microHAM MK2R Manual page 66

4. If you are not using Icom radios, turn the RADIO1 and RADIO2 preamplifiers OFF and turn the
RECORDING-LIVE MIC preamplifier ON. Use a dynamic microphone, there is no bias for an electret
mic.
5. If you mix one Icom and one non Icom radio, you must use a dynamic microphone and take care to
prevent the Icom DC bias from reaching the microphone. Add a 1 uF capacitor in series with the
microphone element (either inside the body of the mic or in the cable between MK2R and the mic). Turn
the RECORDING-LIVE MIC preamplifier ON and, if necessary, turn on the RADIO preamplifier for Icom
radio only.
6. If you are using two Icom radios, you can use either dynamic or electret microphones.
● With a dynamic microphone you must add a blocking capacitor as described for the
"mixed" radio configuration. Turn the RECORDING-LIVE MIC preamplifier ON and if needed
enable the RADIO 1 and/or RADIO2 preamplifiers.
With electret microphones, turn OFF all three preamplifiers
●
NOTE: Microphones with switchable dynamic and electret elements should never be used with MK2R
unless the microphone includes a blocking capacitor for the dynamic element. Even then there will be
significant problems with dual element microphones due to the substantial difference in level between the
electret and dynamic elements.
7. Set the R1 (Radio 1) and R2 (Radio 2) microphone trimmers
(located just to the front of the RADIO1 DB37) in middle of their
range (towards each other).
8. Set the front panel TX1 and TX2 knobs to 3 o'clock.
9. Connect your microphone to MK2R and select Radio 1 for transmit.
10. Open Router's Audio Switching tab and set the VOICE switching to ACmA, Voice codec, SC1 on the
Radio 1 tab. Make sure the VOICE switching has a black (not gray) frame around it.
11. On the PTT tab, set the Radio 1 PTT selector for VOICE to: "PTT1 (microphone jack)."
12. Set your radio to USB or LSB, connect it to a dummy load and switch RADIO1 to transmit. With the MIC
GAIN control on RADIO1 set proper drive level while speaking to microphone (this should be your normal
operating level). When finished, do not touch the MIC GAIN control again.
13. Select Radio 2.
14. Open Router's Audio Switching tab and set the VOICE switching to ACmA, Voice codec, SC1 on the
Radio 2 tab. Make sure the VOICE switching has a black (not gray) frame around it.
15. On the PTT tab, set the Radio 2 PTT selector for VOICE to: "PTT1 (microphone jack)."
16. Press the Radio 2 button on MK2R.
17. Set your radio to USB or LSB, connect it to a dummy load and switch RADIO2 to transmit. With the MIC
GAIN control on RADIO2 set proper drive level while speaking to microphone (this should be your normal
operating level). When finished, do not touch the MIC GAIN control again.
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