Diagnosing ground issues...

[JamesPaul]

It reads zero when I do this.

Then probably measuring 1.7 ohms with both leads on the bridge, is due to dirt or oxidation on the bridge, or the plating not being a perfect conductor.

Going back to that bridge wire to bridge measurement, slowly climbing up to 16 ohms, I have only seen that with a capacitor or inductor being involved in the circuit, or when as Hank- noted with old batteries.

Obviously this will not solve your hum problem, but it may remove the mysterious readings you are getting. If you have not already, try some new batteries in your DMM, and if you have access to a different meter, try measuring with it.

 

[JamesPaul]

I cannot edit my post above, but I see the readings are all good now. I just started working off my notification from your quote. Next time I will check for posts below them.
o

 

[Mincer]

I cannot edit my post above, but I see the readings are all good now. I just started working off my notification from your quote. Next time I will check for posts below them.
o

Sorry, the forum software is a little grumpy since the last update. Hopefully this will be fixed for the future.

 

[JamesPaul]

Sorry, the forum software is a little grumpy since the last update. Hopefully this will be fixed for the future.

No problem. I only seem to have issues when my posts include smilies or tags. So really, it is more my own fault.

 

[alex1fly]

No problem. I only seem to have issues when my posts include smilies or tags. So really, it is more my own fault.

Stop smiling eh?

 

[Clint 55]

Thanks y'all for the input. Unfortunately I can't get rid of the hum.

Don't listen to my advice to solder the ground wire to the bridge. :eek13:

 

[Artie]

Sometimes, they call me when they get home, and say they fixed it by changing to a different cable.

Love this fix. Nice and easy!

I think it's also important to note . . . the 1st cable may not have been "bad" per se. Just the LCR of one was different than the LCR of the other. Enough to shift the problem point.