Setup guide

Table Of Contents
− Connect both B7−COM and B8−COM of right SM together and thru 1Kohm resistor to GND.
Node point connect to KEYIN input of right SM (KEYIN, PA pin6).
− Do same from oposite side of view for left SM.
Configure both SM to activate:
− B7 together with A1
− B8 together with A2
− on PA & Sequencer tab check "Use Key In"
This way, KeyIn input locks TX on MK2R (thru iLink) if has high level on input. Normaly gets GND thru
1kohm resistor (TX enabled). When left SM activates A1, also activates B7 to which other pole is
connected A1 from right SM. So far so good, other pole of B7 is floating, but when you switch A1 on
right SM, right SM puts 12V on A1 which pass thru closed left B7 to its Keyin. Same right SM closes
its B7 which is connected to A1 of left SM from where gets 12V to its Keyin. Result will be that if you
select same antenna port on both SM, both radios will be locked. Same for second port (B2+B8),
hope OK for you.
If you use (have connected) PA with KeyIn (Acom, Alpha etc ...), do not ground end of 1Kohm
resistor, but connect it to amplifier's KEYOUT, it will be grounded thru PA.
Alternative solution
It is also possible to connect nodes with 1Kohm resistors to ACC port inputs on MK2R configured as
INHIBIT inputs instead of SM Keyin, but in this case there must be serial resistors and 5V zeners to
not pass 12V to MK2R ACC's TTL inputs. It will provides equivalent functionality.
2.2.2 Solution 2 by Joe − W4TV
13−2−20092 SO2R Setup at PA1M − microHAM MK2R+ and Station Masters and N1MM logger 16