What mods should I do to my K2?

[Darwin, Keith]

My bare-bones K2 SN 5411 is in the build process (ctrl board done, front
panel 80% done).  I'm wondering what mods I should do now to avoid
teardown / rework later?  So far it looks like I should change C8 on the
control board to 10 pf.  What else?
 
- Keith KD1E -
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[Nick Waterman]

Darwin, Keith wrote:
> My bare-bones K2 SN 5411 is in the build process (ctrl board done, front
> panel 80% done).  I'm wondering what mods I should do now to avoid
> teardown / rework later?  So far it looks like I should change C8 on the
> control board to 10 pf.  What else?

That's only if your AGC gives you grief - hold PRE/ATT and AGC, and if your
S-Meter goes off the scale and your rig goes deaf, you want to change Ctrl-C8.

I don't understand enough about the AGC circuitry to know whether to
recommend it to anyone who's NOT seeing those symptoms. It may be that one
particular batch of X1 crystals was a bit dodgy and needs an extra pull in
the right direction, and there may be some disadvantage in doing this if
your X1 is "normal"...

... after all, there's well over 5000 K2s out there that DIDN'T need
Ctrl-C8 changed, and only a handful of us who DID.

--
"Nosey" Nick Waterman, G7RZQ, K2 #5209.
use Std::Disclaimer;    [hidden email]
It's men like him that give the Y chromosome a bad name.
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[Don Wilhelm-3]

Kieth,

You should need to do nothing - including changing C8.  All the upgrades
have been incorporated in the current K2 kits.

That 'C8' mod was to solve a particular problem with a particular K2 (ok, it
appeared on several in a similar serial number sequence), and should not be
arbitrarily applied unless you experience that particular problem - that
aspect of the AGC design has not changed in over 5000 K2s and has always
worked fine.  Apparently there was a small batch of lower than normal
activity crystals (my opinion, not an Elecraft explaination), and the added
10 pF helped with that situation, but changing the crystal also fixed it
properly, so don't do anything to 'fix' your K2 unless you know it is
broken!!!

Now as an additional subject, there are many mods around that do special
things, and you may elect to add these if you need the special function that
it provides - some are 'bells and whistles' like some added indicators in
the keycaps, the zero-beat detector, and such, and others change the
function of the K2, such as the mods to change the KSB2 compression ratios
or my K2 CW PTT which modifies the keying lines of the K2 to wait for an
external input signal rather than transmitting immeditely when the paddles
are activated.  Chose from these mods as you would wish, but be aware that
they are not 'Elecraft approved' and as such could interfere with any
warranty claims.

73,
Don W3FPR

> -----Original Message-----
>
> My bare-bones K2 SN 5411 is in the build process (ctrl board done, front
> panel 80% done).  I'm wondering what mods I should do now to avoid
> teardown / rework later?  So far it looks like I should change C8 on the
> control board to 10 pf.  What else?
>
> - Keith KD1E -
>

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[Sverre Holm-2]

> -----Original Message-----
> I'm wondering what mods I should do now to avoid teardown / rework later?


Hi Keith,

I'm the one with the mods list on my web-page and I agree with W3FPR - Don.
You should not plan for any mods now.

If you eventually find that you want to modify the K2, it should be in
response to a felt need as none of the mods are necessary to do. Therefore
you should first use and get acquainted with your K2 and then you may
consider modifying it if you like.

I am sure that even many of the low serial number (< 3000) K2 are still
operating without modifications, so a new updated one like yours will have
even less need for mods.

73

Sverre
LA3ZA
http://www.qslnet.de/la3za/
 

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[jmeade]

Just to add my $0.02.  I have s/n 1116 and have done only the volume control
mod (which is in all newer units). I do intend to (eventually) make it a rev
B unit but, even as it is, it works great, and I have made hundreds of QSOs
with it on all bands at different times in good and bad band conditions.

I've added the KAT2, the KSB2, the KNB2 with no additional mods needed.  Now
I am putting the KAF2 and KBT2 into the unit and may need to upgrade the
firmware for the KAF2.  

So, as was said, use the rig as it is, and then decide what you want to
change (if anything).

72,

John W2XS
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