[Elecraft] K3 Hardware Updates

[Ron D'Eau Claire]

Ah! Gotcha Joe. Yes, you are right, they are different. 

After I installed the mod while illustrating the App Note, my VFO A started
moving in 100 Hz steps at random. I spoke with Wayne, who was also very
concerned since the mod had been carefully tested. 

Then I realized that I had forgotten to change the bus timing to SPI 2. I
did so and the instability went away.

Wayne was no longer concerned. 

>From that, I conclude that one must change the API bus timing to SPI 2 after
installing the diodes and resistors, and that's what the App Note says. 

I don't know why Eric made the statement he did. 

If you back up to a pre-3.24 release with the parts installed, I'm not sure
what happens since the SPI bus speed can't be changed in earlier versions.
Perhaps it'll stay unchanged at your last setting, but I don't make guesses.


I'll find out Monday and report back, since there are probably a number of
people wondering the same thing. 

Ron AC7AC


-----Original Message-----
Hi Ron,

> Eric and my statements are quite correct, both of them!

OK, I'm really missing something then.  Eric said (emphasis mine):

> There is no downside to making this h/w mod, EVEN IF YOU DO NOT  
> ENABLE THE MENU OPTION.

That sounds very much like he's saying you can make the mod and not  
change the SPI bus clock rate to SP2.

But you just said (again, emphasis mine):

> If you add the diodes and resistors per the App Note, ... YOU *MUST*  
> CHANGE THE SPI BUS CLOCK RATE TO "SP2" FOR PROPER (STABLE) OPERATION.

I don't see how they can both be correct.

The reason I would like clarification is that I sometimes go back to a  
previous FW release to compare operation with the new release.  If  
what you say is true, that implies that once I make the hardware mod I  
can't go back to the 3.19 release without potentially having VFO  
stability issues.  If that's really and truly the case, I don't want  
to do the mod until I'm sure I won't ever want to go back to anything  
older than 3.24.

73
--
Joe KB8AP