# Beginning RDF Tracking - need advice

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#### Cl(VII)

##### Chris Bender, Lab Rat
I got my Ham license and a Yaesu FT2DR radio I've been playing around with. I want to add a small RDF tracker to my HP rockets as a backup for the Eggfinders that have thus far performed perfectly, but I would like a small, easy to use backup on board as well. I've been doing some research, and I believe I've settled on the below kit to go along with the Yaesu FT2DR. I would appreciate if some of you experienced folk would give the list a look, and make sure I didn;t miss anything, or I am not doing something fundamentally incompatible. For ease and clarity I've linked exactly the items I intend to buy. I relaizes a dedicated reciever would be a better option, but the radio is the expensive part of this equation, and it is really a backup, not the primary tracking method.

EDIT/SUMMARY: The below listed setup almost certainly won't workout. Scroll down if you are interested in what I settled in on after some good advice here. I'm leaving this stuff in as a what not to do, but don't want anyone to get confused if they don't read the whole thread.

Tracker: LL Electronics XLF 6v with loaded antenna and bewit cap

Antenna: Arrow Antenna's Hand Held 220 3-element Yagi

Cable: 4 ft BNC Patch Cable Is 4 ft good, or do I want a different size?

Thanks for any and all advice. Please remember that I am just getting started, so going too deep in the weeds may result in blank stares coming back. Still appreciated, just not necessarily comprehended.

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#### ksaves2

My only question is the LL transmitter FM modulation? If you get a good signal with a full scale reading on the signal strength meter you are in good shape. If the transmitter uses USB or CW modulation you might have a problem there.
You'll need to do a range check to be sure you're in good shape. For future reference Greg Clark's Beeline RDF trackers are FM and compatible with just about any H/T on 70cm. You might have a size requirement hence your choice.

The Adept RDF tracker is 433.920 Mhz and is AM! or CW modulated! so one needs to be aware of that. My old ICOM T-90A receives the AM signal the best for that tracker.
You might need an offset attenuator for close-in tracking unless the FT2DR has one with more than one setting: https://www.west.net/~marvin/k0ov.htm or Arrow Antennas ready-to-go https://www.arrowantennas.com/main/4ofha.html

You'll be able to do rudimentary APRS tracking in the future off the screen on the radio. I do not know if the incoming waypoints can be piped to a port on the side of the rig to send to another application or if the waypoints can be sent via a B/T
link. If it's possible, you'll have future utility. Yaesu has a weird philosophy with APRS and the VX-8R was not that great. The -8GR hit the mark much better but the -8DR was an overprice piece of junk the just so happened to be quad band.

Kurt

#### Cl(VII)

##### Chris Bender, Lab Rat
My only question is the LL transmitter FM modulation? If you get a good signal with a full scale reading on the signal strength meter you are in good shape. If the transmitter uses USB or CW modulation you might have a problem there.
You'll need to do a range check to be sure you're in good shape. For future reference Greg Clark's Beeline RDF trackers are FM and compatible with just about any H/T on 70cm. You might have a size requirement hence your choice.

The Adept RDF tracker is 433.920 Mhz and is AM! or CW modulated! so one needs to be aware of that. My old ICOM T-90A receives the AM signal the best for that tracker.
You might need an offset attenuator for close-in tracking unless the FT2DR has one with more than one setting: https://www.west.net/~marvin/k0ov.htm or Arrow Antennas ready-to-go https://www.arrowantennas.com/main/4ofha.html

You'll be able to do rudimentary APRS tracking in the future off the screen on the radio. I do not know if the incoming waypoints can be piped to a port on the side of the rig to send to another application or if the waypoints can be sent via a B/T
link. If it's possible, you'll have future utility. Yaesu has a weird philosophy with APRS and the VX-8R was not that great. The -8GR hit the mark much better but the -8DR was an overprice piece of junk the just so happened to be quad band.

Kurt
Found the below in this thread.

-snip-

The key here is that the transmitters operate very low output power levels, less than 3 mW of short duration non-modulated CW, while the receivers are highly sensitive with minimum discernible signal levels around -150dbm. This is around 100 times more sensitive than an FM radio. These transmitters have little usable range when used with a pocket scanner.
Because of these specs the units may be susceptible to interference and do not cause "harmful" interference as outlined in part 15 guidelines.

-snip-
I believe based on this page of the FT2DR manual that the answer on the offset attenuator is "Yes" it has one, or am I misunderstanding?

So, because it has the attenuator option am I still ok with this setup? That part I highlighted red is probably the deal breaker, yes?

These questions/advice are exactly what I was hoping for, thanks.

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#### FMarvinS

##### Well-Known Member
Congratulations on the ham ticket! The BRB 70 cm/100 mw transmitter is small, easy to use, FM based, and has very good customer support. Line of sight transmission has been discernible for over a mile when rockets land in open-clear fields. I have 2 in common use with good results. If you haven't bought the HT yet, for financial reasons-the cheap Boafong (?sic) HT's would be adequate for 70 cm wave length FM reception. If you desire an offset attenuator-as suggested by Kurt, check Adept's website-they sell a good attenuator. The purpose of the offset attenuator (which connects to the HT) is to enable tracking when you are located close to the transmitter site. Directional discrimination is quite difficult when located near the tracking transmitter otherwise. Alternatively, you can also get by-by offsetting your receive frequency by 0.05 to 0.15 Mhz (e.g. 433.920 to 433.930). Finally, there is a link on the BRB website that instruct's one on building a low cost simple 70 cm wave length beam antenna. Thus, the saved cash can be used for buying an additional motor or 2.

Fred,
KG4YGP
L2, ROSCO

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#### FMarvinS

##### Well-Known Member
Your set up -i.e.-FTD2R, BRB 100 mw, (expensive) antenna with 4 foot coax & adapters should be fine. As Kurt previously mentioned, its important to pretest. In essence, set up & turn on the transmitter on your porch, connect the HT to your antenna and go on a sojourn (walk or car) to assess: distance, paths with & without obstacles (e.g. trees, houses, etc)to assay performance. Then, go to a field (similar to the launch field) and do the same to complete the same assessment. Goodluck!

Fred

#### ksaves2

Found the below in this thread.

I believe based on this page of the FT2DR manual that the answer on the offset attenuator is "Yes" it has one, or am I misunderstanding?

So, because it has the attenuator option am I still ok with this setup? That part I highlighted red is probably the deal breaker, yes?

These questions/advice are exactly what I was hoping for, thanks.
The attenuator in the rig is fixed by so many dB. You need something that is variable. I believe you will need to get one like the examples I posted above. I got one right off the bat. If you purchased the LL Electronics tracker I fear you will have to buy their receiver if you want it to work properly. These tracking outfits optimize the receiving modes to fit their trackers. I made the mistake of getting an Alinco 220Mhz FM rig and thought I could track the Com-Spec stuff years ago. Fortunately there
is a 1.25M repeater I can use it with 'cause it ain't gonna work with the Walston, Com-Spec or LL stuff.

I've found that a Kenwood TH-F6A has a potential to track the USB CW stuff but I haven't tested mine in a real world situation because I'm setup with FM RDF stuff and GPS trackers.

Right about BRB. A bit bigger. It is you haven't purchased the tracking transmitter? If so you might be limited. There is the Micro-Fox RDF tracker from Byonics that will work: https://www.byonics.com/mf
But of course it is larger. It can be flashed to turn it into a GPS tracker if one wires up a GPS to the device. I did that to one and it does indeed work. Of course, it's much larger than the LL Electronics.
Kurt

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#### Cl(VII)

##### Chris Bender, Lab Rat
Your set up -i.e.-FTD2R, BRB 100 mw, (expensive) antenna with 4 foot coax & adapters should be fine. As Kurt previously mentioned, its important to pretest. In essence, set up & turn on the transmitter on your porch, connect the HT to your antenna and go on a sojourn (walk or car) to assess: distance, paths with & without obstacles (e.g. trees, houses, etc)to assay performance. Then, go to a field (similar to the launch field) and do the same to complete the same assessment. Goodluck!

Fred
Thanks for giving it a going over. Admittedly, I am trading convenience/time for cost on some of these items (particularly the antenna).

#### Cl(VII)

##### Chris Bender, Lab Rat
The attenuator in the rig is fixed by so may dB. You need something that is variable. I believe you will need to get one like the examples I posted above. I got one right off the bat. If you purchased the LL Electronics tracker I fear you will have to buy their receiver if you want it to work properly. These tracking outfits optimize the receiving modes to fit their trackers. I made the mistake of getting an Alinco 220Mhz FM rig and thought I could track the Com-Spec stuff years ago. Fortunately there
is a 1.25M repeater I can use it with 'cause it ain't gonna work with the Walston, Com-Spec or LL stuff.

I've found that a Kenwood TH-F6A has a potential to track the USB CW stuff but I haven't tested mine in a real world situation because I'm setup with FM RDF stuff and GPS trackers.

Right about BRB. A bit bigger. It is you haven't purchased the tracking transmitter? If so you might be limited. There is the Micro-Fox RDF tracker from Byonics that will work: https://www.byonics.com/mf
But of course it is larger. It can be flashed to turn it into a GPS tracker if one wires up a GPS to the device. I did that to one and it does indeed work. Of course, it's much larger than the LL Electronics.
Kurt
Thanks again for your input, and also the byonics suggestion. I ran across that one, but thought for the size I may as well go with the BRB. From your suggestions and Fred's it looks like the BRB will be the closest to off the shelf tech I could hope for, so that is what it will be. This is not something that will threaten to become a hobby unto itself, but purely for rocketry support, so I don't want to overthink/spend undue time on it.

Thanks again for the suggestions gents.

#### OverTheTop

##### Well-Known Member
TRF Supporter
Congrats on the ham ticket also!

BRB seems to be a great system according to everyone who uses it.

I use TeleMega units myself, and although expensive I have had great success with them (and they have tilt detection).

I built a directional patch antenna for 70cm band. If you are curious, search for "goof proof patch antenna" and scale the size up from the 2.4GHz version. It ends up being about 18" square and needs a tripod though.

Stewart
VK3TRK
TRA 13430

#### Cl(VII)

##### Chris Bender, Lab Rat
Congrats on the ham ticket also!

BRB seems to be a great system according to everyone who uses it.

I use TeleMega units myself, and although expensive I have had great success with them (and they have tilt detection).

I built a directional patch antenna for 70cm band. If you are curious, search for "goof proof patch antenna" and scale the size up from the 2.4GHz version. It ends up being about 18" square and needs a tripod though.

Stewart
VK3TRK
TRA 13430
The Telemega will be in my future as I'd like to do some two stage HP after my L3, but I am not doing it without tilt detection. For now I'm just looking for a ride along emergency backup as RRC3s handle all of my DD needs via common ebay setups, but that 2 stage will be a more purpose built ebay.

For now, I just ordered the BRB 70cm 100mW transmitter, and Yagi setup. I was eager to get this done, so I have some practice time before my L3 flight this fall.

#### FredA

##### Well-Known Member
I would strongly recommend you do NOT use:
- wildlife trackers...as it's illegal to call your rocket wildlife.
- Fixed frequency units as sooner or later you'll have a frequency collision.
- something with a non-replaceable hard antenna as it will get broken

BRB's or Altus Metrum products are the preferred solution.

#### markjos

##### Well-Known Member
TRF Supporter
BRB option. Bigger, but rocket-centric, and less stuff if I go to their 70cm GPS tracking later.

Tracker: BRB 70cm 100mW with SMA package

Antenna: Arrow Antenna's Hand Held 440 5-element Yagi

Cable: 4 ft BNC Patch Cable Is 4 ft good, or do I want a different size?

Now this will give me all the distance I want and more, correct?
I think this is a good setup, especially if you add an active/offset attenuator, something like the Adept or Arrow. I've tracked many rockets, some near-space balloons, and plenty of recreational fox hunts using a BRB 70cm beacon (actually, the low-power one), and it's always worked out well. I recommend that, unless you've had previous fox-hunting or radio direction finding experience, you should plan to practice. You may be frustrated if your first or second attempt at this is at a launch when you've lost sight of your rocket. Note that 70cm is somewhat prone to reflections - that won't be much of a problem in really wide-open space, but even the occasional farm house or grain bin can make you turn in the wrong direction. Do be sure to get an idea of the general signal direction before your rocket is below the horizon or on the ground, since you'll lose most of the signal when it does. Knowing which general direction to walk will get you closer and bring the signal level up. The offset attenuator helps you maintain the proper dynamic range of your radio's signal strength meter - so that you "see" the difference in signal strength as you point in different directions. Speaking of s-meters, this is why something like the Baofeng and others with puny s-meters are difficult to use for radio direction finding - but that Yaesu should work well. Forgive me if that's excessive.

Have fun.

Mark

#### ksaves2

Congratulations on the ham ticket! The BRB 70 cm/100 mw transmitter is small, easy to use, FM based, and has very good customer support. Line of sight transmission has been discernible for over a mile when rockets land in open-clear fields. I have 2 in common use with good results. If you haven't bought the HT yet, for financial reasons-the cheap Boafong (?sic) HT's would be adequate for 70 cm wave length FM reception. If you desire an offset attenuator-as suggested by Kurt, check Adept's website-they sell a good attenuator. The purpose of the offset attenuator (which connects to the HT) is to enable tracking when you are located close to the transmitter site. Directional discrimination is quite difficult when located near the tracking transmitter otherwise. Alternatively, you can also get by-by offsetting your receive frequency by 0.05 to 0.15 Mhz (e.g. 433.920 to 433.930). Finally, there is a link on the BRB website that instruct's one on building a low cost simple 70 cm wave length beam antenna. Thus, the saved cash can be used for buying an additional motor or 2.

Fred,
KG4YGP
L2, ROSCO
Forget the BAOFENG's if one is going to depend upon the signal strength meter. It's either full scale with any signal or no indication with no signal.
Not helpful. If one wants to use headphones and their ears for signal strength then O.K. but I'm a visual guy. Kurt

#### ksaves2

CSILocator (Com-Spec) has some really small trackers too. They're fixed freq though. https://www.csilocator.com/rcplane/index.html
OP is looking for trackers that can be used with the radio that has been already acquired. The Com-spec stuff will not work with an FTD2R.
Oh, me thinks the D2R has a "real" signal strength meter so in good shape there. Kurt

#### GrouchoDuke

##### Well-Known Member
Oops, sorry. I thought that was a tri-band radio. Never mind!

#### ksaves2

Oops, sorry. I thought that was a tri-band radio. Never mind!
No apologies necessary. Yes it is a Tri-Band radio but it lacks the proper receive modes in order to use the Com-Spec/Walston stuff appropriately. It's AM/FM with no USB, LSB or CW modulation. Those companies diddle with the mode
parameters so only "their" receivers "hear" their products optimally. I mentioned a Kenwood F6A and I can get it to hear a Com-Spec tracker using USB or CW but I haven't done an all-important range test. I took it to MWP once many
years ago and tuned across the 1.25M "animal/rocket" tracker band (sorry Fred, but I agree with what you said in #12). I was able to tune across and "hear" the trackers going while the rockets were being prepped with the F6A.
Whether or not it would work in "real life" as well as a native receiver remains to be seen. Me thinks it might not work as well. Would be fun to try it though along side the same manufacturers receiver.

I actually moved on to APRS and straight FM RDF stuff for Ham radio because I wanted something optimized off the bat and gave up with pursuing Com-spec Walston with an F6A. Kurt

#### Cl(VII)

##### Chris Bender, Lab Rat
Guys, thanks again for the direct help as it let me reach decision rapidly with what will surely be a good setup. I'm still learning from the ongoing discussion, so feel free to turn this thread into a general rdf tracking thread if you like.

#### Handeman

##### Well-Known Member
TRF Supporter
So, I can't help with the radio technical stuff, but I have done a lot of RDF tracking with our Walston transmitters and receiver.

My suggestion is, put the transmitter in every flight if think you will need it or not. Use the antenna and track the rocket up and down. Keep turning the antenna 90 deg. Check with the antenna vertical and horizontal. It will pick up signals differently. The directional accuracy is different depending on antenna orientation. If your transmitter is inside the rocket and exposed after ejection (taped to shock cord) you should be able to tell when ejection occurs by the change in signal strength.

Getting all the technical parts right is important, but it still takes practice. So practice with every flight until you have it down. Then when you need it, you'll know what you're doing.

BTW, what I've found is that even on the flights where you would find the rocket anyway, many times the RDF can save you time and get you back flying again quicker. It's worth learning and practicing.

#### ksaves2

You're all set if you wish to jump into APRS tracking with your receiver. If you would have sprung for a D72A ($20 or$30 more) there are some mapping options out there for Android and Laptop devices using the USB port on the D72A for APRS tracking.
Plus there is the facility to plug an external mapping GPS into the D72A and have it plot positions on an Etrex Legend, 60Cs or 60CsX. Nice thing is even though those GPS mapping units are out of production, they can be had used on ebay for
a reasonable cost and open source maps (spell that free) are available for them.
Hmmm, an offline tracking solution for Android with storable OSM maps is here: https://www.qsl.net/ja7ude/SmartPhone/w2aprs_osm/indexe.html

I'll give this one a look see an explore if it is better than APRS Droid. Kurt

#### Cl(VII)

##### Chris Bender, Lab Rat
You're all set if you wish to jump into APRS tracking with your receiver. If you would have sprung for a D72A ($20 or$30 more) there are some mapping options out there for Android and Laptop devices using the USB port on the D72A for APRS tracking.
Plus there is the facility to plug an external mapping GPS into the D72A and have it plot positions on an Etrex Legend, 60Cs or 60CsX. Nice thing is even though those GPS mapping units are out of production, they can be had used on ebay for
a reasonable cost and open source maps (spell that free) are available for them.
Hmmm, an offline tracking solution for Android with storable OSM maps is here: https://www.qsl.net/ja7ude/SmartPhone/w2aprs_osm/indexe.html

I'll give this one a look see an explore if it is better than APRS Droid. Kurt
I thought seriously about the Kenwoods when I got the radio, but the FT2DR was still on intro pricing. Also, I hit a Gigaparts sale, so I only ended up paying $279 for a new one. Just too much value at that price. I am definitely looking forward to using it for APRS down the road (high alt balloon hopefully). I also like that it is very small, and goes right in the hiking backpack. We get into some of those no cellular service areas on foot from time to time, and it is good to know I have a way of calling for help and being able to transmit our GPS coordinates should we get in trouble. Just a really versatile thing having a good radio and a license. Last edited: #### ksaves2 ##### Lifetime Supporter TRF Lifetime Supporter I thought seriously about the Kenwoods when I got the radio, but the FT2DR was still on intro pricing. Also, I hit a Gigaparts sale, so I only ended up paying$279 for a new one. Just too much value at that price.

I am definitely looking forward to using it for APRS down the road (high alt balloon hopefully). I also like that it is very small, and goes right in the hiking backpack. We get into some of those no cellular service areas on foot from time to time, and it is good to know I have a way of calling for help and being able to transmit our GPS coordinates should we get in trouble. Just a really versatile thing having a good radio and a license.
Can't argue with that logic. I took a quick look at the manual and I didn't see a way to pipe the waypoints to a jack or port. If there is some way to do that, even over bluetooth you would have the capability to use it with a mapping program
easily. Keep an eye out for that while you're reading the manual if it's possible, you got it made. Kurt

#### manixFan

##### Not a rocket scientist
snipped....
I would strongly recommend you do NOT use:
- wildlife trackers...as it's illegal to call your rocket wildlife..
Can you elaborate as to which wildlife trackers you are referring to? As well as a link to regulations on their use?

Thanks,

Tony

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#### OverTheTop

##### Well-Known Member
TRF Supporter
I know in Australia wildlife trackers use different frequencies and come under different requirements in the band allocations. Can't remember the details though.

#### FredA

##### Well-Known Member
"The use of frequencies in the bands 40.66-40.70 MHz and 216-220 MHz for the
tracking of and telemetry of scientific data from ocean buoys and animal wildlife."

You need to have your usage licensed by the FCC to use these frequencies.
I believe Walston's used the 216-220 range but now notice that all references to frequency have been removed from his website.

#### ksaves2

snipped....
Can you elaborate as to which wildlife trackers you are referring to? As well as a link to regulations on their use?

Thanks,

Tony
Technically, the Wildlife trackers are below the 220 to 225Mhz Ham band (ex. 216Mhz) and is supposed to be used for wildlife tracking. Some "purist's" feel it's a misuse of the band to use it for anything other than wildlife tracking.

Kurt

#### FredA

##### Well-Known Member
Some "purist's" feel it's a misuse of the band to use it for anything other than wildlife tracking.

One of those "purist's" is the FCC who demand you license usage in this frequency band.
Even the wolf trackers at YNP got into a bind when the guy who applied for the license quit/retired/died and nobody did it...the band was re-issued to somebody else.

Don't go there....

#### Steve Shannon

##### Well-Known Member
TRF Supporter
Some "purist's" feel it's a misuse of the band to use it for anything other than wildlife tracking.

One of those "purist's" is the FCC who demand you license usage in this frequency band.
Even the wolf trackers at YNP got into a bind when the guy who applied for the license quit/retired/died and nobody did it...the band was re-issued to somebody else.

Don't go there....
My company (at the time) was the one issued the collar frequencies when the researchers failed to renew their license. It was obvious the animals were not going to come in to be retuned, so the company worked with FCC and the researchers to allow them to keep and relicense their existing frequencies. It was all worked out as friends.

#### ksaves2

Some "purist's" feel it's a misuse of the band to use it for anything other than wildlife tracking.

One of those "purist's" is the FCC who demand you license usage in this frequency band.
Even the wolf trackers at YNP got into a bind when the guy who applied for the license quit/retired/died and nobody did it...the band was re-issued to somebody else.

Don't go there....
I agree with you Fred but there a so many folks using the un-licensed trackers that are danged near impossible to police with the budget cuts to the FCC.
The falconry folks are at least tracking "their" wildlife with them. I have a ComSpec tracking transmitter but it's in the 1.25M Ham band with my callsign
programmed into it.

To be morally right folks should use tracking means that are legally available to them. In reality, enforcement is darn near impossible.

Like in the bad old days with the "Easy Access" motors that were determined to be "illegally" skirting the LEUP requirement laws. I never saw any flier
queried about whether or not they had an LEUP to fly that J motor. Thank heavens those days are past. Kurt