Hi Dale:
(The rookie user name come from chess, I like the Rooks :-)
I am happy to help fellow weather enthusiasts!
The main reason I like the Heathkit weather stations is one, they are nearly instant read, wind speed changes, and you will see it. The fastest modern weather station is 1.5 seconds, in a wind gust A LOT can change in 1.5 secs! Two, they are easy to see across the room except for the id-1290 with the meters. Last, they are "usually" easy to fix. Even the id-1590 with the neon display can "usually" be coaxed back to life with some short term higher current times to burn off the oxidation on the elements. I have two 4001, five 1290, eight 1590, one 1390.
The 4001 and 5001 booms and their parts are exactly the same between them, IR diodes and transistors, bearings, circuit boards, encoders, all the same. I can talk about the encoders in a later post if your interested. The only difference is wiring from the direction side to the speed side.
I have a document some place because I bought a 5001 boom and had to convert it to the 4001 and the wire goes from the direction side to the speed side of the boom.
(Doing this from memory and won't be able to give a detailed conversion right now but I will post it when I find it.)
The main harness is connected on the direction side and in the 4001 boom 4 wires go from the direction side to the speed side.
The 5001 boom is missing the 5VDC on the speed side since Heathkit redesigned the 5001 slightly by feeding the 5VDC through one of the wires going to the speed side instead of a separate wire for 5vdc.
So, all that has to be done to convert the 5001 boom to work with the 4001 is add a wire from the direction side to the speed side and wire it so the IR diode is on. An easy way to check if the IR diode is working is use your cell phone camera and look directly at the diode if your see it glowing in your phone, it's working.
(Sorry its not more detailed, I will look for the document and post the exact steps.)
The great thing about this is you can wire things up and try it, you blow anything out, the IR diodes and transistors are very forgiving.
I know because of all my attempts to get it working I soldered 5VDC to the wrong places and didn't break anything.
If someone has the 5001 boom portion of the schematic, I can tell whats missing, that's if I can't find my document.
(I had a 5001 for a short time and should have kept it but I got $495 on eBay for it. I should have made some notes about those types of differences but forgot.)
I installed the 4001 processor upgrade and was not able to calibrate the temp sensors. According to D8aPro I needed to put a 1meg ohm resistor across the calibrate switch since if the voltage is not right the processor goes wonky. And when switching from cal to operate it might see something it doesn't like because the switch is cheap and the bounce causes problems. So, my current 4001 is stock. I figured I will wait until the processor goes south and then deal with it. The only feature that might be worth installing the processor is the fade when switching between date and time. But I usually leave mine on time anyway.
I am always happy to help in anyway I can. Especially with Heathkit stuff.
As for your plight with your wife, I am in the same boat. But I do it and let her bitch and she gets over it.
Im also a ham operator so there's THAT whole side of things besides the weather stuff she hates.
I attached a annotated schematic of the 4001 boom, hope it helps.
Hope all this helps I'm happy to help in anyway I can.
Thanks for asking.
Steve
P.S. The 4001/5001 wind booms are susceptible to lighting EMP pulses. If yours suddenly stops working, suspect the IR Diodes/Transistors need to be replaced. D8apro has new ones. I had an electrical engineer look at the schematic and suggest some ways to help prevent EMP pulse problems. I have not implemented them yet but it's on the list of things to do.