Elecraft

K3 VSWR Meter Calibration

Classic

List

Threaded

6 messages Options

Ramon Tristani-2

K3 VSWR Meter Calibration

Banned User

The VSWR indication in my K3 seems to be off considerably when connected to a 50 ohm dummy load. An external VSWR meter indicates 1:1 while the K3 most of the time indicates readings varying up to 2:1 at times. I am using the same short coax stub to connect the instruments one at a time to eliminate other possibilities. Is there a way to “calibrate” the VSWR indicator in the K3? My K3 is serial number 4416. The Auto Tuner in it works fine and reduces the indication to 1:1 as it is supposed to but when bypassing it the VSWR indication will always be off. Any suggestions?

Ramón E. Tristani Sr.
[hidden email] <mailto:[hidden email]>
https://www.flickr.com/photos/nq9v/ <https://www.flickr.com/photos/nq9v/>
www.tristaniministries.org <http://www.tristaniministries.org/>
www.tristaniphotography.com <http://www.tristaniphotography.com/>
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to [hidden email]

Don Wilhelm

Re: K3 VSWR Meter Calibration

Ramon,

There is a calibration procedure in the manual to calibrate the
wattmeter for forward power, but not for SWR.
I suggest you contact K3support for further assistance.

73,
Don W3FPR

On 5/6/2016 11:50 AM, Ramon Tristani wrote:
> The VSWR indication in my K3 seems to be off considerably when connected to a 50 ohm dummy load. An external VSWR meter indicates 1:1 while the K3 most of the time indicates readings varying up to 2:1 at times. I am using the same short coax stub to connect the instruments one at a time to eliminate other possibilities. Is there a way to “calibrate” the VSWR indicator in the K3? My K3 is serial number 4416. The Auto Tuner in it works fine and reduces the indication to 1:1 as it is supposed to but when bypassing it the VSWR indication will always be off. Any suggestions?
>

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to [hidden email]

Eric Swartz - WA6HHQ

Re: K3 VSWR Meter Calibration

Administrator

Is the K3 ATU in bypass?

Eric
/elecraft.com/

On 5/6/2016 11:26 AM, Don Wilhelm wrote:

> Ramon,
>
> There is a calibration procedure in the manual to calibrate the wattmeter for
> forward power, but not for SWR.
> I suggest you contact K3support for further assistance.
>
> 73,
> Don W3FPR
>
> On 5/6/2016 11:50 AM, Ramon Tristani wrote:
>> The VSWR indication in my K3 seems to be off considerably when connected to a
>> 50 ohm dummy load. An external VSWR meter indicates 1:1 while the K3 most of
>> the time indicates readings varying up to 2:1 at times. I am using the same
>> short coax stub to connect the instruments one at a time to eliminate other
>> possibilities. Is there a way to “calibrate” the VSWR indicator in the K3? My
>> K3 is serial number 4416. The Auto Tuner in it works fine and reduces the
>> indication to 1:1 as it is supposed to but when bypassing it the VSWR
>> indication will always be off. Any suggestions?
>>
>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to [hidden email]

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to [hidden email]

Ramon Tristani-2

Re: K3 VSWR Meter Calibration

Banned User

Yes, I performed tests with and without the ATU in the circuit. Howard, from Elecraft Support contacted me off the list and requested information that I just sent to him.

Thank you,
Ramon, NQ9V

Ramón E. Tristani Sr.
[hidden email] <mailto:[hidden email]>
https://www.flickr.com/photos/nq9v/ <https://www.flickr.com/photos/nq9v/>
www.tristaniministries.org <http://www.tristaniministries.org/>
www.tristaniphotography.com <http://www.tristaniphotography.com/>

> On May 6, 2016, at 3:06 PM, Eric Swartz - WA6HHQ, Elecraft <[hidden email]> wrote:
>
> Is the K3 ATU in bypass?
>
> Eric
> elecraft.com
>
> On 5/6/2016 11:26 AM, Don Wilhelm wrote:
>> Ramon,
>>
>> There is a calibration procedure in the manual to calibrate the wattmeter for forward power, but not for SWR.
>> I suggest you contact K3support for further assistance.
>>
>> 73,
>> Don W3FPR
>>
>> On 5/6/2016 11:50 AM, Ramon Tristani wrote:
>>> The VSWR indication in my K3 seems to be off considerably when connected to a 50 ohm dummy load. An external VSWR meter indicates 1:1 while the K3 most of the time indicates readings varying up to 2:1 at times. I am using the same short coax stub to connect the instruments one at a time to eliminate other possibilities. Is there a way to “calibrate” the VSWR indicator in the K3? My K3 is serial number 4416. The Auto Tuner in it works fine and reduces the indication to 1:1 as it is supposed to but when bypassing it the VSWR indication will always be off. Any suggestions?
>>>
>>
>> ______________________________________________________________
>> Elecraft mailing list
>> Home: http://mailman.qth.net/mailman/listinfo/elecraft <http://mailman.qth.net/mailman/listinfo/elecraft>
>> Help: http://mailman.qth.net/mmfaq.htm <http://mailman.qth.net/mmfaq.htm>
>> Post: mailto:[hidden email] <mailto:[hidden email]>
>>
>> This list hosted by: http://www.qsl.net <http://www.qsl.net/>
>> Please help support this email list: http://www.qsl.net/donate.html <http://www.qsl.net/donate.html>
>> Message delivered to [hidden email] <mailto:[hidden email]>
>

Ramon Tristani-2

Re: K3 VSWR Meter Calibration

Banned User

Eric;

Here’s what I submitted to Howard from Elecraft a few minutes ago:

Howard:

I performed the tests using an MFJ Model 260C Dummy Load with less that a foot of RG-58 coax to the Antenna 1 output of the K3. Here are the results you requested:

Freq. 3930 KHz
Tuner bypassed: VSWR=1:1
Auto Tuner engaged: VSWR = 1.1

Freq. 7200 KHz
Tuner bypassed: 1.1
Tuner engaged: 1.0

Freq. 10100 KHz
Tuner bypassed: 1.1
Tuner engaged: 1.0

Freq. 14200 KHz
Tuner bypassed: 1.1
Tuner engaged: 1.0

Freq. 18120
Tuner bypassed: 1.2
Tuner engaged: 1.0

Freq. 21200 KHz
Tuner bypassed: 1.3
Tuner engaged: 1.1

Freq. 24950 KHz
Tuner bypassed: 1.4
Tuner engaged: 1.0

Freq. 28300 KHz
Tuner bypassed: 1.7
Tuner engaged: 1.1

Freq. 50100 KHz
Tuner bypassed: 1.1
Tuner engaged: 1.1

I repeated the tests above with the same stub of coax, same dummy load but in series with the wattmeter in a Palstar AT2KD. The indication on the Palstar was always 1.0 VSWR with the K3 tuner in bypass mode in all tests. Power level for measurements was 15 watts in all cases. The MCU in my K3 is 05.38, FPF is 1.25, DSP1 is 2.86. Please update my records from KP4GE to my new callsign: NQ9V. My K3 and P3 have been performing flawlessly until I noticed the variation in the VSWR display. I also ran the transmitter gain calibration this morning using the same dummy load.

Here is the transmitter calibration summary:

K3 Tx Gain Calibration data written on 2016-05-06 at 16:22:43
K3 Serial Number 04416
K3 MCU revision 05.38. RS-232 speed 38400 bit/s.
Elecraft K3 Utility Revision 1.15.12.7
1900 kHz TxGain LP 15
3750 kHz TxGain LP 11
5336 kHz TxGain LP 18
7150 kHz TxGain LP 14
10125 kHz TxGain LP 18
14200 kHz TxGain LP 08
18110 kHz TxGain LP 08
21200 kHz TxGain LP 05
24930 kHz TxGain LP 07
29000 kHz TxGain LP 07
52000 kHz TxGain LP 10
1900 kHz TxGain HP 25
3750 kHz TxGain HP 30
5336 kHz TxGain HP 48
7150 kHz TxGain HP 36
10125 kHz TxGain HP 36
14200 kHz TxGain HP 16
18110 kHz TxGain HP 11
21200 kHz TxGain HP 05
24930 kHz TxGain HP 03
29000 kHz TxGain HP 08
52000 kHz TxGain HP 04

Ramón E. Tristani Sr.
[hidden email] <mailto:[hidden email]>
https://www.flickr.com/photos/nq9v/ <https://www.flickr.com/photos/nq9v/>
www.tristaniministries.org <http://www.tristaniministries.org/>
www.tristaniphotography.com <http://www.tristaniphotography.com/>

> On May 6, 2016, at 5:10 PM, Ramon Tristani <[hidden email]> wrote:
>
> Yes, I performed tests with and without the ATU in the circuit. Howard, from Elecraft Support contacted me off the list and requested information that I just sent to him.
>
> Thank you,
> Ramon, NQ9V
>
>
> Ramón E. Tristani Sr.
> [hidden email] <mailto:[hidden email]>
> https://www.flickr.com/photos/nq9v/ <https://www.flickr.com/photos/nq9v/>
> www.tristaniministries.org <http://www.tristaniministries.org/>
> www.tristaniphotography.com <http://www.tristaniphotography.com/>
>> On May 6, 2016, at 3:06 PM, Eric Swartz - WA6HHQ, Elecraft <[hidden email] <mailto:[hidden email]>> wrote:
>>
>> Is the K3 ATU in bypass?
>>
>> Eric
>> elecraft.com <http://elecraft.com/>
>>
>> On 5/6/2016 11:26 AM, Don Wilhelm wrote:
>>> Ramon,
>>>
>>> There is a calibration procedure in the manual to calibrate the wattmeter for forward power, but not for SWR.
>>> I suggest you contact K3support for further assistance.
>>>
>>> 73,
>>> Don W3FPR
>>>
>>> On 5/6/2016 11:50 AM, Ramon Tristani wrote:
>>>> The VSWR indication in my K3 seems to be off considerably when connected to a 50 ohm dummy load. An external VSWR meter indicates 1:1 while the K3 most of the time indicates readings varying up to 2:1 at times. I am using the same short coax stub to connect the instruments one at a time to eliminate other possibilities. Is there a way to “calibrate” the VSWR indicator in the K3? My K3 is serial number 4416. The Auto Tuner in it works fine and reduces the indication to 1:1 as it is supposed to but when bypassing it the VSWR indication will always be off. Any suggestions?
>>>>
>>>
>>> ______________________________________________________________
>>> Elecraft mailing list
>>> Home: http://mailman.qth.net/mailman/listinfo/elecraft <http://mailman.qth.net/mailman/listinfo/elecraft>
>>> Help: http://mailman.qth.net/mmfaq.htm <http://mailman.qth.net/mmfaq.htm>
>>> Post: mailto:[hidden email] <mailto:[hidden email]>
>>>
>>> This list hosted by: http://www.qsl.net <http://www.qsl.net/>
>>> Please help support this email list: http://www.qsl.net/donate.html <http://www.qsl.net/donate.html>
>>> Message delivered to [hidden email] <mailto:[hidden email]>
>>
>

Nr4c

Re: K3 VSWR Meter Calibration

In reply to this post by Ramon Tristani-2

I don't think the "bypass" in the KAT3 is a true bypass. It sets a "solution" which should be equivalent to a bypass.

The new KAT3a has a true "bypass" relay.

Sent from my iPhone
...nr4c. bill

> On May 6, 2016, at 11:50 AM, Ramon Tristani <[hidden email]> wrote:
>
> The VSWR indication in my K3 seems to be off considerably when connected to a 50 ohm dummy load. An external VSWR meter indicates 1:1 while the K3 most of the time indicates readings varying up to 2:1 at times. I am using the same short coax stub to connect the instruments one at a time to eliminate other possibilities. Is there a way to “calibrate” the VSWR indicator in the K3? My K3 is serial number 4416. The Auto Tuner in it works fine and reduces the indication to 1:1 as it is supposed to but when bypassing it the VSWR indication will always be off. Any suggestions?
>
>
> Ramón E. Tristani Sr.
> [hidden email] <mailto:[hidden email]>
> https://www.flickr.com/photos/nq9v/ <https://www.flickr.com/photos/nq9v/>
> www.tristaniministries.org <http://www.tristaniministries.org/>
> www.tristaniphotography.com <http://www.tristaniphotography.com/>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to [hidden email]