[Elecraft] KSB2 SSB Adapter problem

[Håkan Olsson]

Don, it was a short betwen either RFC1 or RFC2 and one of the crystal 
cases that caused the problem.

Really embarassing because it was basically the first and only real 
problem I have come upon building my K2 #5810 and all the extras... :-)

It's so easy to happen that I really think it should be pointed out in 
the manual.

73 de
Haakan / SM6EQO

------------------------------------------------------



Don Wilhelm skrev:
> Haken,
>
> At this point, do not be concerned about those voltages you found did not
> agree with the chart in the manual.
>
> The no voltages at the diodes is a cause for concern.  The problem may be in
> where you measured for voltage or the settings you were using.  We will get
> to that.
>
> Let's verify that the source for the diode switching voltages are correct:
> First thing, set the SSB FL1 filter to OP1 (using the K2 menu).  Set the K2
> to SSB mode and be certain FL1 is selected.  Now measure the voltage at U1
> pin 21 (should be about 6 volts), and measure the voltage at U1 pin 22
> (should be near zero volts).
>
> Now, switch to CW mode (any of the CW filters is OK), and measure the
> voltage at U1 pin 21 (should now be near zero volts) and U1 pin 22 (should
> now be near 6 volts).  You should also find about 6 volts at the cathode of
> D7 and D8 and at the cahode of D11 and D12.  If you do not have these
> voltages present, check to be certain RFC1 and RFC2 are not shorting to the
> crystal cases (insert a sheet of paper between the choke and the crystal as
> an insulator).
>
> If all the checks above are correct, switch back to SSB mode, FL1 (OP1)
> filter and check for about 6 volts at the cathode of D6 and D9 and at the
> cathode of D10, D13 and D14.
>
> If you find all those voltages correct, the filters should switch between
> the CW filter and the SSB filter.
>
> Just as information if you are following the schematic - the RXC signal
> indicates that receive should be through the CW filter when this signal is
> active (about 6 volts), and RXS indicates that the receive path is through
> the SSB filter when this signal is active.
>
> Make the checks above, and if that did not lead you to fine the source of
> the problem, send us your report of your findings.
>
> 73,
> Don W3FPR
>
>
>   
>> -----Original Message-----
>>
>> I have just put together the KSB2 SSB ADAPTER and I have problems.
>>
>> Referring to the manual on page 15 “Initial Test” the last paragraph
>> “Verify that the K2 performs...” I do not get any sound in the
>> loudspeaker, or the sound I get is very very muted. I can hear some very
>> faint - both CW and SSB – signals but only when the volume is turned up
>> to max.
>>
>> Else there is no problem doing the “BFO Test”, “Receive-Mode SSB Filter
>> Test” and “BFO Setup for LSB/USB”
>>
>> I have checked the voltages as seen on page 23 in the manual and found
>> the following anomalies in receive mode:
>>
>> U1-21... zero volt (should be 5.8)
>> U2-5.... 6.0 volt (should be 0.6)
>> U4-3.... 6.0 volt (should be 0.6)
>>
>> D10-D13 and D6-D9... no voltage in receive mode.
>>
>> So, what could be the matter?
>>
>> 73 de
>> Håkan / SM6EQO
>>
>>     
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