DIYbanter - View Single Post - Wind Speed Problem with Heathkit ID-4001

In article ,
lid says...
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.