In fact, David Clark *does* make some headsets with mics that do not require bias. I'm not sure whether they are only special order but they *are*available.
In general, however, you can assume that any aviation headset has what Graham calls a "carbon mike equivalent." Bill (Long-time DC user for both aviation and radio) On Mon, Jul 11, 2011 at 7:42 PM, Graham Haddock <[email protected]>wrote: > 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. > _______________________________________________ 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.
