Bench Testing Positive Ground AM Radio

Why?

jol50 said:
Also make sure your bench or anything the radio could touch is not grounded.


The radio chassis will be grounded, and powered from the negative side of the supply.

There is no need to worry about isolation.

Perhaps you are thinking of a situation using a supply with the negative already grounded? Or putting the radio in a vehicle with a negative ground battery? THEN you will have problems!
 

65blkbkgt

Member
2007-06-07 11:42 pm
Re: Why?

cliff said:



The radio chassis will be grounded, and powered from the negative side of the supply.

There is no need to worry about isolation.

Perhaps you are thinking of a situation using a supply with the negative already grounded? Or putting the radio in a vehicle with a negative ground battery? THEN you will have problems!

See that's what I'm not sure of. Whether or not the cars back then had negative or positive ground batteries. I almost want to say that being a positive ground radio the battery would almost have to be positive ground?

Anyway.....so I think I have this straight (hopefully). Neg of power supply to power wire w/inline fuse, pos of power supply to chassis, power up and close my eyes. :)
 
Yes, you've got it all right.

A long time ago cars were mostly Postive earth - but not all.

'caused havoc trying to fit any electronics!


There is nothing magic about "earth" or "ground".

Any circuit will quite happily work without any ground connection, just + to + and - to -.

However when connecting 2 or more things together, and for electrical safety, it becomes important.