Mic help needed please

[Turbo T]

Ok I will admit I need some mic schooling here.

First question....

So I purchased a Uniden mic, like what comes stock with the Uniden Pro 510's. I found on my Pro 510 it works fine, but on my Cobra 25 or my Cobra 29, it does not work, even if the mic gain is all the way up on either radio. When I key the mic, I have ZERO modulation on the 25 or the 29.

I tried my Astatic 575-M6 on both of my Cobras and I had modulation.

Why is this? Do the Cobra 25 and 29 use a different/lower ohmage mic than what a Pro 510 uses? FWIW the Uniden mic I have is a 1000 ohm.

Second question....

I have a Royce 1-612 that is my little experimental radio. Yes I know it is not worth anything, but it powers up and provided it works, it makes it the perfect project IMO. I am wanting to wire up a mic but I am having a heck of a time figuring out what colored wires of the mic to solder on the female plug. Can anyone please provide me with a little help?

Thanks in advance.

 

[ExitThirteen]

The reason the 510 mic won't work on the Cobra 25 and 29 is because the 510 mic uses a condenser element. The condenser elements need a small amount of voltage for them to function. The Cobra 25's and 29's do not provide this voltage. The audio circuits in the 25's and 29's are setup to run dynamic mic elements, which are about 600 ohms in most cases. Condenser mics can have anything from 20k ohms to 500k ohms. Hope this helps!


~Cheers~

 

[Turbo T]

Thank you. Yes this does indeed help. Although I wasn't aware of the Cobras were only set up to run the dynamic mic elements.

Were Royce radios equipped with condenser mic elements?