older altimeters still good? How old is too old?

[BSNW]

I know this question has a lot of "well depends" components. However, I am looking for input based on my specific situation, to try and see if there is a trend in replies from people who may have, or still use (or not), older altimeters. Here we Go.

1) Purchased what I was told, were the few last remaining Missile Works RRC2 mini's when I visited Barry at LOC, MANY moons ago
2) They both are like BRAND NEW and have been flown 7 times, then replaced back into their static bags and wrapped in bubble wrap.
3) Again, they work beautifully and look like they have never flown.

The quick question is...do altimeters age out? Are there components on the altimeter that, after 10 or 15 years, are much more prone to breaking? OR simply put, would most of you use them or not use them? I would really like to keep using them despite their age.

Thanks for your input

Andrew
TRA L3

 

[mikec]

I don't think they wear out if stored well. My first RRC2 from 2009 is still flying.

A simple vacuum test is easy if you just want to do a quick verification.

 

[manixFan]

I have several old altimeters (>20 years) that no longer work. I talked to one maker and was told that the baro sensors can fail and generally there isn’t a drop in replacement.

I would vacuum test any altimeter that hasn’t been used in a couple of years. Good peace of mind knowing they are working properly.


Tony

 

[Cape Byron]

I still have a How High alt that I fly occasionally. Not sure of the accuracy these days.

 

[Voyager1]

If they’ve been used without damage and stored as you’ve described they should be fine. As suggested by the others, a periodic vacuum test would be a good idea to confirm proper operation.

Most of the components on altimeters are quite stable over time, although the barometric sensor might degrade due to contaminants, or physical damage. However, the one component that might degrade over time is the electrolytic brownout capacitor that is used on some altimeters. If they are of the non-solid electrolyte type, then they can dry out over time. This causes their capacitance to decrease and internal resistance to increase.

 

[atestani]

My $0.02...
I wouldn't chance it. Take a look at Eggtimer products which work perfectly and are low in cost because they are kits. Very easy to build.

 

[Handeman]

I have a Perfectflite HiAlt45 I bought in '07 for my L1 cert. That rocket eventually lawn darted through no fault of the altimeter. After extensive vacuum testing, it is now the primary altimeter in my L3 cert rocket and has 15 more flight in that rocket. Still going strong.

I would do a vacuum test or three on them and then fly them. If you still have doubts after the testing, fly them as primary or backup to a known good altimeter.

 

[pathtouch]

I’ve been flying a 12 year old Adept22 these past two years and the only issue I had was when I put a used 9v battery in the AV bay. It deployed the drogue but must have browned out on the main charge.

Test them in a mason jar / Tupperware and run em.

 

[cwbullet]

I have some pretty old altimeters. I still use my GiWiz stuff. It has been a while but I have not issue with using a 20 year old altimeter. I would ground test it.

 

[sharkbait]

I know this question has a lot of "well depends" components. However, I am looking for input based on my specific situation, to try and see if there is a trend in replies from people who may have, or still use (or not), older altimeters. Here we Go.

1) Purchased what I was told, were the few last remaining Missile Works RRC2 mini's when I visited Barry at LOC, MANY moons ago
2) They both are like BRAND NEW and have been flown 7 times, then replaced back into their static bags and wrapped in bubble wrap.
3) Again, they work beautifully and look like they have never flown.

The quick question is...do altimeters age out? Are there components on the altimeter that, after 10 or 15 years, are much more prone to breaking? OR simply put, would most of you use them or not use them? I would really like to keep using them despite their age.

Thanks for your input

Andrew
TRA L3

I still have old Adepts, G-Wiz, BlackSky, Transolve, MissileWorks, and Xavien’s, some date back to the 90’s and all fly perfectly fine still

 

[manixFan]

I have at least one old AltAcc that fails the vacuum test, while another is fine.

They all work until they don’t. The question is when is it a point of diminishing returns.


Tony.

 

[PSLimo]

You guy's are making me nervous, lol.

I've been flying the same 2 Missile Works RRC 2's since 2007. The one shown below is in an original first run of Wildman's Gizmo.

I flew that same Gizmo 3 times last year and now I'm thinking it might be time to retire it.

 

[BSNW]

Thanks to everyone for your input. I did fail to mention that these two altimeters were indeed used recently and seem to be in tip top shape. Since they are a tad old, I will apply the many suggestions to ground test these prior to use....just in case. It's just hard for me to retire something that is in great condition and still works.
Andrew

 

[J Blatz]

I fly a lot of old baro altimeters...anyone got a link on how to do cheap and dirty vacuum testing?? I probably should check em out.

 

[RocketRev]

uh.....the only altimeters that I own were bought in the last century........and they are all still working fine. Of course I have a serious vacuum pump and a gallon pickle jar with a tight metal lid with soldered brass air-hose fittings.

At LDRS 29 in the Tim Lehr Wildman's N10000 Drag Race, I flew my 6" diameter fiberglass rocket "God Is Awesome" thru Mach 2.6 to 14887 feet AGL, and recovering on a 2nd generation Adept Alts-25 with the four pin main recovery altitude selector with no problems. I also have an Alts-2, an Alts-20 (I think, its been a while), an Alts-2-50K, and a 2nd Alts-25.

I also have an old Transolve that worked fine for about 2 years. But I haven't used it since sometime in the 90's when I got my first Adept at Danville.

So like most folks, I'd go with President Ronald Regan's dictum, "Trust but Verify." And I would do the same with a brand new altimeter.

If they test out operating correctly several times in a good vacuum jar? Fly 'Em!

Brad, the "Rocket Rev.," Wilson

 

[kjhambrick]

You guy's are making me nervous, lol.

I've been flying the same 2 Missile Works RRC 2's since 2007. The one shown below is in an original first run of Wildman's Gizmo.

I flew that same Gizmo 3 times last year and now I'm thinking it might be time to retire it.


View attachment 628766

What a beautiful Av-Bay !

Is that a key lock above the door ?

-- kjh

 

[kjhambrick]

Boy !

I hope the old ones are OK

I've got a bag full of used, bubble-wrapped AltAccs and a brand new one never flown.

On my Do-List is to port the old PRODATA C-Programs to x86_64 and come up with a USB -to- serial adapter so I can chat with the AltAcc on my Laptop.

Then I plan to test and calibrate that 'new' AltAcc so I can eventually fly it in a 2.95 inch Rocket along side a Blue Raven for a taste-test:

One-DoF AltAcc at 8-bits /16 Hz -vs- 6 DoF Blue Raven at 12 bits / 500 Hz ... Whee !

Just for fun

-- kjh

 

[PSLimo]

What a beautiful Av-Bay !

Is that a key lock above the door ?

-- kjh

Yep, dozens of flights on that 15+ year old altimeter.

 

[Spacedog49Krell]

I have at least one old AltAcc that fails the vacuum test, while another is fine.

They all work until they don’t. The question is when is it a point of diminishing returns.


Tony.

Tony,
If you can post a picture or the model # of the barometric sensor on the old AltAcc, I may have a replacement sensor. Scott and I were both using the MPX4115 in the early 2000's. I still have 50-60 sensors in my old junk box.

 

[manixFan]

Tony,
If you can post a picture or the model # of the barometric sensor on the old AltAcc, I may have a replacement sensor. Scott and I were both using the MPX4115 in the early 2000's. I still have 50-60 sensors in my old junk box.

Without testing it, I’m not sure if this is one that works or not, but all the AltAccs I have are the same. I’d love to resurrect it if nothing more than for the nostalgia.

Thanks for checking it out, let me know if you need a different photo.


Tony

 

[Spacedog49Krell]

Without testing it, I’m not sure if this is one that works or not, but all the AltAccs I have are the same. I’d love to resurrect it if nothing more than for the nostalgia.

Thanks for checking it out, let me know if you need a different photo.


Tony


View attachment 629829

I have 5 in hand of the MPXA4100A from 1999. I think I got them when Scott asked if I could help with programming the AltAcc-2A. For my own understanding, I did a comparison test between the MPX4115 and MPX4100. I found that the vacuum reference cell in the die, for both sensors, is prone to fracture on hard landings. If yours is failing the vacuum test, reference cell leakage is probably the issue.

I look back with some regret that I didn't have more time to help Scott in 1999. I was hired by Unit Instruments to develop an automated R&D lab for the semiconductor industry and it took most of my time. I was already flying 2DoF 12-bit data flight computers at 100Hz.

 

[Papa Elf]

I'd say, if it's made with lead free solder, I would suspect trouble after 5-6 years, based on the average life expectancy of electronics made with lead free solder. The more complex the design, the greater the chance of a problems developing. If you use leaded solder, your limited by the life expectancy of durability of the components. Caps and resisters do go bad, but that can take decades. More likely they'll get damaged due to hard landings or slips of the screw driver.

 

[supertaco]

FWIW, I have an Adept dual deployment altimeter that uses the a23 12v battery that I got in 1993 and it still works today. Those were solid units. YMMV

 

[AZ_Ron]

I just picked up an old Cambridge IAX96 that I want to play with for old times sake. We'll see how it tests out, coming up on 30 years old!

Ron

 

[Handeman]

Just be careful with the old altimeters. About 2005 I watch a flier climb up on a ladder to arm his electronics and when he turned them on, they immediately blew the main deployment charge. Fortunately he was nibble and able to fall off the ladder without injury. Turns out the output transistors on the board had been bent and twisted and a couple leads were crossed, causing the deployment channel to fire on power up.

Modern surface mount components don't have those types of issues. You have a few more things to worry about and keep track of with older altimeters, like Mach lockout jumpers.

 

[lr64]

I'd say, if it's made with lead free solder, I would suspect trouble after 5-6 years, based on the average life expectancy of electronics made with lead free solder. The more complex the design, the greater the chance of a problems developing. If you use leaded solder, your limited by the life expectancy of durability of the components. Caps and resisters do go bad, but that can take decades. More likely they'll get damaged due to hard landings or slips of the screw driver.

Do the lead free ones go bad because of "whiskers" or for some other reason? Wouldn't a nice brushing or a conformal coating take care of the whiskers? Or maybe they're so thin that blowing them off with compressed air now and then would be fine? Or, and this is likely, there's other stuff I don't know.

 

[Papa Elf]

The "Whiskering" causes the solder joints to expand and crack. The expansion and cracking causes poor to no electronic connections. Now how long it will take till that happens depends on how good a quality the Lead Free solder is, but all LFS will still have this problem eventually. One of the military branches (I think airforce) actually did a study to see how much lead was needed to prevent the "whiskering" and if I remember correctly from reading the paper their conclusion was around 10%.

One of the common "quick fixes" for problems with LFS is "reflowing." For example, The RRoD on X-Box 360's or the YLoD on PS3's. Just heat the solder on the mobo at the GPU so it melts and "Reflows" This was a temporary fix and you risk cooking the components. The chemicals in the LFS meant to prevent Crystallization has already broken down, so the reflowed solder will usually last about 3 months if you lucky before the device fails again. The best thing to do if you had something that needed "reflowed" was to get it "reballed," which means they completely remove the old solder and replace it with new. However, that service is not cheap, and the machine to do it, I think I saw a cheap Chinese one for around $6000.

 

[OzHybrid]

Do the lead free ones go bad because of "whiskers" or for some other reason? Wouldn't a nice brushing or a conformal coating take care of the whiskers? Or maybe they're so thin that blowing them off with compressed air now and then would be fine? Or, and this is likely, there's other stuff I don't know.

The original lead free composition solders were brittle and that caused fracturing at the joints from heating and cooling leading to a dry joint with partial or no conduction. This happens over time.

 

[AZ_Ron]

I just picked up an old Cambridge IAX96 that I want to play with for old times sake. We'll see how it tests out, coming up on 30 years old!

Ron

Just an update if anyone is interested... I fired up this Emmanuel Avionics (Cambridge) IAX96 and it boots as normal and goes ready.
My current issue is trying to get the DOS software to communicate with the Serial cable through a USB-Serial adapter. I downloaded DOSBox and was able to get the software to fire up, but haven't had any luck getting the software to see the IAX96. Tried the USB Adapter set to both COM1 and COM2 and neither worked. According to the manual, those are the only two ports that it'll accept. I'll keep playing with it. It's possible I have an old desktop that has a serial port on it. If anyone has any hints/tips/tricks to getting a antique to talk with a modern PC, I'm all ears!

 

[cerving]

You could try buying an older Windows 95/98 computer... but if you look around, they're ridiculously priced. Apparently if you leave something laying around long enough it becomes a "collector's item"...