Tektronix 2235 100K and 10K Input Attenuators

[jdragoset]

When you have a channel going goofy (high amplitude, 1,2,5 volt, 100k, .1, .2, .5 volt, 10 k) it may not be the cam operated switch but the attenuator (six internal solder joints) the problem.
Swap the attenuator (they plug in) to verify.
Easy fix compared to cam/switch leaf dis-assembly and cleaning.
Re-flow the six pin-to-ceramic attenuator connections after removing the cover.

[bob91343]

This is confusing.  Only one message on this topic and it appears to be responding to some other one.

[David Hess]

I have had the same problem once so far.  The pins are riveted to the attenuator hybrid and the electrical connection may fail.  I soldered them with silver solder.

Beware that swapping the attenuators will compromise the input capacitance and compensation until calibration is done.

[jdragoset]

Did not mean to confuse.
Had high amplitude noise in the 1,2 & 5 volts/div on one channel only.
I unplugged the attenuator to clean the cam switch contacts for that attenuator with a narrow manila strip and IPA.
After the problem remained I temporarily swapped the attenuator into the good channel, where the problem followed the attenuator.
David,
Is there a low temp silver solder?
The one used on the ceramic terminal strips?

[David Hess]

David,
Is there a low temp silver solder?
The one used on the ceramic terminal strips?

Common leaded 2% silver solder (Sn62Pb36Ag2) is suitable.  The only risk is if you use normal solder, the silver used to make the trace on the hybrid may dissolve leaving no trace behind.