For Sale Custom Comspec Receiver Compatible Beacons

[MichiganJohn]

Yes I'll take a couple, been looking for some extras and they sound awesome. 223.23 and 223.13 please. Will I be able to program these myself, ie change the frequency or add a callsign? (no worries if not, just curious).

 

[Brainstormz123]

First draft of reprogramming instructions for the rocket beacon. If anyone gives this a try and is successful (or isn’t) please let me know so I can improve on it. Feedback would be very nice

https://drive.google.com/drive/folders/1ept8xX9jvuACS7xe_rICjNajERtbykez?usp=drive_link

 

[mikec]

I haven't tried it but it looks pretty straightforward if you have experience with microcontroller stuff. Thanks!

For USB-UART adapters that don't get powered from the V+, I assume this is a 3.3V device?

 

[Brainstormz123]

I haven't tried it but it looks pretty straightforward if you have experience with microcontroller stuff. Thanks!

For USB-UART adapters that don't get powered from the V+, I assume this is a 3.3V device?

The voltage on V+ can be anywhere from around 2.5v to 5.2v, but I have been using 5v when I program it. Ill make sure to update the notes with that info.

 

[David Schwantz]

Got my beacons today. They came programed with the 4 beeps. My mistake for not asking, but after a couple pm's he already has 2 new shipped out to me with my choice of programming. That's pretty good CS in my book. Thanks,

 

[Brainstormz123]

My mistake as well for not following up and asking everyone. This offer stands for anyone who is not happy with their beacons and is not comfortable programming them. I have them configured to send out 4 beeps at differing power levels.

This gives you an estimate on the distance you are to the rocket (comspec beacons do not have this feature). 1 beep means you are about 3 miles away, 2 means under a mile, 3 means within a quarter mile, 4 means you are very close. I find it convenient for me, but others may not like this feature. They are easily reprogrammable and I can compile firmware for you if you arent comfortable working with the coding.

Please let me know if any of you who have requested beacons have any issue with them at all and I will work to make it right.

 

[manixFan]

I got a couple of the trackers today and immediately tested them out by reprogramming them between two different receivers – an old RocketHunter (ComSpec) and a much newer Marshall. A simple modification to the standard cable used to program the Eggtimer products and a little creative wiring to connect it to the beacon (I didn't have a spare 4 or 5 pin male cable handy) was all it took. I downloaded the Mac versions of the ST software which ran fine on my Mac Studio. (M series chip.) It was insanely easy to update the beacon by just changing a few numbers in the firmware code and then sending it off. It was quite the moment when I fired up the Marshall and heard the beacon that a few minutes earlier had been beeping out on the RocketHunter. It literally takes a couple of minutes at the most to reprogram the units. The fact that I can use my Mac is icing on the cake for me.

So far I like the four beeps that are the default setting. Any extra little help in tracking down a rocket is a good thing. With the RocketHunter beacons, I often tracked 38mm and 54mm MD rockets several miles, with the farthest being 4.5 miles. I'm confident I'll get just as good if not better results with these beacons.

I'm planning on flying one in an H13 rocket at the end of January, which should be a good test. But so far, I am extremely pleased with the units.


Tony

 

[kjhambrick]

Mine arrived last night, a day earlier than the USPS predicted.

I like the idea of the beep-count indicating signal strength.

The device without the enclosure fits very nicely in the new 29mm and 24mm fiberglass nose cones that @gltruett made for me.

No worries there, I already fly my Walston CA MODA 2338 transmitters wrapped in a little black tape and foam and they're vey happy that way ...

And I really like the 29 cm antenna -vs- the 48.25 cm antenna on my Walston CA MODA 2338 transmitters !

Much less antenna wire to tangle in my shock cords !

Gotta go get some fresh CR2032 batteries and tune my Walston to Band B Channel 9 ( 220.255 MHz )

Then, as soon as the weather clears, I'll take my my 4 -and- 8 year old granddaughters to the local elementary school to play hide-n-seek

THANK YOU, Alexander !

-- kjh

EDIT: Q for @Brainstormz123 ... do you recommend some sort of strain relief for the antenna wire, with or without the enclosure ?

 

[Brainstormz123]

Regarding strain relief, I wouldnt put any load on the antenna for sure. If i have a high G flight or one that can get dicey, I put a drop of epoxy or hot glue on where the antenna is soldered to the beacon board just as another layer of protection.

 

[mccuesteve]

Selling a couple comspec receiver compatible radio beacons. Works with the comspec receiver and transmits at 100mW. Integrated removable coin cell connector on the back (also works with a 1s lipo battery). Battery life approximately 8 hours. Case included. Programmable to any comspec channel and has a 220mhz wire whip antenna. These beacons are programmable to different frequencies and are capable of transmitting different powered beeps to get a guesstimate of range to the rocket. Also optionally programable with a callsign if you want to keep the FCC happy

Asking $40 each

I'm interested in 2 223.450 and 223.550 4 beep. Send me pm

 

[manixFan]

For those wondering about the two different beacon types – Continuous Wave (CW) vs. Frequency Shift Keying (FSK), I've attached some audio samples below:

• first is the default programing with both FSK and CW beacons turned on and set to 4 beeps (it's easy to see why many would not want the FSK tones turned on)
• second is CW only with only 1 beep at the default 2 second interval, which is a typical beacon notifier
• third is CW with 4 beeps at 1 second internals
• fourth is CW with 4 beeps at 1.5 second intervals
• fifth is CW with 4 beeps at 2 second intervals

Tony

original settings with FSK tones followed by CW:
View attachment Original with FSK and CW.wav

CW 1 beep @ 2 sec second intervals:
View attachment CW 1 beep 2 second interval.wav

CW 4 beeps @ 1 sec intervals:
View attachment CW 4 beep 1 sec interval.wav

CW 4 beeps @ 1.5 sec intervals:
View attachment CW 4 beeps 1.5 second interval.wav

CW 4 beeps @ 2 sec intervals:
View attachment CW 4 beeps 2 sec interval.wav

Here’s what the 4 beep beacon looks like. First are the FSK beeps, then the CW ones. The 4th beep got lost in the waveform when I normalized the volume to -3db, but you can see it in the spectrum display below the waveform:

 

[tfish]

@Brainstormz123
Wow..very cool/good.
I just did a ground test..layed on the ground in my front yard..with the antenna coiled up..could still hear it with my old ears at 1 mile.
2nd test ....with half the antenna un-coiled got it out to 1.5 miles..
I was using an old Wakston unit.
A few years back I had made up some antenna out of very flexible coated stainless leaders..I think I have some left to try..
Very nice product..Thanks!





Tony

 

[Brainstormz123]

Glad to hear they worked well for you!

 

[cwbullet]

They worked for me also. Good ground test on one. I will test the others in the next couple weeIs. I am sure they will work fine.

 

[rfjustin]

Glad to hear they worked well for you!

Received my two, so far so good on testing!

Best,

 

[markg]

Out of curiosity, what are some receiver options that would work with these transmitters?

 

[Brainstormz123]

Out of curiosity, what are some receiver options that would work with these transmitters?

Comspec receivers, LL (maybe its FL) electronics, kenwood, and theres a few more I can’t remember, but any 220mhz directional receiver can be made to work (since these are heavily programable). Let me know what you have and I can tell you if its compatible.

 

[markg]

Comspec receivers, LL (maybe its FL) electronics, kenwood, and theres a few more I can’t remember, but any 220mhz directional receiver can be made to work (since these are heavily programable). Let me know what you have and I can tell you if its compatible.

I don't have any receiver, was just wondering what one would cost to see if this would be an economical backup for the eggfinder equipment I use.

cheers - mark

 

[jd2cylman]

I don't have any receiver, was just wondering what one would cost to see if this would be an economical backup for the eggfinder equipment I use.

cheers - mark

I can help with that. I’ve got two…

 

[StreuB1]

@Brainstormz123

Are these transmitting on a sideband or carrier centered?

What is the modulation?

Do you have a screen shot of the receive spectrum (spectrogram) that you can post up, please?

Or for that matter, anyone else that has received one?

Thanks!!!

 

[Brainstormz123]

@Brainstormz123

Are these transmitting on a sideband or carrier centered?

What is the modulation?

Do you have a screen shot of the receive spectrum (spectrogram) that you can post up, please?

Or for that matter, anyone else that has received one?

Thanks!!!

These transmit directly on 220mhz (or whatever programmed frequency) using what is basically lora that has been bullied into transmitting either CW or FSK (optionally programmable to transmit either type).

As for a spectogram, @manixFan posted a couple screenshots and audios a bit ago, and I can post some more when I get back home after new years.

 

[jd2cylman]

@Brainstormz123

Are these transmitting on a sideband or carrier centered?

What is the modulation?

Do you have a screen shot of the receive spectrum (spectrogram) that you can post up, please?

Or for that matter, anyone else that has received one?

Thanks!!!

Ya know, late at night while laying in bed, I often ask myself these questions…

 

[manixFan]

For those wondering about call signs, I programmed a friends call sign into the beacon and then tested it out. I recorded the tones and played them back on a website that decodes audio morse code. It spit out the correct callsign, which was a good verification that that the code works correctly. And just for @StreuB1, I've attached a screenshot of the received audio spectrum below.

FWIW, I've found that so far I like single beeps, 30ms long, 1500ms spacing.


Tony

(actually, I just like how the graphs look, I would have posted it anyway):

 

[kjhambrick]

That's awesome Tony !

Where do you normally fly in Texas ? Dooh ! I already asked that Q !

You fly at Seymour, TX with TNT !

I've really got to get up there this coming Year !

-- kjh

 

[manixFan]

That's awesome Tony !

Where do you normally fly in Texas ? Dooh ! I already asked that Q !

You fly at Seymour, TX with TNT !

I've really got to get up there this coming Year !

-- kjh

We'd love to have you (and all others) come fly with us – it's a fantastic field and the landowner is just unbelievably supportive. He's installed several permanent shelters and added a bunch of gravel to the site to help out on rainy days. We have a 32K' waiver, so you can really test out your tracking skills. Hope to see you there.


Tony

 

[kjhambrick]

Woo Hoo @Brainstormz123 !

The Comspec transmitter worked great with my Walston yesterday !

I actually like the beep pattern but my rocket landed only 1200 ft from the pad so I never got to hear it change with distance.

I flew it sheathed in bubble wrap and duck tape on my drogue shock cord because that's how I always flew the Walston CA MODA 2338's

I REALLY like the shorter antenna wire which meant that I didn't have to shoe-horn a springy braided steel cable ( Walston antenna ) into my relatively short booster.

I didn't think to get any pictures of the Comspec transmitter in the rocket because I was a little rushed -- yesterday was an AARG "Extra Launch" and the window was only two hours and I had to work in the morning.

There is a launch report: Bird on a Wire ( How Spock's Johnson Avoided Landing in a Tree or a Pond )

I was still receiving the signal after the rocket landed on the power line but it was sheathed pretty well and the transmitter antenna was well below the power line:


It is the blob of duck tape on the shock cord behind the fins ...

I'll be sure to get some pictures of the gadget in the rocket next time when I set up !

Thank you !

Will these be available for a while ?

I want a couple spares but I'll have to wait a week or two after spending money on motors so my wife doesn't 'ground'' me

Thanks again Alexander !

-- kjh

EDIT: p.s. I added a little blob of epoxy to the antenna solder joint and it held just fine ...

 

[Art Upton]

Did the power company retrieve the rocket?

 

[kjhambrick]

Did the power company retrieve the rocket?

No, I didn't need them.

The way it was draped over the wire, all I did was cut the shock cord and it fell to the ground.

-- kjh

 

[Brainstormz123]

Woo Hoo @Brainstormz123 !

The Comspec transmitter worked great with my Walston yesterday !

I actually like the beep pattern but my rocket landed only 1200 ft from the pad so I never got to hear it change with distance.

I flew it sheathed in bubble wrap and duck tape on my drogue shock cord because that's how I always flew the Walston CA MODA 2338's

I REALLY like the shorter antenna wire which meant that I didn't have to shoe-horn a springy braided steel cable ( Walston antenna ) into my relatively short booster.

I didn't think to get any pictures of the Comspec transmitter in the rocket because I was a little rushed -- yesterday was an AARG "Extra Launch" and the window was only two hours and I had to work in the morning.

There is a launch report: Bird on a Wire ( How Spock's Johnson Avoided Landing in a Tree or a Pond )

I was still receiving the signal after the rocket landed on the power line but it was sheathed pretty well and the transmitter antenna was well below the power line:
View attachment 622256

It is the blob of duck tape on the shock cord behind the fins ...

I'll be sure to get some pictures of the gadget in the rocket next time when I set up !

Thank you !

Will these be available for a while ?

I want a couple spares but I'll have to wait a week or two after spending money on motors so my wife doesn't 'ground'' me

Thanks again Alexander !

-- kjh

EDIT: p.s. I added a little blob of epoxy to the antenna solder joint and it held just fine ...

Glad to hear it worked out for you (with some unfortunate circumstance).

As for how long these will be available for, I only have a few left, but will have time to make a bunch in a short while (maybe next week or the one after). Some parts are going out of stock so I may stockpile a few of them for future beacons.

 

[kjhambrick]

Your timing sounds abour right for me Alexander.

My wife does not share my enthusiasm for rocketry so I have to tippy toe around my rocketry purchases

-- kjh