King Fire

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scannerbuff999

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the good news here is that these are link most of the time

the good news here is it looks like most of the time everything above 13 are used as links
so we can hear whats going with one radio and search with a different one
 

SCPD

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the good news here is it looks like most of the time everything above 13 are used as links
so we can hear whats going with one radio and search with a different one
I don't follow what you are saying. Linking is done with UHF frequencies. How do these VHF frequencies relate to the UHF ones?
 

scannerbuff999

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sure i am sorry i am getting old . If you look at all of the comm plans you will always see that command 1 thought 13 is used for one div or at one end of the fire and one of these unknown Nifc like command 37 58 are used to link all the division together or that one it looks like to me because when a bog fire starts to grow they link every together and that is when you start to see the new freq from the fed pool show up
that why when you read the calif fire scope plan that why you only nifc command 1 thought 7 hope that makes what i was saying clear and yes they seam to using the these New VHF Freqs to link i have not seen any UHF links in calif this year every thing seems to the new vhf freq to links
 

scannerbuff999

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i just got it after looking at this these are fill in Repeaters that why we always see at least one of the 1 thought 12 command repeaters as the fire grows they will add repeaters when the fire start they always start with command 1 thought 12
 

SCPD

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You are mistaken. Command repeaters are only linked using UHF (406-420 MHz) frequencies. Different command repeaters allow more than one to be linked together and yet transmit all at the same time. The radio user chooses the repeater that provides coverage to the area of the fire they are in. That repeater then transmits to the area it covers. That VHF repeater is hard wired to a UHF transceiver. The UHF radio then transmits to a location that can receive the UHF signals from each of the additional command repeaters installed on the net. That location is often called the "hub." This central location has one UHF link for each of the VHF repeaters on the net. These UHF link radios are hard wired together. The signal received by any one of these UHF link radios is passed to the others on the hub. Each of the UHF link radios in the hub then transmits to the UHF link radio hard wired to each VHF repeater on the net.

Linking the VHF repeaters together with UHF links allows each repeater to transmit to all the rest, each of which utilizes a different VHF frequency pair. This allows the same signal to be transmitted on two or more repeaters at the same time. For example if there are four repeaters on the net, which we will call repeaters "A, B, C and D." When a radio using the repeater A frequency pair is transmited the signal is simultaneously transmitted over repeaters B, C and D at the same time. If each repeater used the same frequency two or more repeaters, each on the same frequency pair, interference would be experienced as two FM transmitters on the same frequency try to cancel each other out.

This differs from a forest, park or BLM district net where each repeater is chosen by the user by switching tones. All the other repeaters on the net use the same frequency pair so only one repeater can be used at the same time. The dispatcher can hear all the repeaters on the net, but again, only if one is transmitting at the same time. The field units within range of the selected repeater can hear whatever the repeater is "repeating," but can't hear some repeaters on the other end of the forest, park or district. If a forest wanted everyone on the entire forest to hear every repeater all over the forest, it would require as many VHF frequency pairs as repeaters, which for some forests in California numbers 16. There aren't enough frequencies available to do this.

Those using the command net on a large fire need to hear all the traffic on the net. This is why two or more repeaters need to be used simultaneously. This system of multiple repeaters and links is only used if one repeater can't cover the entire fire.

VHF repeaters are not linked using other VHF repeaters. The federal government does not use VHF frequencies to link radio sites, remote bases or repeaters. The UHF band is the only one used for linking.

I hope you can grasp all of this. It is easier to diagram radio networks on a white board than to write a description.
 

SCPD

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i just got it after looking at this these are fill in Repeaters that why we always see at least one of the 1 thought 12 command repeaters as the fire grows they will add repeaters when the fire start they always start with command 1 thought 12
The term "fill in repeater" is used to describe a conventional repeater used on a trunked radio system to cover small areas not covered by trunked radio sites. The small amount of radio traffic at these conventional repeater sites does not justify locating multiple computer controlled repeaters at the site. The conventional repeater is then patched into the nearest trunked radio site on the talkgroup the radio using the conventional repeater is set on.

You are mixing trunked radio system terms in with conventional radio systems. You are mixing UHF linking with VHF repeater uses.

As far as I know repeater channel use from commands 1-12 is no different than using commands 13-61. There aren't groups of command channels for one use and another set for some different use.

I still wonder if the frequency pairs labeled command 13 and up come from the unused federal frequency pool and aren't used the same way in future years if the one of the pool frequencies starts to be used by the federal agency it is assigned to. I wonder if each assignment of a pool frequency pair is labeled command 13 and the next 14 and so on. As the years pass new command pair numbers are assigned each time a new frequency pair is authorized for an incident. We might start seeing a channel labeled as command 114 five years from now and command 151 some years later before the number 13 is used again.

When I retired there were 7 commands, 7 tacticals, 6 or 7 air to grounds, and a similar number of air to air AM tactics. The air to ground frequencies were also used for air to air FM tactics as well. It is a lot harder trying to figure out what is going on now. When I retired frequency use information was available to the public. Changes were few and far between.

I don't think the good old days have ever existed, but the accessibility of radio system information tempts me to use the phrase.
 
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scannerbuff999

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well your guess is as good as mind all i know is that i have been at about maybe 20 or more fire where
NIFC has set up repeaters and they have always had one of the 1 thought 12 command in play and going before anything other repeters are going , maybe that will change in the future i have look everywhere to find info on the new freqs with no luck can not find anything out sounds like you have great contacts see what you can dig up
 

SCPD

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The UHF link frequencies do not show up on a comm plan. They are unseen by the radio users. All they need to understand is what channel to use for different areas of the fire. How the repeaters are linked is not something they need to know about. I've been on some very large fires where more than on command repeater is set up and UHF frequency use information is not available.

UHF linking is often used when only one command repeater is involved. The command repeater may not provide good coverage of the incident command post while covering the fire very well. A UHF link to the command repeater may be installed to alleviate the problem. This link would be located on a peak or in a valley where coverage of both the link and command repeater exists. A UHF radio is used by the incident dispatcher. I've seen UHF base stations with boom mics, mobiles with a mobile mike and handhelds utilized on fires. When command personnel are at the ICP they carry UHF portables. When they go out on the line they carry VHF handhelds.

A ranger station on a district adjacent to where I worked was located in a canyon where handhelds could not key up the nearest repeater. The ranger station had a master base station with small desk set units hardwired to it in some of the rooms. If someone was away from their desk or, in the case of fire employees, rarely sat at theirs or did not have one, running to a desk set was impractical. The radio tech found a source of a dozen or so King UHF handhelds surplused by another agency and picked them up dirt cheap. He then hard wired a UHF repeater (also surplused by another federal agency) to the station's master base station. Employees were then able to carry around these UHF handhelds with them in the station area and not miss calls from the field. Employees that did not have a desk set did not have to get up to use the nearest one. He painted the King's plastic cases green so as not to confuse a UHF handheld from a VHF handheld. He built the UHF antenna from scratch using surplus material he picked up at the Navy Logistics Facility in the Bay Area and could find fairly new coax there too. The cost for this system, not counting labor, was less than $500. Surplus is not necessarily free for other federal agencies. Most Forest Service radio techs are, and always have been, master scroungers and add all kinds of useful features to a radio system.

This same tech built portable "extender" repeaters that could be backpacked into remote portions of wilderness areas to provide seasonal coverage of large areas in repeater blind spots. He used old Motorola MT-500 crystal tuned handhelds mounted in old ammo boxes with small solar panels and batteries picked up surplus. He kept the MT-500's when they were replaced with programmable handhelds. Again, a great service for next to nothing.

I pass these stories along to everyone to highlight the hard work of group of dedicated radio techs that have provided system design, construction, maintenance and product development since the 1920's. It is a proud tradition in the Forest Service, often times without management recognition, performing duties in spite of what some presidential administrations and the congress dumps on them.
 
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scannerbuff999

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sorry it all related it is a fire that IS using NIFC RADIO equipment
ANYWAY DO EVEN KNOW WHO NIFC is anyway i do think is all related
have a nice day
 

DayTrippen

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Hey ExSmokey, I appreciate your post, which was very informative, a "Summary" which I found, easy to follow & able to comprehend, from start to finish!! Thank You for taking the time to share your knowledge, along with your opinion, which I personally feel is valuable, Sir ExSmokey. I base my High Regards to you & your post/summary, with all the information you set forth, however I must admit, when I read your statement of, & I quote; "I began my career more than 10 years before the development and use of the ICS," "I've watched the positive changes evolve in ways I don't think the interagency organization that developed this system could foresee." end quote, I had no room but to have complete Respect & feel honored to have the luck in stumbling upon this thread...
Thank You
Ps. "donnowhatiwannabe" moved on to a "wannabe" became "abe" and now I'm a "wasabe" is Awesome & Humorous...
 

davedaver1

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scannerbuff999 - Yes, I do know who NIFC is. The point is that you're having a general discussion of how the radio systems are set up and used. While that's interesting, it's not unique to this incident and therefore it's off topic. It's interesting, but belongs in a thread elsewhere about NIRSC/NIFC or the USFS or whatever.
 

SCPD

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scannerbuff999 - Yes, I do know who NIFC is. The point is that you're having a general discussion of how the radio systems are set up and used. While that's interesting, it's not unique to this incident and therefore it's off topic. It's interesting, but belongs in a thread elsewhere about NIRSC/NIFC or the USFS or whatever.
The discussion might seem off topic at first glance. The reason it headed that direction is that scannerbuff999 was making some comments about the command net being used on the King Fire. He thought that some of the VHF command repeaters were used as links or that they were "fill in repeaters.' It IS clear that he doesn't understand how a multiple command frequency and repeater net works, which affects what command frequencies are used on this fire.

Admittedly, I took the discussion away from the topic when I mentioned how UHF linking was used on a ranger district adjacent to one the ranger district I worked on. I was explaining how UHF linking and repeater installation works in non fire situations.

It is obvious that scannerbuff999 has a lot to learn about how radio systems work and if he understands more he will make a better observer and reporter for future incidents such as the King Fire, most especially when the use of the National Incident Radio Support Cache system is involved. For some reason I thought he was in receiving range of the command network on this fire and didn't notice he was actually in Fremont, obviously out of range. If he was in receiving range his knowledge of how command networks work could have led to better observations of the frequencies being used on the King Fire.

It's a possibility that there are others within receiving range the King Fire that can use the information I posted to help them listen better and/or make more effective observers. I receive PM's from people who benefit from me "going off topic" to help them better understand what they are hearing. I get PM's from people who say my stories help them understand the workload of the agency they are listening to and what some of the terminology they hear means. What might seem off topic might be helping others who are listening to the King Fire and have not posted here.

It may be helpful for me to start a sticky thread where I could cover this type of information. I can also write a Wiki article doing same. People have a hard time finding things in Wiki so a sticky thread might work better.
 

BirkenVogt

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I've been told on some forum somewhere that the higher numbered command channels were only good for a particular season and then they disappeared and the same number might be issued for a different pair next season.

No confirmation of this, however.

When it is the same federal government running the fire that controls the airwaves, they are allowed to make it up as they go along. Most of these higher numbered freqs seem to be forest nets or otherwise from other parts of the country being recycled. The common numbered commands that we all know are nationwide and not recycled anywhere that I know of.
 

scannerbuff999

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the king fire is just about over now till next time radio fans
Acres Burned - Containment 97,099 acres - 84% contained
 

davedaver1

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From the morning radio briefing: The Foresthill ICP is closing tonight. The transfer to CA IMT 1 happens tonight also. Winds are frecast to pick up a lot and the emphasis is on knocking the doglegs down that exist on the fringes of the fire. They're doing a lot of chipping on the contingency lines in all areas. They don't expect much growth, but everyone is cautioned to be careful in the windy conditions. Air Tac and Helco are just on request and will not be over the fire unless needed.
 
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