Re: [TenTec] Scout 555 MIC Gain Question...

["Dr. Gerald N. Johnson" <geraldj@weather.net>]

On 3/28/2010 1:41 PM, Ben Hall wrote:
> Hi Bob,
>
> Great suggestion!  I'd not thought that the Ten-Tec would be an
> electret, but it is.  (Well, at least the one that came with it and the
> desktop 707 are)  So I checked the voltage - 9.9 volts.  This is higher
> than the +4 volts shown in the manual.  But a quick check of the
> schematic shows that the mic voltage come from the regulated +10V line
> thru a 680 ohm resistor.  So unloaded, it will be the full regulated
> voltage...
>
> thanks much,
> ben
>
> And that 680 ohm resistor sets the input impedance as low.
73, Jerry, K0CQ