Wanted Wanted: Jerry's Beeping Transmitter (or similar)

[techrat]

Looking for a dead-simple radio frequency beeper that I can stuff in a rocket and then locate via a handheld (such as a Baofeng) and a tape-measure yagi antenna. Ideally on the 2-meter band, but 440 is OK too as most of my handhelds are dual-band. I think Jerry's kit ran on 108Mhz FM.

Basically I'm looking for a Fox in a Fox-hunt that doesn't cost $60 or more, ideally only about $20 plus shipping. If you've got something in your junk box that still works, and you've moved on to GPS tracking at 900Mhz and up, let me know. I do not need a xmitter/reciever combo as I already have a handheld ham radio, and that's what I'm looking to make use of.

I find it kind of funny that I can buy a brand-new Baofeng on Amazon for $25, but a simple beeper is $60 or more.
If I can't find anything, I'll launch a Baofeng with the xmit button taped down. Thanks!!

 

[StreuB1]

Look into making one. Lots of plans online.

 

[alexzogh]

I've many versions of these for $25 or less. Wondering what search terms you are using. If you search "ham radio beacon" you will pick up all of the knock-off cheap Chinese beacons. I've used several of them, and they've all worked pretty well.


This one is $18.

UHF - defaults to 433 band, but you can switch it, need to hunt to find the directions. I own one of these, works pretty well. Uses a 2032 button battery. Claims it sips 20ma, but actually sips 30 or so. That should give you about 3 days of tracking before a fresh battery dies. When the rocket is on the ground, you will need top be within about 1.5 miles of the tracker to pick it up.

https://www.aliexpress.us/item/2255800661939106.html
You can also find them from US sellers on eBay for double the price.



This one is $21

Holy crap is it small. You will also need to do some soldering to get an antenna and power connected to it. Great if you want to integrate it into an eBay with a lithium battery and an optimized antenna in a nosecone, or your own custom portable version. I have a few of these laying around. Only made one into a workable unit so far, about half the range as the one above, or below.

View attachment vCmUOvNtaP0jGTEz5uw_257578854297_ld_hq.mp4

https://www.aliexpress.us/item/2255800661703190.html



This one is $24

I have several of these, they are my favorite. Can handle varying voltage, Variable beep interval, and variable frequency. About twice the range as the first one, with a similar power draw.

https://www.aliexpress.us/item/2255800206633834.html

Like the others, you can also find them on eBay for twice the price.


Lots of instructions online to build your own - https://www.instructables.com/433-MHz-UHF-lost-model-radio-beacon/ . or software driven one: https://github.com/Guenael/tinybeacon . Not sure it's worth anyone's time at this point unless you like to build these things for fun.


Hope this helps.

 

[ksaves2]

Technically, one is supposed to be a Ham operator to run in the 2 meter or 70cm (144Mhz and 400Mhz) bands. Even if low power is used. In reality, no one including the FCC is going to care. The Feds only get involved if they get a complaint. With a low power rocket tracker, yeah it carries far while in the air but I doubt anyone outside the flier is going to be listening. On the ground, the range is going to be short. 900Mhz is worse on the ground but if one has a fair idea where the rocket is, especially with GPS tracking, they'll get within range and do the recovery. 900 Mhz GPS tracking is fine for unlicensed use and I've had 100% success with it unless a deployment failure trashes everything. On the Ham bands, propagation is better and the ground footprint is farther. It's best for projects going high and staying out of sight for a longer time. Even then, a GPS tracker on the ham bands 400 Mhz is better. 144 Mhz is even better with propagation but the required longer optimal antenna is hard to stuff into a smaller rocket.

A Yagi-Uda antenna on the receive end with an offset attenuator is a better bet in the ham bands for Rf tracking by pointing a Yagi antenna. I know they say "one can use their body" to shield a "plain" receiver antenna but when one gets closer and the signal gets stronger, unless a Yagi with an attenuator is used, all directionality is lost. For modrocs, I'd say a tracker with a simple receiver is probably adequate but with serious flying hardware, a Yagi with an offset attenuator is a must for tracking. I've seen rockets lost with simple Rf trackers even when the flier had a good "tracking kit" on the receive end. They just couldn't keep a good fix to do the recovery as the rocket landed so far away. With rockets with less "out of sight" time Rf tracking works good. For larger and pricier hardware, GPS tracking is a must. For serious flights, APRS Ham band tracking is the best in my opinion. Longer the "out of sight" time, the better tracking modality should be used to help with recovery.

On the 900 Mhz bands, they say a Yagi-Uda antenna is useless for directional tracking. That's true but it does increase the receiving range on the receiver end if one has an idea where the rocket is going and points the antenna accordingly. 900 Mhz of course in rocketry is doing GPS tracking and I'm convinced a 900 Mhz Yagi increases the receiving range. It's the "last known position" that's key to make the recovery. At 900 Mhz (the "experts" say) the directionality of the signal is practically impossible due to the nature of the high frequency. Hence one doesn't see simple Rf 900 Mhz trackers. As I mentioned above, a 900 Mhz Yagi will increase the range of the rocket in flight. Gives a chance of getting a better "last known" position on descent.

Shoot I did an experiment one time with a downed rocket with a 900 Mhz GPS tracker. I had a 900 Mhz, multi-element Yagi and of course when the rocket was down, I lost the signal. I had the last received position when the rocket was 50 feet in the air and likely would recover the rocket nonetheless.
As I got closer to the rocket, I was pointing the Yagi antenna in the general direction of the rocket as I knew it. This was a clear farm field mind you and the crops were in.
When I just got close enough to get a position fix, I took the Yagi antenna off and put the straight "rubber duck" stock antenna on the receiver. The signal disappeared. Put the Yagi back on and the signal returned. O.k. I still would have recovered the rocket with the "duck" antenna but with a very serious high-powered project flying on 900 Mhz trackers, a Yagi can help maximizing the range of the "last known" position in the air as long as one knows the general direction to point the Yagi antenna.

Now in my case, I was getting a lat/long position of the downed rocket. In reality, if the GPS antenna was facing the dirt, I might not have that "rocket on the ground" position. The 50 foot in the air position would have brought me close enough to find it though.

Kurt KC9LDH L2

 

[techrat]

Ok, Thanks Alex. I have ordered one of the Red $18 one and one of the Pink $24 one and I'll try them out. Worth it right now just to show the Radio Club guys as well, and we can always do a "soccer field" fox hunt as well.

 

[ksaves2]

Ok, Thanks Alex. I have ordered one of the Red $18 one and one of the Pink $24 one and I'll try them out. Worth it right now just to show the Radio Club guys as well, and we can always do a "soccer field" fox hunt as well.

Sounds like you know what you're doing! Kurt

 

[DabCat]

I've many versions of these for $25 or less. Wondering what search terms you are using. If you search "ham radio beacon" you will pick up all of the knock-off cheap Chinese beacons. I've used several of them, and they've all worked pretty well.

View attachment 586576
This one is $18.

UHF - defaults to 433 band, but you can switch it, need to hunt to find the directions. I own one of these, works pretty well. Uses a 2032 button battery. Claims it sips 20ma, but actually sips 30 or so. That should give you about 3 days of tracking before a fresh battery dies. When the rocket is on the ground, you will need top be within about 1.5 miles of the tracker to pick it up.

https://www.aliexpress.us/item/2255800661939106.html
You can also find them from US sellers on eBay for double the price.

View attachment 586577

This one is $21

Holy crap is it small. You will also need to do some soldering to get an antenna and power connected to it. Great if you want to integrate it into an eBay with a lithium battery and an optimized antenna in a nosecone, or your own custom portable version. I have a few of these laying around. Only made one into a workable unit so far, about half the range as the one above, or below.

View attachment 586578

https://www.aliexpress.us/item/2255800661703190.html

View attachment 586579

This one is $24

I have several of these, they are my favorite. Can handle varying voltage, Variable beep interval, and variable frequency. About twice the range as the first one, with a similar power draw.

https://www.aliexpress.us/item/2255800206633834.html

Like the others, you can also find them on eBay for twice the price.


Lots of instructions online to build your own - https://www.instructables.com/433-MHz-UHF-lost-model-radio-beacon/ . or software driven one: https://github.com/Guenael/tinybeacon . Not sure it's worth anyone's time at this point unless you like to build these things for fun.


Hope this helps.

What ground equipment is needed for the pink and red one? I might be interested in pursuing RDF tracking.

 

[techrat]

What ground equipment is needed for the pink and red one? I might be interested in pursuing RDF tracking.

Look up Amateur Radio Direction FInding (also known as Fox-Hunting). Basically, you take a handheld ham radio and a directional antenna, you circle around looking for the direction in which the signal is strongest, and then continue to follow. You may also need an attenuator. But another trick is to dial a little off-frequency when you grow closer which can mimick attenuation.

I use a Yeasu handheld, a 3-element tape-measure Yagi, and an attenuator I picked up used at a hamfest. You need a radio where the signal strength meter really does work, so although I love Baofengs, they don't always have a signal strength meter that is true. That said, I've successfully used a UV-5R, but I also must admit that I get lucky a lot. Since you are only recieveing the signal, you don't really need a ham radio -- a handheld scanner like the old Radio Shack Pro-51 will also work well.

 

[ksaves2]

Techrat is 100% correct. I never tried the body shield technique with a "duck" antenna as I went straight to an Arrow antenna Yagi and an attenuator kit.
I wanted to do GPS tracking before the 900 Mhz stuff came out and got a Ham General license as I also wanted to talk on the Hf bands with a ham radio. I did some Rf tracking and I tell you, a decent Yagi with an attenuator makes it very, very easy. I went on to GPS APRS tracking and never went back to Rf tracking. It was just so darned easy as I was piping the position packets to a laptop tracking program and "seeing" on a map where the rocket was going. That is the cat's meow. I interfaced a Kenwood D7Ag and a D72A (the Ag is oop and don't buy one used as they are so old the frequency tuners are off and can't be fixed.) I interfaced from a D72A to a Garmin 60Csx handheld mapping GPS and I had the rocket position on a map! That was my portable set for recovery and I used a laptop interfaced with a radio and TNC to track from the launchsite on a map.
The no license required 900 Mhz GPS tracking hardware came out and I thought that was great so folks who weren't amateur radio operators could get into the GPS tracking game. Perfectly fine for sport fliers. For really extreme projects, the Ham bands offer a bit better propagation and extra edge for tracking.
I tried using higher powered amateur radio trackers in the 150Mw. range and it was bad ju-ju all around. The tracker interfered with the circuits on the deployment altimeters and would shut them down or interfere and blow the charges while sitting on the launch pad. If you deal with tracking products or kits made by "rocket folks", specifically for rocket tracking you won't have a problem.
On ascent the GPS will lose lock due to G's and GPS limitations. After apogee is passed and the speed drops, positions will start to come in especially once under a drogue and or main chute.
Be aware, I have seen rockets lost with Rf trackers in the situation with a main at apogee event at extreme altitude. Even though the rocket had an Rf tracker, the fliers couldn't keep up to it in a chase car and it drifted out of range on the receiver end. Might have landed in the Illinois river too.
Kurt

 

[Kelly]

Since Baofengs have such bad s-meters, is there a cheap alternative that would allow one to do RDF? I'm not talking about a full-function radio (can't get cheaper than Boafeng there) but just a simple receiver/meter that you could pair with a Yagi? Seems if transmitters are less than $20 than a receiver shouldn't be more...

 

[techrat]

Yes, I'd say hit eBay or Craigslist and get yourself a cheap old analog Radio Shack handheld scanner. An old scanner should be $20 or less.
Don't get the Uniden digital trunking ones that are $400.