Elecraft

KRX3 Problem

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K8RDD

KRX3 Problem

It seems my second receiver has went deaf. A 20 over signal gives me about an s3 on the sub. I can barely hear the signal phone or cw. I unplugged the tmp connector at the KAT3 and jumped the dipole directly into it with the same results. Deaf all modes all bands. I checked connections etc and see nothing obvious. Suggestions? Looks like it would be tough to get to anything to troubleshoot. Worked fine last night. Got home from work and it was dead.

Randy

K8RDD

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Barry N1EU

Re: KRX3 Problem

K8RDD wrote

It seems my second receiver has went deaf. . . Suggestions?

Check the filter configuration for the subreceiver. Use the K3 Utility and go to Configuration - Edit Crystal Filters - Sub Receiver. Make sure you have the correct filters enabled.

73,
Barry N1EU

K8RDD

Re: KRX3 Problem

In reply to this post by K8RDD

Ok. More weirdness. If the 2 receivers are on the same antenna ports the sub is always way down. If the receivers are on opposite ports they work fine! I set up the sig gen this morning and I can set A to 1 and B to ant2 and swap the inputs with my sig gen and they are fine. If I put B on ant 1 and A on ant2 a-ok also. If I put them both on the same ant port the sub rx is always down. They seem to be in parallel on the print. I must be missing something. I'm going out with my wife to eat Chinese. Maybe that will help. The saga continues this afternoon.

Randy

K8RDD

----- Original Message -----

From: [hidden email]

To: [hidden email]

Sent: Friday, December 26, 2008 11:05 PM

Subject: RE: [Elecraft] KRX3 Problem

Possible but I would not think that would go out like that when it was working when you shut down....then not when you powered up the next day. As for what levels to be looking for, Gary needs to get involved with that.

Enjoy the Chinese food tomorrow!

Greg

-----Original Message-----
From: Randy Downs [mailto:[hidden email]]
Sent: Friday, December 26, 2008 7:53 PM
To: Greg
Subject: Re: [Elecraft] KRX3 Problem

Thanks I'll try in the morning. I checked them but did not unplug and plug back in. I need to get it back on my bench where I can hook up the sig gen and start checking it out. Is there a level chart available for the synth outputs etc that I can check with a scope? I have a 400mhz. I forgot I have to take my wife out for Chinese tomorrow so it will be tomorrow afternoon. Anyway I'll do a more thorough check tomorrow. I have the feeling it's somewhere between the preamp and the tmp con. Maybe the protection relay?
Randy
K8RDD

On Fri, Dec 26, 2008 at 10:50 PM, Greg <[hidden email]> wrote:

I was thinking it may be a problem with the TMP connector on the KRX3 near the back corner near the KIO3 stack. But if you are not getting anything when sharing the main connection I doubt that's it.

Please double check the TMP connections from the KRX3 and the sub SYN boards. Make sure they are good and snug. Then try and redo the VCO CAL for the sub again.

Greg

-----Original Message-----
From: Randy Downs [mailto:[hidden email]]

Sent: Friday, December 26, 2008 7:26 PM
To: Greg
Subject: Re: [Elecraft] KRX3 Problem

On 160 meters with a 20 over signal on vfo A, I can see no difference when I unplug the tmp going to the krx3 it stays at about s2, preamp on but 20 over on vfo A. If I touch the antenna to the tip of the tmp going to the krx3 I still see no increase in signal strength. Preamp on krx3 does brings up noise floor. It appears to be working. The signal appears to go directly into the krx3 via J92. I guess I'll have to pull the krx3 tomorrow. Maybe a connection on the board or a problem somewhere before the preamp. Bummer.
Randy
K8RDD

On Fri, Dec 26, 2008 at 9:43 PM, Greg <[hidden email]> wrote:

Do you get signals when you set it to main so that it shares the RF path with the main rx?

-----Original Message-----
From: Randy Downs [mailto:[hidden email]]

Sent: Friday, December 26, 2008 6:31 PM
To: Greg
Subject: Re: [Elecraft] KRX3 Problem

Yeah it's set to atu and no decimals blinking.

On Fri, Dec 26, 2008 at 9:21 PM, Greg <[hidden email]> wrote:

Did you double check that KRX3 is set to the correct setting...either BNC or ATU as appropriate?

Are any of the frequency display decimals blinking?

Greg

-----Original Message-----
From: Randy Downs [mailto:[hidden email]]
Sent: Friday, December 26, 2008 6:10 PM
To: Greg
Subject: Re: [Elecraft] KRX3 Problem

I tried that. I actually bypassed it by connecting the tmp directly to the antenna. I think it's really broke. I'll download the schematic and take a look. And it was working so good last night when 10 was open. Searching with the main and talking with the sub. Dang-it.
Randy
K8RDD

On Fri, Dec 26, 2008 at 9:12 PM, Greg <[hidden email]> wrote:

Try HOLDing the RX ANT button to switch between MAIN and AUX to see if the signal comes back.

Greg

AB7R

-----Original Message-----
From: [hidden email] [mailto:[hidden email]]On Behalf Of Randy Downs
Sent: Friday, December 26, 2008 5:46 PM
To: [hidden email]; [hidden email]; [hidden email]
Subject: [Elecraft] KRX3 Problem

It seems my second receiver has went deaf. A 20 over signal gives me about an s3 on the sub. I can barely hear the signal phone or cw. I unplugged the tmp connector at the KAT3 and jumped the dipole directly into it with the same results. Deaf all modes all bands. I checked connections etc and see nothing obvious. Suggestions? Looks like it would be tough to get to anything to troubleshoot. Worked fine last night. Got home from work and it was dead.

Randy

K8RDD