Inyo National Forest Radio Frequencies.

[silverspy]

There is a "Sierra Intercom"? That is something I was not aware of. So just to clarify that I have a solid understanding of your first post. The monitors pick up all traffic on the "simplex" direct frequency (output) that is not toned (as far as I understand, the Sierra does not have a "direct" tone like some of the other forests, but they do have the "unconventional" tones on most of the repeater outputs, which I find interesting. So then, talking about a remote base vs. a monitor, it sounds like a monitor is more limited in functionality vs a remote base and a remote base relays "direct" and repeater traffic. So on Forests where there is no tone required for "direct" access, "simplex" traffic on the "output" frequency of the net is passed along to dispatch, no tone necessary, forests that do require a tone for "direct", if the tone is not activated, then the traffic will not be passed along to dispatch? I'm just making sure that I have a correct understanding of what you are saying. I also find it interesting that almost every forest has a different configuration. Thanks,
Bill

 

[vlarian]

There is a "Sierra Intercom"? That is something I was not aware of. So just to clarify that I have a solid understanding of your first post. The monitors pick up all traffic on the "simplex" direct frequency (output) that is not toned (as far as I understand, the Sierra does not have a "direct" tone like some of the other forests, but they do have the "unconventional" tones on most of the repeater outputs, which I find interesting. So then, talking about a remote base vs. a monitor, it sounds like a monitor is more limited in functionality vs a remote base and a remote base relays "direct" and repeater traffic. So on Forests where there is no tone required for "direct" access, "simplex" traffic on the "output" frequency of the net is passed along to dispatch, no tone necessary, forests that do require a tone for "direct", if the tone is not activated, then the traffic will not be passed along to dispatch? I'm just making sure that I have a correct understanding of what you are saying. I also find it interesting that almost every forest has a different configuration. Thanks,
Bill

Yes, the Sierra Intercom exists, it is a microwave network not sure the freq but you would have to have a microwave antenna and be in direct line of sight to a transmitter to pick it up. the intercom was established by CDF to replace their green phone network it is maintained by the California Department of General Services, it is a pain to deal with since only DGS Radio Techs may service it or its terminals. These was at one time and it is still functioning, but little used VHF radio network. When I started in 2007 these networks North OPS net and South OPS net were all but abandoned. It had been replaced by the CDF intercom. I was told to not use those channels and to ignore any traffic on them. If the CDF intercom failed, our fall back was these channels. however as time goes on I see less and less of these channels. when new or upgraded radio equipment is installed those channels are left out.

Sierra is not one of those forests where only certain tones reach dipsatch. if a field unit use any tone between 1-9, dispatch hears them. Heck we hear them even if they don't use a tone.

So as I understand it on the sierra we have repeaters, monitor/repeaters, repeater/remote bases, and Remote bases. Exsmokey might know of a better term for these.
For the sake of being on the same page;
Repeaters, are set to an input of 169.9250 for Emerg net and 169.8750 for Admin net, all of them only open when they decode the proper tone (1-9 are used). Sierra Repeaters output 172.2250 for emerg net and 171.4750 for admin net. These same repeaters use a CTCSS tones on their output, due to equipment limitation at the dispatch center only tones 1-8 are used. When signals are received by the transceiver at Dispatch they are feed to a tone decoder this decodes the CTCSS tones and triggers a relay that signals the ModUcom which tone is being received.
The Remote Bases. These sites do not repeat anything, but they do allow Dispatch to Transmit and receive transmissions on 172.2250 for emerg net and 171.4750 for admin net.
The remote base-repeater, these sites combine the functions of both sites into one.
The Monitor-repeater, of which Sierra has one, Patterson Tone 9. This is a repeater that also monitors 172.2250 and returns that audio to dispatch. Dispatch has no control over this site, they can only monitor the audio that comes down from it.

the monitor/repeater, remote base/repeater, and remote bases. these have little icons on the ModUcom screen that light up when their respective site is active. otherwise the ModUcom displays a number for for tha tone it is picking up. often the dispatcher sees both as the base transceiver at Fresno is picking up the traffic at the same time as one or more of the monitor/repeater, remote base/repeater, and remote bases out in the field.

I can't say why sierra has equipment that monitors the repeater output freqs, I can guess. maybe exsmokey knows. This does create the curious situation where many field units. presumably not knowing that the sierra radio net is configured this way. Will switch over to the simplex channels and transmit and receive on 172.2250 or 171.4750 no tones. Dispatch hears most of these transmissions and enjoys a few.

hopefully that was clear as mud?

 

[Norman]

vlarian, do you have any info on the MNF? I keep hearing LE units on their LE frequency say that they
are on T11. But there is no such tone listed for them. You can PM me, or reply on my LE thread.
Thanks, Norm.

 

[silverspy]

Yes, that helps to clarify. Thanks.

 

[SCPD]

Yes, the Sierra Intercom exists, it is a microwave network not sure the freq but you would have to have a microwave antenna and be in direct line of sight to a transmitter to pick it up. the intercom was established by CDF to replace their green phone network it is maintained by the California Department of General Services, it is a pain to deal with since only DGS Radio Techs may service it or its terminals. These was at one time and it is still functioning, but little used VHF radio network. When I started in 2007 these networks North OPS net and South OPS net were all but abandoned. It had been replaced by the CDF intercom. I was told to not use those channels and to ignore any traffic on them. If the CDF intercom failed, our fall back was these channels. however as time goes on I see less and less of these channels. when new or upgraded radio equipment is installed those channels are left out.

Sierra is not one of those forests where only certain tones reach dipsatch. if a field unit use any tone between 1-9, dispatch hears them. Heck we hear them even if they don't use a tone.

So as I understand it on the sierra we have repeaters, monitor/repeaters, repeater/remote bases, and Remote bases. Exsmokey might know of a better term for these.
For the sake of being on the same page;
Repeaters, are set to an input of 169.9250 for Emerg net and 169.8750 for Admin net, all of them only open when they decode the proper tone (1-9 are used). Sierra Repeaters output 172.2250 for emerg net and 171.4750 for admin net. These same repeaters use a CTCSS tones on their output, due to equipment limitation at the dispatch center only tones 1-8 are used. When signals are received by the transceiver at Dispatch they are feed to a tone decoder this decodes the CTCSS tones and triggers a relay that signals the ModUcom which tone is being received.
The Remote Bases. These sites do not repeat anything, but they do allow Dispatch to Transmit and receive transmissions on 172.2250 for emerg net and 171.4750 for admin net.
The remote base-repeater, these sites combine the functions of both sites into one.
The Monitor-repeater, of which Sierra has one, Patterson Tone 9. This is a repeater that also monitors 172.2250 and returns that audio to dispatch. Dispatch has no control over this site, they can only monitor the audio that comes down from it.

the monitor/repeater, remote base/repeater, and remote bases. these have little icons on the ModUcom screen that light up when their respective site is active.m otherwise the ModUcom displays a number for for tha tone it is picking up. often the dispatcher sees both as the base transceiver at Fresno is picking up the traffic at the same time as one or more of the monitor/repeater, remote base/repeater, and remote bases out in the field.

I can't say why sierra has equipment that monitors the repeater output freqs, I can guess. maybe exsmokey knows. This does create the curious situation where many field units. presumably not knowing that the sierra radio net is configured this way. Will switch over to the simplex channels and transmit and receive on 172.2250 or 171.4750 no tones. Dispatch hears most of these transmissions and enjoys a few.

hopefully that was clear as mud?

You indicate that Tone 1-8 are used on the output. I can hear both repeaters on Shuteye Peak from the eastside of the Sierra and it has an output of 85.4. On My last trip to the west side where I could hear most of the repeaters I heard 67.0, 74.4, 77.0, 82.5 in use. I don't have my notes from that trip in front of me so one of those might be incorrect, however, they were all in the lower range of available CTCSS tones. I don't believe there are several repeaters on each of these low range CTCSS tones as shown on the Wiki table for this forest, but a very savvy member reports that 3 or 4 repeaters have a common output tone of 85.4.

I'm not sure why the Sierra has a "monitor/repeater" station at Patterson and I don't know how it is linked back to Musick. Musick is the hub of the Sierra NF microwave remote base system with Musick linking to the Fresno Air Attack Base, where the Sierra NF and Fresno-Kings Unit have their dispatch centers co-located. Musick in turn links to Whitebark Vista and Goat Mtn. The ranger station at North Fork links to Goat. All three of these microwave linked remote bases have to have the capability to receive the output frequencies of both nets and apparently those receivers don't need a tone to accompany the repeater output frequency. Thus, they are able to pick up simplex traffic occurring in the field. Perhaps the remote receiver at Patterson is linked back to Musick via a 400 MHz link that we don't know the frequency of.

I've recently come across some information of UHF link frequency assignments for Region 5. I'm going to post them in a thread as soon as I can. There are three assigned to the Sierra and perhaps some members may wish to listen to them. The three are: 406.2250, 406.2750 and 406.4250. The lower frequency is designated for downlink uses and exactly 9 MHz higher the uplink frequencies can be found. When two mountaintops are linked the main remote base is the one that is considered the ground level station. For example, if Patterson is linked to Musick, Musick would be considered the ground level station, so it would transmit to Patterson on the uplink frequency and Patterson would transmit back to it on the downlink frequency. So if 406.2250 is the downlink frequency it would be used to transmit to Musick from Patterson and Musick would transmit to Patterson on 415.2250.

I hope this helps clarify a couple of issues.

 

[vlarian]

You indicate that Tone 1-8 are used on the output. I can hear both repeaters on Shuteye Peak from the eastside of the Sierra and it has an output of 85.4. On My last trip to the west side where I could hear most of the repeaters I heard 67.0, 74.4, 77.0, 82.5 in use. I don't have my notes from that trip in front of me so one of those might be incorrect, however, they were all in the lower range of available CTCSS tones. I don't believe there are several repeaters on each of these low range CTCSS tones as shown on the Wiki table for this forest, but a very savvy member reports that 3 or 4 repeaters have a common output tone of 85.4.

I'm not sure why the Sierra has a "monitor/repeater" station at Patterson and I don't know how it is linked back to Musick. Musick is the hub of the Sierra NF microwave remote base system with Musick linking to the Fresno Air Attack Base, where the Sierra NF and Fresno-Kings Unit have their dispatch centers co-located. Musick in turn links to Whitebark Vista and Goat Mtn. The ranger station at North Fork links to Goat. All three of these microwave linked remote bases have to have the capability to receive the output frequencies of both nets and apparently those receivers don't need a tone to accompany the repeater output frequency. Thus, they are able to pick up simplex traffic occurring in the field. Perhaps the remote receiver at Patterson is linked back to Musick via a 400 MHz link that we don't know the frequency of.

I've recently come across some information of UHF link frequency assignments for Region 5. I'm going to post them in a thread as soon as I can. There are three assigned to the Sierra and perhaps some members may wish to listen to them. The three are: 406.2250, 406.2750 and 406.4250. The lower frequency is designated for downlink uses and exactly 9 MHz higher the uplink frequencies can be found. When two mountaintops are linked the main remote base is the one that is considered the ground level station. For example, if Patterson is linked to Musick, Musick would be considered the ground level station, so it would transmit to Patterson on the uplink frequency and Patterson would transmit back to it on the downlink frequency. So if 406.2250 is the downlink frequency it would be used to transmit to Musick from Patterson and Musick would transmit to Patterson on 415.2250.

I hope this helps clarify a couple of issues.

This does for me! thank you for taking time to provide this info.

I am at the mercy of what I am told from the Sierra radio tech, sometimes I don't understand him, or don't ask the right questions. I also have the great privilege of being able to interact with these system first hand. Exsmokey is right and I knew better, the CTCSS tone on the output is very low. I believe now I misunderstood mt friend from the Sierra. what the radio tech was attempting to explain was that the equipment at dispatch cannot decode the low tones that come from Mt Givens (Admin Net), White Bark Vista (Emerg Net) both Tone 9 and Tone 12 Fence Meadow (Newly upgraded as of last year to handle traffic for both Admin and Emerg nets). when field units uses these tones, the ModUcom console shows activity but no tone detected, this would explain why. I learned today the Mtn Bullion remote base repeater comes down to Dispatch via a T1 line. Also Paterson does use a UHF link with the receiver located at dispatch.

Not sure why Some of our Scanning brothers and sister only pickup a small number of these low CTCSS tones.

I also notice in one of my earlier posts I said Sierra use Tones 1-9 this is incorrect Tone 12 is also used. I am sorry for the error, as I do know better.

 

[vlarian]

I recently Learned there is a Radio Telephone Network on the Sierra it uses a combination of Microwave and UHF links between sites. The dial tone is provide by a link to Ponderosa telephone Co in the North Fork Ranger Station.

From North Fork it heads Via Microwave to Goat Mt then to Musick Mt then the microwave link terminates at White Bark Vista. From White Bark the system uses three separate UHF links; one for the High Sierra Office, One for the Clover Meadow Office, and The last is to the Mount Tom Lookout. In the recent past there was a fourth UHF link that ran from Musick Mt to the Blue canyon Work center. The link to Blue canyon was abandoned when a Land line was brought in.

 

[silverspy]

Do you know if the primary access is VHF and, if so, what the
Frequency is? I think I have an older frequency somewhere for
A wilderness telephone, don't know if this is the same system
That you are describing. I'll have to look for the frequency.
Thanks
WB

 

[Progline]

Drove up/down 395 last week and BOTH the old and new output freqs for both North & South net are active (simulcast on both pairs). Did some quick comparisons and noted the new output repeaters are not as strong as the old pair when compared from Bishop & Mammoth Lakes.

 

[SCPD]

I just returned from Klamath Falls, visiting friends and decided to take the U.S. 395 route down to Highway 58 to I-40 and back to Northern AZ. Spent two nights in Bishop with some folks we know. You are not hearing the new Inyo nets on the 173 MHz frequencies. At present these are the input frequencies for the 168.1250 North Net and 168.7250 South Net. When the switch occurs the 173 mhz frequencies will become outputs and a 165.0125 will become the input for the north net and 166.2625 will become the input for the south net. I managed to pick up the 173 MHz as well and thought the same as you. But there was no activity on the proposed input frequencies during transmissions on the existing nets. The weakness on the 173 frequencies is due to those being input frequencies. I did some close call work near some of the mobile units at the White Mtn. ranger station on 395 and confirmed that the 173 frequencies were being used as repeater inputs. The wikipages show that the south net as being changed this summer, but it hasn't yet.

 

[Progline]

Thanks for clarifying!

 

[Progline]

At the risk of resurrecting last year's thread, can anyone confirm that the Inyo switched both north & south nets to the new channels listed in the DB?

 

[f40ph]

At the risk of resurrecting last year's thread, can anyone confirm that the Inyo switched both north & south nets to the new channels listed in the DB?

I know for certain they switched the "South" net over to the new pair. Not so sure about "North".

 

[silverspy]

I am not able to actually physically verify, that the Inyo has actually switched their North Net to the
new frequencies, however, I've recently seen at least two "official" documents, that indicate that the
new frequencies are being used for this Season.

 

[silverspy]

Also, I didn't want to start a whole new thread for this question, so I hope this is acceptable, since we
are talking about changes in Forest Service frequencies, I was wondering if anyone knows when the
Shasta-Trinity will be switching their Forest Net over to the new scheme, and if anyone knows anything
about changes in the Humboldt-Toiyabe. I'm pretty sure that the Bridgeport RD has been switched over
to different frequencies, and that area is not too much further North than the Inyo North Net operational area. But again, without a report from someone in the area, I have no way of verifying this.

 

[f40ph]

I am not able to actually physically verify, that the Inyo has actually switched their North Net to the
new frequencies, however, I've recently seen at least two "official" documents, that indicate that the
new frequencies are being used for this Season.

They have been lagging behind their "expected" dates. I would get someone to verify if possible. I haven't seen anything official forwarded to our agency.