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K2 # 1574 (& SHURE 414B)

Mine is from Oct. 2000. It has in it the KSB2, KNB2,KIO2 and K160RX options.

I brought it up to near-current K2's with the following:

Matched Xtals & enhanced 2nd Xtal MOD
AF POT MOD
AGC MOD (a little different though-see below)
Increased headphone audio
Side tone MOD (a little different too - see here TF3MA's page)
PTT LED indicator (see little hole above LOCK key above)
External AMP key- port
External CW-zero- beat device port

Some experience I gained: (click thumbnail 4 details)

	K2IO - alternative connector (DB25)
	How to pull the Xtals out -" KISS" method
	Alternative AGC MOD implementation

Spectrogram Photos Before & After Xtals Change

(click thumbnail 4 larger view)

Filter in Use	Before MOD image	After MOD image
FIL1 OPT1 USB
FIL1 OPT1 LSB
FIL3 LSB

In the following photos I used my drawing program to establish a 20Db scale, divided to 3 major & 6 minor divisions. All photos were taken on a 30 Db scale in Spectrogram. The entire RED group is 6.66 Db, so is the Blue one, and of course the Purple one too. These scales were superimposed on the photos so that one can estimate insertion-loss & ripple. It's not scientific, but close.

These are final settings for SSB filters at ~2000 & ~1800 Hz. (Fil 3's 1.65 is actually 1800 Hz).

These are final settings for CW filters at 700, 400 & 100 Hz respectively for both NORMAL & REVERSED modes-almost identical

Last modified: 11/07/2009 13:25:03 +0300