[Elecraft] K3 STATUS -- a note from the lab

[wayne burdick]

Since the K3's PCB modules are pre-assembled, we have to 100% test 
them, whether they're destined for a kit or for a fully-assembled unit. 
I thought I'd give you some flavor of what goes into this.

For the K3 RF Board, we use a computer-controlled signal generator and 
spectrum analyzer, along with the K3's built-in true-RMS audio 
voltmeter, to do MDS tests on each band (receive mode). While the 
process is partially automated, each unit's band-pass filters, first 
I.F. trap, and mixer balance must be carefully aligned by hand. We also 
sweep each band for return loss from the antenna through the T-R 
switch. During this test, some low-pass filter toroid windings must be 
hand-adjusted. In transmit mode, each band is checked for drive range, 
max power output, key-down current drain, spectral purity, etc.

Performance tests of this kind are also done on all other modules 
(there are over a dozen in even a basic K3). The results are highly 
repeatable, ensuring that both kit and factory-assembled K3s work 
equally well.

However, this turns out to be very time-consuming, so reducing test 
time through automation is one of our major ongoing efforts. I'm now 
pitching in to help our manufacturing-engineering team (Brian, W6FVI 
and Rene, WR6MTR) by adding test firmware to the K3 itself. K3 owners 
will benefit from this effort in another way, since some tests are 
added to the K3's POST routine (power-up self-test), and all of the 
added remote control commands can be used to advantage in third-party 
software applications.

That's the news from the lab. Back to work....

73,
Wayne
N6KR

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http://www.elecraft.com