[Elecraft] Further clarification of my troubleshooting steps for K2 # 5061

[M. P. Haynes]

Don, Jim, and Joe,

Over the weeks now of  troubleshooting this problem here are some of the
steps I have taken:

        * I suspected either a defective low pass filter or bandpass
filter for this band and one other. (I had damaged K7 with a soldering
iron that 
           put an ever-so-small dimple in one end of the relay case. 
This prevented the slide from fully engaging one set of contacts. I
replaced it and 
           that band was then okay.) After replacing the defective relay
I lifted one end of W1 to isolate the two sections of filters and hooked
a 
           signal  generator to the antenna connection.  I hooked my
scope to W1 and found all low pass filter characteristics as one would
expect,
           no loss of signal strength on the selected band but noticeable
attenuation on the next higher band.  I forgot to say that I had already
           reflowed all solder connections on both the LPF and BPF
circuits.  

        * I replaced C22 (2.7 pF).  

        * I hooked a jumper to the BPF test point (I had soldered a loop
of wire onto D7 cathode to prevent damaging the component leads with 
           my scope probe) and could hear stations on both 20 and 30
meters.  I coupled this lead through a capacitor (to prevent shorting 8R)
and 
           the signals were as loud on the two bands in question as the
other, functional bands.  

        * My friend Ron used a high quality capacitance / inductance
meter and found L9 to vary from, as I recall, about 3.9~4.9 uH with the
slug 
            top to bottom. The capacitors in circuit measured
approximately their stamped values considering stray circuit
capacitances.  Each of us 
            checked and rechecked the values of all components and they
were correct.  Neither capacitors nor inductor were shorted to ground 
            except the ends of caps that were supposed to be.

        * I have measured contacts 2,3,4 and 7,8,9 on relays K3 and K4
and they function as you would expect from the relay truth table.  I even

           tried a relay reset (control board removed on power up) and
then rechecked with identical results.  I also have cheched that the
signal line 
           (W1, W6 and BPF T.P.) is not shorted to ground on 20/30.

        * When feeding a signal from my sig generator through the coax
connector and checking at the BPF T.P. there is no noticeable attenuation

            on any bands except 20 and 30 which was down about 70 dB.

        * L8 peaks properly on 30 meters.  With the added cap acrross L9
it peaks about two turns from the top of the can.

At this point I had already decided to arbitrarily replace C24 and C25
but I don't really expect any change since they check okay with a
capacitance meter in circuit. (C19 and C20 check the same as C24 and
C25).  I am really getting discouraged at this point, but like Little
Orphan Annie sings, "The sun will come out tomorrow!"  Thanks to all for
your suggestions.  If I have an epiphany, I'll let you know!

73,

Pat-K4BEH