[Elecraft] K3 Hardware Upgrades

[Ian White GM3SEK]

David Pratt wrote:
>In a recent message, Dave G4AON <elecraft at astromag.co.uk> writes
>>
>>I have now done all the hardware mods to my K3, none were particularly
>>difficult to do. I even did modifications that are of no use to me, such
>>as the -ve ALC and "pull up" resistor mods... At least my K3 is close to
>>the same mod state as the current production units. The AF amplifier
>>(replacement RF choke feeding the audio amp) did not seem to make any
>>difference at my station, I am using a pair of HiFi bookshelf speakers.
>>Likewise the line out mod didn't appear to make any difference, although
>>for the most part I run Amtor or Pactor rather than sound card data modes.
>>
>>There is no real reason to not do these mods, they have no unwanted side
>>effects and may in fact be of benefit.

>Although I don't recall seeing anything about it on here, the latest
>KRX3 Errata Sheet C-6, dated 3 March 2009 refers to the cutting of two
>tracks on the main RF board to "ensure D-A converters always receive the
>proper signal level".
>
>I have yet to do this mod on my K3.


Those track cuts were part of the negative ALC mod, and according to the 
website, that is now "Included on all K3s shipped on Dec 10, 2008 and 
later.... Approx s/n 2362+ "

Presumably that also includes the track cuts, but it's easy enough to 
check - they are in clear view underneath the front bottom cover.

The ALC mod sheet gave no specific reason for cutting the tracks, and it 
seems very odd that the same track cuts should appear again in an errata 
sheet for KRX3 installation - the two topics seem totally unrelated.




-- 

73 from Ian GM3SEK