When you say patch antenna, is that for the TRS, or the LCD? If on the TRS, for the radio link to the LCD right? There is no way to add a external GPS antenna is there? I did mean to get a second SMA adapter for the TRS but guess I didn't make it super clear in my order e-mail. For now I will use the whip then change it out.
That's on the receive end you plug into the LCD. The picture below the "Patch" is the square antenna. I got it from a link that Cris had posted in the first user guide. Afraid it is not available anymore. Was $18.95 so that's why
I jumped at it. The fiberglass pole is an old 27Mhz fiberglass antenna I had lying around I use to get the antenna up in the air.
It does seem to improve the decoding of positions at altitude but it's not absolutely necessary for sport flying whatsoever. If one were trying to push the range of the system this would certainly help. Once the rocket is down, one can disconnect the patch antenna cable and connect something else. This assumes one uses some kind of SMA connector on their receiver. I had a bunch of plain SMA connectors lying around and not SMA-RP like can be had as an option.
I do have an adapter though if one wanted to "borrow" the patch with their SMA-RP receiver.
Again, if you're sport flying and just interested in getting your rocket back, this could be superfluous and is not absolutely necessary.
One thing that can help for ground recovery is a Yagi antenna of which one can find several on Ebay. It's easy to get one that's easy to carry in one hand. The technique is use your "duck" or vertical antenna to track the rocket in flight and when the rocket is down, you connect the Yagi. The Yagi has too narrow a beamwidth to properly aim at an out of sight rocket. That can lead to loss of position decoding and heaven forbid, a lost rocket with a completely
sight unseen profile. Use a patch, stock, or duck antenna to get some positions "in the can" so you know where to proceed to the last known position "after" the rocket is down.
I've proven to myself that the ground footprint is increased pretty significantly if there are no obstructions or the rocket doesn't land in a depression. If one is paranoid as I am, a Yagi will give peace o' mind once the beeping starts coming back on the LCD receiver. It will start beeping "sooner" rather than later. Absolutely necessary for a sport flier? Nah. But again, it's a little trick that can increase the range.
Ok, you say you see people pointing "Yagi" antennas skyward all the time. What's the deal? Am I full of animal excrement? (Full of garlic tinged excrement but definitely my own) Well, the beamwidth on the radio frequencies
that "those" fliers are using are workable for those bands. 2 meter, 1.25 meter and 70cm one can reasonably be able to point the Yagi in the proper direction and get a signal. You won't find anyone using the 33cm band (900Mhz)
"beeping" RDF tracking systems for in flight tracking for that reason. It works once the rocket is on the ground because the rocket isn't generally moving fast and you know the direction the rocket is at to point your Yagi.
Another modality is to use the Android app "GPS Rocket Locator" so you can get some positions plotted on a map to develop a drift trendline while rocket is coming in. If you get to the last known position and see no rocket
(or a fincan sticking up out of the ground, don't laugh that's how I found one rocket though the EF died an honorable death) you can proceed in the direction suggested until you hear the beeping. By this time, you might be antsy
and that Yagi can get you some peace o' mind here.
I'd say stock you're in pretty good shape for 2 to 3 miles. The key is getting the last position when the rocket is as low to the ground as possible. That will get you close enough if you don't see it, you get a new position.
You have to remember, I'm talking about a completely sight unseen flight. If one gets a visual on descent, that's icing on the cake if using any kind of radio tracking. The sight unseen one is where it really pays off.
Kurt