KRX3 Status Update from Wayne 

March 11, 2008

We expect to receive the initial batch (20) of production KRX3 modules this week. We'll post a photo as soon as they arrive. Subreceiver operating firmware is still in progress, but the basics have now been tested successfully on prototypes. I don't anticipate any serious issues with the production boards, so we should be able to start ramping up production in the next several weeks.

Diversity receive is working (as you may have guessed when the "VFO Linking" feature showed up in the latest firmware release.) With headphones, it sounds a like an extra-rich version of our "AFX" function; but more important, it helps with fading if two different antennas are used. I also spent some time operating split -- listening to VP6DX in the left headphone channel (main) and the pileup (sub) on the right. No need to press REV to check the TX frequency!

Wayne

Posted to the elecraft@mailman.qth.net list on Jan 16, 2008

I wanted to give those who've ordered a K3 subreceiver a status update. First, thanks for your patience; I realize the subreceiver has been significantly delayed. (This is also pushing out the DVR. Lyle, KK7P and I are collaborating on the PCBs and firmware for both units.)

When we release a product, it has to meet a number of criteria. Raw performance by traditional measures is just one of these. Fortunately the subreceiver has met our expectations in this regard, with dynamic range virtually identical to that of the main.

But there are two other requirements that we must meet: excellent mutual isolation between the main and receivers, and ease of installation. Recently, we made the difficult decision that both must be improved.

Isolation between the receivers is critical to usability. For example, if you're listening to an extremely strong signal on one receiver, none of it should leak into the other's I.F. After extensive testing, we concluded that we were close, but needed more isolation.

Regarding installation: Someone with no experience should be able to install or remove the subreceiver without much difficulty. The present installation process is just a bit too complex once all other modules and their associated cables are in place; the left side, chassis stiffener, and several cables have to be removed. This has a secondary effect, which is to make it very time-consuming to change crystal filters on either receiver. We felt that we should improve this now, before all fabrications were cast in stone.

Both isolation and installation can be improved with changes to our original KRX3 PCB layout. I'm working on this now. Once the PC board and shield designs are complete, we'll quickly build first articles and run them through all of the tests again.

I'm confident that these improvements will allow the subreceiver to live up to your expectations as well as ours. We'll post further updates as we make progress.

(I know, I know -- "Stop rambling and get back to work!")

73,
Wayne
N6KR