Wind Speed Problem with Heathkit ID-4001

Does this system controller measure the speed by reading a voltage from the sensor (with voltage being proportion to wind speed) or is it counting pulses (1, or N pulses per revolution, hence frequency is proportional to speed)?

If it's counting pulses, then I might suspect either of:

- A "bouncing" switch in the sensor, which is just barely making contact at the point at which the sensor has stopped spinning, and is vibrating open and closed. The cure for this would be a better sensor-switch - one with enough hysteresis that it opens or closes firmly and doesn't jitter back and forth.

- RF interference from a local transmitter, with the RF signal "looking like" contact opens and closures to the control unit. The cure here would be some amount of RF snubbing being added to the line to the sensors - possibly wrapping the wires around some ferrites, possibly adding a small amount of capacitance across the line to shunt out the RF, or possibly both.

--
Dave Platt                                    AE6EO
Friends of Jade Warrior home page:  http://www.radagast.org/jade-warrior
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It is indeed counting pulses.

It is not a mechanical switch. The pulse generator consists of an IR LED that shines on IR sensor with a plastic disk in between that has a series of black stripes painted around the edge of it. When the wind cups spin, the disk spins so the black stripes interrupt the IR path between transmitter and sensor generating pulses. The pulses then to go to a base of a transistor that I assume is a switching transistor that is either fully on or fully off. It is an NPN transistor in common emitter configuration and the output of that is fed directly into the CPU for counting the pulses in a given time frame for wind speed determination.

I thought about the possibility of noise pickup and put some a capacitor across the line where it connects to the weather station and it did not seem to help.

Thanks for taking the time to reply.

>

If the disk happens to stop partially blocking the IR transmission path, you might get random pulses...

Probe the signal at both the input and output of the NPN transistor. That'll tell you if it's the sensor, the transistor, or the CPU which is causing the issue.

Sounds to me as if there may not be enough (any?) hysteresis in the IR-sensor / transistor-switch system. If the disk comes to rest in just the right position (with one of the stripes partially but not completely blocking the IR path) the amount of IR energy reaching the sensor, and thus the amount of current going into the switching transistor base might be right around the transistor's switching threshold. Varying amounts of random electrical noise in the photosensor or transistor could then cause the output to switch state unpredictably.

If I were going to try to fix this, I'd do one of two things:

- AC-couple the output of the sensor to the transistor's base, adding a biasing network to hold the base a comfortable distance on one side or the other of the switching threshold. That way, only fairly substantial (and relatively fast) sensor transitions would dump enough current into the base to cause the transistor to switch state.

- Use a Schmitt trigger, or some other sort of transition-detection circuit with explicit hysteresis (e.g. a comparator with a bit of positive feedback added).

--
Dave Platt                                    AE6EO
Friends of Jade Warrior home page:  http://www.radagast.org/jade-warrior
  I do _not_ wish to receive unsolicited commercial email, and I will
     boycott any company which has the gall to send me such ads!

I have an ID-4001 and I'm running into a similar problem. Mine, however is with the direction giving random readings. In normal operation, say the wind is from the southeast. All of a sudden, the indicator will jump to northwest. It doesn't "turn" to the northwest, it will all of a sudden "jump" there. I've tried to get it to do it by manually rotating the wind vane, but just can't seem to re-create the problem.

I'm kind of thinking that the problem may be in the 8-wire cable. I'm still using the original cable that came with the kit. Having wire outside for that many years, maybe it's corroding and not allowing the full 5 volts through.

Just a thought. Anyone care to comment?

Since it's not a constant problem, I haven't set aside time to check voltages.

Have you tried the simplest and just clean the disc and semiconductors? We have tape machines at work with optical tachs that require cleaning on occasion (many years between cleanings). My Kensington trackball (optical tach) was screwing up last week, cursor bouncing like your wind speed readings. A good cleaning has it working well again.

GG

I agree with the suggested cleaning of the optics.

... or wait for a service pack release from Heathkit!

ROFL on that last statement. I could be waiting one heck of a long time for Heathkit to rise from the dead.

As for cleaning, I have had the wind sensors down for repair on many occasions and not being clean is not the problem. The last time was just the other day when I replaced both the LED and photosensor as a possible cure thinking one of those might be the problem. The disk was just fine. Often they rub against one of the LEDs and it wears the paint off so the striping is no longer effective but this is not the case here.

Actually I think I am tired of fighting with it. It is almost 30 years old and it is very prone to static and nearby lightning strikes. It is so bad that I unplug it and disconnect the wind sensors for most of the summer because if I don't, I will be taking the wind sensors down at least once during the summer to put new parts in. One time it was so bad that when I took it apart, I found the top had actually been blown off one of the components and several others were also dead. It also doesn't have humidity, rainfall, and other features that some of the newer units do. After 30 years it deserves a rest and I deserve a better instrument.

The only decision left is to pick a brand and decide whether to go wireless or wired on the sensors. I like the instant update that wired sensors give but I am also concerned that if I go wired perhaps I will be letting myself in for more of the same problems I currently have.

Thanks to all who offered suggestions. I did try the AC coupling as suggested by connecting a large capacitor in series between the photosensor and transistor. That worked until the capacitor built up a charge and then it failed to pass the pulse. I also tried putting a resistor to ground on the sensor side but could not find a value that kept the capacitor from fully charging without killing the pulse completely. I could have investigated the Schmitt trigger or looked for a better way to AC couple but in truth, I shouldn't have to. It worked before in the current configuration for many years so obviously something has changed and altering the circuit shouldn't have to be the cure. As I said, I have been looking for an excuse to treat myself to an upgrade with some new features and to rid myself of the static/lightning problem and think I have found it.

Thanks again to everyone for their assistance and suggestions.

It might very well be the wire but in my experience the problem with erroneous wind direction indications has always been the failure of one the photosensors or LEDs due to a static discharge or a nearby lightning strike. The LEDs are wired in series so that if one goes they all do not work and wind speed goes to zero and the wind consistently indicates only one direction which I believe is SE. This does not appear to be the case for you so I would suspect one of the photosensors - or a bad wire as you suggest. The wind direction indication is the only function that does not go through the CPU so you can rule that out as a possible problem.

Before replacing the wire, I might have someone slowly spin the weathervane around full circle several times while you note exactly which of the direction indicator LEDs light and in what order. I would then examine the Gray code listing in table 5-3 on page 21 of the Operations manual and see if you can see a pattern that would point to a particular failed photosensor. If not a photosensor it might also point to which of the wires is the problem.

Good luck.

My apologies. I missed in the first reading that you had already tried spinning the weathervane manually and that it was intermittent. The only thing I can think of in that case is to check the wires on the bottom of the display where the sensor connects to the station. I have found those flex over time and the small individual strands of wire that make up the complete wire break one by one where they are soldered to the connector. Perhaps one connection is now intermittent. I have also found that a connector can shift and touch an adjacent connector if the screw is not really tight. There are a lot of wires under there and it is easy for one to touch another if things are not exactly right.

Thanks for that tip. I will check all the connections on the display unit.

I really would hate to have to put the ID4001 to rest and get one of the new units on the market. For one, I love the nice bright display. All of the new stuff has LCD's that you can't see from across the room. And I don't like the idea of waiting 7 to 15 seconds for an update on the wireless sensors.

One other quick question. Does your wind vane move around alot? Let me explain. During a breezy period, mine moves around as though someone is spinning it with their hand. It doesn't hold in the direction the wind is blowing from. I realize that there will be some veriation for instance if the wind is from the SW, the display will vary between south and west, but mine actually spins all the way around! This isn't anything electrical and I can go outside and watch it sping around like the anemometer! I've balanced it like the instruction manual says, so that's not the problem. It's just annoying to see it spinning like there is a tornado on top of me:)

It's not all the time, but during breezy conditions, it seems to do it more than I think it should. Any suggestions?

I agree with you 100%. Both those features, a display readable from across the room even with the lights off and wired sensors for rapid updates, would be my ideal on any replacement although I could weaken on the wired sensors. I cannot count the number of times the wind sensor has been up and down to replace parts because of nearby lightning strikes or static discharges. This is despite my trying two different locations and grounding as much as I can. Have you had any trouble from static and lightning?

I am currently looking a Peete Brothers The Weather Picture since it has large LEDs that can be easily seen, but I am still concerned about the wired sensors. They say their unit is "bullet proof" for static discharge but they also say not warranted against lightning. I am not sure if that means only a direct hit, which I can understand, or if it includes any impulse damage as well.

Mine also spins like that, particularly under light wind conditions. I think in my case it is because it is only about 20 feet off the ground and there are objects (trees and shrubs) nearby including the house to the WNW about 70 feet way. I think the wind is affected by nearby objects that tend to make it change direction as it goes around them. When I had the wind sensors mounted on the roof of my two story house about 15 feet up it was not as bad but it was still not perfect due to nearby trees.

I think the bottom line is that if the weather vane is spinning it is because the wind is changing direction and about the only thing you can do is try to have it away from as many objects as you can. The good news is that it is sensitive to even light winds. Mine will change direction even when there not sufficient wind to spin the cups.

>

Just a few comments and a question. I also have a ID-4001 thats been running flawlessly for the past 30?? or so years. I have no problems with the speed or direction electronics but the outdoor plastic is starting to disintigrate. Last winter I lost one wind cup. I did have to replace the outdoor multistrand cable when the insulation crumbled. A shorting cable may be part of your problem. At one point in the distant past I had the 4001 hooked up to a H8 for data loging. I was an avid kit builder back then. Many T storms have passed over the 4001 and never caused any problems. I have looked for a replacement wind cup and there is none to be found. One company still markets a

5001 (lcd) using the same boom and sensors but they seem to be vaporware. So my question is, anyone know where I can get a replacement or something that I can fit in place. Also tried Data Professionals none left in stock.

Steve

It looks like each person has a different problem. I suppose I should knock on wood but my plastic parts seem to be holding up fine. I would offer you my wind cups but I have not completely given up hope on fixing mine down the road. I might perhaps tinker with the wind speed problem in the future even though I have taken the 4001 off line for the moment and am looking into a different station. I really do like LED display over todays LCD displays.

The cable seems fine but I will investigate further. It has been buried for several years between the house and the sensors after I moved the sensors off the roof - and it is the original cable. I took down the boom yesterday and cut the wire in anticipation of a new station but I left about 10 feet of wire attached so I could test it further inside if I felt the urge. I guess in my heart of hearts, I really hate to see it go despite its headaches.

That I just don't understand. I have replaced the LEDs and photosensors more times than I can remember and the CPU a couple of times (the last one from d8apro.com). I haven't lost a CPU since I moved the sensors off the roof and mounted them on a cast iron pipe set in cement covered by a couple of feet of soil so the boom is directly grounded, but I still have lost components in the wind sensors. To be honest I think the CPU has not been damaged only because I take it off line when ever it even looks like there might be Ts within 50 miles and not because of anything I did to make the installation better.

I did look at a site that offered to take a 4001 in trade for a 5001 but when you look for prices they say they are in the middle of a move and to check back later. As you say - vaporware.

Not off the top of my head but I will keep that in mind and if I ever decide I am never going to try to fix mine, I will post something here letting you know my wind cups are available.

Don is really great to work with and very helpful. I only wish the programming in his CPUs more closely matched the programming in the original Mostek CPU. I really liked the way the original CPU worked over the new one.

This is despite my trying two different

Have never had any trouble with lightning or static discharge. Lived in Nebraska for many years, and never a problem in the spring. Now, I live in Arizona, so thunderstorms are few and far between.

I checked out the Peet Brothers web site. Don't care for the indoor unit. The "additional" display looks nice, but not worth the extra $400

Guess I'll just have to put up with those minor problems. I love the ID4001 too much to chuck it for those. I've added the Heathkit humidity "kit" as an add on. Doesn't fit in the current display, but still looks nice sitting next to the ID4001. For a rain guage, I bought a wireless guage at Walmart. It's made by Accurite. The display isn't led, but it's still a good size display and works quite well. Batteries last almost a year before having to replace them.

One quick note: I remember living in Nebraska and watched as the wind chill reading on the ID4001 hit 92 below zero!!!!!!! Will never forget that reading as long as I live. Too bad I couldn't keep it in the memory. Now, in Phoenix, I don't get to use the wind chill reading. All I ever see is the temperature climb up and up the 115. :)

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Hi Steve, I was going to try to replace my CPU with the one from d8apro.com, but sounds like there are flaws in it. I hope my CPU never goes out!

Sorry to hear that you lost one of the cups. Guess I'm luck. Even with the extreme heat in Arizona, my cups seem to be holding up. I did loose the plastic end on my wind vane a few years back and ended up fabricating one on my own from a piece of aluminum. Painted it white and doesn't look too bad. You might want to try to see if you can fabricate ones for yourself. This web site might give you some ideas.

Other than that, watch on e-bay. I've seen some parts being sold on there as replacements. Good luck.

I concur. I have moved on from Peete Brothers. After looking at prices and the reviews at eHam.com I am now favoring the Davis Vantage Pro2 The only down side that I can see is that the display is so small after using the ID-4001. I guess it is always about compromises (sigh). The good news is that I think if I do a little looking around I can find the Pro2 at a substantial discount. Based on that I think I can buy the complete station with a second console for less money than the Peete Brothers unit with the Weather Picture. The result would be a more reliable unit (based on many eHam reviews) and a display in more than one location in the same room or in different rooms. Perhaps one in the living room and one in my den near the computer. Nothing is ever perfect but that should help soothe not having a super large display.

At least those are my current thoughts. As the say, "Indecision is the key to flexibility" so until I place the order, I still can consider my options. I would however like to have it installed before December. I am not a big fan of any outside work here in northern New England during the winter months.