[Elecraft] RE: K1 2427 operational, but a quick question

[Mike Morrow]

Bernie wrote:

>During the voltage checks in the first part of the RF board 
>assembly:  the voltage on pin 5 of U3 was 3.73, slightly less
>than the specified 3.8-4.2 range.

It's all OK and within expected circuit variations.

Pin 5 of U3 is the audio output signal of the AF preamplifier, and there will be variations in the DC voltage levels at that point.  The output of the 8 volt regulator U5 (feeds U3 pin 6) and the strength of input signal (U3 pins 2 and 3) will affect voltages measured elsewhere on U3.

You have no problems.  Enjoy the K1.  Mine is more than seven years old, and it remains my favorite QRP rig of all time.  It's great to see something other than "K3" (especially delivery status report complaints) on the Elecraft list.

73,
Mike / KK5F
K1 SN 175