K2 # 4670, finishing up test and alignment of a KPA-100.
Page 46 (all checks within norm to here)
Two Questions
1 - External Amplifier Keying Test (PA KEY)
Use the MODE switch to select CW mode (mode letter changes to C). Enter CW TEST mode by holding VOX. The letter C should now be flashing. In this mode, the K2 will not put out any power when you key the rig either with a key or with the TUNE switch.
Set your DMM to its lowest resistance scale. Connect the (-) probe to ground, and touch the (+) probe to the tab of Q9 on the KPA100 board (or to the center conductor of the PA KEY output
jack, J7).
The DMM should be indicating a high resistance (typically indicated by a flashing display).
OK to here -
Hold TUNE on the K2 to key the transmitter. The resistance reading should drop to less than 3 ohms.
THE OHMS start dropping, but before I can pull the + probe off the Q9 tab, something clicks/pop and the K2 drops out of the tune mode (sort of like of a reset?)
IS THIS WHAT IS SUPPOSED TO HAPPEN? OR ????
The MM shows 3 OHMS at this time.
Never get to this part - Tap any switch to exit TUNE mode. Exit CW test mode by
holding VOX. The mode letter will stop flashing.
2 Bias Current Adjustment
Connect the (+) lead of the DMM to the power supply side of the circuit, and the (-) lead to the KPA100 side. Turn on the high-current power supply, then turn on the K2.
EXACTLY WHERE DO I CONNECT THE + AND - LEADS?
73,
KI4HRN
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