OK now for some more TEA. Maybe the grey beard will have a clue and give me some info on this little gizmo I just did a quick tear down of for you people.
The guy I bought one of my two Metrix nixie counters (not the one picture earlier, another one with only 6 digits, 10Mhz not 160Mhz), also gave me this little artifact as a bonus. Said it was so crap he didn't even find it worth the effort putting it up for sale as for sure nobody would want it.
I always wondered what it was for ! Seller had no clue either !
Looks old, looks military looking maybe... it's tiny, fits in the hand !
If I believe the scale on the galvanometer, it's an ohm-meter, with two ranges. There as switch on the side of the case to let you select that.
Also on the side there is a handle that you can crank to energize it.
So far so good, looks like your typical ancient mega-ohmmeter to measure earth resistance.
Problem is... the scale should read in the tens of Mohms..... whereas here, it's the opposite : it measures very LOW values : one scale for 0 - 50 ohms, other scale is 0 - 150 ohms !!!
What use is that ?!
I guess it must be some nice instrument for a very specific application... but what application ? Civil ? Military ?
Inside there is not much... the meter, the generator, the switch to select the range... and what looks like a primitive form of coil / inductance, or might a wire wound resistor, not sure...
The movement is fucked though, sadly : the tiny coil spring that brings the needle home, is completely out of shape. Not much springiness in it left, and sometimes it just jams somehow. Needle will get stuck even though it's free to move. don't think that can be fixed.... not that I would have any use for the thing any way !
Anyway I thought this was an interesting / curious find. Would not mind knowing what it's purpose in life is, if anyone knows... just to satisfy my curiosity.
This evening a friend just brought to me his " iRobot " vaccum cleaner clone. It "misbehaves"... keeps banging / bouncing off walls instead of following them along. I hate these things but still curious to see how it's made. Said I would have a look at it.. with some luck there will be something obvious... bad SMD electrolitic caps, bad solder joint, some corrosion, I don't know.... can't do much more than basic trouble shooting, given the absence of a service manual.
Have already repaired one of these things last year. A friend (another) spilled water on his (genuine this one) iRobot Roomba. Thes ide brush quit working as a result. Was easy : corrosion on the main board, a broken trace/via that supplied power to the driver chip for the motor in charge of that brush... ran a wire and off you go.
Not so hopefully on that other robot though, since the symptoms are hard to translate in electronic terms.... "misbehave".. hmmmm...
He did say that it started doing it a while ago and that it got worse and worse over the months. So I am thinking analog problem no t digital. So there might be a hope of finding the problem.... else, it's a write-off and hopefully he will let me keep it for parts !