Jim is technically correct, the MS document is a System Design Guide which guides using a resistor from the bias source to the ring and a separate resistor to the tip; not a single resistor supplying

Andrew Thanks it arrived to today. Just what I was looking for Mel

Both sold.

This is a PRACTICE, not a STANDARD. STANDARDS are developed and agreed upon by established international organizations not affiliated with companies like Society of Motion Picture and Television

The MS PC standard for tip, ring, shield (TRS) mic connectors is to have the electret element bias supplied on the ring. A low VDC is applied to the ring via a limiting resistor. In some PC sound

I frankly do not know either.   I am just quoting from the book and admit I do not know exactly what that means Thanks Rich

I don't have Fred's book. K3 schematics are online. I don't know what you mean by "floating ground." 73, Jim K9YC

Sorry everything is sold Mal

Thanks, so the floating ground showed in Fred's book is significant, correct? Rich

To be technical, it's a 3-circuit jack. Although it's most common use is for stereo audio, it can be used for other signals. Elecraft, for example, uses one for RS232 on some gear, including the

Just to clarify, I believe that the rear panel mic jack is a stereo jack. The mic plug should also be a stereo plug with the ring not connected. Based on Fred's book. Rich

1 Elecraft KX3 including KXFL3 Roofing Filter, KXAT3 Antenna Tuner, KXBC3 NiMH Battery Charger, KXPD3 Keyer, and MH3 Hand Mic Factory Box and Manual and all cables that came with unit $1350 including

Bias for all unbalanced electrets is applied through a moderately high value resistor between audio high and signal return. Electret capsules have very high output impedance, so they drive a FET

Sandor, If the rear mic connector on the K3(s) is used, it is a simple 2 conductor phone plug, so in that case wouldn't the bias voltage have to be carried on the audio line? Ron WA2EIO

Hi Larry, It’s a great project and well documented on how to set up and configure. A lot of people use a second monitor on their PC to show the Panadapter in full screen. I was using it on a K3.

The Elecraft website has a link to the FTDI driver site.  It's about half way down on this page under dependencies:     https://elecraft.com/pages/firmware-software The link takes you to this

Note that I was not asking why I see the KPA500 or STANDBY message. I was trying to see if anyone experienced what I did where I see the message all the time. In case anyone else experiences a similar

I did some more playing around with this thing.  Under "Other devices" i double clicked on the 232 icon that was showing.  It did something and now it shows USB serial port.  However the KX3

Under other devices it shows a FT@#@R USB UART. Scanning for hardware changes is quick with nothing being returned as having been found. Same thing when i scan for hardware

Mic bias (8v) is sent on pin 6 not the audio line. That is Icom that shares audio/bias Sandor KG4FET GOD SAVE OUR NATION!