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Author Topic: HF and aircraft radios for search & rescue  (Read 8102 times)
WE6BB
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Posts: 6




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« on: January 27, 2013, 11:19:07 PM »

I am a volunteer with the Placer County Sheriff's Search and Rescue Communications Unit. We own two radios I have never used before... one installed and the other ready to install. I am trying to understand a situation where they would come into use. Just to paint of picture, we have a truck that looks similar to a Type I ambulance (F450 4x4 chasis with big box on back.) In this vehicle, we have 2 800 MHz radios programmed to at least the new nearest 800-trunked systems. We also have 4 VHF (high-band) radios that are programmed with all the Placer Count Sheriff's Department frequency, Search & Rescue frequencies and numerous other public safety agencies. Next we have 3 UHF radios, one with a low split and the other two include the higher split; again with several public safety and standard mutual aid frequencies. Last, we have two VHF Low band radios. All of these radios are tied into a Telex RoIP system. We then have an Icom IC-M802 HF radio, which I read was made for marine use and an aircraft radio. These two radios have never been used since I've been around; the aircraft radio is not currently installed but the HF is (complete with a HUGE, fiberglass whip, antenna switch and dummy load). I believe the HF radio has several pre-programmed frequencies. Our truck is used primarily for Search and Rescue, but it is also used as a mobile command/dispatch center when the situation calls for it. In addition to all this, we have a satellite hand-held phone, a commercial 2-way satellite Internet link (not WildBlue or Hughes Net) with fairly decent bandwidth, VoIP telephone over our 2-way Internet link and both a Verizon and AT&T cellphone. Currently, when we deal with aircraft, it is typically either an air ambulance helicopter or more likely a rescue helicopter and CalCord (a mutual-aid channel primarily used for air-to-ground communications for public safety in California); we have not used Civil Air Patrol to my knowledge. With all this, I'm not exactly sure what situations would warrant the HF radio or the aircraft radio. While it seems like one could never have too many radio options, I'm questioning these two radios. What I'd like to know from this group is if anyone has used these type of radios for search and rescue work and if so, how?

When it comes to our primary communications, that would be our VHF High radios and repeaters. We use these for communications between searchers and ourselves to facilitate the search and/or rescue mission. I guess there is always the worst-case-scenario, but if the worst were to happen, I want to know who and how I can contact people with these radios. I'm guessing that if there was a HUGE, significant disaster that takes all the infrastructure, including ground links for satellite Internet, the HF may increase our reach, but who would we communicate with? Homeland Security? American Red Cross? If so, what channels/frequency? For the aircraft radio, is there a channel/frequency we should be listening to and use?
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KB4QAA
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« Reply #1 on: January 28, 2013, 12:04:31 AM »

The aircraft band is useful for well, communicating with aircraft.  In particular working with civilian aircraft who might be volunteering in a search, and always as a backup to your own agency aircraft losing public service radio.

122.75  Multicom, is a general use frequency
122.9    Multicom, is used at airports with no assigned frequency and was previously the general use frequency.
123.1    SAR frequency

HF communications are useful for beyond line of sight.  There are several active networks:

FEMA SHARES Net, manned 24/7
CAP
Red Cross
Salvation Army SATERN Net

And of course military units such as National Guard, USCG.  Any of whom could be important for SAR and disaster relief.

I would not consider a SAR comm unit to be fully equipped without these two capabilities.

Sounds like you have a well equipped unit!  Good luck.  bill
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N7WR
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« Reply #2 on: January 28, 2013, 06:39:30 AM »

It would be interesting to know whether PCSO is even licensed to use the aircraft and HF radios.  My experience in SAR and in building Mobile Communications Units is that getting licensed to use those radios is not an easy task.
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WE6BB
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« Reply #3 on: January 28, 2013, 10:18:04 AM »

I notice in the FEMA SHARES net, the frequencies are outside normal ham bands. Is there a particular license we need to have? If so, is it a group license or an individual license? I know that when it comes to ham frequencies, there are a few of us that have a general or better license, I myself am planning on taking both my general and extra exam in the near future (I believe nearest test date is in late February). As the training director of the communications unit, I want to have nearly all the answers and working knowledge of everything in the truck.

When I asked an open question in a meeting about license for the aircraft radio, I was given the "in an emergency, use whatever works" type of answer. While that may be true, we ought to know HOW it operates so that when an emergency does exist, we know HOW to use it. In order to do so, it may require some testing. In order to do testing, we ought to have a license for what we are doing if it is required.
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N7WR
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« Reply #4 on: January 28, 2013, 12:32:07 PM »

There are only designated government entities that are permitted on the SHARES Network under a blanket license and individual counties are generally not considered critical enough users for that purpose.  As for the VHF AM Aircraft radio "ground stations" especially portable/mobile ones are generally not considered for licensing.  Conrol towers, FBO's (usually on limited UNICOM frequencies)are and the PCSO comm truck is neither.  From SAR experience in both CA and OR I have never seen the need to use airband for ground, aircraft communications.  Almost every law enforcement, fire, and medical fixed wing or helo I have worked with generally has a multi-band programable radio and can talk to your MCU on the PCSO frequency, CLEMARS, CALCORD, SAR, or some other channel for which PCSO is licensed.  In the case of CAP aircraft, CAP can talk to them from your MCU using their equipment/channels.  I have yet to see a CAP deployment where they did not use one of their own comm people for communications.  In the rare event a private (not CAP) aircraft is used generally the spotter (non pilot crew) is a member of some government entitiy involved in the search.  That person, using a handheld, can communicate to the PCSO MCU on one of the aforementioned channels.
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WB6BYU
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« Reply #5 on: January 28, 2013, 12:35:02 PM »

I was on the SAR team in Santa Barbara county years ago, and we did have a
license for an aircraft radio in the command post, which we used several times
to talk with aircraft involved in a search.  I don't remember what we had to go
through to get the license issued.

Whether it is useful or not depends on what resources your department has
in terms of aircraft.  We often worked with Air Force rescue helicopters, and
couldn't always count on them having the desired VHF FM frequencies
installed.  We occasionally worked with CAP or other private aircraft, Coast
Guard, etc.  We perhaps only used it every few years, but it was useful in
those cases.

We usually left it on 121.5 MHz to listen for ELTs.


Regarding HF, if the radio is programmed for specific frequencies then you should
find out what they are, and who uses those frequencies.  In most cases, without
having a plan in advance for who you will talk to, the HF isn't going to help much.
There could be some ARES/RACES frequencies in the ham bands, which would
require a ham license, otherwise it might be FEMA, State, CAP, etc., each of
which probably has a different license requirement.  (Once you find out whose
frequencies you have programmed, you can contact them for further details,
and whether your group is already licensed and registered, etc.)

That said, if you are trying to contact Sacrament you'll find that a horizontal
antenna works much better than a vertical whip in most cases.  Even from the
bottom of a deep canyon, NVIS propagation (below 10 MHz) is likely to get
a signal out when there is no coverage on VHF/UHF, as long as you choose
the proper frequency and an antenna designed to radiate straight up.
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KF7GFL
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Posts: 44




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« Reply #6 on: January 28, 2013, 06:08:51 PM »

With regards to the Icom IC-M802, it is what most sailors use for marine SSB communications. If you compare it against the inexpensive Icom IC-718 radio, you can kind of see the differences between a marine SSB radio and a general HF ham radio.

Looking at the receive of both radios, the 718 goes from 0.030 - 29.999 MHz while the 802 goes from 0.5 - 29.999 MHz. So the 718 gives you a bit more listening capabilities on the lower frequencies. I'm not sure it is much of an advantage though.

Looking at transmit frequencies (718 listed first, 802 listed second):
  1.800- 1.999999 MHz   vs.  1.6 - 2.9999 MHz
  3.500- 3.999999 MHz   vs.  4.0 - 4.9999 MHz & 6.0 - 6.9999 MHz
  7.000- 7.300000 MHz   vs.  8.0 - 8.9999 MHz
10.100-10.150000 MHz  vs. 12.0 - 13.9999 MHz
14.000-14.350000 MHz
18.068-18.168000 MHz  vs. 16.0 - 18.9999 MHz
21.000-21.450000 MHz  vs. 22.0 - 22.9999 MHz
24.890-24.990000 MHz
28.000-29.700000 MHz  vs. 25.0 - 27.5 MHz

So you can set that there are some overlap in frequencies, but also some holes for each radio.

Finally, if you look at the types of emission, the 718 can deal with SSB (USB, LSB), CW, RTTY (FSK), and AM. The 802 can do most of these but only listen on AM and not transmit, not that anyone would really see that as a huge hole.

You can see that the IC-M802 is really geared towards ocean-crossing sailing and I imagine it doesn't have much use with Placer County SAR (a mountain region between Roseville and Truckee if my memory is correct).

As a sailor, I know that the IC-M802 is rather expensive. WB6BYU has some good information regarding NVIS and HF, but I would suggest a different radio. I hope this helps.

Matt
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WE6BB
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« Reply #7 on: January 29, 2013, 07:46:35 PM »

Yes, Placer County is quite a bit inland... from the relatively flat areas of Lincoln, Rocklin and Roseville and up to the high Sierra Nevada mountain range. I brought up these two radios as I personally see little need for them, but others apparently thought they were needed. As the training director for the communications unit, I want to know how everything works, so I can explain it to others; it kind of sucks when the blind lead the blind. As for the Icom IC-M802, it pre-dates my involvement with the communications unit; no matter the price, it's been paid for.

I understand all the other radios and equipment. We are also planning on adding a tri-band amateur radio, but THAT I can see some use... at least potentially. The majority, but not all, of us have at minimum a amateur technician license. Members of our unit maintain a few amateur repeaters for our own use under our club license of W6SAR, but they are not normally used for searches.
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AG2AA
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« Reply #8 on: January 30, 2013, 02:49:04 AM »

maybe the case that whoever bought and equipped the van was told by the "expert" that they "needed" one of these HF radios, and there was an extra couple grand in the grant account they had to spend or (god forbid) give back.
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VE6FGN
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« Reply #9 on: February 24, 2013, 08:32:19 AM »

Pretty much all Military and commercial aircraft always monitor Guard frequencies (121.5//243.0).  The civil aviation guys that I know do the same (within their capabilities).  If you need to contact an aircraft, do so on one of these freq's, then arrange another freq to move to on initial contact.

Another good one to keep in mind is 126.7- aircraft flying VFR outside of controlled airspace will be monitoring it.

Cheers
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N6NMZ
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« Reply #10 on: February 24, 2013, 10:43:00 AM »

Maybe the guys that purchased and set up these radios have been doing it for 25 years or more and you should maybe ask them if you are a "newbie" and want to know their reasoning.
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LA9XSA
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Posts: 376




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« Reply #11 on: February 27, 2013, 07:10:47 PM »

Any boat traffic on Lake Tahoe that's out of VHF range? I don't think so.

Find out if the M802 was aquired for some special reason, like it's been re-programmed for DSC to government frequencies. If not, try to get the M802 sold and the funds used for a regular HF radio, maybe a marine VHF set if there's boat traffic on Lake Tahoe, and the balance used for other upgrades. I can't think of any reason why you'd need the M802's DSC and alerting features. See, much of the reason for the M802 being expensive is that it has digital selective calling, and sending and reception of digital emergency alerts. It even has a sub-receiver that 24/7 listens to the DSC distress channels even while you talk on a different channel.

There might be a perverse situation when a ship in distress sends a DSC distress call, and it can be picked up your area due to propagation, but the odds of you being activated at the same time, and that you're the only ones that can hear them, are as close to 0 as I can think of. A GMDSS vessel beyond VHF range might only have the HF radio for two-way communication with the shore, but it will also have a satellite EPIRB. (This redundancy is mandated by the GMDSS, for vessels it applies to.)

Incidentally, EPIRBs and Personal Locator Beacons have a homing signal on the same frequency as mentioned for aircraft ELTs: 121.5 MHz.
« Last Edit: February 27, 2013, 07:27:46 PM by LA9XSA » Logged
K7RBW
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Posts: 392




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« Reply #12 on: February 27, 2013, 08:38:41 PM »

Incidentally, EPIRBs and Personal Locator Beacons have a homing signal on the same frequency as mentioned for aircraft ELTs: 121.5 MHz.

I'm pretty sure the EPIRBs broadcast on 406 MHz and not 121.5 MHz. IIRC, 121.5 is no longer monitored by the SAR satellites, but it is used for emergency and distress calls (at least in the U.S.).
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LA9XSA
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« Reply #13 on: February 28, 2013, 02:22:55 AM »

406 MHz beacons still have the 121.5 MHz homing signal. You are correct that the satellites don't monitor 121.5 MHz anymore - they listen for a digital signal on 406 - but once search and rescue units arrive they can use the analog 121.5 MHz signal to home in on the beacon.

406 beacons can optionally transmit a GPS position in the distress call, but in case the beacon lacks GPS or can't get a fix, the COPSAS/SARSAT system will use doppler shift to approximate the position of the beacon, and the 121.5 MHz would be used by aircraft or land units for local homing.
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K7RBW
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« Reply #14 on: March 01, 2013, 06:41:40 AM »

I think it depends on the beacon. The 406 beacons that are for aircraft installations do have 121.5 and 243.0 as well. The personal 406 EPIRBs don't. Don't know about the ship-board beacons.
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