DIY Antenna for BigRedBee/Altus Metrum/Eggfinder 70cm

[John Kemker]

For those of us who are using 70cm (430-470MHz) Amateur band tracking/telemetry transmitters, I found some interesting low-cost DIY antenna projects.

First up is this dual-band (2m, 70cm) "Arrow" style "satellite" antenna. While it's meant for using for AmSat contacts, it can be modified for 70cm only use as a tracking antenna. Use only the 70cm elements and leave out the diplexer and you're good to go.

https://ve2zaz.net/Arrow_Ant/Arrow_Style_Ant.htm

For a cheap $4 solution, there's this one:

https://www.kb6nu.com/diy-for-cheap-satellite-operation/

This one might be even cheaper!

https://www.amsat.org/articles/n2spi/JulAug06AmsatJournal.pdf

And one more:

https://makezine.com/projects/make-24/homemade-yagi-antenna/

If anyone else has a link to add to the collection, please do! To me, rocketry is about DIY and building projects like this are part of what I enjoy about both my rocketry and my ham radio hobbies!

 

[UhClem]

Programmig By Pete

 

[John Kemker]

Thanks, David! I like that one a lot. Nowadays, I'd replace the BNC with an SMA connector, but looks like a great solution.

 

[RocketDestroyer]

For the more adventurous...

The name says it all... cheap yagi.

https://www.wa5vjb.com/yagi-pdf/cheapyagi.pdf

These two don't require pointing at the rocket. Just set them up and they work. I've used the crossed moxon loop antenna for flights to 20K with a low powered TeleGPS.

https://www.qsl.net/l/lu7did/docs/NOAA/DoubleCross_137Mhz AntennaMARTES.pdf

https://www.oocities.org/w9bci/VHFUHFSatelite.pdf

 

[John Kemker]

Those last two are only good for transmitters that are using GPS telemetry to tell you where they are. If you're using a Big Red Bee or an Altus Metrum TeleMini to find your rocket, you'll need a directional antenna.

Great links, though! I might build the crossed Moxons for sat-work at the home QTH!

73 de W5NNH

 

[John Kemker]

Recalling the gain and other attributes of rhombics, I did a bit of research into building one for 70cm. I found this link and am looking into what it would take to build one for direction finding.

A bit more research found this page.

I'm thinking something collapsible, so I can take it down to carry to the field and quickly put together to find the rocket.

 

[DaveW6DPS]

I have used yagi antennas based on WA5VJB's cheap yagi design with Big Red Bee 70cm GPS and beacons.
https://www.qsl.net/w6dps/SimpleYagi.html

Mostly now for Big Red Bee GPS I use a good 70 cm mobile antenna and my Yaesu FTM-100D mobile. Then just drive the direction the needle points. I have re-acquired a rocket on the ground at Black Rock from over 2 miles away. Usually once they are down you have to be very close to hear them again, although usually before you get to the last beacon location.

Even with an HT a mag-mount mobile antenna can extend your range quite a bit, and they are handier than trying to keep a yagi point in the right direction.