Date   

Re: K3 Receive Function Attenuated Immediately After Transmission

Michael Kopec
 

Hello Harry, I experienced the same problem here a couple a times. It also showed on the P3. Turned out both times to be a dirty PL259 connection at the antenna. I inspected the pl259, it is soldered and sealed, and then cleaned everything with Deoxit. Problem solved for 2 yrs and then reoccurred. Same fix took care of it. de Mike K8NS

On Tuesday, August 11, 2020, 12:13:03 AM EDT, Harry Rudolph via groups.io <hgrudolphs@...> wrote:


Was playing around in the WAE CW contest this past weekend and began to experience some problems with the receive function.  I believe I ran into this on several bands but I was mostly on 20 meters so this is where I mostly experienced the condition.  The performance issue was that immediately following a transmission, perhaps in about 10% of the instances, the receive function would come back sounding as if the attenuator was on.  Usually if I added a quick "dit" it would return to the normal receive level.  I fooled around with the AGC which had no effect.  I changed from Ant 1 input to Ant 2 input with no effect.  If I switched to the RX antenna input, it seemed normal.  I was running with a Microham MK II interface and with an amp but did not see any indication that the problem was related to the overall setup, including the antenna.

Curiously, I switched to a different K3 and initially the problem seemed to be resolved.  But after a few more hours of operation, I noticed that I did actually have the problem with the replacement  but just at a much lower frequency.

Anyone experience anything like this or have any suggestions?  I plan to do some more A/B comparisons and take the MK II and amp out of the equation but wanted to see if anyone else has run into this.

Thanks.

Harry
WX8C


Re: K3 Receive Function Attenuated Immediately After Transmission

Joe Subich, W4TV
 

Start by removing any amplifier from the signal path. Then check
all feedline connectors and antenna switches for loose connections
and/or water ingress.

I plan to do some more A/B comparisons and take the MK II and amp out
of the equation but wanted to see if anyone else has run into this.
MK II (or any other microHAM interface) does not impact the RF path.
It can not possibly cause attenuation of the receive signal.

73,

... Joe, W4TV


On 2020-08-10 7:38 PM, Harry Rudolph via groups.io wrote:
Was playing around in the WAE CW contest this past weekend and began to experience some problems with the receive function.  I believe I ran into this on several bands but I was mostly on 20 meters so this is where I mostly experienced the condition.  The performance issue was that immediately following a transmission, perhaps in about 10% of the instances, the receive function would come back sounding as if the attenuator was on.  Usually if I added a quick "dit" it would return to the normal receive level.  I fooled around with the AGC which had no effect.  I changed from Ant 1 input to Ant 2 input with no effect.  If I switched to the RX antenna input, it seemed normal.  I was running with a Microham MK II interface and with an amp but did not see any indication that the problem was related to the overall setup, including the antenna.
Curiously, I switched to a different K3 and initially the problem seemed to be resolved.  But after a few more hours of operation, I noticed that I did actually have the problem with the replacement  but just at a much lower frequency.
Anyone experience anything like this or have any suggestions?  I plan to do some more A/B comparisons and take the MK II and amp out of the equation but wanted to see if anyone else has run into this.
Thanks.
Harry
WX8C


Re: KPA3 output erratic

James Kvochick
 

Chuck;

If you’d like, and we can get our schedules to align, I would be happy to chat with you via phone and or zoom.
For my money, I’m still betting on an issue with the final module, assuming low power TX gain calibration works.

Jim
k8jk@...


Re: K3 Receive Function Attenuated Immediately After Transmission

David Cutter
 

I've known it happening on other transceivers and it has turned out to be a relay

David G3UNA

On 11 August 2020 at 10:51 KE1F Lou <lmecseri@...> wrote:

I don't know if it happens after transmission, but I will look for it.
I experienced similar problem. My P3 clearly shows the "atennuation of the RF signal" and a "dit" restores the RF gain.
I am also using microHam II interface.
73 Lou KE1F. 



Sent from my Galaxy Tab® A

-------- Original message --------
From: "Harry Rudolph via groups.io" <hgrudolphs@...>
Date: 8/10/20 7:38 PM (GMT-05:00)
To: Elecraft-K3@groups.io
Subject: [Elecraft-K3] K3 Receive Function Attenuated Immediately After Transmission

Was playing around in the WAE CW contest this past weekend and began to experience some problems with the receive function.  I believe I ran into this on several bands but I was mostly on 20 meters so this is where I mostly experienced the condition.  The performance issue was that immediately following a transmission, perhaps in about 10% of the instances, the receive function would come back sounding as if the attenuator was on.  Usually if I added a quick "dit" it would return to the normal receive level.  I fooled around with the AGC which had no effect.  I changed from Ant 1 input to Ant 2 input with no effect.  If I switched to the RX antenna input, it seemed normal.  I was running with a Microham MK II interface and with an amp but did not see any indication that the problem was related to the overall setup, including the antenna.

Curiously, I switched to a different K3 and initially the problem seemed to be resolved.  But after a few more hours of operation, I noticed that I did actually have the problem with the replacement  but just at a much lower frequency.

Anyone experience anything like this or have any suggestions?  I plan to do some more A/B comparisons and take the MK II and amp out of the equation but wanted to see if anyone else has run into this.

Thanks.

Harry
WX8C

 

 


Re: K3 Receive Function Attenuated Immediately After Transmission

KE1F Lou
 

I don't know if it happens after transmission, but I will look for it.
I experienced similar problem. My P3 clearly shows the "atennuation of the RF signal" and a "dit" restores the RF gain.
I am also using microHam II interface.
73 Lou KE1F. 



Sent from my Galaxy Tab® A

-------- Original message --------
From: "Harry Rudolph via groups.io" <hgrudolphs@...>
Date: 8/10/20 7:38 PM (GMT-05:00)
To: Elecraft-K3@groups.io
Subject: [Elecraft-K3] K3 Receive Function Attenuated Immediately After Transmission

Was playing around in the WAE CW contest this past weekend and began to experience some problems with the receive function.  I believe I ran into this on several bands but I was mostly on 20 meters so this is where I mostly experienced the condition.  The performance issue was that immediately following a transmission, perhaps in about 10% of the instances, the receive function would come back sounding as if the attenuator was on.  Usually if I added a quick "dit" it would return to the normal receive level.  I fooled around with the AGC which had no effect.  I changed from Ant 1 input to Ant 2 input with no effect.  If I switched to the RX antenna input, it seemed normal.  I was running with a Microham MK II interface and with an amp but did not see any indication that the problem was related to the overall setup, including the antenna.

Curiously, I switched to a different K3 and initially the problem seemed to be resolved.  But after a few more hours of operation, I noticed that I did actually have the problem with the replacement  but just at a much lower frequency.

Anyone experience anything like this or have any suggestions?  I plan to do some more A/B comparisons and take the MK II and amp out of the equation but wanted to see if anyone else has run into this.

Thanks.

Harry
WX8C


Re: K3 Receive Function Attenuated Immediately After Transmission

 

The times I encountered this, the problem was in the linear T/R relay.

Solution: check/replace relay   or    Do some CW with QSK at normal power. Sometimes long strings of dots will have a sort of cleaning effect on the relay contacts.

73,

Arie PA3A

Op 11-8-2020 om 01:38 schreef Harry Rudolph via groups.io:



Anyone experience anything like this or have any suggestions?  I plan to do some more A/B comparisons and take the MK II and amp out of the equation but wanted to see if anyone else has run into this.

Thanks.

Harry
WX8C


K3 Receive Function Attenuated Immediately After Transmission

Harry WX8C
 

Was playing around in the WAE CW contest this past weekend and began to experience some problems with the receive function.  I believe I ran into this on several bands but I was mostly on 20 meters so this is where I mostly experienced the condition.  The performance issue was that immediately following a transmission, perhaps in about 10% of the instances, the receive function would come back sounding as if the attenuator was on.  Usually if I added a quick "dit" it would return to the normal receive level.  I fooled around with the AGC which had no effect.  I changed from Ant 1 input to Ant 2 input with no effect.  If I switched to the RX antenna input, it seemed normal.  I was running with a Microham MK II interface and with an amp but did not see any indication that the problem was related to the overall setup, including the antenna.

Curiously, I switched to a different K3 and initially the problem seemed to be resolved.  But after a few more hours of operation, I noticed that I did actually have the problem with the replacement  but just at a much lower frequency.

Anyone experience anything like this or have any suggestions?  I plan to do some more A/B comparisons and take the MK II and amp out of the equation but wanted to see if anyone else has run into this.

Thanks.

Harry
WX8C


Re: WSJT-X audio problems

Bob McGraw - K4TAX
 

Reduce power to 10 - 20 watts and see if it happens. If not, it most likely is a RF problem that appears at higher power. Add 2 or 3 clamp-on ferrite chokes to the cables between the radio and computer.

Bob, K4TAX


Re: KPA3 output erratic

Bob McGraw - K4TAX
 

Power distribution strips will always add series resistance of some value. Likewise, it is strongly suggested one connect the radio power leads directly to the power supply terminals.

In-line fuses will always add series resistance and likewise for any in-line switch. Remember E = I x R? Therefore, any value of series R will cause a voltage drop, E, with the TX current of the radio.

Bob, K4TAX


Re: KPA3 output erratic

mikerodgerske5gbc
 

Lou, I thought it was where did it read the voltage?  

Maybe not. 

Mike R

7!
Absolutely Awesome 


Re: KPA500, Win4K3, and DDU

Bill Mader
 

Apparently, the DDU design requires it to querry the KPA500, according to your description.  That design doesn't consider how many, if not most, KPA500's and KAT500's are connected to logging or other programs and what a second RS-232 transmitter will do to that communications.  I am glad to know this is how these work and sorry for your predicament Mike.

73, Bill, K8TE


Re: KPA3 output erratic

Ed Pflueger
 

Push the DISP button and turn the VFO B knob until you see the voltage.

 

Ed.. AB4IQ

 

From: Elecraft-K3@groups.io [mailto:Elecraft-K3@groups.io] On Behalf Of KE1F Lou
Sent: Monday, August 10, 2020 8:41 AM
To: Elecraft-K3@groups.io
Subject: Re: [Elecraft-K3] KPA3 output erratic

 

I have similar issues.

Where is the internal K3 Volt meter measures the voltage?

Lou KE1F 

 

 

 

Sent from my Galaxy Tab® A

 

-------- Original message --------

From: Brian K0DTJ <huntinhmb@...>

Date: 8/10/20 12:12 AM (GMT-05:00)

Subject: Re: [Elecraft-K3] KPA3 output erratic

 

Hi Chuck,
I would say that 1.2v is excessive.  I started out with the 60 inch or so #12 Elecraft standard power lead and had a slow power hunting problem.  It varied by band but each time I changed the power setting or bands it go to max and then drop down and slowly come to set power.  The power calibration ran OK but didn't solve the problem.

I changed to about 3 ft of #10 stranded automotive wire in a twisted pair setup.  I set the RS-35A Astron supply to about 14.2v.  With that I get 14v at the K3 on receive and 13.3v on transmit at 100w (80m).  Measuring the voltage at the PS under load I get less than 0.1v sag in the Astron regulator.  Then ran the K3 Utility TX gain calibration _twice_ and all is OK now.

Note, in all cases the high current K3 power lead was connected directly to the Astron terminals, not though the RigRunner I use for low current 12v distribution in the shack.

Hope this helps.  Good luck.

73,
Brian, K0DTJ

On 8/9/2020 16:23, Chuck Miller wrote:

What amount of sag is useable? I removed the inline fuse from the power cable, and cranked the 35 amp Astron up to 14.2 volt according to the K3. It drops to 13 volts at 100w watts. The power cable is about 6 feet long as the Astron is a rack mount, and sits on the floor. The power is slow to rise mostly on 160 and 80, and to a less amount on 60 meters. 30 meters and up don't have that lagging power. Still got to check all my coax jumpers
.
73, Chuck
N0NC

 


Re: KPA3 output erratic

KE1F Lou
 

I have similar issues.
Where is the internal K3 Volt meter measures the voltage?
Lou KE1F 



Sent from my Galaxy Tab® A

-------- Original message --------
From: Brian K0DTJ <huntinhmb@...>
Date: 8/10/20 12:12 AM (GMT-05:00)
To: Elecraft-K3@groups.io
Subject: Re: [Elecraft-K3] KPA3 output erratic

Hi Chuck,
I would say that 1.2v is excessive.  I started out with the 60 inch or so #12 Elecraft standard power lead and had a slow power hunting problem.  It varied by band but each time I changed the power setting or bands it go to max and then drop down and slowly come to set power.  The power calibration ran OK but didn't solve the problem.

I changed to about 3 ft of #10 stranded automotive wire in a twisted pair setup.  I set the RS-35A Astron supply to about 14.2v.  With that I get 14v at the K3 on receive and 13.3v on transmit at 100w (80m).  Measuring the voltage at the PS under load I get less than 0.1v sag in the Astron regulator.  Then ran the K3 Utility TX gain calibration _twice_ and all is OK now.

Note, in all cases the high current K3 power lead was connected directly to the Astron terminals, not though the RigRunner I use for low current 12v distribution in the shack.

Hope this helps.  Good luck.

73,
Brian, K0DTJ

On 8/9/2020 16:23, Chuck Miller wrote:
What amount of sag is useable? I removed the inline fuse from the power cable, and cranked the 35 amp Astron up to 14.2 volt according to the K3. It drops to 13 volts at 100w watts. The power cable is about 6 feet long as the Astron is a rack mount, and sits on the floor. The power is slow to rise mostly on 160 and 80, and to a less amount on 60 meters. 30 meters and up don't have that lagging power. Still got to check all my coax jumpers
.
73, Chuck
N0NC


Re: KPA3 output erratic

Brian K0DTJ
 

Hi Chuck,
I would say that 1.2v is excessive.  I started out with the 60 inch or so #12 Elecraft standard power lead and had a slow power hunting problem.  It varied by band but each time I changed the power setting or bands it go to max and then drop down and slowly come to set power.  The power calibration ran OK but didn't solve the problem.

I changed to about 3 ft of #10 stranded automotive wire in a twisted pair setup.  I set the RS-35A Astron supply to about 14.2v.  With that I get 14v at the K3 on receive and 13.3v on transmit at 100w (80m).  Measuring the voltage at the PS under load I get less than 0.1v sag in the Astron regulator.  Then ran the K3 Utility TX gain calibration _twice_ and all is OK now.

Note, in all cases the high current K3 power lead was connected directly to the Astron terminals, not though the RigRunner I use for low current 12v distribution in the shack.

Hope this helps.  Good luck.

73,
Brian, K0DTJ

On 8/9/2020 16:23, Chuck Miller wrote:
What amount of sag is useable? I removed the inline fuse from the power cable, and cranked the 35 amp Astron up to 14.2 volt according to the K3. It drops to 13 volts at 100w watts. The power cable is about 6 feet long as the Astron is a rack mount, and sits on the floor. The power is slow to rise mostly on 160 and 80, and to a less amount on 60 meters. 30 meters and up don't have that lagging power. Still got to check all my coax jumpers
.
73, Chuck
N0NC


WSJT-X audio problems

Richard Lawn
 

Since the last Windows 10 update I've been having erratic audio issues with WSJT=X and my K3. When I try to initiate transmit on WSJT the K3 goes into transmit and there is a brief sign of RF on the radio but suddenly an error message regarding audio pops up in WSJT-X. Audio is set correctly and I've checked the output from the computer and it is correct. 

I set up FlDigi and expected to see the same results and I did not. It works fine. So I'm beginning to suspect a problem with WSJT-X. Maybe I should just uninstall it and reinstall. Anyone else experience this problem withe their K3 with WSJT-X?

Rick, W2JAZ


Re: KPA3 output erratic

Chuck Miller
 

Yep, I tested it with 2 different dummy loads, acts the same way on both. One in the MFJ tuner, and a cantenna.

Thanks, and 73
Chuck
N0NC


Re: KPA3 output erratic

mikerodgerske5gbc
 

I guess your running D.C. Straight from the astron to the k3 which is preferred. 

73
Mike R

7!
Absolutely Awesome 


Re: KPA3 output erratic

Ray Maxfield
 

Have  you tested it with a Dummy Load ?

Ray  WA6VAB

 

From: Chuck Miller
Sent: Sunday, August 9, 2020 4:23 PM
To: Elecraft-K3@groups.io
Subject: Re: [Elecraft-K3] KPA3 output erratic

 

What amount of sag is useable? I removed the inline fuse from the power cable, and cranked the 35 amp Astron up to 14.2 volt according to the K3. It drops to 13 volts at 100w watts. The power cable is about 6 feet long as the Astron is a rack mount, and sits on the floor. The power is slow to rise mostly on 160 and 80, and to a less amount on 60 meters. 30 meters and up don't have that lagging power. Still got to check all my coax jumpers
.
73, Chuck
N0NC

 


Re: KPA3 output erratic

Chuck Miller
 

What amount of sag is useable? I removed the inline fuse from the power cable, and cranked the 35 amp Astron up to 14.2 volt according to the K3. It drops to 13 volts at 100w watts. The power cable is about 6 feet long as the Astron is a rack mount, and sits on the floor. The power is slow to rise mostly on 160 and 80, and to a less amount on 60 meters. 30 meters and up don't have that lagging power. Still got to check all my coax jumpers
.
73, Chuck
N0NC


Re: KPA500, Win4K3, and DDU

w3qt_mike
 

That's the problem, Bob.  I need 2 physical ports and only have one on the KPA500.  (Labeled RS232 (PC)).  Before I went with the DDU I had the amp connected to the PC through this port and then everything (DXLab Suite, K3s, KPA500, KAT500) controlled via Win4K3.  The DDU must be connected to the KPA500 port for polling, meaning I'm now short the port for connecting the amp to the PC.   Am I missing someting?

73, Mike, W3QT

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