiple key-ups on 172.4 (future MNF svce net) and 164.125 (input) together. No audio.
172.4 had a pl of 123. however did not catch the pl if any for 164.125 Testing? Interesting.
 

SCPD

QRT
Joined
Feb 24, 2001
Messages
0
Location
Virginia
Just heard multiple key-ups on 172.4 (future MNF svce net) and 164.125 (input) together. No audio.
172.4 had a pl of 123. however did not catch the pl if any for 164.125 Testing? Interesting.

Norman, this is interesting as the service net on the Mendocino is not scheduled to change to the new repeater pair until fall of 2017. I'm updating all my files to include the scheduled changes and I'm locking out those that are down the road a ways. Perhaps I should unlock them.

You really are great about listening carefully to frequencies that most scanner listeners are not interested in until a big fire breaks. At that point everyone wants to know what frequencies they should listen to. A good scanner hobbyist does not wait for someone else to find the frequencies, they go out and make the effort to figure it out. You are a great scanner listener Norman!
 

ecps92

Member
Joined
Jul 8, 2002
Messages
14,360
Location
Taxachusetts
Sadly Fred Searching is a Lost Art

BTW Glad to see you back in the Wiki and Forums
Check your mail (email) this week and updated Google Earth file

Norman, this is interesting as the service net on the Mendocino is not scheduled to change to the new repeater pair until fall of 2017. I'm updating all my files to include the scheduled changes and I'm locking out those that are down the road a ways. Perhaps I should unlock them.

You really are great about listening carefully to frequencies that most scanner listeners are not interested in until a big fire breaks. At that point everyone wants to know what frequencies they should listen to. A good scanner hobbyist does not wait for someone else to find the frequencies, they go out and make the effort to figure it out. You are a great scanner listener Norman!
 

Norman

Member
Joined
Dec 19, 2002
Messages
327
Location
N CA
Thanks for the kind words Fred, but, I never would have found this without your Wiki updated info.
Also, I'm glad to have the time to devote to monitoring. I'll try to keep on top of this, sure there is more to come.
Hope you are doing better.
 

silverspy

Member
Joined
Jan 30, 2003
Messages
253
Location
Portland,Oregon
Additional Info for California Forest Service Wiki

This is mostly intended for ExSmokey, as I was reading through the Wiki pages for the National Forests in California, and there is a request for additional info, if we have it. Regarding the Modoc National Forest, I believe that the remote base for both the Forest and Admin Nets is on Happy Camp Mtn, which is located to the NW of Alturas and is not one of the Forest repeater sites. I believe the Air Guard for the Modoc is also on Happy Camp Mtn. Last time I was up that way, which was awhile ago, there were UHF downlinks from Happy Camp Mtn, for both Forest and Admin Nets. I'm fairly certain that the two remote bases for the Lassen National Forest are on Hamilton Mtn (west of Susanville) and Haney Mtn (Fall River Mills area). These two sites are also not repeater sites and not listed on the repeater plan for the forest. I'm also fairly certain that the Shasta-Trinity has remote bases collocated at most of their repeater sites, but I can't remember exactly which ones. Also, one question, does anyone know if the input for the Shasta-Trinity is slated to change, as the current one does not appear to follow the NTIA rules. Thanks,
Bill
 
Status
Not open for further replies.
Top