UK BP altitude contest? Interest?
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nialloswald
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Mike, what tracker did you use?
Paul Shackleton's TRAXAs brought back a PML Nimbus from 9500ft/2.5 miles downrange and a shock value from 16500ft/4.5 miles downrange on Sunday.
They're small, light, cheap and very good.
Also, you might want to read this:
https://www.bobarnott.com/rocketry/stuff/farts/contact.shtml
Very nice flight BTW, Ben and I watched it from the hut (mid-prep), to get 5 stages going even vaguely up is a great achievement! The acceleration as the second and third stages kicked in was very noticable from a distance. Would have been even nicer against blue sky.
Paul Shackleton's TRAXAs brought back a PML Nimbus from 9500ft/2.5 miles downrange and a shock value from 16500ft/4.5 miles downrange on Sunday.
They're small, light, cheap and very good.
Also, you might want to read this:
https://www.bobarnott.com/rocketry/stuff/farts/contact.shtml
Very nice flight BTW, Ben and I watched it from the hut (mid-prep), to get 5 stages going even vaguely up is a great achievement! The acceleration as the second and third stages kicked in was very noticable from a distance. Would have been even nicer against blue sky.
Mike
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The tracker was something I was going to bring up...
I built both the transmitter and receiver using RF modules that I bought from Rapid Electronics, the transmitter had 10mW power which was the same as TRAXA ones. I had a track in the air but then lost it as it landed. I walked out about a mile from the pads, I couldn't get a signal from mine but I was picking up signals from rockets back at the range.
3 scenarios,
1) I could have picked up my transmitter from a mile away but never got that close - I don't think this is too likely as it couldn't have gone *that* far and I walked a pretty big area.
2) I could only pick up my transmitter from a few hundred metres and just never got close enough.
3) The transmitter broke on landing so I never got a signal.
Personally I think scenario 2 is the most likely, so why couldn't I pick up my transmitter from as far? It had the same power as TRAXAs and I presume I was listening to TRAXAs from the pads. My transmitter/receiver are pretty similar to the ones on Programming by Pete https://www.birch.net/~petek/rockets/RDF/70cm.html
Really wishing I had put my name on it somewhere...
I built both the transmitter and receiver using RF modules that I bought from Rapid Electronics, the transmitter had 10mW power which was the same as TRAXA ones. I had a track in the air but then lost it as it landed. I walked out about a mile from the pads, I couldn't get a signal from mine but I was picking up signals from rockets back at the range.
3 scenarios,
1) I could have picked up my transmitter from a mile away but never got that close - I don't think this is too likely as it couldn't have gone *that* far and I walked a pretty big area.
2) I could only pick up my transmitter from a few hundred metres and just never got close enough.
3) The transmitter broke on landing so I never got a signal.
Personally I think scenario 2 is the most likely, so why couldn't I pick up my transmitter from as far? It had the same power as TRAXAs and I presume I was listening to TRAXAs from the pads. My transmitter/receiver are pretty similar to the ones on Programming by Pete https://www.birch.net/~petek/rockets/RDF/70cm.html
Really wishing I had put my name on it somewhere...
nialloswald
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Just another thing, and I don't mean this as any kind of insult!
How experienced are you at tracking? I personally have never even tried it, but after following Damian and Nigel around the countryside down in Devon looking for Uncle Bob, and then the two transmitters dropped in from on high on their own, I understand that it's quite an art form.
Speaking to others who are experienced in tracking - Chris Eilbeck and Paul Shax himself, I understand that especially when the signal is faint, picking it out from the background noise is also something of an art that requires practise. Equally once the signal is good, tracking it down is also a bit of an art. The issue with other trackers is very real, the best thing is to co-ordinate with other fliers and the RSO.
If I was going to launch something really high, I'd make **** sure no other trackers were on at the time. We only ever have one rocket in the air at a time, its quite possible to set up a power switch for the tracker (mine is set up like that), so with a little co-operation between people.....
Anyhow,
Perhaps you could get someone to hide your transmitter somewhere, and you could practise finding it.
Up at Pete's there aren't many high spots, and if your TX is in a dip you can lose the signal. I have heard of people going to a bridge in Heckington to get a bit more height, and on the WRS site there are pictures of Pete stood on his van, with the tracking gear.
If your rocket's in the crops, you'll probably never see it again, but the name thing is really important!
How experienced are you at tracking? I personally have never even tried it, but after following Damian and Nigel around the countryside down in Devon looking for Uncle Bob, and then the two transmitters dropped in from on high on their own, I understand that it's quite an art form.
Speaking to others who are experienced in tracking - Chris Eilbeck and Paul Shax himself, I understand that especially when the signal is faint, picking it out from the background noise is also something of an art that requires practise. Equally once the signal is good, tracking it down is also a bit of an art. The issue with other trackers is very real, the best thing is to co-ordinate with other fliers and the RSO.
If I was going to launch something really high, I'd make **** sure no other trackers were on at the time. We only ever have one rocket in the air at a time, its quite possible to set up a power switch for the tracker (mine is set up like that), so with a little co-operation between people.....
Anyhow,
Perhaps you could get someone to hide your transmitter somewhere, and you could practise finding it.
Up at Pete's there aren't many high spots, and if your TX is in a dip you can lose the signal. I have heard of people going to a bridge in Heckington to get a bit more height, and on the WRS site there are pictures of Pete stood on his van, with the tracking gear.
If your rocket's in the crops, you'll probably never see it again, but the name thing is really important!
nialloswald
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What kind of antenna does your tracker have?
TRAXAs have a proper 1/4 wave antenna, i've seen little Tx modules that have the antenna built in and offer much lower performance.
TRAXAs have a proper 1/4 wave antenna, i've seen little Tx modules that have the antenna built in and offer much lower performance.
Mike
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The antenna was about 6.25" of ~1mm wire, I wasn't using the little internal one. I (foolishly) never did a full range test, I was just about picking it up 100m away with lots of trees and houses in the way but I never tested it on open ground.
Mike
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Originally posted by nialloswald
Just another thing, and I don't mean this as any kind of insult!
How experienced are you at tracking? I personally have never even tried it, but after following Damian and Nigel around the countryside down in Devon looking for Uncle Bob, and then the two transmitters dropped in from on high on their own, I understand that it's quite an art form.
Not insulting at all - I have absolutely no experience of tracking whatsoever. That was the first flight of the tracker too
andysrockets
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What Niall said, plus even with a tracker, use a beeper if you can. If you have got close with RF tracker, then you will saturate the receiver. The beeper helps if it is in the crops or in a dip.
Also you need some understanding of RF. For a 1/4wave whip antenna, there are 2 nulls along the whip axis for starters, and if the antenna is in contact with the ground, then expect bad things. Also, if something is badly matched, then all the RF power might be reflected back into the transmitter, and not radiated. Ditto on the RX side, if the antenna/coax etc. is bad, then the received RF might not even be making it into the receiver!
The issue of multiple trackers switched on simultaneously has become problematic. If you (or anyone) had a problem with this, let me know, and I'll bring the issue up at the next UKRA meeting. People are already trying to find other less populated frequencies, but that is not the solution - it is only avoiding the issue.
Also you need some understanding of RF. For a 1/4wave whip antenna, there are 2 nulls along the whip axis for starters, and if the antenna is in contact with the ground, then expect bad things. Also, if something is badly matched, then all the RF power might be reflected back into the transmitter, and not radiated. Ditto on the RX side, if the antenna/coax etc. is bad, then the received RF might not even be making it into the receiver!
The issue of multiple trackers switched on simultaneously has become problematic. If you (or anyone) had a problem with this, let me know, and I'll bring the issue up at the next UKRA meeting. People are already trying to find other less populated frequencies, but that is not the solution - it is only avoiding the issue.
hokkyokusei
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Originally posted by Mike
Not insulting at all - I have absolutely no experience of tracking whatsoever. That was the first flight of the tracker too
Felt slightly guilty about that, would have gone out looking with you, but had family to find, and they weren't wearing locators!
nialloswald
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BTW, what kind of Rx were you using? Chris and Shax track with handheld scanners, yours looked 'interesting'
What about your Rx antenna?
Mike
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It wasn't a serious problem, certainly didn't stop me finding it. There were, I think, two transmitters on at least part of the time I was out. Obviously I have no problem if the rockets were out in the field but it would have understandably annoying if they were sat on someones prep table.
Not at all mate.
Well, ermm, it certainly wasn't a scanner
I used a Rx module similar to the transmitter and an audio amplifier (LM386) to a small speaker. My receiver antenna was a 6-element Yagi that I made myself with 3mm brass rod. Is it not a surprise I didn't pick up the signal?
andysrockets
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I would have recommended a scanner/receiver and borrowing a known working Yagi, at least for the first time. Better still, have one person tracking with a known working system, while you go hunting in parallel.Originally posted by Mike
Well, ermm, it certainly wasn't a scanner
Is it not a surprise I didn't pick up the signal?
A commercial 433MHz Yagi can be had brand new with properly fitted coax/connectors for 30GBP, and with the right impedance coax and a scanner you should be sorted. Doing everything by hand is probably not the best move unless you really know what you are doing with the RF.
The scanner/receiver also allows you to tune for the best signal, and also to de-tune or tune a harmonic when you are up close. Probably has better sensitivity than the 433 RX module.
