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
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used
> for posting topics related to SDR software development and
experimentalist
> who are using beta versions of the software.
>
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This is the FlexRadio Systems e-mail Reflector called FlexEdge. It is
used
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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.
