Elecraft K2 - Serial Number 007239 Build. Day 3

Hours 2:23:00    Total Build Time:   9:11:00

Well its day 3 of the build and everything seems to be going OK.  Today I finished the "Control" board for the K2.

The day started off installing the connectors on the board.  Connectors P1, P2, and P4 are used to connect the control board to the main RF board.

Control Board at the start of the day.  Plugs haven't been added at this point.

All Plugs and Connectors installed on the board

After all of the plugs and connectors were installed on the board, it was time to install the integrated circuits (IC's ) on the board.  Well guess what?  The 2nd IC installed on the board presented a problem.  The problem was that the chip number that was specified in the manual was not included with the kit.

Installation of IC's

The first IC, U1 was a NE602.  As shown in the photo, the manual indicated that the chip was either a NE602 or a SA602.  Well guess what?  That chip was not included.  I continued on and installed the other chips shown in the manual.  When I was finished, the only IC left was a SA612AN.  What in the heck is a SA612AN???  I went to the internet and did a search for replacement chips for the NE602.  I learned that the NE602 is an old chip.  In a forum, someone mentioned that an SA612AN is a newer replacement that will work.

I wish they would tell you this in the manual.  Well, up to this point, this is the only problem that I have found in the manual so far.  I looked on Elecrafts web site to see if there was an errata sheet for the K2 that showed this but I was unable to find one.  I will have to send them an email showing the problem.

CW key shaping modification

Over the years since the K2 transceiver kit has been introduced there have been several modifications to improve the kit.  One of these modifications has been the Key Shaping Components.  As shown in the photo above, two capacitors have been added to the circuit board on the back side.  I had to be careful installing the electrolytic capacitor to make sure I got the polarity correct.

Completed K2 Control Board

The manual calls for a final inspection of the control board when all components have been soldered to the board.  Checks are made to see if parts have been installed correctly and in the correct position.  Next the solder joints on the back side of the circuit board are checked to see if  1) All components have been soldered.  2) Look for Cold solder joints, and finally 3) Check to see if there are any solder bridges.

The manual provides a list of resistance checks that need to be made.  The manual states that you are checking "to ensure that there are no shorts in the most critical control circuits."

As you can see from the photo below, everything checked out.