Arrow Antennas vs Ebay

[gcanroc]

I’m hoping to use RDF with 70 cm BRB Tx so as to recover a lost rocket should the occasion arise. I see three element antennas on EBay for $32 and Arrow antennas for $60. Is the price difference worth it??

Geoff

 

[cerving]

Do the eBay antennas have specs, other than a simple gain figure? I don't trust most of them... they rarely have specs, whereas somebody like Arrow always does.

 

[dinoburb]

If you are only working the 70cm band you really could make your own fairly easily. The Arrow, which is a good antenna and you should only need a single yagi design. If I were buying a commercial antenna Arrow makes a good product. Drop me a PM if you would like more information.

Good basic 440 yagi design:

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

This is a good beginning. Just make the 440 portion, ignore the splitter and make the support long enough to hold.

 

[Voyager1]

Yep, make your own for a few dollars. Much more satisfying and very easy to build with readily available components.

 

[gcanroc]

Actually I’ve already built a six element yagi. I used 1/8 inch aluminum tubing. But if you’ve ever tried to solder to aluminum tubing you’ll understand how hard it is to get a good bond with the coaxial. My concern is tuning the Yagi. Is this necessary? I’ve read many posts on this website about fox hunting and the art to it. My next step is to build a attenuator to help with close rocket tracking. Such as:
https://kc9on.com/product/fox-hunt-v6-smd/

With products like Eggfinder’s GPS I’m really starting to believe the using RDF to locate lost rockets is somewhat antiquated. RDF might just become my “back-up”.
Another project I’m probably going to try and build:

https://www.handi-finder.com/

Geoff

 

[Voyager1]

Actually I’ve already built a six element yagi. I used 1/8 inch aluminum tubing. But if you’ve ever tried to solder to aluminum tubing you’ll understand how hard it is to get a good bond with the coaxial. My concern is tuning the Yagi. Is this necessary? I’ve read many posts on this website about fox hunting and the art to it. My next step is to build a attenuator to help with close rocket tracking. Such as:
https://kc9on.com/product/fox-hunt-v6-smd/

With products like Eggfinder’s GPS I’m really starting to believe the using RDF to locate lost rockets is somewhat antiquated. RDF might just become my “back-up”.
Another project I’m probably going to try and build:

https://www.handi-finder.com/

Geoff

You don't need to solder the coax to the Al dipole. Just solder some solder lugs onto the coax conductor and braid and screw them onto the dipole. Tuning the Yagi is probably not necessary unless you're way out on your dipole length calculations. When used for receive only, it's not that critical.

 

[warnerr]

Arrow antennas are great. if transmitting getting a great antenna optimizes your signal, however for receive only anything close will usually get you by. I fly rdf on ALL my high flyers in addition to one or two gps systems located in different parts of my rockets.

 

[dinoburb]

You only need to solder to the driven element so use a piece of ⅛” brass rod. A three element yagi is plenty, however, an attenuator should be on your list of ‘stuff’. Makes in-close work easier.

 

[billdz]

Yep, make your own for a few dollars. Much more satisfying and very easy to build with readily available components.

Agreed, here is mine, with a TeleBT velcroed to the boom, based on the Kent Britain "Cheap Yagi," see https://www.repeater-builder.com/antenna/pdf/cheap-yagis.pdf.

 

[gcanroc]

...thx for all the input. I’ll work with this, I got caught up with the antenna tuning issue.