This is a nice quality 916Mhz Yagi antenna that can be used for ground recovery of
the 900Mhz trackers out there: https://www.ebay.com/itm/NIB-Linx-5...613018?hash=item540c6b52da:g:KoEAAOSwbqpTvrAV
Price is cheap and I picked one up. Get an N male to SMA adapter cable to fit ones receiver
and would be in business for ground recovery.
Note well. This antenna solution is generally best used after ones rocket is down and it or
other 900Mhz Yagis can increase the ground footprint of the tracker. If your rocket lands nearby, you don't need it but if it lands quite a distance away and you have to walk to it, you can put this on your receiver and point it in the direction you know the rocket is at. Generally hold the elements horizontally or if you think the rocket is in a tree and the antenna is up and down, hold the elements so they are vertical. Doing a search on Ebay will lead to higher gain Yagis available but beware, you need to be comfortable carrying the thing. The goal is to achieve a larger ground footprint to improve one's chance of recovery when pushing a 100mW tracker to the limits.
Trying to point a Yagi antenna at a sight unseen rocket might result in lost positions and if receive gain is desired for flight tracking, try a patch antenna like this:
The beamwidth on a patch antenna is wider than a Yagi on this frequency so one can achieve some additional in-flight range and still have some directivity.
I noticed increased reception of positions with 100mW trackers with the patch antenna (which at the time I got it was $19.99. Lucky to find anything like that anymore.) and the Yagi does
indeed improve the ground footprint for recovery.
I've done two ground recoveries with EggFinders where once loss of signal (LOS) occurs, I
plug the Yagi antenna in and proceed towards the last known position. When the EggFinder LCD starts beeping a new position as I approach the rocket (which both times I still couldn't see lying on the ground) I replaced the Yagi cable with the vertical dipole "duck" antenna.
Both times the signals disappeared. This proves the Yagi increases the ground footprint
as would be expected.
Again, this might be helpful when pushing a 100mW tracker to the limits. What are the limits? It would depend where one is flying. A lot of hillocks and depressions and the ground
foot print can be drastically cut with the tracker. If the LOS occurs at a 2 miles out from 100 feet in the air and there are hills are depressions a Yagi might be the edge at getting a 900Mhz tracked rocket recovered especially if the final lie of the rocket is quite some distance away from the last known position.
Kurt
the 900Mhz trackers out there: https://www.ebay.com/itm/NIB-Linx-5...613018?hash=item540c6b52da:g:KoEAAOSwbqpTvrAV
Price is cheap and I picked one up. Get an N male to SMA adapter cable to fit ones receiver
and would be in business for ground recovery.
Note well. This antenna solution is generally best used after ones rocket is down and it or
other 900Mhz Yagis can increase the ground footprint of the tracker. If your rocket lands nearby, you don't need it but if it lands quite a distance away and you have to walk to it, you can put this on your receiver and point it in the direction you know the rocket is at. Generally hold the elements horizontally or if you think the rocket is in a tree and the antenna is up and down, hold the elements so they are vertical. Doing a search on Ebay will lead to higher gain Yagis available but beware, you need to be comfortable carrying the thing. The goal is to achieve a larger ground footprint to improve one's chance of recovery when pushing a 100mW tracker to the limits.
Trying to point a Yagi antenna at a sight unseen rocket might result in lost positions and if receive gain is desired for flight tracking, try a patch antenna like this:
The beamwidth on a patch antenna is wider than a Yagi on this frequency so one can achieve some additional in-flight range and still have some directivity.
I noticed increased reception of positions with 100mW trackers with the patch antenna (which at the time I got it was $19.99. Lucky to find anything like that anymore.) and the Yagi does
indeed improve the ground footprint for recovery.
I've done two ground recoveries with EggFinders where once loss of signal (LOS) occurs, I
plug the Yagi antenna in and proceed towards the last known position. When the EggFinder LCD starts beeping a new position as I approach the rocket (which both times I still couldn't see lying on the ground) I replaced the Yagi cable with the vertical dipole "duck" antenna.
Both times the signals disappeared. This proves the Yagi increases the ground footprint
as would be expected.
Again, this might be helpful when pushing a 100mW tracker to the limits. What are the limits? It would depend where one is flying. A lot of hillocks and depressions and the ground
foot print can be drastically cut with the tracker. If the LOS occurs at a 2 miles out from 100 feet in the air and there are hills are depressions a Yagi might be the edge at getting a 900Mhz tracked rocket recovered especially if the final lie of the rocket is quite some distance away from the last known position.
Kurt
