[Elecraft] K3s: microphone connector 8V current

[Grant Youngman]

i’m not interesting in using the 8V line for mic element bias.  That was someone else.  My application is to power an external device between a mic and a K3/K4 from that line.  

I can, of course, use a battery.  But it would be much simpler if the 8V line could supply at least 20ma without releasing smoke :-)

The individual that asked this question initially, was looking for the possibility of 50ma.

Grant NQ5T

> On Jul 26, 2020, at 8:21 PM, Don Wilhelm <donwilh at embarqmail.com> wrote:
> 
> Grant,
> 
> The MH2/MH4 mic does not use the 8 volts directly - there is a resistor between the 8 volt supply and the AF line,
> and that is where the 10ma is used to power the electret elemant.
> The 10 ma. used by the microphone has nothing to do with the total current available from pin 6.
> 
> 73,
> Don W3FPR
> 
> On 7/26/2020 8:05 PM, Grant Youngman wrote:
>> I have the same question about the current available for the 8V at the mic connector.  Is it limited to 10ma, or will it actually support a somewhat higher continuous current draw safely.  Not just for the k3, but also the K4.
>> 
>> Grant NQ5T
>> 
>> 
>>> On Jul 26, 2020, at 7:46 PM, Don Wilhelm <donwilh at embarqmail.com> wrote:
>>> 
>>> Henk,
>>> 
>>> If indeed it is for a mic preamp, then try it without the preamp.  The K3S has 2 stages of mic AF gain.  Normal for the usual ham mics, and a Hi level for low gain mic elements.
>>> 
>>> You must turn on bias to have the 8 volts appear at the mic jack.  Do not use with direct connection of a dynamic mic - it makes the mic 'sound funny'.
>>> 
>>> 73,
>>> Don W3FPR
>>> 
>>> On 7/26/2020 5:40 PM, Nr4c wrote:
>>>> What are you going to use this  voltage for? I think it’s for a mic preamp. It is not the source of bias for an electret mic. That comes on the mic pin when turned On in the menu.
>>> ______________________________________________________________
>