Hi Eric,
Just a thought here - you said:
¡°I am having issues with 60, 20 and 6. With them also causing some havoc on auto range as well. When I have a situation where they are working the unit locks in and works as expected. These are supposed to have a 5Vdc coil but when I was testing one with a square wave it would not trip till about 8Vdc.¡±
So from your description, it sounds from this like they are working but perhaps mysteriously intermittent?
If so, one thing I¡¯ve seen on DC powered reed switches that are ¡°vintage¡± (i.e. old far beyond their rated service life) is that sometimes the application of a DC voltage to a coil over a very long period of time (i.e. years) can induce residual magnetism somewhere in the switch assembly. This residual magnetism can make them act ¡°sticky¡±. They stay on when they are off, or they are hard to energize at the rated voltage.
I admit I have not seen this on Tek scopes - no experience there - but I¡¯ve definitely seen this on vintage analog recording consoles and vintage analog tape machines, which use a lot of Reed relays. My solution was to use a spot tape demagnetizer tool to demagnetize the switch assembly. It seemed to work for me, assuming the relay wasn¡¯t actually bad.
Maybe not useful info in your case, but I thought I would throw it in.
