KSB2

[David Gordon-3]

Hello,

I recently purchased a k2 wth kaf2, ksb2 and knb2.  Well, it seems good
except I cannot get any transmit drive on ssb.  It easily puts out 10
watts in cw on all bands, but barely goes 500 mw on ssb.  I tried all
the settings for ssba and ssbc and still no change.  I ran the voltage
checks, and rather than relist the whole table, here is what is
different then spec:
            rx            tx    
u1-2     6.0         6.0
u1-3      2.15      2.15
u1-6      5.64       0
u1-15     0         5.93
u1-21    5.68       0
u1-25      0          .7
u1-28     5.7        2.4


u2-1          6.0              6.0
u2-2          6.0              6.0
u2-5          .48               .48
u2-8          6.0              6.0

u4-4           .48             .48
u4-6           5.62            0

Other than those, the rest are within .1 volt of spec.  The diodes all
check out fine too.  It is as if there is no alc.  If someone could
point me in the right direction to check, that would be appreciated.  
It is serial no 2534, mcu 2.01h and ksb 104.

Apparently it was working before shipping, but when I received it, the
filters were quite far off.  Now they are fine but opt1, the ssb filter,
is much quieter then the other settings.  That seems like it may be
related to the low alc.

73,

David  AA9PZ



_______________________________________________
Elecraft mailing list
Post to: [hidden email]
You must be a subscriber to post to the list.
Subscriber Info (Addr. Change, sub, unsub etc.):
 http://mailman.qth.net/mailman/listinfo/elecraft   

Help: http://mailman.qth.net/subscribers.htm
Elecraft web page: http://www.elecraft.com

[Don Wilhelm-3]

David,

Well, the filters would not change during shipping, so you may want to take
the statement that 'it was working fine' with a grain of salt.  ALC controls
only the transmit level, which means that the receive situation of OP1 being
'more quiet' than the other filters has no relationship to the alc area -
look for a problem on the KSB2, particularly in the filter area - most
likely a poor solder conection (and don't forget the header pins soldered on
the top side).

Your voltages are not far enough off normal to indicate any source of the
problem, so it may be a question of tracing the audio through the KSB2 if
there is no other easy answer.

For one 'easy' answer to the transmit problem, did you set the mic
configuration header to match the pinout of your microphone?  If you are
using an electret mic and you have not added the required resistor, that
alone could explain your problem.  Look for the easy, 'dumb' stuff before
digging too deep into the KSB2.  The chart of the mic configuration header
connections is in the KSB2 manual.

Above all, check the soldering carefully (3 times over will not hurt).  Poor
solder joints are the most common cause of failure.

73,
Don W3FPR

> -----Original Message-----
>
> I recently purchased a k2 wth kaf2, ksb2 and knb2.  Well, it seems good
> except I cannot get any transmit drive on ssb.  It easily puts out 10
> watts in cw on all bands, but barely goes 500 mw on ssb.  I tried all
> the settings for ssba and ssbc and still no change.  I ran the voltage
> checks, and rather than relist the whole table, here is what is
> different then spec:
>             rx            tx
> u1-2     6.0         6.0
> u1-3      2.15      2.15
> u1-6      5.64       0
> u1-15     0         5.93
> u1-21    5.68       0
> u1-25      0          .7
> u1-28     5.7        2.4
>
>
> u2-1          6.0              6.0
> u2-2          6.0              6.0
> u2-5          .48               .48
> u2-8          6.0              6.0
>
> u4-4           .48             .48
> u4-6           5.62            0
>
> Other than those, the rest are within .1 volt of spec.  The diodes all
> check out fine too.  It is as if there is no alc.  If someone could
> point me in the right direction to check, that would be appreciated.
> It is serial no 2534, mcu 2.01h and ksb 104.
>
> Apparently it was working before shipping, but when I received it, the
> filters were quite far off.  Now they are fine but opt1, the ssb filter,
> is much quieter then the other settings.  That seems like it may be
> related to the low alc.
>
>

_______________________________________________
Elecraft mailing list
Post to: [hidden email]
You must be a subscriber to post to the list.
Subscriber Info (Addr. Change, sub, unsub etc.):
 http://mailman.qth.net/mailman/listinfo/elecraft   

Help: http://mailman.qth.net/subscribers.htm
Elecraft web page: http://www.elecraft.com