[Elecraft] KSB2 SSB Adapter Problem
Hi everyone! I recently bought a used K2 with the KSB2 SSB adapter. The builder did a very clean, professional building job on both the radio and the KSB2 and I can find nothing wrong with the construction - i.e. no cold solder joints, no shorts, no solder bridges, all circuit paths are as they should be and have been verified several times. The radio works perfectly normal in CW mode, and RX in the SSB modes is fine. So here is my problem - when I key the radio in SSB mode via either the mic jack or the cw jack, I get a brief HI CUR warning and I get 12 watts of carrier which is unaffected by the carrier balance pot. Also, there is virtually SSB TX audio. ONLY SSB mode is affected. I have taken voltage readings as suggested in the KSB2 manual and found (2) voltages to be out of line, both on U2: U2 pin 5 - 5.99v, should be 0.6v U2 Pin 8 - 0.45v, should be 6.0v These are way out. All connections, components, etc. have been verified correct and good so I am thinking that U1 (the PIC) is the problem as it does affect this part of the circuit. I ahve reflowed all solder connactions on the entire board without success. Toroids have been checked for shorting against the crystal cans, no shorts. Q2 on the K2 RF board has been checked for proper installation and is verified good. Again, the symptoms are: constant 12w output with inability to balance carrier. No TX audio on SSB (yes the mic is good and is correctly wired) Hi Cur message. TX cur is set in the menu @ 2.5A so this should not be a problem. Any thoughts are appreciated, thank you! __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
[Elecraft] KSB2 SSB Adapter problem
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 ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net 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
RE: [Elecraft] KSB2 SSB Adapter problem
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 -- No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.5.432 / Virus Database: 268.15.28/605 - Release Date: 12/27/2006 12:21 PM ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net 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
Re: [Elecraft] KSB2 SSB Adapter problem
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 -- No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.5.432 / Virus Database: 268.15.28/605 - Release Date: 12/27/2006 12:21 PM ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net 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