So, maybe I'll try a three-stager

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Jim- that's crazy that that actually works. How close are the electronics to it? Right under it, or so you have some leeway?

My guru thought it would be best to have it further away from the slot, so it is on the other side of the center axis, not directly under the slot. Maybe 2 inches away from the slot? I figured it would work but I had no idea it would do as much as it did.

Jim
 
I don't think so. The one on the top stage has very little weight above it, and the middle stage air frame is a pretty thick tube. I will also fill the slot with epoxy, mainly to keep the wind out.

Jim

I assume you will test one more time after filling the slot with epoxy?
 
Pay attention to the position you hold the remote in when testing, be sure to replicate that position in the field to prevent strangeness. If your worried about structural integrity issues after cutting the slot you can back fill it with a radio transparent material. This can have some some effects on slot antenna geometries so talk to your antenna guy if you plan to backfill. Your basically dealing with babinet's principal.

If your guru feels like working on a project let me know. I have been playing with some simulations for a phased array sticker that goes on the out side of a CF airframe to help folks with GPS and telemetry.
 
Pay attention to the position you hold the remote in when testing, be sure to replicate that position in the field to prevent strangeness. If your worried about structural integrity issues after cutting the slot you can back fill it with a radio transparent material. This can have some some effects on slot antenna geometries so talk to your antenna guy if you plan to backfill. Your basically dealing with babinet's principal.

If your guru feels like working on a project let me know. I have been playing with some simulations for a phased array sticker that goes on the out side of a CF airframe to help folks with GPS and telemetry.

I'm pretty sure that when this is used, strangeness will be abundant.

Actually, I don't have to fill the slot. It is backed up by the altimeter bay, which isn't slotted. I think I'll just leave it alone.

I'm sitting here wondering why on earth I have never arranged for my Guru to meet your trailer. You have probably met him, but I don't think the trailer was there. Send me some pics to whet his appetite.

Jim
 
I'm pretty sure that when this is used, strangeness will be abundant.

Actually, I don't have to fill the slot. It is backed up by the altimeter bay, which isn't slotted. I think I'll just leave it alone.

I'm sitting here wondering why on earth I have never arranged for my Guru to meet your trailer. You have probably met him, but I don't think the trailer was there. Send me some pics to whet his appetite.

Jim

I don't have any current photos, but I will try to get some soon. The latest additions are the repeater and the ADS aircraft tracking system. Still working on the margarita machine...
 
The reason this works is because the slot acts as a waveguide antenna for the 2.4 GHz radio waves, whose half-wave length is about 6.25 cm. The desired range is about 20', so as long as you get that much range out of it then it's all good.
 
Just a quick update ....

I cut the antenna slots in both stages. They work, but not as well as my test section. I don't know why, but I think there is enough range added to do the trick.

My certificate of authorization is apparently being processed (Woohoo!), but it looks like I will again be banished to BR15, some 2.4 miles from the range. At least it's peaceful there.

Otherwise, I'm now heavily involved in prepping for the trip and the flight. My biggest concern is what I suspect will be a shortage of help at the pad and during the flight (i.e., a smaller turnout of folks who have their own flights and/or are running the launch). Texas has pretty much bailed, so getting the rocket in the air may be a challenge. But, I think it will happen, and it should be either cool or really cool.

Jim
 
Man I wish I was a bit closer, but 3,800KM is a bit more of a drive than I am up for. I am excited for you Jim and looking forward to your results, either way it should be interesting.
 
Just a quick update ....

I cut the antenna slots in both stages. They work, but not as well as my test section. I don't know why, but I think there is enough range added to do the trick.

My certificate of authorization is apparently being processed (Woohoo!), but it looks like I will again be banished to BR15, some 2.4 miles from the range. At least it's peaceful there.

Otherwise, I'm now heavily involved in prepping for the trip and the flight. My biggest concern is what I suspect will be a shortage of help at the pad and during the flight (i.e., a smaller turnout of folks who have their own flights and/or are running the launch). Texas has pretty much bailed, so getting the rocket in the air may be a challenge. But, I think it will happen, and it should be either cool or really cool.

Jim

I'll be there anyway and I'm probably only bringing one rocket, so if I can be of any assistance I would enjoy it.


Steve Shannon
 
Man I wish I was a bit closer, but 3,800KM is a bit more of a drive than I am up for. I am excited for you Jim and looking forward to your results, either way it should be interesting.

It's closer to 4,000 km, but it appears that there are better ways....

Jim

Edit - I checked on flights from Austin, and it's like $280 round trip. Wow. A year ago, that trip was twice as much.

Cheap!.jpg
 
It's closer to 4,000 km, but it appears that there are better ways....

Jim

Edit - I checked on flights from Austin, and it's like $280 round trip. Wow. A year ago, that trip was twice as much.

So tempting. I just popped on-line to check out flights from my end, and there are some cheap flights to be found. You had me seriously thinking about it for a second but then I look at my inbox and project board and I am going to have to live this one vicariously though video. You do have me thinking, so I may put something together that I have been thinking about for a while now, and make my way out there for 2018.
 
So tempting. I just popped on-line to check out flights from my end, and there are some cheap flights to be found. You had me seriously thinking about it for a second but then I look at my inbox and project board and I am going to have to live this one vicariously though video. You do have me thinking, so I may put something together that I have been thinking about for a while now, and make my way out there for 2018.

I think it would be about time.

Jim
 
a little late, but if ya have to build something like this again, you can cut those holes a little oversize and line the edges with some foam weatherstripping like this
https://www.lowes.com/pd/M-D-13-ft-Expand-N-Seal-Foam-Window-Weatherstrip/3434324

Why would I build something like this (box) again? Ummm, well, this is the third version with many modifications of the prior two versions. Could a fourth be far behind.

Actually, the holes are a little oversized and I have lined them with some felt, although I don't know why - this isn't a very pretty rocket. On the other hand, the box lid is lined with the weatherstripping to keep the dust out. That IS important.

Jim
 
Jim, if I am not busy I will be more than will to assist you. Besides, being at the edge of "rocket civilization" would be cool. And quiet. :)
 
Jim, if I am not busy I will be more than will to assist you. Besides, being at the edge of "rocket civilization" would be cool. And quiet. :)

Thanks Gary! I'll let Tom know you're on the team so that you can get an away cell wrist band (if you won't already be getting one).

Yes, it's very quiet at BR15. No pesky research motor catos or classic rock tunes.

Jim
 
Will you be testing the spinning Fin can at AF? Hope to stop by and meet you and checkout your work on the spin can
 
Will you be testing the spinning Fin can at AF? Hope to stop by and meet you and checkout your work on the spin can

I expect to be there for at least some of AF, but I won't be flying the spinning fin can. Can't afford to have it damaged so close to Balls.

Jim
 
Jim, when do you plan to head up to AF?

Depends. We have our launch scheduled for Saturday, and in the past, we've driven up Saturday afternoon to be there Sunday/Monday. This year, with Harvey, our launch is in doubt. The field dries fast, but I'm not sure how it will do with 20" of rain. Could come up earlier I suppose. The situation is, um, fluid.

Jim
 
Depends. We have our launch scheduled for Saturday, and in the past, we've driven up Saturday afternoon to be there Sunday/Monday. This year, with Harvey, our launch is in doubt. The field dries fast, but I'm not sure how it will do with 20" of rain. Could come up earlier I suppose. The situation is, um, fluid.

Jim

Looks like you might need a boat to get out of Texas. Hope to see you at Airfest, I'm finally bringing a two stage rocket to the rocket pasture!

It's sims to 330k, I'll have him bring his binoculars.

So, what are you using to bring it back down out of orbit?
 
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