D104 MIC ELEMENT TEST?

[ClaimJumper]

I know someone with three d104 Mic elements. How do I know if they are any good or not? They are not installed in the microphone.

 

[nomadradio]

Haven't tried that. Only test them inside the mike's head.

To test one in the "lollipop" round head we use a 1960s gadget meant for calibrating sound-level meters. Got it on fleabay decades ago. The straight output from the cartridge goes to the oscilloscope. Comparing the test head to our known-good head is the quick way.

But in any event, to test a cartridge you need a steady sound source and a way to measure the output level. The glue that holds the element inside the cartridge comes loose sooner or later, and the output becomes weak and muffled-sounding. Never have tried to actually calibrate the output voltage the cartridge should have. It's just quicker to compare it to our good cartridge.

The foil diaphragm is incredibly fragile. If the fiberglass mat has come loose, any bumps or crinkles in the surface of the aluminum would suggest it could have problems.

73

 

[Wire Weasel]

Easiest way is actually wire them into the mic head one at a time and test them over the air with a neighbor for how they sound - you can measure their audio volume strength by watching how well they drive the modulation on your wattmeter compared to a known good one.

 

[KneeBiter]

Easiest way is actually wire them into the mic head one at a time and test them over the air with a neighbor for how they sound - you can measure their audio volume strength by watching how well they drive the modulation on your wattmeter compared to a known good one.

I have had some that actually drive the radio harder and have a very hollow sound when bad. Best test I have found is like you said put it on a mic. But listen to yourself on a monitor radio. Best to use a non amplified stand and a Hi-Z tube radio for test.