anemometer help

[WQ9E]

Anyone here care to share your experiences with building an anemometer?

This tale starts when I found a new Heathkit ID-1390 digital thermometer at a little hamfest earlier this year.  Given where this has led, I probably should have put the kit on Ebay because I decided it would be nice to find some of the other matching Heath instruments.  I acquired the rain gauge with sensor and I just picked up the ID-1590 wind speed/direction gauge mostly assembled but never used (due to some wiring errors I corrected).  It came with the direction indicator assembly but the speed sensor was MIA.

Lots of googling and searching revealed a good possibility with the speed sensor sold by "Fascinating Electronics".  Comparing the calibration chart versus the original Heath unit it would be a very close match except it only outputs two pulses per revolution instead of four and was listed for $45 in kit form.  That seemed reasonable and I called today to order only to find that the line was sold to another company which still sells the sensor (in kit form) for $65 IF you buy five of them at a time.  Otherwise, it is $85 assembled which I would then have to take apart and modify to produce the 4 pulse per rotation output.

So I am back to the homebrew route.  I have googled and found some reasonable (and unreasonable) approaches but I am curious if anyone on here has personal experience to share.

Rodger WQ9E

[Todd, KA1KAQ]

Rodger, you're finding yourself in a situation that many Heathkit wx station nuts find themselves in. Most often, they find the main unit with no remote units. A few years back someone had offered reproduction wind cups, but I don't know if they ever came up with a sending unit.

If all else fails, keep your eyes open for some of the nice old Taylor analog gear like the Windscope (speed or direction versions) or Weatherscope, the complete wall unit with speed, direction, barometric pressure and outside temp. That's wat I've got here, plan to hook it up this fall sometime once it cools down. I've got a spare wall unit if you find the sensors without one (hey, the reverse does actually happen sometimes).

Swift also offered a nice unit back in the 80s with 3 square analog meters on a nice wood-look board. If you're absolutely set on the Heathkit stuff, keep and eye on the 'bay and be ready to bid high, because the piece you need is the one everyone else wants, too.

[WA1GFZ]

Why not spend your money on a nice function generator and do a little math.
Say an HP3325A. then whne you are done you have a nice audio generator and one heck of a programable sweeper that is good to 20 MHz. On top of all that is has a very nice function that would be perfect for a Saturday night in the danger zone SBE VFO......all for $100

[Pete, WA2CWA]

I remember many years ago during one of our many lunch time projects at work, we made a wind speed indicator. For the sensor, I pulled from my stock of Lafayette cassette motors, a motor where the shaft protruded from both ends. On the long end, I installed a bushing (held in place by an allen screw) and then threaded 4 holes in the bushing for 4, identical length, threaded rods. At the ends of the rods, I glued four "Leggs" cup containers(held women hosiery) for the wind catchers. At the other end of the shaft, I installed a nylon gear from an old tuner, On the bottom of the motor, I installed a sensitive micro switch and positioned it so that the gear teeth would just make/break the contact. Using wire cutters, I cut the gear teeth I didn't need, so that in one rotation of the gear, it would make/break the micro switch, I believe three times, for the wind speed indicator we were putting together. I can't remember if we pulled an article from somewhere, or we just "table napkin" the whole project. The same concept could be used for additional pulses. Old tuners generally had a number of different size gear diameters to chose from since that would be an important parameter. Making a homemade rotating pulser is probably not that difficult to fabricate either.

[WA1GFZ]

You could take it for a ride in the car to calibrate the speed...

[WQ9E]

Guys,

Thanks for all of the suggestions.  Now that my central vac install is finished I can move back to fun stuff like this weather system.  (yes, I did install a vacuum port near the bench for quick cleanups so there was also a vintage gear motivation for the central system).

Todd,  I have seen a system like yours and they do look neat.  I remember the first "weather channel" on our local cable in MS was a video camera aimed at a system like yours.  Being a vintage gear type, I will probably go for the difficult way (goes with the territory).  Since I have 3 matching Heathkit indoor units I am going to come up with something for the speed sensor. 

A little voice is telling me I should just order one of the $85 sensors and modify it with an optical sensor to output the desired 4 pulses per revolution since I will spend a lot more than $85 worth of my time building and calibrating a homebrew system.  I will call the new vendor Monday and see if they will sell the $65 kit one at a time since I have to pull it apart anyway for modifications.

Pete,  one of the "local" AM guys built a similar system but built it using parts from an old hard drive. 

The car calibration idea is a good one and my wife's new Malibu has a convenient AC power port in the back.

Rodger WQ9E

[W1RKW]

Rodger,
I have one of those cheapie weather stations and the anemometer uses a reed switch.  As far as I can tell the switch provides 4 pulses per revolution.  The magnet is tiny and has four poles on it.

[WQ9E]

Bob,

Which station do you have?  I had thought of investigating some of the sensors from other stations to see if one can be made to work.  I am not looking for NIST level accuracy and the Heath unit can be re-calibrated fairly easily as long as the rotation speed based upon wind speed is fairly close.

Rodger WQ9E