Ham radio in rocketry?

The Rocketry Forum

Help Support The Rocketry Forum:

spacepotato88

Member
Joined
Jun 16, 2021
Messages
7
Reaction score
1
Hi! I was wondering how do folks incorporate ham radio into rocketry? I have my technician's license (and I'm an RF engineer at a space company with a EE degree) and I've been trying to get more into model rocketry as a hobby (have an L1). So, naturally I was wondering how could one use ham radio in model rocketry since when I try to google it there's mostly work arounds to launching without a license which I don't care about (note, I've never done electronics in any rockets I've built but I want to start, so please excuse my inexperience/basic question -- also if anyone has good guides or resources they'd be willing to share I'd be super appreciative!). Thank you for your time!
 

mbeels

Yes balsa
TRF Supporter
Joined
Feb 9, 2019
Messages
2,917
Reaction score
1,648
Welcome to the forum! There are a few ways people incorporate ham radio int rocketry, probably the most common are either using GPS trackers on HAM frequencies (eggfinder has a HAM option), beacon trackers with RDF equipment, or even APRS. Literally the sky's the limit, so plenty of more options out there.
 

spacepotato88

Member
Joined
Jun 16, 2021
Messages
7
Reaction score
1
Welcome to the forum! There are a few ways people incorporate ham radio int rocketry, probably the most common are either using GPS trackers on HAM frequencies (eggfinder has a HAM option), beacon trackers with RDF equipment, or even APRS. Literally the sky's the limit, so plenty of more options out there.
Neat, thanks for the information!
 

watheyak

Barnstormer
TRF Supporter
Joined
May 11, 2009
Messages
1,021
Reaction score
822
Location
Arizona
You might find it odd that I find myself in your exact opposite predicament. I got a HAM license expressly for tracking rockets. As pointed out by mbeels, it's been great for RDF and GPS packets, although these days there are license free alternatives that are perhaps more capable. But here's two outstanding HAM based tracker/rocketry electronics companies. I've used both. Great companies and great people behind them.


So, now that I my use for the HAM license has stalled somewhat, I find myself wondering "What do people actually do with these privileges?" I talk on 118.0-137.95 when I'm at work, so I'm looking for something besides just seeing who I can talk to. Suggestions?

It's embarrassing that I took the test out of necessity and literally know nothing about any of it. Something I think I 'd like to rectify...
 

OverTheTop

Well-Known Member
TRF Supporter
Joined
Jul 10, 2007
Messages
5,505
Reaction score
2,865
Location
Melbourne Australia
Welcome to the forum.

I have an advanced amateur ticket (VK3TRK) and only got that because I wanted to track rockets. I use a TeleMega (435MHz) mainly as my flight electronics, although I am now doing a Vertical Trajectory System that is to steer the rocket vertical. It also has a HD video camera with data overlay so there is some 1.3GHz video telemetry involved with that. I also recently added a long-range 915MHz telemetry link to feed the location of the bird to my automatic antenna tracker that will receive the video. Also, that video will have a short-range telemetry link to the 24" LCD TV at the launch site.

So there is plenty you can do with a HAM radio license around rockets :)
 

WillMarchant

Well-Known Member
TRF Supporter
Joined
Jan 15, 2009
Messages
2,441
Reaction score
113
Tracking and telemetry are great projects.

There are lots of things to do with your ham ticket outside of rocketry. Www.AMSAT.org and https://www.ariss.org/ for example.

Next week, the ISS will be transmitting pictures that you can receive with your 2m handheld and decode with a smartphone app like the Black Cat Systems SSTV app for iPhone. Details at http://ariss-sstv.blogspot.com/
 

plugger

Well-Known Member
Joined
May 1, 2009
Messages
554
Reaction score
235
Not to mention checking in with home base when you have to go on those long retrievals... a 5W handheld is good for that.
Having a radio tuned into the local aerodrome Airband is also a good thing to have on the flight line. Often you hear aircraft over the radio before you hear them in the air.
 

FMarvinS

Well-Known Member
Joined
May 27, 2015
Messages
482
Reaction score
102
Welcome to the forum and ham radio. Another site of interest with great products is the Byonics site where 2 watt 2 meter transmitters and GPS are some of the offerings. I also 2nd the excellent products of the Big Red Bee (look at their 70 cm band trackers and 2 meter GPS units) and the Eggtimer gps products. If live transmission is of interest (kinda like FPV) then check out the www.hamtv.com site where small TV (up to 5 watts) 70 cm band transmitters are described for ATV use. There are 2 meter transceivers in development whereby a ground signal would be received by the transceiver on the rocket which can then be used to trigger a servo or other device. The possibilities are only limited by your imagination and the size of your wallet.
Finally, when it comes to setting up a ham gps tracking unit-you can't beat ksaves2 numerous posts. I use the Kenwood 72A cabled to a garmin 60csx as he describes to acquire excellent tracking maps. The main thing is to have fun!

73,
Fred
KG4YGP
 

plugger

Well-Known Member
Joined
May 1, 2009
Messages
554
Reaction score
235
Another site of interest with great products is the Byonics site where 2 watt 2 meter transmitters and GPS are some of the offerings.
Last I checked Byonics was using SiRFStar IV chipsets, which are less than ideal for rocketry use.
Link here for more info.

There are 2 meter transceivers in development whereby a ground signal would be received by the transceiver on the rocket which can then be used to trigger a servo or other device.
There are plenty of homebrew GPS/flight computers that have DTMF capabilities that allow for issuing commands to a GPS/FC in flight as well as switching from various modes (eg bench to flight mode) while on the ground. I've got a handful of them in the shed myself.
 

FMarvinS

Well-Known Member
Joined
May 27, 2015
Messages
482
Reaction score
102
Plugger-Byonics produces several 2 meter transmitters which work with ublox, sirf, and possibly other chipsets. They offer the SIRF IV which is personally fine for sport rocketry . In fact I've used it on multiple flights < 20,000feet without problems. What's exceptional about Byonics, BRB, and Eggfinder is their customer service. So, the ability to connect a ublox 6 or newer chipset to a Byonics unit is doable, particularly with available company customer directed advice. Furthermore, the Byonics transmitters I use have integrated slide switches (that were kindly added in response to my request) to change the frequency of transmission. This is helpful if other units or repeaters are operating on or near the initial transmitter frequency intended for use.

You state there are plenty of homebrew DTMF based flight GPS computers available. The operative word in my post is "commercial. " Aside from Missile Works which sells an independent (non-ham band) transmitter, I am not aware of other "ham-band" commercial dealers with such products. However, I've been informed of such units currently being beta tested in the ham bands.

The request by spacepotato was for applicable general info on the interplay between ham radio and HPR. That's what I and others conveyed without a detailed comparison of product A vs. B which would be more appropriate if the inquiry was so worded.
 

Buckeye

Well-Known Member
TRF Supporter
Joined
Sep 6, 2009
Messages
2,731
Reaction score
543
Model rocketry is nerdy enough. Do you really want to add "ham radio" to that image? :p
 

ksaves2

Lifetime Supporter
TRF Lifetime Supporter
Joined
Nov 25, 2009
Messages
6,230
Reaction score
449
Location
Central Illinois
You might find it odd that I find myself in your exact opposite predicament. I got a HAM license expressly for tracking rockets. As pointed out by mbeels, it's been great for RDF and GPS packets, although these days there are license free alternatives that are perhaps more capable. But here's two outstanding HAM based tracker/rocketry electronics companies. I've used both. Great companies and great people behind them.


So, now that I my use for the HAM license has stalled somewhat, I find myself wondering "What do people actually do with these privileges?" I talk on 118.0-137.95 when I'm at work, so I'm looking for something besides just seeing who I can talk to. Suggestions?

It's embarrassing that I took the test out of necessity and literally know nothing about any of it. Something I think I 'd like to rectify...
Hmmmmm,

I take it you're in the aviation industry as the aircraft band is 118-136.975 and not Ham radio. It's AM modulation.

Back in the day I had to get a restricted radiotelephone operators license (eventually) while taking flying lessons. Just send in the money, no test and the FCC sent me a wallet license so I could be so called legal operating air band radios. Suffice it to say the flight instructors taught and monitored us anyways and it was easy to learn the lingo by just monitoring on an air band receiver.

In the Ham bands there is a "----pile" of digital modes one can operate. Just look them up. Low powered digital protocols are popular now.

I tested to General at one setting and got an FT-857 with an antenna tuner. Slung a 100 foot wire up into a tree for an inverted L antenna, added a counterpoise wire and started transmitting. It's fun to see who you can bring up on such a low tech system.
I talked to England, Hawaii, Ireland, France, West Germany, Russia, several states in South America, Tahiti, Spain, Canada of course and all across the U.S. One memorable one besides Tahiti was a fellow coming home from work in California on a motorcycle on the 17 meter band! He had a helmet mike, headphones and PTT switch on the left side of the handlebars! I'm in Illinois so that was two way communication simply using a radio with no other technology in the way. Quite a jump to California I'd say.
With such a low tech setup, I was at the mercy of atmospheric propagation but if the propagation gods are smiling, signals can travel far! I think they are in cahoots with the rocket gods too!
That's a longer story.

For folks who just need a Technician license to get into the 70cm trackers that's fine. I didn't think I'd get into the HF bands even though I tested to General but did. For me it's fun but did take a bit of an investment.

There are some economical 2 meter band GPS trackers out there like the Sainsonic AP510 but one needs to be forwarned. The higher Rf output has the potential to dork deployment electronics and I was burned with it with a specific altimeter kit and a low powered tracker.

Kurt Savegnago (aka KC9LDH)
 

RocketDestroyer

Well-Known Member
Joined
Jul 31, 2014
Messages
318
Reaction score
104
The nice thing about Ham Radio is that there are so many different ways to enjoy it. Personally I've bounce signals off the moon and talked to other hams via satellites in earth orbit. I enjoy working (talking) to hams around the world on HF using voice, CW and even the new digital modes like FT8. You can run high power or low power, chase DX (stations in other countries) or rag chew with somebody in the next town. The list of things to try goes on and on. I have always wanted to put a camera on board the rocket and watch the launch live like Over the Top does but have still to try it. Find what interests you and have at it.
 

ksaves2

Lifetime Supporter
TRF Lifetime Supporter
Joined
Nov 25, 2009
Messages
6,230
Reaction score
449
Location
Central Illinois
The only thing that might be a bit intimidating is that Rf power amps can be costly but there is so much that can be achieved with 100 watts and lower.

Kurt
 

cerving

Owner, Eggtimer Rocketry
TRF Sponsor
TRF Supporter
Joined
Feb 3, 2012
Messages
4,434
Reaction score
1,833
I would imagine you'd get pretty good range with 100 W in your rocket...
 

msjohnso

Well-Known Member
Joined
Apr 6, 2009
Messages
59
Reaction score
33
Hmmmmm,

I take it you're in the aviation industry as the aircraft band is 118-136.975 and not Ham radio. It's AM modulation.

Back in the day I had to get a restricted radiotelephone operators license (eventually) while taking flying lessons. Just send in the money, no test and the FCC sent me a wallet license so I could be so called legal operating air band radios. Suffice it to say the flight instructors taught and monitored us anyways and it was easy to learn the lingo by just monitoring on an air band receiver.

In the Ham bands there is a "----pile" of digital modes one can operate. Just look them up. Low powered digital protocols are popular now.

I tested to General at one setting and got an FT-857 with an antenna tuner. Slung a 100 foot wire up into a tree for an inverted L antenna, added a counterpoise wire and started transmitting. It's fun to see who you can bring up on such a low tech system.
I talked to England, Hawaii, Ireland, France, West Germany, Russia, several states in South America, Tahiti, Spain, Canada of course and all across the U.S. One memorable one besides Tahiti was a fellow coming home from work in California on a motorcycle on the 17 meter band! He had a helmet mike, headphones and PTT switch on the left side of the handlebars! I'm in Illinois so that was two way communication simply using a radio with no other technology in the way. Quite a jump to California I'd say.
With such a low tech setup, I was at the mercy of atmospheric propagation but if the propagation gods are smiling, signals can travel far! I think they are in cahoots with the rocket gods too!
That's a longer story.

For folks who just need a Technician license to get into the 70cm trackers that's fine. I didn't think I'd get into the HF bands even though I tested to General but did. For me it's fun but did take a bit of an investment.

There are some economical 2 meter band GPS trackers out there like the Sainsonic AP510 but one needs to be forwarned. The higher Rf output has the potential to dork deployment electronics and I was burned with it with a specific altimeter kit and a low powered tracker.

Kurt Savegnago (aka KC9LDH)
Field strength of any transmitter above Part 15 (100 mW) limits at VHF or above can definitely play hob with a nearby altimeter. In order to keep the weight of altimeters down, there's little or no electronic shielding. A multi-watt telemetry or TV transmitter in a rocket could easily cook anything in the same rocket. Altimeters, deployment timers, and firing circuits should be shielded (I can easily see a 5 watt transmitter inducing enough current in a staging or deployment igniter wire to fire an e-match!).

A side gig for somebody - Custom-fitted small metal cans (vented for altimeters) to shield sensitive electronics in HPR rockets from a high-wattage transmitter.

Mark J
WB9QLR (1975)
Rocket flyer since 1966
 

UhClem

Well-Known Member
Joined
Feb 6, 2009
Messages
1,815
Reaction score
277
I would imagine you'd get pretty good range with 100 W in your rocket...
Line of sight is the primary limitiation even at much lower power. 300mW on 2m was sufficient to reach from Argonia to AB0XM (100miles+) but only at altitude:

KC5WSV-9>APT202,AB0XM-10*,WIDE,qAo,KA0MR-15:!3710.49N\09744.25W^061/020/A=007118
 

UhClem

Well-Known Member
Joined
Feb 6, 2009
Messages
1,815
Reaction score
277
A side gig for somebody - Custom-fitted small metal cans (vented for altimeters) to shield sensitive electronics in HPR rockets from a high-wattage transmitter.
BlackSky sold just such a thing for the AltAcc2.
 

ksaves2

Lifetime Supporter
TRF Lifetime Supporter
Joined
Nov 25, 2009
Messages
6,230
Reaction score
449
Location
Central Illinois
Field strength of any transmitter above Part 15 (100 mW) limits at VHF or above can definitely play hob with a nearby altimeter. In order to keep the weight of altimeters down, there's little or no electronic shielding. A multi-watt telemetry or TV transmitter in a rocket could easily cook anything in the same rocket. Altimeters, deployment timers, and firing circuits should be shielded (I can easily see a 5 watt transmitter inducing enough current in a staging or deployment igniter wire to fire an e-match!).

A side gig for somebody - Custom-fitted small metal cans (vented for altimeters) to shield sensitive electronics in HPR rockets from a high-wattage transmitter.

Mark J
WB9QLR (1975)
Rocket flyer since 1966
Yeah,

They're called Faraday cages and the cage I've been told needs to be attached to the deployment altimeter ground (- Minus side). Also twisting the lead wires to the ematches is supposed to help. I remember John Demar mentioned that a long time ago. Would probably entail splitting the ematch wires and twisting them. I'd recommend an ematch continuity tester to test to make sure the process doesn't dork the match. (Sky lighter doesn't have one forsale now. Wonder what to do if mine dies. Comments?) I have some copper screen I bought eons ago in case I was going to have to use it for a Faraday cage. I read where copper screen is ideal though a thin sheet metal should do fine too.

Oh with any new high power Rf output installation, I recommend putting contained ematches on all the deployment circuits, setup the rocket outside and turn on the high powered Rf tracker or TV circuits and the altimeters and wait 30 to 45 minutes. If the ematches don't spontaneously pop or the altimeter(s) don't shut down, one is good to go.

I was burned years ago with a kit built altimeter (out of production) twice! Before I knew what was happening. What I saw was apogee deployment on ascent with a 4 inch Loc tubed rocket I knew danged well wasn't going supersonic. Big zipper time. The next event was apogee deployment while the same (rebuilt/new sustainer) rocket was sitting on the pad waiting to be launched. Altimeter stopped the "ready to go beeping" and I knew something was up. I stepped toward it thinking I could turn off the altimeter and then wisely stepped away. Pop goes the apogee and with the upper bay on the ground, pop goes the main. Only scraped the paint on that one. Still fly the rocket with different electronics.

That was about the time I was getting my Tech and General Ham license when I learned about Rf interference and the light bulb went pop in my brain.
I posted what I thought was happening here and the smarter folks than me mentioned I was correct about the Rf interference. In fact the NAR magazine had a section where they posted which altimeters had Rf issues. The Entacore AIM usb specifically states in the instructions it is prone to Rf interference hence I only fly mine in sport rockets that have aural beepers for terminal recovery.

Any combined altimeter/tracker (GPS or otherwise) has been thoroughly tested by the manufacturer for compatibility so a buyer can rest assured the system they invest in is going to work. Also I believe all of the newer altimeters out there are resistant to Rf interference but if I was going with a high powered tracker, testing as I outline above is cheap insurance for a safe flight.

Kurt (KC9LDH Getting ready for Field Day!!)
 

hobie1dog

Hi-Fi Addict
Joined
Jul 26, 2009
Messages
4,882
Reaction score
1,226
Location
NC
I got my ham radio license just so that I could buy the electronic devices for the rocket, then I got messed up and I have not shot off a rocket since, but I ended up getting all three licenses. I took all three test the first day but missed the extra by two questions,so I then went to the Dayton Hamvention and took the extra test there and aced it in 12 minutes. Getting ready to get out of it though in my continuing downsizing.
W4SEX
 
Last edited:

FMarvinS

Well-Known Member
Joined
May 27, 2015
Messages
482
Reaction score
102
After getting WAS and DX100 about 12 years ago, my HF QSO's are non-existent. I'm planning to get back on HF in the fall (if the HOA doesn't intercede). It might be fun and of interest to form a net of those hams into rocketry maybe every 1-2 weeks or so on 40 or 17 meters for round robin discussions of rocketry related topics. If there is such a group currently, please let me know. If not, how much interest would there be in setting up such a group?

Fred, L2
ICBM, S.C.
KG4YGP
 

ksaves2

Lifetime Supporter
TRF Lifetime Supporter
Joined
Nov 25, 2009
Messages
6,230
Reaction score
449
Location
Central Illinois
Line of sight is the primary limitiation even at much lower power. 300mW on 2m was sufficient to reach from Argonia to AB0XM (100miles+) but only at altitude:

KC5WSV-9>APT202,AB0XM-10*,WIDE,qAo,KA0MR-15:!3710.49N\09744.25W^061/020/A=007118
Ditto yep,

I used to track high altitude balloons not as a participant but as a "hanger on". It was when I just got my Ham license and starting with rockets. The HAB's used milliwatts to a couple of watt APRS trackers. There was a digi-peater with an antenna on a 100 foot tower just 1200 feet away from my house.
I recall a balloon at 100,000 feet transmitting a position from over 425 miles away. I don't remember the tracker they were using but by reading the data it sent out that the 100 foot digipeater tower was receiving the signal directly.

There was a website that used to announce when and where balloon launches were to occur. I'd always check and see if there were any launches nearby especially my state of Illinois but also neighboring states. One time I read where a group was going to fly a Kenwood D7A(g) Ham radio handi-talkie. Personally I thought they were nuts to risk a pricey (at the time) radio in a balloon. I knew danged well that radio had messaging capability and lo' and behold, when flown it hit the local digi-peater and hence my local Xastir laptop. I messaged back to the balloon a couple of times with some silly stuff ("I see you!") and of course my Ham radio callsign. I knew the messages wouldn't be seen until and if the balloon was retrieved. Sure enough, 10 days later I get an envelop with a CD of all the pictures the onboard camera took at altitude and a metal ID tag that commemorates the flight. They thanked me for messaging their balloon with my location.

High altitude ballooning doesn't seem as popular as it was in 05-07. Perhaps the cost of helium has put the kibosh on it though I did read where some folks started using the infamous hydrogen. To the uninitiated, the balloons would be filled with a calculated amount of H or He and as the balloon rose the gas would expand as the balloon gets to altitude. It eventually would burst due to the expansion of the lifting gas and the degradation of the envelop from the vicious UV radiation at altitude. An inline parachute allows recovery of the payload.

An extreme example of this is https://amsat-uk.org/tag/party-balloon/ Leo Bodnar flew party balloons with GPS trackers around the world. http://www.leobodnar.com/balloons/ As I recall, one of them went around something like 5 times before going down off Iceland. Leo has a webpage and
sells radio items.

Tracking balloons got me more addicted to putting GPS trackers in rockets to recover them (an investment) a lot easier than depending on eyes alone or RDF.

RDF is good but one has to have a good final bearing before the rocket goes out of range. Also off-bearing tracking to go around obstructions can be problematic. With RDF one wants a great a range as possible with the rocket on the ground to have the largest Rf footprint as possible. This it to compensate for possible off-bearing tracking. Off-bearing tracking is the rocket is down, one has an RDF final fix before loss of signal. One has to jump in their car or truck and try to drive on roads (unless this is the playa where one could drive the bearing to the rocket) to get close enough to the rocket to receive the signal and home in to get the rocket. Believe me, I've seen people lose rockets with RDF trackers because they lost the bearing fix when the rocket landed a long ways away.

With GPS trackers, one may get a position fix with the rocket still 25, 50, 75 or 100 feet in the air depending on the distance away. That position fix is likely very close enough to get one into Rf range of the tracker/rocket. If the GPS receiver antenna is facing close to skyward, one will get a "final lie" of the rocket and can then pick it up. Rf ground footprint is a bit less important as it is with RDF trackers as off-bearing tracking is easier because one knows where to go for the last position fix. More likely a signal will be received at that point if the rocket isn't already seen. GPS makes recovery a lot easier.

Yeah I understand some rockets don't have room for a GPS tracker and RDF is the only way to go. It's probably a bit more economical to get a Ham Radio Tech license and get the bits together (H/T, tracker, attenuator and Yagi antenna) rather than buying a commercial tracker. A commercial system will be more dollars but is well tested and one technically doesn't need a license to use. One pays for that privilege though.

Sorry to drift off topic here but I wanted to make clear that GPS tracking is a reliable means to track rockets and has been proven in some really noxious environments. 100k feet is pretty cold and many times heating has to be done to keep the batteries warm.

Kurt KC9LDH
 

Art Upton

Well-Known Member
Joined
Jan 23, 2009
Messages
2,012
Reaction score
88
Model rocketry is nerdy enough. Do you really want to add "ham radio" to that image? :p
Yes we do... since long time... Note that that first "Sticky" to this thread is about using a Ham radio...
 
Last edited:

Art Upton

Well-Known Member
Joined
Jan 23, 2009
Messages
2,012
Reaction score
88
I see a "medium" balloon go buy on APRS about every 3-4 weeks. Many times it is MI or MO Balloons
 

Art Upton

Well-Known Member
Joined
Jan 23, 2009
Messages
2,012
Reaction score
88
Lets not forget CB radio and Model Rocketry , The FoxMitter followed by the Estes TransRoc Transmitter on Channel 14 ... Breaker 14, do we got a fix on that rocket that was launched? Hi HI
 

ksaves2

Lifetime Supporter
TRF Lifetime Supporter
Joined
Nov 25, 2009
Messages
6,230
Reaction score
449
Location
Central Illinois
Lets not forget CB radio and Model Rocketry , The FoxMitter followed by the Estes TransRoc Transmitter on Channel 14 ... Breaker 14, do we got a fix on that rocket that was launched? Hi HI
Shoot, I built a Foxmitter and a Minimitter when I was about 13. They both worked. (I had a job as an early teen as child labor laws didn't apply to a family business. I had a liberal amount of spending money back then.) I lost the box that contained them in one of my moves about 25 years after I last launched them. Only launched both of them once when I was a kid but actually didn't need them as the rockets came down within sight. BP only back then.
I did pull the box out containing them 20 years after I last launched them and the crazy Burgess 22.5V batteries still had enough juice to power them up.
I think the Foxmitter was 22.5V and maybe the Minimitter ran on a lower voltage battery. Perhaps 9V but don't hold me to that. I wished I still had them.
Discrete components on perf board. I think back and am amazed I constructed them as a 13 year old and they both worked. (I'm 64 now.) One had to hack an Allied Radio/Radio Shack AM receiver kit to hold next to a CB walkie talkie to hear the carrier from the Minimitter. That Minimitter was really tiny considering that was from the late 60's early 70's. The Foxmitter was larger and just needed a CB walkie talkie to hear the signal or use the audio from the earphone jack to record on a portable cassette recorder for later processing when using analog data. Directional antenna was a bent coat hanger with no attenuator.

Man, I was crushed when I lost them in a move as they both still worked. I had some of the additional modules for the Foxmitter still un built in their parts bag. I only built the "beeping" tracker module for the Foxmitter. I had the accelerometer module and the photocell "cardiac" pulse detector module one was supposed to be able to monitor a mouse's heart rate during a flight. This was in the era before launching "mammals" was outlawed. Seems they didn't mind having Stuart Little come in on a core sample as a big deal. Heck they're slaughtered in medical labs by the thousands anyways in research. Supposedly humanely though. ;)

Kurt Savegnago
 

cerving

Owner, Eggtimer Rocketry
TRF Sponsor
TRF Supporter
Joined
Feb 3, 2012
Messages
4,434
Reaction score
1,833
Lets not forget CB radio and Model Rocketry , The FoxMitter followed by the Estes TransRoc Transmitter on Channel 14 ... Breaker 14, do we got a fix on that rocket that was launched? Hi HI
That goes back to the days when the only license-free band was 27 MHz (R/C was 27 MHz too, outside CB), and Channel 14 was the only one approved for general purpose use but only up to 100 mW. I built a Ch14 transmitter when I was in Jr High, from a book that I found at the library, basically a 27 MHz LC oscillator with an output transistor. It was a bear to tune, but I flew it a couple of times in the nose of a Centuri Orion (which had a nice tube in the nose for payloads). At the time, just hearing a tone in flight was enough...
 
Top