The PHILCO Phorum

Ran across an old output gauge that I thought I would use when adjusting radios. It reads from 0 to 1.2 with various numbers in between. Printed on the gauge is Output R.M.S. I connected it to the small speaker wires (on the cone) on my Philco 40-190. It moved the needle slightly at high volume, but nothing at medium volume. Is it the wrong type of meter for radio volume? The wires have a positive and negative. Switching them made no difference.

With positive and negative leads, it is probably a dc, and not a true RMS instrument. Try putting a diode in series with it.

All of the output meters I've seen were simply AC voltmeters with a capacitor connected inn series with them. Try replacing the capacitor, and it might start working.