[Elecraft] KI6WX modes for the KSB2 ?

[Tom Hammond NØSS]

Jeff:

>First the simple one. I have a whole box of parts marked "2N2222". Are these
>equivalent to the PN2222? If not, what is the difference? It would be nice
>to know for future reference.

As far as I know, the 2N2222 is(was) generally a matal-cased device, with 
the PN2222 being the plastic equivalnet. However, I can recall when BOTH 
case types were labeled 2N2222. The devices are only used for switching, 
not in a linear mode, so either can be used, AS LONG AS, if the metal cased 
version is used, the case is INSULATED from shorting out to ANYTHING.

>Now the more difficult question. I have a Heil HC4 microphone element, and
>changed R2 to get more drive. Everything works now, including VOX, but I
>suspect that a little more drive would be beneficial.
>
>As I read John's notes the "KSB2 Increased Gain Modification" is appropriate
>for my microphone, but I should leave R2 as I have it and skip the "KSB2
>Reduced Intermodulation Distortion Modification." Is this correct? Would it
>be better to do the "KSB2 Reduced Intermodulation Distortion Modification"
>and add a pre-amp to my microphone if the drive is insufficient? I have had
>the parts for a pre-amp in an envelope for almost 2 years.

 From my field testing of John's mod before it was completely written up, I 
RETURNED my R2 back to 5.6k AND I changed R14 BACK to 1K. The changing of 
R2 (back to 5.6K) was suggested quite a while ago. Seems reducing it to 1K 
tended to overdrive U5.

With R2 and R14 returned to 'stock', and with the mod installed, using a 
Heil HC5 element, I can now run my SSB A at about 2 with no problem and 
apparent full output.

I don't think you'll require a preamp after this mod's been installed.

73,

Tom Hammond   N0SS