Backup altimeter advice needed.

This is probably a common question that everyone goes through. Once you start putting electronics into your rocket it seems to just lead to more. I am seriously considering getting a BRB900. This is good as it will help me find my rocket. But I don't want to loose the BRB900 either. The way I loose my BRB would be if there is a recovery failure, so I want to reduce the chances of that happening. One step that's probably a good idea is to use a backup altimeter. The platform I will be flying is 54mm so there is lots of room.
At the moment I have a stratologger, which I actually have not had a chance to use yet. But so far I am very happy with it. As a backup I don't want another of the same because I think that it's best if the backup is different so that it's unlikely to fail in the same way in the event of a failure.

Option A: I could buy a cheap altimeter. After all it's still a backup, and the main is likely to work anyway. One thing I am worried about is the stratologger is barometric as are any of the cheap ones I find. As a backup it might be nice to have a different system like an accelerometer. That way it would not be susceptible to the same issues.

Option B: accelerometers are more expensive. Or a multifunction altimeter. On the one hand my inclination is to buy the best I can afford, as I will get lots of use out of it regardless. Still not sure if I need it though. I have not lost faith that a cheap one will work.

So, I suspect several people have gone through this same process. What did you do and how happy are you with the result?

Thanks
Andrew

I would suggest going with a less functional (cheaper) backup altimeter and investing more into radio location equipment (whether GPS or beacon).

I use Adept DDCS2 as backup, and RRC2 looks very attractive

-Alex

I just built and flew a Wildman Extreme with L3 in mind down the road, and it has redundant electronics. I had a Raven sitting around and a Power Perch to put it in, plus the new RRC3, so that made my redundant altimeter choices easy. They worked very well too (love the Power Perch magnetic switch). If I were to do it again in as simple and cheap a way as possible, I would get an RRC2+ and a Stratologger and call it good--you can practically get both for just over $100. You also get a lot more altimeter if you sprung for the RRC3 vs the RRC2+.

I have the BRB900, and I find it easier to use the RF trackers, like the Big Red Bee Beeline TX and Comspec/Wildman series with a Yagi. My BRB900 loses lock on launch and sometimes does not get it back very quickly, if at all. An RF tracker with the Yagi actually tells me where the rocket is at in the sky--very helpful for out-of-sight flights where you don't know where it is at other than using a spotwatch and assuming all is well. You can get a Beeline TX for $59 and a used radio off eBay for around $100--cheaper, easy & effective.

Another choice coming out soon is the RRC3 with a GPS add-on board, killing two problems with one purchase--that's what I am excited for.

Hmm, getting consensus on cheap altimeters are pretty good. I have looked at the fancier ones and a lot of the features I don't really need. Just deploy the chutes please.
Have not heard anything about the more expensive ones being better at that.

Thanks
Andrew

Hal8472 said:

At the moment I have a stratologger, which I actually have not had a chance to use yet. But so far I am very happy with it. As a backup I don't want another of the same because I think that it's best if the backup is different so that it's unlikely to fail in the same way in the event of a failure.

Click to expand...

Fundamental flaw in logic, IMO.

You have one altimeter and state "... so far I am very happy with it", but OTOH "...I actually have not had a chance to use yet." Does that mean it looks nice?

1) If you are an electronics noob but want to use 2 altimeters, use two of the same kind. The most common failures are user error. I would say the common altimeters fail less than 5% of the time. Each brand has subtle differences in wiring, switches, interface software, continuity tones, etc. Master the Stratologger before branching out to other brands. If you wish use two of them. Use two of everything else, too: e-matches, switches (or twist and tape), ejection charges, etc. They won't fail in the same manner.

2) If you are just learning, fly your 1st altimeter deploy low for an easy recovery and forget the BRB900 if it makes you nervous. You will discover that electronic deployment is MORE RELIABLE and REPEATABLE than motor ejection.

Good luck with your project, --Lance.

^+1 on what Lance said.

Altimeters don't fail (usually)
People fail with altimeters (mostly)

Select a simple system and master it. Then increase the complexity if you must. Adding another altimeter increases the complexity. Adding a different altimeter increases the complexity more.