KX1 RX deaf after KB3080 installation
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KX1 RX deaf after KB3080 installation
 
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I thought I found _all_ the problems with my KX3080, but I guess not. THe
receiver is now very insensitive on all bands. It works, but I don't hear an increase in noise on any band when I connect an antenna. Tracing from the antenna jack toward the mixer, I get a good increase in noise when I touch the antenna to the junction of L6 and the RF gain pot. On the antenna side of L6, there's no increase in noise. Rereading the assembly instructions, the manual says to connect A on the KXB3080 to B on the KX1, and B on the KXB3080 to A on the KX1, because the markings for A and B on the KX1 are incorrect. But if this is the case, why was the KXB30 connected A to A and B to B? I'm wondering if this is my problem... 73, Bruce N7CEE _______________________________________________ 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 |
Re: KX1 RX deaf after KB3080 installation
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On Thursday 20 April 2006 06:05 pm, you wrote:
> Do you have the jumper installed in the jack next to the BNC? > Yes, the jumper is in place. That's not where I looe the RX signal. It's at L6. Also, the TX puts out normal power into a dummy load, so it looks like the low pass filter part pf the KXB3080 is OK. > The markings on the BACK of the board are wrong. The ones shown in > the manual on page 9 are okay. > That's strange, becaue I had the KXB30 option, and its manual doesn't mention that the markings on the back of the KX1 board are wrong. A goes to A and B to B, when installing the KXB30. Thanks, Randy. Back to troubleshooting... 73, Bruce N7CEE _______________________________________________ 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 |
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Hey gang,
I seem to have a K2 that is stuck in key down (i.e. xmit). When I turn the radio on all I get is the ELECrAFt message, that relays cycle normal, and then a frequency. No front panel controls work except the power knob and it is obvious that I am transmitting and the finals start heating up. What do I need to check or do???? Any and all help appreciated! Yes, I have turned it off... 73, Bill Allen - WA5PB -- No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.1.385 / Virus Database: 268.4.4/319 - Release Date: 4/19/2006 _______________________________________________ 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 |
RE: KX1 RX deaf after KB3080 installation
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In reply to this post by Bruce Grubbs
Bruce, N7CEE wrote:
I thought I found _all_ the problems with my KX3080, but I guess not. THe receiver is now very insensitive on all bands. It works, but I don't hear an increase in noise on any band when I connect an antenna. Tracing from the antenna jack toward the mixer, I get a good increase in noise when I touch the antenna to the junction of L6 and the RF gain pot. On the antenna side of L6, there's no increase in noise. Rereading the assembly instructions, the manual says to connect A on the KXB3080 to B on the KX1, and B on the KXB3080 to A on the KX1, because the markings for A and B on the KX1 are incorrect. But if this is the case, why was the KXB30 connected A to A and B to B? I'm wondering if this is my problem... ------------------- No. You have it right. Those marks on the KX1 PCB are correct for the KXB30 and incorrect for the KXB3080. I suspect L6 is open. Have you ohmmed it? You moved L6 to the underside of the KX1 PCB as part of the KXB3080 install. Is it in the right holes on the bottom? You should see about 1 k ohm from L6 to ground with the RF gain at minimum on either end of the inductor. With the RF gain at maximum, it should show about 1 to 2 ohms to ground. The inductor itself has a DC resistance of about 1 ohm so it'll be about 1 ohm higher from one end than the other. Ron AC7AC _______________________________________________ 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 |
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In reply to this post by Bill Allen-6
Unplug the key and microphone. I think its something simple like that, I do
recall seeing that problem mentioned before. 73/72 - Mike WA8BXN _______________________________________________ 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 |
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In reply to this post by Bill Allen-6
Mike, Key and Mike are unplugged. At first I thought, I have got something bumped into my key. But I have everything unplugged. Same problem. 73, Bill - WA5PB -----Original Message----- From: Mike WA8BXN [mailto:[hidden email]] Sent: Thursday, April 20, 2006 8:55 PM To: [hidden email]; [hidden email] Subject: Re: [Elecraft] K2# 1068 stuck in keydown! Unplug the key and microphone. I think its something simple like that, I do recall seeing that problem mentioned before. 73/72 - Mike WA8BXN -- No virus found in this incoming message. Checked by AVG Free Edition. Version: 7.1.385 / Virus Database: 268.4.4/319 - Release Date: 4/19/2006 -- No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.1.385 / Virus Database: 268.4.4/319 - Release Date: 4/19/2006 _______________________________________________ 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 |
RE: K2# 1068 stuck in transmit mode
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In reply to this post by Bill Allen-6
Wow. I am still puzled over this one. Everything under the hood looks good. Sometimes it is easy to get a visual on an obviously blown component, but I see absolutely nothing amiss. Even passes the sniff test! The problem exists even with no microphone or key plugged in. Any of you all K2 gurus have any notions on this? I did try a reset of the K2, but that did not make a difference other than giving me an Info 201 code and resetting my displayed frequency and mode to 7100.00c . Again any help or suggestions appreciated. Thanks Mike for the previous suggestion. 73, Bill Allen - WA5PB -----Original Message----- From: [hidden email] [mailto:[hidden email]] On Behalf Of Bill Allen Sent: Thursday, April 20, 2006 8:32 PM To: [hidden email] Subject: [Elecraft] K2# 1068 stuck in keydown! Importance: High Hey gang, I seem to have a K2 that is stuck in key down (i.e. xmit). When I turn the radio on all I get is the ELECrAFt message, that relays cycle normal, and then a frequency. No front panel controls work except the power knob and it is obvious that I am transmitting and the finals start heating up. What do I need to check or do???? Any and all help appreciated! Yes, I have turned it off... 73, Bill Allen - WA5PB -- No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.1.385 / Virus Database: 268.4.4/319 - Release Date: 4/19/2006 _______________________________________________ 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 -- No virus found in this incoming message. Checked by AVG Free Edition. Version: 7.1.385 / Virus Database: 268.4.4/319 - Release Date: 4/19/2006 -- No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.1.385 / Virus Database: 268.4.4/319 - Release Date: 4/19/2006 _______________________________________________ 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 |
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Bill,
Do you think it could be the key input jack itself? I've had trouble with the headphone jack on one of my K2's. I've had to replace it 3 times, not fun. I think the key jack is about the same thing and maybe prone to the same type problem. Just a thought. John, k7up _______________________________________________ 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 |
RE: K2# 1068 stuck in transmit mode
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In reply to this post by Bill Allen-6
Bill,
It may be time to drag out the schematic and ohmmeter to see what if the DOT/PTT line has a short to ground. You can check at Control Board U6 pin 30, but that may not be where the trouble is. If you find no short with the ohmmeter check, then try it with power on - you should find both U6 pin 30 and U6 pin 29 at a high level (near 5 volts). If all the above is OK and it still is in transmit mode (turn the power control to minimum and be certain you have a dummy load connected), check pins 27 and 28 of U6 - pin 27 should be at a low level when the uP is trying to receive and pin 28 should be high - if they are the other way around, then the uP is telling the K2 to transmit and the problem is inside the uP. Let us know what you find and we can go forward from there. 73, Don W3FPR > -----Original Message----- > > Wow. I am still puzled over this one. Everything under the hood looks > good. Sometimes it is easy to get a visual on an obviously blown > component, > but I see absolutely nothing amiss. Even passes the sniff test! The > problem exists even with no microphone or key plugged in. Any of > you all K2 > gurus have any notions on this? I did try a reset of the K2, but that did > not make a difference other than giving me an Info 201 code and > resetting my > displayed frequency and mode to 7100.00c . Again any help or suggestions > appreciated. Thanks Mike for the previous suggestion. > > 73, > Bill Allen - WA5PB > > _______________________________________________ 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 |
Re: KX1 RX deaf after KB3080 installation
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In reply to this post by Ron D'Eau Claire-2
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> > > No. You have it right. Those marks on the KX1 PCB are correct for the KXB30 > and incorrect for the KXB3080. > > I suspect L6 is open. Have you ohmmed it? > > You moved L6 to the underside of the KX1 PCB as part of the KXB3080 install. > Is it in the right holes on the bottom? > > You should see about 1 k ohm from L6 to ground with the RF gain at minimum > on either end of the inductor. > > With the RF gain at maximum, it should show about 1 to 2 ohms to ground. The > inductor itself has a DC resistance of about 1 ohm so it'll be about 1 ohm > higher from one end than the other. > > Ron AC7AC > > L6 is good, it measures 1 ohm. But I'm seeing only 1 to 4 ohms from min to max RF gain. That tallies with what I'm hearing- the RF gain has almost no effect on received sigs. So I'll look for whatever is pulling R1 down. Thanks again- it always helps to have a second set of "eyes". 73 Bruce N7CEE _______________________________________________ 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 |
RE: KX1 RX deaf after KB3080 installation
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L6 is good, it measures 1 ohm. But I'm seeing only 1 to 4 ohms from min to
max RF gain. That tallies with what I'm hearing- the RF gain has almost no effect on received sigs. So I'll look for whatever is pulling R1 down. Thanks again- it always helps to have a second set of "eyes". 73 Bruce N7CEE ------------------ If you can lift one end of L6, you can then tell which side of it the short is on. Since part of the mod was to install T2, I'd suspect it's somewhere there. Maybe a short between the turns of the two windings since both the primary and secondary of T2 have one end at DC ground. Ron AC7AC _______________________________________________ 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 |
Re: KX1 RX deaf after KB3080 installation
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This sounds like the problem I had with the old 30m module, finally I
just took it out and re-installed, I never did figure out what I did wrong although I'm sure one wire went in the wrong hole, then went in the right one the 2nd go. 73 de Alex NS6Y. On Apr 20, 2006, at 9:54 PM, Ron D'Eau Claire wrote: > L6 is good, it measures 1 ohm. But I'm seeing only 1 to 4 ohms from > min to > max > RF gain. That tallies with what I'm hearing- the RF gain has almost no > effect > on received sigs. So I'll look for whatever is pulling R1 down. > > Thanks again- it always helps to have a second set of "eyes". > > 73 > Bruce > N7CEE _______________________________________________ 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 |
Re: KX1 RX deaf after KB3080 installation
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In reply to this post by Ron D'Eau Claire-2
> ------------------ > > If you can lift one end of L6, you can then tell which side of it the short > is on. Since part of the mod was to install T2, I'd suspect it's somewhere > there. Maybe a short between the turns of the two windings since both the > primary and secondary of T2 have one end at DC ground. > > Ron AC7AC > > > I can't see anything wrong with L6 or the circuitry around CA and C26. I'll lift one end of L6 tomorrow- but now I'm starting to wonder if Q7 might be shorted. Bruce N7CEE _______________________________________________ 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 |
RE: KX1 RX deaf after KB3080 installation
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I can't see anything wrong with L6 or the circuitry around CA and C26. I'll
lift one end of L6 tomorrow- but now I'm starting to wonder if Q7 might be shorted. Bruce N7CEE -------------------------- If you can see the 1 ohm or so difference that represents the resistance of L6 when measuring from each end of it to ground, you can tell which side the short is on without lifting one lead: it'll be on the end with the lower resistance to ground. That will tell you whether to look in the direction of T2 or toward Q7. The other possibility to a shorted Q7 is that Q7 is somehow locked "on". There should be no bias to ground on the base of it to leave it off. If there's about 0.6 VDC at the base then it's being held on by a current through R2 that should not be there in receive mode. If that seems to be case, grounding R2 at the end connected to the base of Q7 will turn it "off" and make the short go away. Ron AC7AC _______________________________________________ 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 |
Re: KX1 RX deaf after KB3080 installation
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I got so..... dismayed... .with this problem with my 30m module I just
finally decided to remove it and see if the KX1 would work again, I did and it did. Then I replaced the pieces of wire for the 30m module and started again, really from scratch, installed it again, and the 2nd time worked the charm. It's kind of the IBM Field Tech way to fix a problem but it did work...... 73 de Alex NS6Y On Apr 20, 2006, at 11:42 PM, Ron D'Eau Claire wrote: > I can't see anything wrong with L6 or the circuitry around CA and C26. > I'll > lift one end of L6 tomorrow- but now I'm starting to wonder if Q7 > might be > shorted. > > Bruce > N7CEE _______________________________________________ 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 |
Re: K2# 1068 stuck in keydown!
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In reply to this post by Bill Allen-6
Bill Allen wrote on Friday, April 21, 2006 2:31 AM
Hey gang, I seem to have a K2 that is stuck in key down (i.e. xmit). When I turn the radio on all I get is the ELECrAFt message, that relays cycle normal, and then a frequency. No front panel controls work except the power knob and it is obvious that I am transmitting and the finals start heating up. What do I need to check or do???? Any and all help appreciated! Yes, I have turned it off... ---------------------------------------------------------------------- I had a similar problem with the K2 getting stuck in receive, not transmit. In my case the cause was poor contact between one or more pins of the Control Board MCU U6 and its socket, perhaps due to corrosion. Removing U6 and plugging it back into its socket cured the problem. Later I changed the socket to a turned pin type (not fun) for peace of mind! 73, Geoff GM4ESD _______________________________________________ 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 |
RE: KX1 RX deaf after KB3080 installation
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In reply to this post by Bruce Grubbs
Bruce,
Check the end of L6 closest to the wire you added at trimmer cap CC - L6 should not connect to the trimmer pad, but it is close, so a slight solder splash will cause a short there. 73, Don W3FPR > -----Original Message----- > > L6 is good, it measures 1 ohm. But I'm seeing only 1 to 4 ohms > from min to max > RF gain. That tallies with what I'm hearing- the RF gain has > almost no effect > on received sigs. So I'll look for whatever is pulling R1 down. > > Thanks again- it always helps to have a second set of "eyes". > > 73 > Bruce > N7CEE > _______________________________________________ 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 |
RE: KX1 RX deaf after KB3080 installation
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Bruce,
Check the end of L6 closest to the wire you added at trimmer cap CC - L6 should not connect to the trimmer pad, but it is close, so a slight solder splash will cause a short there. 73, Don W3FPR ---------------------------- Good idea. As compelling is it may seem at times, something else like the transistor failing by "coincidence" happens so seldom I can't think of a single incidence that I've seen in half a century of fixing gear. I'm not saying it hasn't happened, I just can't recall a case, but I can recall many, many times where I chased phantoms convinced I had experienced a coincidental failure before going back and finding the problem in something I had worked on already. It's almost certainly something you touched while installing the KXB3080. That includes an accidental "touching" like an accidental solder bridge. If the short is on the R1 (RF GAIN) / T2 side of inductor L6, my next steps would be a very careful visual inspection of the traces and solder pads in that direction. If that doesn't turn up anything, I'd pull the lead T2-2 to disconnect the transformer from the circuit. Then you can see if the short is in the transformer or if it is something associated the circuit around RF GAIN control R1. T2-2 is the green lead that goes right down through the center of T2 into the solder pad (See Figure 4 in the manual). Ron AC7AC _______________________________________________ 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 |
Re: KX1 RX deaf after KB3080 installation
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In reply to this post by Don Wilhelm-3
On Friday 21 April 2006 04:47 am, Don Wilhelm wrote:
> Bruce, > > Check the end of L6 closest to the wire you added at trimmer cap CC - L6 > should not connect to the trimmer pad, but it is close, so a slight solder > splash will cause a short there. > > 73, > Don W3FPR > No short there- thanks, Don. It looks like it's in the T2 side of L6, so Ron's probably right, it involves T2. 73, Bruce N7CEE _______________________________________________ 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 |
Re: KX1 RX deaf after KB3080 installation
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In reply to this post by Ron D'Eau Claire-2
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> > If you can see the 1 ohm or so difference that represents the resistance of > L6 when measuring from each end of it to ground, you can tell which side the > short is on without lifting one lead: it'll be on the end with the lower > resistance to ground. That will tell you whether to look in the direction of > T2 or toward Q7. > > The other possibility to a shorted Q7 is that Q7 is somehow locked "on". > There should be no bias to ground on the base of it to leave it off. If > there's about 0.6 VDC at the base then it's being held on by a current > through R2 that should not be there in receive mode. If that seems to be > case, grounding R2 at the end connected to the base of Q7 will turn it "off" > and make the short go away. > > Ron AC7AC Looks like it's Q7. I pulled T2-2 and still had the short. So I pulled Q7. The short went away at L6 and the RX works. Q7 is shorted- only 3 ohms collector to emitter. I don't think it's not a random failure. The original problem with the KXB3080 was a hot Q6 but very low output power. That problem was caused by a solder bridge between B and A on the KXB3080 so I'll bet too much TX RF got into Q7 and fried it. If I'd caught the problem during RX testing I would have avoided this. At least I can play with the receiver while I wait for a new Q7. The sensitivity does seem improved, at least on 20 m, by the KXB3080. Thanks Ron, Don, and Alexandra, for all the help! 73, Bruce N7CEE _______________________________________________ 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 |
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