Guidance on frequency band for transmitters

I'm about to buy my 1st radio tracking setup, both a transmitter and a receiver from the same company. I'm pretty comfortable with the model I'll be purchasing and the company I'll be purchasing from (for those who care, the MNS-4000 receiver with the LF-3 2G Special transmitter from L.L. Electronics). But what I'm close to at my wits end at trying to figure out what frequency/channel to use.

What I think I've found out so far:
-216 MHz to 217 MHz - available to non-ham users
-218 MHz to 219 MHz - used to be OK but is now depreciated by FCC???
-220 MHz - Not sure
-221 MHz - Not available
-222 MHz to 224 MHz - only for ham licensed users

Is that accurate?

Which makes it seem like somewhere in the 216 MHz - 217 MHz range is best for me as a non-ham licensed person (or easiest anyway). But how do I pick within that range (said another way, how do I pick a channel)? Specifically, it seems like someone else with the same frequency is a significant problem when one goes to a large launch event. (For me Snow Ranch in CA is the most frequent, but also want to go to the AeroPac launches at black rock NV) How should I pick a frequency with the least likelihood of conflicts?

Any guidance would be greatly appreciated.

OK, I'm trying to track this to the source, and here's what I've found:

I found this FCC document: https://transition.fcc.gov/oet/spectrum/table/fcctable.pdf (FCC ONLINE TABLE OF FREQUENCY ALLOCATIONS - 47 C.F.R. § 2.106 - Revised on August 13, 2015)

For the relevant frequencies it has the following (see page 26 of document (labeled page 25)):
"Federal Table":
216-217 MHz: Fixed Land mobile (references: US210 US241 G2) (FCC Rule Part(s)
217-220 MHz: Fixed Mobile (references: US210 US241)

"Non-Federal Table":
216-219 MHz: FIXED MOBILE except aeronautical mobile (references: US210 US241 NG173) (FCC Rule Part(s): Maritime (80) Private Land Mobile (90) Personal Radio (95))
219-220 MHz: FIXED MOBILE except aeronautical mobile, Amateur (references: NG152 US210 US241 NG173) (FCC Rule Part(s): Maritime (80) Private Land Mobile (90) Amateur Radio (97))

And applying to both Federal and non-Federal:
220-222 MHz: FIXED LAND MOBILE (references: US241 US242) (FCC Rule Part(s): Private Land Mobile (90))
222-225 MHz: AMATEUR (FCC Rule Part(s): Amateur Radio (97))

Those references translate to:

US210 In the bands 40.66-40.7 MHz and 216-220 MHz, frequencies may be authorized to Federal and non-Federal stations on a secondary basis for the tracking of, and telemetering of scientific data from, ocean buoys and wildlife. Operation in these bands is subject to the technical standards specified in:
(a) Section 8.2.42 of the NTIA Manual for Federal use, or
(b) 47 CFR 90.248 for non-Federal use. After January 1, 2002, no new assignments shall be authorized in the band 216-217 MHz.

US241 The following provision shall apply to Federal operations in the band 216-220.035 MHz:
(a) Use of the fixed and land mobile services in the band 216-220 MHz and of the aeronautical mobile service in the sub-band 217-220 MHz is restricted to telemetry and associated telecommand operations. New stations in the fixed and land mobile services shall not be authorized in the sub-band 216-217 MHz.
(b) The sub-band 216.965-216.995 MHz is also allocated to the Federal radiolocation service on a primary basis and the use of this allocation is restricted to the Air Force Space Surveillance System (AFSSS) radar system. AFSSS stations transmit on the frequency 216.98 MHz and other operations may be affected within: 1) 250 km of Lake Kickapoo (Archer City), TX (33° 2' 48'' N, 98° 45' 46'' W); and 2) 150 km of Gila River (Phoenix), AZ (33° 6' 32'' N, 112° 1' 45'' W) and Jordan Lake (Wetumpka), AL (32° 39' 33'' N, 86° 15' 52'' W). AFSSS reception shall be protected from harmful interference within 50 km of: 1) Elephant Butte, NM (33° 26' 35'' N, 106° 59' 50'' W); 2) Fort Stewart, GA (31° 58' 36'' N, 81° 30' 34'' W); 3) Hawkinsville, GA (32° 17' 20'' N, 83° 32' 10'' W); 4) Red River, AR (33° 19' 48'' N, 93° 33' 1'' W); 5) San Diego, CA (32° 34' 42'' N, 116° 58' 11'' W); and 6) Silver Lake, MS (33° 8' 42'' N, 91° 1' 16'' W).
(c) The sub-band 219.965-220.035 MHz is also allocated to the Federal radiolocation service on a secondary basis and the use of this allocation is restricted to air-search radars onboard Coast Guard vessels.

NG152 The use of the band 219-220 MHz by the amateur service is limited to stations participating, as forwarding stations, in point-to-point fixed digital message forwarding systems, including intercity packet backbone networks.

NG173 In the band 216-220 MHz, secondary telemetry operations are permitted subject to the requirements of 47 CFR 90.259. After January 1, 2002, no new assignments shall be authorized in the sub-band 216-217 MHz.


My conclusions from all of that:
* If I REALLY want to understand all the details, I need to lookup the rules for Maritime, Private Land Mobile, Personal Radio and Amateur Radio transmissions. But I'm assuming that the Personal Radio is what these transmitters fall under (I think?) and the commercially available products meet those rules. "Amateur Radio" is what is generally called "ham radio".
* All of 216 to 220 is available with the exception of 216.965-216.995 MHz and 219.965-220.035 MHz
* If I was wanting an exclusive use within 216-217 MHz, I needed to get that in before 2002 (but I'm not as clear on this)
* 219-220 MHz requires a ham license (but I'm not as clear on this)
* 220-222 MHz is off limits
* 222-225 MHz requires a ham license

But that seems to suggest, that my safest range is 217-219 MHz, and I can safely use that range, within the bounds of what is allowed by "Personal Radio" without breaking the law.

Did I get that right? Anyone disagree with that?

(and don't forget my original question about how to avoid frequency conflicts at group launches)

My response to this problem was to get my technician's license so I wouldn't have to worry about unlicensed use.

Why don't you ask LL if you can use their device without a license? Com-spec for all of the frequencies they currently simply says you have to have a license.

I believe for the wildlife tracking frequencies there is some debate about whether rocket tracking is authorized (if you were tracking a falcon you wouldn't need a license), but I'm not sure.

mikec said:

My response to this problem was to get my technician's license so I wouldn't have to worry about unlicensed use.

Why don't you ask LL if you can use their device without a license? Com-spec for all of the frequencies they currently simply says you have to have a license.

I believe for the wildlife tracking frequencies there is some debate about whether rocket tracking is authorized (if you were tracking a falcon you wouldn't need a license), but I'm not sure.

Click to expand...

I agree. Check https://www.com-spec.com/ for legal ham radio solutions. Prices are good, and the technician ham test is easy.

Bob

If you get a Tech license, DO NOT make the mistake of getting "any old" 1.25 meter (220Mhz) transceiver and expect it to work with the 200Mhz RDF trackers. There are some Ham receivers out there that are all-band and all-mode modulation that will work but they cost as much as the manufacturers stock offerings of the rocket trackers. A Kenwood TH-F6A might be feasible as I've tried some close in testing but never a long range test. Can use the B band and fine tuning along with upper sideband, lower sideband or CW modulation. I've received some good signals from a com-spec (the one on the funky 216Mhz and SSB modulation) and rocket tracker types. Since I moved on to GPS tracking (read that as "too lazy") I haven't pursued it. Get the Ham Tech license and it opens up APRS tracking which is rapidly dropping in price. I have a ComSpec RDF tracker on the 1.25 meter ham band that is simply FM modulated and is programmed with my callsign at requisite intervals. It can be received with any run-of-the-mill FM 1.25M transceiver. My other Comspec/Rocket Tracker type was old and one of my friends destroyed his tracker and his frequencies on his receiver were geared for the earlier offferings. No new trackers were available for him so I gave him my "old style one I believe was 216mhz or something or other.

Kurt

ksaves2 said:

I have a ComSpec RDF tracker on the 1.25 meter ham band that is simply FM modulated...

Click to expand...

I thought all of the Com-spec transmitters were CW, which one do you have?

Sheesh you're probably right. I'll have to pull it out again and see. I might be confusing it with a 2 meter tracker I got from here: https://www.west.net/~marvin/microhnt.htm

It's on 2 meters though. That could be where I got confused. I'll fire up my com-spec that's on 222.130 and recheck it. Might be it's CW and I'll stand corrected. Kurt

ksaves2 said:

Sheesh you're probably right. I'll have to pull it out again and see. I might be confusing it with a 2 meter tracker I got from here: https://www.west.net/~marvin/microhnt.htm

It's on 2 meters though. That could be where I got confused. I'll fire up my com-spec that's on 222.130 and recheck it. Might be it's CW and I'll stand corrected. Kurt

Click to expand...

Yes,

I stand corrected here. My old 222.130 com-spec RDF tracker is on 222.130 and comes through the best on CW modulation with the Kenwood F6A Handi-Talkie. I got confused with another tracker. Kurt

kencraw said:

(and don't forget my original question about how to avoid frequency conflicts at group launches)

Click to expand...

The only way to deconflict a frequency with these fixed frequency transmitters would be to find the other user (s) on the same frequency and come up with an agreement of when to turn them on. This would be akin to the old "clothespin boards" used at RC airplane fields.

On a different note altogether...have you seen one of these systems in use? Do you have any RDF experience? If you are flying in a desert then this type of system will do alright. In an area that has valleys and hills you may not get the results you are hoping for. For the cost of the receiver alone there are many available options. As a Amateur Extra I am very satisfied with my Eggfinder and have witnessed one other rocketeer with an Eggfinder that walked right to his rocket over a mile away in a ravine. This is anecdotal and YMMV. The latest version is able to select different transmitter frequencies to help with exactly the situation you are trying to avoid. I am not affiliated with Eggtimer Rocketry but I do like their products and phenomenal customer support.

Good luck with your selection and like they say in the movies "choose wisely".

Joe