Re: [Elecraft] KSB2 Problem Continued
Gareth, Yes, 100mV audio should be adequate to drive the KSB2. Do you have the K2 wired to use an Elecraft or Icom microphone? If so, try lifting the bias resistor to see if the DC bias is interfering with the output level of your audio generator - instead of lifting the bias resistor, you could put a capacitor (1 to 10uF) between the signal generator and the K2 mic input. I need to know which KSB2 board you have installed (there are 3 different ones and you can only tell me what I need to know by physical inspection of KSB2 U3. First, is this a new KSB2 board (purchased within the last year) or is it the older type with an SM2165 at U3? Is U3 an SMD component or is it a thru-hole device? Your first check should be to measure the DC voltages to KSB2 U3 - they should agree with the voltages listed in the KSB2 manual. If the voltages are not within reasonable agreement with the chart, then U3 is your problem. Did your KSB2 board work properly in the past? If so, something has failed and the challenge is to find it. OTOH, if this is a newly built board that has never worked before, check all the components for proper values and placement and check all diodes for proper orientation. If all else fails, do you have access to an oscilloscope with a 10x probe? If so, I can give you some typical AC voltage values at given points along the signal path to isolate the problem to a particular stage. 73, Don W3FPR On 1/15/2015 2:07 PM, Gareth - M5KVK wrote: K2 S/N 03885 Symptoms: low power and no ALC action when on SSB. CW With E= 13.0V on the K2 display, if I transmit CW into a dummy load PWR=10 gets me 10W according to my un-calibrated power meter and draws 2.3A (40m). SSB If I inject 1kHz sinewave into the Mic socket, for 100mV pp i/p I see about 6W out. Current varies between 1.9 and 2.2A and E comes down to 12.5 under load. Interestingly, there's zero action on the bargraph in ALC mode. Needing 100mV to get 60% of set power seems high. I thought I should get 100% with 50mV. Even with 1.6V pp i/p, I only see 8W o/p __ 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 Message delivered to arch...@mail-archive.com
[Elecraft] KSB2 Problem with Assembly
I am currently in the process of assembly a KSB2 (REV E KSB2 PC Board) which I purchased with my K2 in November 2011. I am currently completing the installation of the resistors on the back side of the board. After I completed installing the resistors I noticed that I had an extra 10K resistor. I then checked my inventory and it showed that I had inventoried 3 10K resistors versus the 2 called for in inventory sheet. Just to be safe I downloaded the latest manual and compared it to my manual. It lists an additional four resistors on the back of the board (R21, R22, R23 and R24). I have two questions: 1. Should I be concerned that these resistors are not on the Rev E board? 2. What is the purpose of the additional resistors? Thanks, Fred, KC9QQ -- View this message in context: http://elecraft.365791.n2.nabble.com/KSB2-Problem-with-Assembly-tp7560131.html Sent from the Elecraft mailing list archive at Nabble.com. __ 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
Re: [Elecraft] KSB2 Problem with Assembly
Fred, Look carefully, that new manual does not match your KSB2. Yours has an SSM2165 Speech Compressor and the new one uses an SSM2166 - the added resistors support that new IC. As far as the extra 10k resistor, one is supplied with every KSB2 for use as a bias resistor if needed. It is listed in the parts list as a component on the front panel. 73, Don W3FPR On 8/1/2012 3:30 PM, KC9QQ wrote: I am currently in the process of assembly a KSB2 (REV E KSB2 PC Board) which I purchased with my K2 in November 2011. I am currently completing the installation of the resistors on the back side of the board. After I completed installing the resistors I noticed that I had an extra 10K resistor. I then checked my inventory and it showed that I had inventoried 3 10K resistors versus the 2 called for in inventory sheet. Just to be safe I downloaded the latest manual and compared it to my manual. It lists an additional four resistors on the back of the board (R21, R22, R23 and R24). I have two questions: 1. Should I be concerned that these resistors are not on the Rev E board? 2. What is the purpose of the additional resistors? __ 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 problem
I recently bought a KSB2 that was advertised here. It's an early release, rev B board, so I picked up a number of update kits and started assembly, slowly and carefully, as Gary advises. I got through it in a couple of evenings. Last night, I installed it in my K2 and got INFO 080. Drat! I was so slow and careful! I checked voltages on the MCU, they were fine, so I got the silly scope out to see if there was AUXBUS traffic on pin 28 where there should be. Yes, there was. And ... also on pin 27! That can't be good. I inspected carefully for solder bridges, found none. I contemplated diking out part of the socket to ease removal. Gary suggested heating the pins and wiggling. Ultimately, I clamped the thing in the vise, put on my finest soldering tip, and sucked up the solder, pin by pin. After about three passes, I was able to remove the socket, intact, and no damage was done to the board. I inspect the socket, no joy. I inspect the top of the board ... no joy! Pins 27 and 28 are 0.1 ohms. Drat. I lift R12 to isolate that part of the board ... still beeping. Bright light, magnifier, ask my XYL to look, too. Nothing. Finally decide to put it away for the night. Then I go give it one more. I thought that perhaps the trace that comes off pin 27 had grown too much and was touching the pad for 28, so I scraped away the solder mask. No joy. I started contemplating where I could cut a trace to divide the problem and still make a reasonable, perhaps invisible repair. As I did, I noticed a slightly darker spot around pin 1, between the traces from 27 and 28. Sure enough, there must have been just a stray bit of resist laid down there, about half a hair's width, because there was copper under the mask connecting the traces. Free! Free! Pins 27 and 28 are free again! It's tempting, but I'm not going to rush soldering the socket back in and then rush a test. I'll do it tomorrow when I can go through the whole procedure and update the front panel, too. One for the archives... 73 de chris K6DBG ___ 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 Problem: Big attenuation of received signals SOLVED
Thanks for the suggestions. I followed them all. I found some 27 AWG red enamel wire and re-wound RFC1 2, and I believe this is what fixed my problem. The enamel on the wire that came with the KSB2 kit, seemed to shear off with the sharp edges of the toroid cores, and this may have been causing a short to the crystal can. The new wire seemed to be a little thinner, even though it was smaller guage (27 vs. 28 - go figure), and the enamel seemed to stay on it a little better. Perhaps the enamel on the new wire was thinner. The KSB2 option is now installed, aligned, and working! Thanks, -Andrew KF7HB --- Ron D'Eau Claire [EMAIL PROTECTED] wrote: The problem is that the receiver became very quiet. I could still hear the strongest signals if I turn the AF Gain way up, and instead of S9 on the meter, they're way down to S1. The KSB2 manual specifically states (page 15, final step of initial test) this should not happen, and if it does, to go to the troubleshooting section. Andrew: Don's suggestions are right on track. I have one to add, assuming this is a new build. Check for d-c continuity from each pin of each crystal to ground. It should be an open circuit for d-c. If not then most likely you used enough solder to form a small fillet around the pad. On the crystal side of the pad, the fillet easily shorts the signal path to the crystal case and so to ground. If so, then remove the crystal involved, clean off the solder, the carefully replace it, using a minimum of solder. (Note that you have jumpers across a couple of capacitor locations, so a short there will require that you open the jumper to see which crystal is involved). Ron AC7AC __ Do you Yahoo!? Yahoo! Small Business - Try our new resources site! http://smallbusiness.yahoo.com/resources/ ___ 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
[Elecraft] KSB2 Problem: Big attenuation of received signals
My first post, this is regarding my attempt to install the KSB2 option into my K2/100 #4363. I built the KSB2 option, and removed C167 and the two jumpers from the RF board, plugged in the KSB2 board, applied power, and got the Elecraft on the display. The problem is that the receiver became very quiet. I could still hear the strongest signals if I turn the AF Gain way up, and instead of S9 on the meter, they're way down to S1. The KSB2 manual specifically states (page 15, final step of initial test) this should not happen, and if it does, to go to the troubleshooting section. I confirmed about half of the DC measurements in the troubleshooting section. I noticed when I jiggle around RFC2 I get some noise in the receiver, and those little RFC1 2 toroids on the KSB board were a challenge to wind, so I'm wondering if I have a problem there. I removed the KSB2 board, put the jumpers and the C167 back into the RF board, and now I am back to my well-performing K2/100. The KSB2 board is sitting on the bench waiting to be fixed. Have any of you seen receiver attenuation problems when you first plugged in the KSB2? What was your solution? Thanks, -Andrew, KF7HB __ Do you Yahoo!? Yahoo! Small Business - Try our new resources site! http://smallbusiness.yahoo.com/resources/ ___ 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 Problem: Big attenuation of received signals
Andrew, Plug the KSB2 in again and be certain that it is properly positioned on the headers. It is easy to misplug the KSB2 - if you see the standoff and TP2 properly aligned with the holes in the SSB board, it probably is mounted correctly. As a check (but not a permanent fix) slide a small sheet of paper between RFC1 and RFC2 and the adjacent crystal cans. That is a quick check of whether or not the windings of the chokes are shorting to the crystals - if they are, rewind the chokes being careful not to scrape the insulation on the wire. Check the orientation of the diodes - all of them should have the banded end away from the board. Lastly (or maybe best doen first) check the soldering carefully, particularly in the crystal filter area. 73, Don W3FPR -Original Message- The problem is that the receiver became very quiet. I could still hear the strongest signals if I turn the AF Gain way up, and instead of S9 on the meter, they're way down to S1. The KSB2 manual specifically states (page 15, final step of initial test) this should not happen, and if it does, to go to the troubleshooting section. I confirmed about half of the DC measurements in the troubleshooting section. I noticed when I jiggle around RFC2 I get some noise in the receiver, and those little RFC1 2 toroids on the KSB board were a challenge to wind, so I'm wondering if I have a problem there. ___ 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 Problem: Big attenuation of received signals
Andrew Meier wrote: I noticed when I jiggle around RFC2 I get some noise in the receiver, and those little RFC1 2 toroids on the KSB board were a challenge to wind, so I'm wondering if I have a problem there. Be sure to check for PTTL (Poorly Tinned Toroid Leads). -- 73, Vic, K2VCO Fresno CA http://www.qsl.net/k2vco ___ 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 Problem: Big attenuation of received signals
The problem is that the receiver became very quiet. I could still hear the strongest signals if I turn the AF Gain way up, and instead of S9 on the meter, they're way down to S1. The KSB2 manual specifically states (page 15, final step of initial test) this should not happen, and if it does, to go to the troubleshooting section. Andrew: Don's suggestions are right on track. I have one to add, assuming this is a new build. Check for d-c continuity from each pin of each crystal to ground. It should be an open circuit for d-c. If not then most likely you used enough solder to form a small fillet around the pad. On the crystal side of the pad, the fillet easily shorts the signal path to the crystal case and so to ground. If so, then remove the crystal involved, clean off the solder, the carefully replace it, using a minimum of solder. (Note that you have jumpers across a couple of capacitor locations, so a short there will require that you open the jumper to see which crystal is involved). Ron AC7AC ___ 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
[Elecraft] KSB2 Problem
Hi all, I am trying to install the KSBS2 into my K2. Problem symptoms are that I get the Hi Current warning, plus I get no variance on my separate receiver when trying the fine balancing. The rest of the alignment went okay, SSBA on BAL gave me good nulls with tweaking R1 both on USB and LSB (I just cannot hear any null with the receiver. I get a very strong carrier (S9+) on my separate receiver with SSBA at 3. Doing the voltage checks on rx, everything looks okay with the exception of: U1, pin 22 - 5.6v instead of 0.2 U2, pin 5 - 5.95v instead of 0.6 U3, pin 6 - 1.4v instead of 0 U4, pin 3 - 5.95 instead of 0.6 Since I get the hi cur warning I have not tried any tx voltage measurements. I looked at the archives and saw some people put RF board Q2 in backwards but the 'silver' side is facing the front of the rig. Any ideas? N ___ 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 Problem
Neal, The Hi-Cur messages are likely not due to the KSB2 installation. Torubleshoot the Hi-CUR problem first. The Hi-CUR problem is most likely associated with either the Low Pass filter, OR a problem with the RF detection and the related transmit ALC. Do you get the Hi-CUR warnings at all settings of the Power Control? Do the Hi-CUR messages appear on only some bands? Do you get the Hi-CUR messages in CW mode, or only in SSB mode? The answer to those questions will tell where to begin looking for the problem. Orientation of Q2 - one side is slightly rounded (or rather the corners are 'cut off'), and that is the only real way to tell which side is which. Do not rely on which side is silver (and contains the labeling) - I believe that point is made clear in the K2 manual. 73, Don W3FPR -Original Message- I am trying to install the KSBS2 into my K2. Problem symptoms are that I get the Hi Current warning, plus I get no variance on my separate receiver when trying the fine balancing. The rest of the alignment went okay, SSBA on BAL gave me good nulls with tweaking R1 both on USB and LSB (I just cannot hear any null with the receiver. I get a very strong carrier (S9+) on my separate receiver with SSBA at 3. Doing the voltage checks on rx, everything looks okay with the exception of: U1, pin 22 - 5.6v instead of 0.2 U2, pin 5 - 5.95v instead of 0.6 U3, pin 6 - 1.4v instead of 0 U4, pin 3 - 5.95 instead of 0.6 Since I get the hi cur warning I have not tried any tx voltage measurements. I looked at the archives and saw some people put RF board Q2 in backwards but the 'silver' side is facing the front of the rig. Any ideas? N ___ 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 ___ 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 Problem
Neal, A normal K2 will have more gain on 40 and 30 meters than on the other bands. I would check the LPF for those bands carefully - number of turns on the toroids (count the times the wire goes through the center - counting the outside turns often results in a toroid with an extra turn), then check each capacitor for proper value, and check the soldering. i.e. The current draw on 40 meters will normally be lower than that for other bands - fix that problem first and your other conditions may just 'go away'. The KSB2 can sometimes reduce the overall gain through the transmit chain, which will cause a higher current draw for a given power output. Don't be overly concerned about it until you have the KSB2 operating properly at lower power. (the KSB2 has no band dependency, but it can influence the gain of the transmit chain - so check the soldering there too and check the values of the resistors on the bottom of the KSB2 for proper values) - not saying there is necessarily a problem in the KSB2, I am just pointing out how things normally work. Even though your current draw is high, it will usually cause no harm (other than possibly overloading your power supply, so if you need to do testing at full power output, you can easily bump up the CAL CUR setting in the menu to get rid of the message while you troubleshoot the real cause of the increased current draw. 73, Don W3FPR -Original Message- Hi Don The Hi Cur was not happening before (on CW). I also installed the noise blanker yesterday and did some CW so I think prior to inserting the KSB2 it was okay. The Hi cur only happens on 40m SSB. On CW at full output it varies from 3.3 (on 80 40) to 2.8 (on the rest of the bands). So, its only 40m SSB. Sorry about the confusion on the Q2 orientation, I read that in one of the archive emails. It looks like its installed correctly to me, in viewing from directly above it. Any clues? Neal ___ 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 problem status: befuddled
Hi all, Thanks for giving some ideas! I checked the resistors on the bottom of the ssb board, they are all correct. I must say that trying to identify parts on the top of the board is a real challenge, its so stuffed that its almost impossible! Don, I redid the output amperage at 10 watts: 80 - 2.68 40 - 2.72 30 - 2.28 20 - 1.96 17 - 2.42 15 - 2.50 12 - 2.24 10 - 2.16 At 10 watts on 40, the voltage on rx is 13.5 on tx its 12.9. The group is right, I did not notice the power output on lower than 17m (which is 15 watts). On 15 through 10, highest output is 13.3 watts. Do I still need to investigate the 40m current usage? Do I need to replace the 3 resistors and jumper that I pulled out to eliminate the noise blanker module from the mix of things to investigate? I should have done one module and waited to know it worked before doing a second one! Neal On Feb 21, 2005, at 5:37 PM, W3FPR - Don Wilhelm wrote: Neal, There may be nothing wrong with 40 meters after all - I had missed the point that you were setting the Power control to absolute max. What is your power supply voltage? 13.8 volts is typical (13.6 on the display), and lower power supply voltages will result in increased current draw. What is the voltage when you are seeing a current of 3 amps or greater? I don't have a straightforward answer here. Can it be that your Carrier Balance is not correctly set and you are really generating more RF drive with SSB than with CW? It is not really a fair comparison to compare current draw from band to band with the Power control set all the way clockwise. Set it to 10 watts and check the current drawn for each band and both CW and SSB modes. Actually SSB mode should draw little current without audio if the carrier is balanced because there should be little or no RF output. 73, Don W3FPR -Original Message- Hi Don and all, I have spent the afternoon looking for where I could have made a mistake on the 40m LPF circuit. I didn't find any obvious ones, the toroids came from 'The guy de Toroids' but I counted them all anyway, and they are (luckily!) correct. Same for capacitors. Did the run of voltage checks and didn't notice anything really wrong. On cw, cranking the output knob to the max, the display readings for current are 80 3.22 40 3.36 30 2.84 20 2.38 17 3.08 15 2.84 12 2.62 10 2.42 Output reads over 15 watts in all cases, usually abt 15.2. This reads pretty much the same with or without the SSB module installed. I take it from your comments that the fact that 40m is the highest cw reading, its indicative of something wrong. Looked at LPF and BPF areas. What should I expect on the amp readings, 2.35 on 40 and a gradual increase as I go towards 10m? I could reinstall the resistors and jumper and take out the noise blanker module as thats something put in yesterday, I take it that I need to do that if I want to test without it? I have boosted cal cur to 4.0 and still can get hi cur signal with output fully counterclockwise on both usb and lsb. I have been very happy working cw all week as it is (set the cal cur to 3.5 and it hasn't tripped yet). Any more ideas to look at? ___ 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 ___ 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 problem status: befuddled
Your current readings don't look out of hand to me! 40 is normally higher because that is the band that usually produces the greatest RF output. Your readings are consistent with my K2. Interesting that you say the output reads over 15 watts in all cases,... Few K2's make 15 watts on 10. Many are capable just over 10. When they do produce more power they draw more current. The current is proportional to the actual power output. The maximum power output varies according to the overall RF gain available in the transmitter strip and that tends to be highest in the 7-10 MHz range. So in that range the current draw is the highest too. Your current draw on 10 meters is consistent with an output of just about 10 watts output wide open. I don't see how that's connected to your overcurrent with the SSB module plugged in, but it's an anomaly. Have you confirmed that your K2 internal current sensor is accurate by putting an ammeter in the lead from the external power supply? If it's okay, then there's little else but for your SSB module itself to be making up the extra current draw. Something on that module is drawing more current than it should. Ron AC7AC -Original Message- Hi Don and all, I have spent the afternoon looking for where I could have made a mistake on the 40m LPF circuit. I didn't find any obvious ones, the toroids came from 'The guy de Toroids' but I counted them all anyway, and they are (luckily!) correct. Same for capacitors. Did the run of voltage checks and didn't notice anything really wrong. On cw, cranking the output knob to the max, the display readings for current are 80 3.22 40 3.36 30 2.84 20 2.38 17 3.08 15 2.84 12 2.62 10 2.42 Output reads over 15 watts in all cases, usually abt 15.2. This reads pretty much the same with or without the SSB module installed. I take it from your comments that the fact that 40m is the highest cw reading, its indicative of something wrong. Looked at LPF and BPF areas. What should I expect on the amp readings, 2.35 on 40 and a gradual increase as I go towards 10m? I could reinstall the resistors and jumper and take out the noise blanker module as thats something put in yesterday, I take it that I need to do that if I want to test without it? I have boosted cal cur to 4.0 and still can get hi cur signal with output fully counterclockwise on both usb and lsb. I have been very happy working cw all week as it is (set the cal cur to 3.5 and it hasn't tripped yet). Any more ideas to look at? ___ 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 ___ 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 Problem
In a message dated 21/02/05 14:53:44 GMT Standard Time, [EMAIL PROTECTED] writes: I am trying to install the KSBS2 into my K2. Problem symptoms are that I get the Hi Current warning, plus I get no variance on my separate receiver when trying the fine balancing. The rest of the alignment went okay, SSBA on BAL gave me good nulls with tweaking R1 both on USB and LSB (I just cannot hear any null with the receiver. I get a very strong carrier (S9+) on my separate receiver with SSBA at 3. --- It has not come up in any replies to your question, but it looks that you may be getting problems with RF into your microphone socket and the KSB2 audio input. Are the KSB2 tests being carried out into a good 50 ohm dummy load? There have been various methods described on the list for combatting problems of RF getting into the microphone input, the main one being to provide a ground on the microphone socket outer. Bob, G3VVT ___ 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 problem status: befuddled
Neal, Taking things in reverse order - go ahead and put the Noise Blanker itself back in rather than the 6 dB pad resistors. It will only affect the receive path and not the Transmit path. OK - your current draw at a constant 10 Watts output looks just fine to me. It is a bit unusual that your minimum current draw for 10 watts out is at 20 meters - usually that will occur at 40 or 30 meters - but this does not look like a real problem to me (actually it indicates better efficiency than normal on the higher bands). so now that still leaves us with the original problem of excessive current draw in SSB mode. Actually something is 'fishy' here, because an SSB signal with no audio will result in very little output power (and quite low current draw). So my thinking now is that you do not have the SSB balance set properly - or there is something incorrect on the KSB2 board. I know it is difficult to do, but do look again - particularly at the balanced modulator and those things shown around it in the schematic. It does now seem that your problems are coming from the KSB2. Just as a wild guess I must ask - did you remove C167 from the RF board when installing the KSB2? If you fail to remove it, that alone could explain the conditions you are seeing. 73, Don W3FPR -Original Message- Hi all, Thanks for giving some ideas! I checked the resistors on the bottom of the ssb board, they are all correct. I must say that trying to identify parts on the top of the board is a real challenge, its so stuffed that its almost impossible! Don, I redid the output amperage at 10 watts: 80 - 2.68 40 - 2.72 30 - 2.28 20 - 1.96 17 - 2.42 15 - 2.50 12 - 2.24 10 - 2.16 At 10 watts on 40, the voltage on rx is 13.5 on tx its 12.9. The group is right, I did not notice the power output on lower than 17m (which is 15 watts). On 15 through 10, highest output is 13.3 watts. Do I still need to investigate the 40m current usage? Do I need to replace the 3 resistors and jumper that I pulled out to eliminate the noise blanker module from the mix of things to investigate? I should have done one module and waited to know it worked before doing a second one! Neal On Feb 21, 2005, at 5:37 PM, W3FPR - Don Wilhelm wrote: Neal, There may be nothing wrong with 40 meters after all - I had missed the point that you were setting the Power control to absolute max. What is your power supply voltage? 13.8 volts is typical (13.6 on the display), and lower power supply voltages will result in increased current draw. What is the voltage when you are seeing a current of 3 amps or greater? I don't have a straightforward answer here. Can it be that your Carrier Balance is not correctly set and you are really generating more RF drive with SSB than with CW? It is not really a fair comparison to compare current draw from band to band with the Power control set all the way clockwise. Set it to 10 watts and check the current drawn for each band and both CW and SSB modes. Actually SSB mode should draw little current without audio (if the carrier is balanced because there should be little or no RF output. 73, Don W3FPR -Original Message- Hi Don and all, I have spent the afternoon looking for where I could have made a mistake on the 40m LPF circuit. I didn't find any obvious ones, the toroids came from 'The guy de Toroids' but I counted them all anyway, and they are (luckily!) correct. Same for capacitors. Did the run of voltage checks and didn't notice anything really wrong. On cw, cranking the output knob to the max, the display readings for current are 80 3.22 40 3.36 30 2.84 20 2.38 17 3.08 15 2.84 12 2.62 10 2.42 Output reads over 15 watts in all cases, usually abt 15.2. This reads pretty much the same with or without the SSB module installed. I take it from your comments that the fact that 40m is the highest cw reading, its indicative of something wrong. Looked at LPF and BPF areas. What should I expect on the amp readings, 2.35 on 40 and a gradual increase as I go towards 10m? I could reinstall the resistors and jumper and take out the noise blanker module as thats something put in yesterday, I take it that I need to do that if I want to test without it? I have boosted cal cur to 4.0 and still can get hi cur signal with output fully counterclockwise on both usb and lsb. I have been very happy working cw all week as it is (set the cal cur to 3.5 and it hasn't tripped yet). Any more ideas to look at? ___ 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 problem status: befuddled
Neal, Just an additional note - I usually adjust the SSB Carrier balance by looking at the RF output (with no audio signal) with my 'scope - I adjust the carrier balance for minimum power output (compromising if necessary between USB and LSB). You should find the proper point near the mid-point setting of the carrier balance pot. If it is not near the midpoint, look for some component misplaced or improper soldering. 73, Don W3FPR -Original Message- Taking things in reverse order - go ahead and put the Noise Blanker itself back in rather than the 6 dB pad resistors. It will only affect the receive path and not the Transmit path. OK - your current draw at a constant 10 Watts output looks just fine to me. It is a bit unusual that your minimum current draw for 10 watts out is at 20 meters - usually that will occur at 40 or 30 meters - but this does not look like a real problem to me (actually it indicates better efficiency than normal on the higher bands). so now that still leaves us with the original problem of excessive current draw in SSB mode. Actually something is 'fishy' here, because an SSB signal with no audio will result in very little output power (and quite low current draw). So my thinking now is that you do not have the SSB balance set properly - or there is something incorrect on the KSB2 board. I know it is difficult to do, but do look again - particularly at the balanced modulator and those things shown around it in the schematic. It does now seem that your problems are coming from the KSB2. Just as a wild guess I must ask - did you remove C167 from the RF board when installing the KSB2? If you fail to remove it, that alone could explain the conditions you are seeing. 73, Don W3FPR -Original Message- Hi all, Thanks for giving some ideas! I checked the resistors on the bottom of the ssb board, they are all correct. I must say that trying to identify parts on the top of the board is a real challenge, its so stuffed that its almost impossible! Don, I redid the output amperage at 10 watts: 80 - 2.68 40 - 2.72 30 - 2.28 20 - 1.96 17 - 2.42 15 - 2.50 12 - 2.24 10 - 2.16 At 10 watts on 40, the voltage on rx is 13.5 on tx its 12.9. The group is right, I did not notice the power output on lower than 17m (which is 15 watts). On 15 through 10, highest output is 13.3 watts. Do I still need to investigate the 40m current usage? Do I need to replace the 3 resistors and jumper that I pulled out to eliminate the noise blanker module from the mix of things to investigate? I should have done one module and waited to know it worked before doing a second one! Neal On Feb 21, 2005, at 5:37 PM, W3FPR - Don Wilhelm wrote: Neal, There may be nothing wrong with 40 meters after all - I had missed the point that you were setting the Power control to absolute max. What is your power supply voltage? 13.8 volts is typical (13.6 on the display), and lower power supply voltages will result in increased current draw. What is the voltage when you are seeing a current of 3 amps or greater? I don't have a straightforward answer here. Can it be that your Carrier Balance is not correctly set and you are really generating more RF drive with SSB than with CW? It is not really a fair comparison to compare current draw from band to band with the Power control set all the way clockwise. Set it to 10 watts and check the current drawn for each band and both CW and SSB modes. Actually SSB mode should draw little current without audio (if the carrier is balanced because there should be little or no RF output. 73, Don W3FPR -Original Message- Hi Don and all, I have spent the afternoon looking for where I could have made a mistake on the 40m LPF circuit. I didn't find any obvious ones, the toroids came from 'The guy de Toroids' but I counted them all anyway, and they are (luckily!) correct. Same for capacitors. Did the run of voltage checks and didn't notice anything really wrong. On cw, cranking the output knob to the max, the display readings for current are 80 3.22 40 3.36 30 2.84 20 2.38 17 3.08 15 2.84 12 2.62 10 2.42 Output reads over 15 watts in all cases, usually abt 15.2. This reads pretty much the same with or without the SSB module installed. I take it from your comments that the fact that 40m is the highest cw reading, its indicative of something wrong. Looked at LPF and BPF areas. What should I expect on the amp readings, 2.35 on 40 and a gradual increase as I go towards 10m? I could reinstall the resistors and jumper and take out the noise blanker module as thats something put in yesterday, I take it that I need to do that if I want to test without it? I have boosted cal cur to 4.0 and still can get
