[Elecraft] [Fwd: Making mods]

[Eric Swartz WA6HHQ - Elecraft]

Sent to my admin addr by mistake :^)
73,  Eric

-------- Original Message --------
Subject: Making mods
Date: Thu, 14 Nov 2002 19:29:23 +0100
From: "Sverre Holm - LA3ZA" <la3za@qsl.net>
Reply-To: <la3za@qsl.net>
To: <elecraft-admin@mailman.qth.net>

Had a good time making mods a few nights ago and now my K2 #2198 has the

- VFO ALC mod
- Improved decoupling of Vcc for U4 (RF board) for reduced interaction
VFO-PLL 
- AGC pot mod
- Reduced temp drift in VFO

I removed crystal X2 and added the 220 ohm resistor and was able to get
a pulling range of 11 kHz with one of the original crystals so I was
happy with that.

Also, if someone is doing the RFC11 mod and the mod for decoupling U4,
note that the old RFC11 of 100 uH can be reused for the U4 decoupling.

I managed to mount a miniature pot on the control board in place of R1
and noticed a better AGC action. Before the mod, pin 5 of U2 measured
4.05 V, afterwards I adjusted it to 3.9V as required. The effect was
that the AGC kicks in later and there is no gain reduction for the
weaker signals and the background noise on 40/80 m.

Did I notice much difference? Yes, the AGC was better: and the K2
performed well for 5 W CW contacts all over Europe on 80 and 40 m. 

And the feeling: I just _know_ it has to be better!


73 Sverre


Sverre Holm, LA3ZA
---------------------------------
www.qsl.net/la3za