George: Almost all aviation mikes are "carbon mike equivalent" at the connector, and require a bias voltage/current to operate. So, yes it has a dynamic mike as the the audio pickup, but then has a transistor amp following it, and the combination requires power, and expects it to be fed from an approximate ~600 Ohm load/source.
So a resistor from mike hi to +5 Volts, typically 560 Ohms (not 100 Ohms) will provide the bias and the approximate 600 Ohms the mike is designed to work against as a load. This is built inside all aviation radios and intercom panels, so David Clark is probably not used to seeing their customers adding resistors externally. --- Graham / KE9H == On Mon, Jul 11, 2011 at 6:34 PM, George R Allen <[email protected]>wrote: > I have interfaced my H10-76 to the F5K. > > > > Phones work, mic doesn't. I see the slightest output from the H10-76. > > > > I have had suggestions from this group to put a 100ohm resister from + 5v > to mic+; but, the David Clark web site advises against this stating that the > mic is a dynamic mic. > > > > Any suggestions? > > > > George > > K2CM > _______________________________________________ > Flexedge mailing list > [email protected] > http://mail.flex-radio.biz/mailman/listinfo/flexedge_flex-radio.biz > This is the FlexRadio Systems e-mail Reflector called FlexEdge. It is used > for posting topics related to SDR software development and experimentalist > who are using beta versions of the software. > _______________________________________________ Flexedge mailing list [email protected] http://mail.flex-radio.biz/mailman/listinfo/flexedge_flex-radio.biz This is the FlexRadio Systems e-mail Reflector called FlexEdge. It is used for posting topics related to SDR software development and experimentalist who are using beta versions of the software.
