[Elecraft] SSB TX signal mystery SOLVED !!!

[Ken G3WCS]

Cyberia wrote:
> I made that exact same mistake!!! When it came time to install R10, however,
> I realized the through-hole should not be occupied, and I discovered my
> mistake.

Make that three!

I just completed my KSB2 yesterday and very nearly made the same mistake 
with D14. I had placed it in the PCB and was just about to solder it 
when I thought it didn't look quite right. I quickly turned it through 
90 degrees and soldered it correctly.

I think the thing that throws you is the fact that everything on the 
right hand site of the board up til this point is symmetrical, from top 
to bottom. Therefore I had subconsciously thought that D14 was a mirror 
image of D4 on the lower part of the board which is mounted 90 degrees 
differently.

It might be worth a quick one liner in the KSB2 manual to warn against 
this pitfall. My KSB2 is now fitted to my K2 (#4489) and I had my first 
SSB QSO on 40m's this morning. Reports were good. Touch wood, an XV144, 
XV50 and now my K2 has gone together perfectly without a hitch. Built 
the KNB2 today and will be fitting tomorrow.

Just one more small observation with regard to mic pinouts. I am using 
an Icom HM-12 electret condenser mic with my K2. Table 2 on P18 of the 
KSB2 manual seems to indicate that the 10K resistor to feed the DC to 
the mic should go from the 5V side of the mic config block to pin 2 of 
the mic. This is not correct, as according to the circuit of the HM-12 
in the Icom IC-735 manual, there is no connection to pin 2 in the mic 
itself. The DC voltage is fed up the audio cable (pin 1) and blocked 
from the audio path inside the mic by a capacitor and routed to the 
mic's internal pre-amp. Connected the 10k from 5v to pin 1 and away it 
went with stacks of audio.

Happy holidays and New Year.


Ken.
-- 

Ken G3WCS <ken at g3wcs.com>
IO83rh : Cheshire : NW England
(+44) (0)1606 892677 (home)
(+44) (0)7733 400950 (mobile & sms)