Emergency A/G COMMS

[blackrain]

Been a day or two since I've been on CAP Talk but finally decided get back on. I wanted to circle back on a topic from several years ago. I found an old thread from 2010 (which I had participated in) dealing with how to contact someone in distress in a remote area where cell service was unavailable. The thread primarily dealt with use of FRS radios in the UHF band that clearly are outside of our CAP Radio and Becker  capabilities. There is or was at one time a software package that can greatly expand the CAP Becker spectrum coverage but it isn't cheap. The other day on a mission we dialed in a couple MURS frequencies on the Becker (154.57 BLUE and 154.60 GREEN) and we got solid hits as far as DF from what sounded like business handhelds and a intermittent data transmission on 154.60 but the frequencies didn't seem overly crowded (which is a good thing). Transmitters on these frequencies are available to any US Citizen to use without a license and are limited to 2 watts. Assuming regulatory hurdles could be overcome I would imagine they could also be programmed into the TDFM-136. I completely get there are many tools available to summon help like PLBs and satellite texting but VHF handhelds generally do better than UHF in non-urban areas and radios with these frequencies could be beneficial in remote areas to communicate with ground elements as well.

[NovemberWhiskey]

Per Part 95, MURS is not authorized for operation aboard aircraft in flight.

https://www.ecfr.gov/cgi-bin/text-idx?SID=2b9cf0ad4ea7cc0859372d69d5d9766c&mc=true&node=se47.5.95_12707&rgn=div8

[SarDragon]

As I understand the "rules", use of the TDFM-136 on those frequencies would be restricted to receive only. How would that add to our mission capabilities?

[etodd]

how to contact someone in distress in a remote area where cell service was unavailable

As in dropping a radio to them via parachute or something? Just drop them a note saying help is on the way. Maybe I'm missing your scenario here?

[blackrain]

As I understand the "rules", use of the TDFM-136 on those frequencies would be restricted to receive only. How would that add to our mission capabilities?

Yes the regs/red tape were always going to be an issue. To your point two way communication would be required to be effective to communicate with someone on the ground. Could permission be obtained for airborne use from all entities if used only as a part of an emergency operation I can't say. I looked at it from the standpoint is MURS is available on relatively inexpensive radios accessible to just about anyone and could be carried in the backcountry. I wouldn't think most comms on MURS frequencies are critical where interference with day to day users could cause problems. Someone else out there who knows of any please chime in.

[NovemberWhiskey]

To your point two way communication would be required to be effective to communicate with someone on the ground. Could permission be obtained for airborne use from all entities if used only as a part of an emergency operation I can't say. I looked at it from the standpoint is MURS is available on relatively inexpensive radios accessible to just about anyone and could be carried in the backcountry.

If we're talking about a CAP ground team, they should have CAP VHF radios to talk to CAP aircraft on e.g. AIR1/AIR2 simplex.

If we're talking about a non-CAP ground team (e.g. volunteer SAR team) without a CAP radio operator, realistically you would either have to be on some pre-arranged inter-op channel, passing messages via mission base, or you could be on air-band 123.1MHz in a live mission.

If we're talking about a search subject, they're not going to have a MURS radio unless they happen to have gone missing from the local Walmart. No-one owns those radios; if it's a pilot there's some chance they have an air-band HT; if it's a hiker, there's some chance they'll have an FRS/GMRS HT.

If we're talking about something else, can you specify?

From my point of view, MURS is a solution in search of a problem for CAP.

[blackrain]

I would officially designate both MURS blue and green as usable emergency frequencies for remote area use. Completely up to an individual if they want to carry a MURS capable radio and there's nothing stopping family members or others to help locate someone in distress using the same frequencies. From a CAP perspective I would like all our radios to be capable of two way communications on both frequencies so if we know or suspect someone has a MURS capable radio we would have the ability to communicate directly from a CAP Aircraft or GT. We can already DF the frequencies. Clearly we would want to use CAP designated frequencies whenever possible. The advantage is we wouldn't need any more equipment than we already have and it would be a practical matter of just programming in two more frequencies along with regulatory buy off. Yes FRS/GMRS is more popular but obviously our available equipment doesn't have that capability.

[Eclipse]

Aren't there tenants, not to mention practical reality, that anything may be used
to contact an individual(s) in distress if life or property can be saved?
That's certainly the case with FRS

With that on the table, why would anyone bother with the expense and effort in
getting an obscure spectrum approved that no one has anyway?

[blackrain]

Oh yes from a practical standpoint anything that gets the job done in an emergency is good to go and the FCC as I recall allows an exception in an emergency. As for obscure spectrum I know several who have these frequencies programmed in their radio which admittedly using outside of an emergency would be frowned upon by the FCC. In fairness most don't own MURS only radios. Yes (cue the exploding heads of some on here) these frequencies among many others are common in the prepper community but so are FRS and other popular modes. Not that I'm looking to talk with preppers and their kind, just pointing out that they're not as obscure as some think. Again we're talking emergency use. Right now the only way I see accessing two way comms outside the aircraft radio and the TDFM-136 would be an after market programmable radios linked to an ANR headset through a Bluetooth feature. I've heard rumors like most that the TDFM-136 radios will be replaced by DC-Daylight SDR Mil-Spec radios at some point but I'll believe it when I see it. I still haven't located a hardwired impedance matched adapter that will link a normal non-aircraft handheld radio to an aviation headset. To me the appeal of MURS are they are unlicensed VHF frequencies and their use shouldn't cause interference issues with other more critical users of the spectrum and as mentioned above don't require any more equipment than CAP already has. Realistically I'll be surprised if this happens but I just put it out there as an idea.   

[etodd]

... how to contact someone in distress in a remote area where cell service was unavailable.

^^^^ Getting back to your original question. These new radios you mention.  Who in distress will have one?  Anyone that is a hiker, naturalist, hunter, etc., etc. ... already has a plethora of options for PLBs and more. The ones that are not interested in getting any type of existing device, would not be any more interested in your new fangled radio.

[blackrain]

https://www.ameradio.com/doc/Icom-IC-V10MR-brochure.pdf

I guess about half the cost of a PLB/Satellite Texter though I wouldn't call it newfangled  .

Cheaper MURS radios out there of course. I would say one thing about handhelds is you can use them for more things and they don't require a subscription. Of course we all talk about 406 beacons/PLBs/Sat Capable Communicators taking the most of the search out of search and rescue. Guess it depends on you're budget. 

[Fubar]

Comm guys can never quite understand that the muggles just aren't interested in carrying a radio, no matter how important you make it sound....

[SarDragon]

I just looked at the specs for the MURS radios, and the A/C FM radio. I see two incompatibilities: the output power of the A/C unit exceeds the permissible power for the frequency set, and the bandwidths for individual frequencies don't match, causing audio intelligibility issues.

MURS has specified operating parameters, and adapting our A/C radios to meet those specs on a small number of channels is impractical at best, and expensive if even doable.

[blackrain]

I just looked at the specs for the MURS radios, and the A/C FM radio. I see two incompatibilities: the output power of the A/C unit exceeds the permissible power for the frequency set, and the bandwidths for individual frequencies don't match, causing audio intelligibility issues.

MURS has specified operating parameters, and adapting our A/C radios to meet those specs on a small number of channels is impractical at best, and expensive if even doable.

Actually I was wondering about that. Our power settings at least on the TDFM 136 are 1 and 10 watts (low/high power setting) if I remember correctly and MURS is limited to 2 Watts. Also on the Bandwidth (narrowband vs wideband issue) is what I understand you are referring too? Can the TDFM 136 utilize Marine Band Channels which are still wide band? Anyone out there know the TDFM 136 and the programming capabilities? Can we set bandwidth and power settings for individual channels/frequencies? Our GT handhelds are another question.

[blackrain]

Comm guys can never quite understand that the muggles just aren't interested in carrying a radio, no matter how important you make it sound....

After my time in the military (much to my significant others chagrin)I keep a handheld and VS-17 panel in the car at all times. 😆

When individuals question the need for reliable comms I tell them to watch "Lone Survivor". Essentially one reliable means of comms between them all going home safe in anonymity to being the subject of a feature film.

[NovemberWhiskey]

Actually I was wondering about that.

But seriously, why?

As pointed out previously, under part 95 you are not permitted to transmit on MURS frequencies from the air. Moreover, our equipment is not type qualified under part 95.

If you are going to rely on the assumption that "all bets are off in an emergency", then go ahead and transmit at whatever power level on whatever frequency you want.

However, be prepared

• to be unable to practice any of this during training missions,
• to explain yourself during the AAR ("and then the observer spent fifteen minutes head down trying to program the radio to a MURS frequency on the off-chance that the lost hiker was carrying a radio of a type that is almost never used by hikers, particularly the kind that get lost"), including
• accounting for why you felt there was an imminent life/property safety threat, especially bearing in mind that CAPR 100-1 section 9.16 indicates a typical CAP search mission does not qualify under that standard.

[blackrain]

Actually I was wondering about that.

But seriously, why?

As pointed out previously, under part 95 you are not permitted to transmit on MURS frequencies from the air. Moreover, our equipment is not type qualified under part 95.

If you are going to rely on the assumption that "all bets are off in an emergency", then go ahead and transmit at whatever power level on whatever frequency you want.

However, be prepared

• to be unable to practice any of this during training missions,
• to explain yourself during the AAR ("and then the observer spent fifteen minutes head down trying to program the radio to a MURS frequency on the off-chance that the lost hiker was carrying a radio of a type that is almost never used by hikers, particularly the kind that get lost"), including
• accounting for why you felt there was an imminent life/property safety threat, especially bearing in mind that CAPR 100-1 section 9.16 indicates a typical CAP search mission does not qualify under that standard.

Just to clarify I wouldn't want any changes to CAP equipment/procedures not bought off by CAP FCC NTIA etc. As for the purpose I guess it's a chicken or egg first scenario. If frequencies are officially designated and people know that official assets now have the capability to operate on those frequencies would people carry a capable radio? I don't know. Again having been around government bureaucracy I wouldn't hold my breath. Just putting it out as a thought exercise. On a side not it appears the TDFM 136 has been replaced by the TDFM 136B. Apparently parts obsolescence is at least part of the reason. Also some of the higher end Techsonic radio have repeater capability. Could we get rid of that monster highbird repeater in the back seat🤨

[Eclipse]

If frequencies are officially designated and people know that official assets now have the capability to operate on those frequencies would people carry a capable radio?

No.

[Fubar]

If frequencies are officially designated and people know that official assets now have the capability to operate on those frequencies would people carry a capable radio?

No.

Think of all the common sense precautions a person can already take to prevent the likelihood of them being in a situation where they need to be rescued. Adding one more precaution of carrying a two-way radio won't reduce the amount of people who ignore common sense precautions.

[etodd]

If frequencies are officially designated and people know that official assets now have the capability to operate on those frequencies would people carry a capable radio?

No.

Think of all the common sense precautions a person can already take to prevent the likelihood of them being in a situation where they need to be rescued. Adding one more precaution of carrying a two-way radio won't reduce the amount of people who ignore common sense precautions.

Exactly. Blackrain is thinking nobly with good intentions, but he is a techie and thinks in those terms. The group of teenagers that get lost in the forest, or the old person with alzheimer's who wonders off, or any number of examples ... will simply not be carrying a radio.

[Spam]

If frequencies are officially designated and people know that official assets now have the capability to operate on those frequencies would people carry a capable radio?

No.

Think of all the common sense precautions a person can already take to prevent the likelihood of them being in a situation where they need to be rescued. Adding one more precaution of carrying a two-way radio won't reduce the amount of people who ignore common sense precautions.

Exactly. Blackrain is thinking nobly with good intentions, but he is a techie and thinks in those terms. The group of teenagers that get lost in the forest, or the old person with alzheimer's who wonders off, or any number of examples ... will simply not be carrying a radio.

Never underestimate the unpreparedness of our civil SAR "customers". Combat SAR is another story, of course, with CSELs and so forth, but even there that field is evolving (doing away with DF, etc.).

It would be a serious error to invest in the belief that we should equip and train to a cooperative target when the vast majority of them are not. (Cite?  Well, the majority of them are incapacitated or gone by the time they are found, for one, which is why TSOc91A exists).
 
V/r
Spam

[SarDragon]

I just looked at the specs for the MURS radios, and the A/C FM radio. I see two incompatibilities: the output power of the A/C unit exceeds the permissible power for the frequency set, and the bandwidths for individual frequencies don't match, causing audio intelligibility issues.

MURS has specified operating parameters, and adapting our A/C radios to meet those specs on a small number of channels is impractical at best, and expensive if even doable.

Actually I was wondering about that. Our power settings at least on the TDFM 136 are 1 and 10 watts (low/high power setting) if I remember correctly and MURS is limited to 2 Watts. Also on the Bandwidth (narrowband vs wideband issue) is what I understand you are referring too? Can the TDFM 136 utilize Marine Band Channels which are still wide band? Anyone out there know the TDFM 136 and the programming capabilities? Can we set bandwidth and power settings for individual channels/frequencies? Our GT handhelds are another question.

MURS bandwidth is 11.5 kHz; TDFM bandwidth is either 12.5 kHz or 25 kHz. I have programmed TDFMs. It is certainly something I would not want to be doing in flight.

As for your later Q about marine freqs, we already have them in our CAWG channel plans. Each channel has its own set of parameters regarding frequency, bandwidth, squelch/tones, conventional/digital mode, and a few other things.

[blackrain]

Thanks for the Noble Techie title etodd! My son won't believe it though.  I've tried 25khz to 12.5 kHz with different radios and there is definitely a loss. I didn't notice the odd bandwidth of the MURS radios and what the 20khz to 25khz distortion would be I can only imagine. Interesting fact is the most reliable means of comms in most 3rd world localeles is the cell network and in Afghanistan we actually bought cheap local phones with scratch card minutes. They would often work where other means didn't. Go figure. Certainly not secure but in an emergency the bad guy's probably knew where we were and at that point we wanted the good guys to know too. Spent about $150 or so on the phone and minutes and we all agreed it would seem mighty cheap if things ever went south. Don't get me wrong and I agree that most who get into trouble are there because they aren't the plan ahead types anyway.

[blackrain]

https://ncwg.cap.gov/media/cms/TDFM9100_QRM_v1_BB8786485F830.pdf

Apparently NC Wing has the TDFM 9100 and on page 20 they address the use of contacting individuals in distress via FRS. I had no idea and our radios aren't even capable of UHF. Hopefully we'll get the upgraded radios.