You just don't get no respect, Lee...
On Mon, Jul 11, 2011 at 10:23 PM, Lee Mushel <[email protected]>wrote: > Ya know, there was an article in QST earlier this year on the subject. > As I recall it went into some detail. As usual, no one paid any attention > to me when I nicely gave the issue and page number.... > > 73 > > Lee K9WRU > ----- Original Message ----- From: "William H. Fite" <[email protected]> > To: "Graham Haddock" <[email protected]> > Cc: <[email protected]> > Sent: Monday, July 11, 2011 6:41 PM > > Subject: Re: [FlexEdge] David Clark H10-76 and and F5K > > > If you want a sketch of the interface of a DC headset to the Flex mic >> connector, here it is. >> >> >> >> >> 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<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<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<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.
