Re: [Elecraft] K3s: microphone connector 8V current

2020-07-26 Thread 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

Re: [Elecraft] K3s: microphone connector 8V current

2020-07-26 Thread Don Wilhelm
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,

Re: [Elecraft] K3s: microphone connector 8V current

2020-07-26 Thread Grant Youngman
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 wrote: > >

Re: [Elecraft] K3s: microphone connector 8V current

2020-07-26 Thread Don Wilhelm
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

Re: [Elecraft] K3s: microphone connector 8V current

2020-07-26 Thread Nr4c
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. Sent from my iPhone ...nr4c. bill > On Jul 26, 2020, at 2:57 PM, Henk de Vries wrote: > > Hi all, > At the

[Elecraft] K3s: microphone connector 8V current

2020-07-26 Thread Henk de Vries
Hi all, At the K3s microphone connector the 8V output (pin 6) is specified at 10 mA max.However a UA78M08CDC voltage regulator - which is directly connected to +12V - provides the voltage/current to this pin.The UA78M08CDC is specified at 500 mA max. Is there any reason why a current of approx.