Date   

Re: To much output power?

Wes Stewart
 


 It's funny (curious) that I referenced this three year old conversation just a couple of days ago. http://elecraft.365791.n2.nabble.com/K3-SWR-Numerical-Indication-td7643839.html

If you muddle through this you can see my comments, which address SWR uncertainties, but are somewhat applicable to this conversation because the same hardware is involved. The essence of this is that there are many sources of error in these measurements and we (you guys) are arguing about differences of 85 to 100 watts.  I don't know if anyone else bothered to compute this in dB, but I did and it's 0.7 dB.

That's a pretty small number to be generating all of this anguish,

Wes  N7WS


On Mon, Jun 14, 2021 at 01:24 PM, Larry wrote:

I have an LP-100A here as well that i bought just a couple months back.  I see the same differences you are seeing but to me it has to do with the SWR it's seeing.  I also run my K3 at 85W out.  My best band is 30M with an inverted V ant.  I typically see an SWR of 1:13:1 on that band and the LP100A shows close to 90W out with the K3 running 85W.  If i go up to 20M where i have a 4 El yagi  that's about 130 ft from the shack, i typically see around 100W out on the LP-100A  with 85 watts out of the K3.

Other bands like 15, 10, 40M i still run the K3 at 85W but the output showing on the LP-100A varies due to the SWR of the antenna.

Right or not that's the way it is.

Larry W0OGH

 

On 6/14/2021 10:09 AM, Russ Tobolic via groups.io wrote:

After reading this thread I decided to finally look into the power output issues I have had over the last year or so in which the readings on my LP100 were always 10 -15 W higher than the display on the K3. I had been setting the output on the K3 to 85W to to get 100 on the LP100. Reading WE6R's comment on early failures of D36 and D37, I replaced them both on my vintage 2008 ser. #732 with new BAS70's. However when I run the TX gain calibration I now always get a ERR TXG at 14.2MHz as shown:

 

Elecraft K3 Utility Version 1.20.1.15

OS Version 10.0 Build 19042

K3 MCU version 05.57 on COM4 at 38400 bit/s

Starting 5 watt calibration

Calibrating at 1.900 MHz

Calibrating at 3.750 MHz

Calibrating at 5.336 MHz

Calibrating at 7.150 MHz

Calibrating at 10.125 MHz

Calibrating at 14.200 MHz

TX Gain calibration failed because transmit power did not reach the expected value

5 watt calibration failed

Elapsed time: 30 seconds

 

I also noted that during the test run at 5W, the LP100 would always indicate around 6.1W, but that may be because I haven't calibrated the internal wattmeter. I read elsewhere where someone having similar problems on 12M readjusted some trimmers in the BP filter and it fixed the problem at least temporarily. Before I start “tweaking” things are is there something else I should be looking at?

 

Russ, N3CO


Re: K3s and DXL Commander or N1MM+

Jim Denneny
 

What is history/reliability of KIO3B I/O board.  I am beginning to believe mine has suffered a partial / full  failure??

Jim K7EG


K3s and DXL Commander or N1MM+

Jim Denneny
 

I am having an I/O communication issue  with DXL Commander, N1MM+ etc.  Cable is not issue. Connection is over Com 8 using FTDI driver.  PC says COM8 is working OK.

Here are the symptoms:

1. K3s / Commander Commander is receiving VFO A data but not mode. I must enter mode manually into Commander.  Commander cannot control K3s. Commander does not read VFO B. I have tried several baud rates and polling rates.

2. N1MM+ cannot discover radio at all.

Hard to imagine K3 I/O board failed. Has anyone experienced that? If it were Windows port failure, OS would tell me port failed.

In short I am totally stumped

Jim


Re: USB rig control

W2XJ
 

Fine, but I was responding to Colon.

On June 14, 2021 3:04 PM Joe Subich, W4TV <lists@subich.com> wrote:


On 2021-06-13 7:07 PM, W2XJ wrote:
> There is no carrier in the ATSC signal, just a low level pilot.

I said, "Analog UHF TV" ... in case you have forgotten analog TV
that is NTSC (not ATSC) and was vestigial sideband *with carrier*.

73,

... Joe, W4TV


On 2021-06-13 7:07 PM, W2XJ wrote:

There is no carrier in the ATSC signal, just a low level pilot.




On June 13, 2021 6:30 PM Colin Smithers <colin@crsmithers.com> wrote:


It can only re-appear if carrier is present for the wanted sideband to mix with in the non-linear amplifier.

In an SSB transmitter with good carrier suppression it is not possible to regenerate the unwanted sideband through poor IMD in the final stages. In my experience the K3 has negligible carrier content. Given that, It would require an inappropriate TX filter or TX filter adjustment for the unwanted sideband to truly be present.

I think in TV transmitters there is still carrier present.

73, Colin G4CWH

-----Original Message-----
From: Elecraft-K3@groups.io <Elecraft-K3@groups.io> On Behalf Of Joe Subich, W4TV via groups.io
Sent: Sunday, June 13, 2021 10:13 PM
To: Elecraft-K3@groups.io
Subject: Re: [Elecraft-K3] USB rig control


On 2021-06-13 4:45 PM, Lou W7HV via groups.io wrote:
Subsequent distortion in the rig or external amplifier can broaden
> that signal but can't create and add back the opposite side band.

Au contraire! IMD in amplifier stages *will* regenerate the missing
sideband. I saw with my own eyes (spectrum analyzer) in the days of
analog UHF TV ... in "high efficiency" Klystrode/IOT amplifiers. It
was necessary to do significant precorrection (early "Pure Signal")
to prevent the lower sideband from exceeding the "spectral mask"
requirements for protecting the next lower channel.

73,

... Joe, W4TV


On 2021-06-13 4:45 PM, Lou W7HV via groups.io wrote:
I am not a well known engineer and certainly not a respected engineer.  It is my understanding that normal superhets produce SSB by mixing audio with the LO up to the IF where the unwanted sideband is stripped off by the same xtal filters used for RX.  This is fixed and doesn't change with TX band or frequency because mixing to the TX frequency occurs after that.  Subsequent distortion in the rig or external amplifier can broaden that signal but can't create and add back the opposite side band.  So, based on that, I would think if someone is hearing the opposite sideband, there's a problem with the rig unrelated to being used outside the ham bands.

Direct conversion rigs are another matter.

Perhaps a well known and respected engineer will weight in.




Re: [Elecraft] KAT3 (not KAT3A) issue - older K3 take note

Joe Subich, W4TV
 

On 2021-06-14 6:48 PM, jeff stai wk6i wrote:
hi Alan - Thank you, I have done those mods as well, but this one was
a surprise!
And to my knowledge, not documented anywhere other than the recent
mention on-line. I know that all of my KAT3 still have L10 and C10
installed (in what condition, I do not know).

73,

... Joe, W4TV


On 2021-06-14 6:48 PM, jeff stai wk6i wrote:
hi Alan - Thank you, I have done those mods as well, but this one was a
surprise! 73 jeff wk6i
On Mon, Jun 14, 2021 at 3:44 PM Alan Baker <g4gnx@g4gnx.com> wrote:

There's a whole stack of mods done over the years. They were on the
Elecraft website in pdf format. If you can't find them, I have all of
them here and have performed most of them on an older K3.

73,

Alan. G4GNX


------ Original Message ------
From: "Jeff Stai" <wk6i.jeff@gmail.com>
To: Elecraft-K3@groups.io; "Elecraft Mailer" <elecraft@mailman.qth.net>
Sent: 14/06/2021 22:36:08
Subject: [Elecraft] KAT3 (not KAT3A) issue - older K3 take note

TL;DR: Got a KAT3 in your K3? Next time you have your K3 open, pull out
KAT3 and preemptively remove L10 and C10, and replace with a jumper. You
don't need them and they are probably messing you up at times.

(Are there any other older K3 issues like this? Tell me!)

I have an early model K3 that still has all of its original modules. I was
having an issue where the power output was sometimes dropping to just a
few
watts.

Running the TX calibration would sometimes fail completely with weird
error
messages, but if I could get it to run it would get through most of the
way
but always fail on 52MHz due to high SWR (over 2). With a dummy load or a
matched antenna, SWR was over 2 also in normal operation.

Of course, this low power situation would magically correct itself after
some poking around, though the 52MHz high SWR was consistent.

I finally decided that I wanted to do some 6m operating and I used the
KAT3
to get matched to the load. I would just operate until something finally
decided to fail fully.

It did. After a few hours C10 on the KAT3 blew, LOUDLY and smokily.
Undoubtedly due to some crazy high voltages presented by the tuner.

After some sleuthing in the Elecraft reflector I found the C10/L10 filter
issue being well discussed. Pulling them out and jumpering solved all my
issues. With the K3, anyway. :)

This filter was not included in the KAT3A. If you have one of those,
you're
good. If you want to know more about the history of this filter it's easy
enough to find in the email archives. :)

Hope this helps - jeff wk6i






Re: [Elecraft] KAT3 (not KAT3A) issue - older K3 take note

jeff stai wk6i
 

hi Alan - Thank you, I have done those mods as well, but this one was a surprise! 73 jeff wk6i


On Mon, Jun 14, 2021 at 3:44 PM Alan Baker <g4gnx@...> wrote:
There's a whole stack of mods done over the years. They were on the
Elecraft website in pdf format. If you can't find them, I have all of
them here and have performed most of them on an older K3.

73,

Alan. G4GNX


------ Original Message ------
From: "Jeff Stai" <wk6i.jeff@...>
To: Elecraft-K3@groups.io; "Elecraft Mailer" <elecraft@...>
Sent: 14/06/2021 22:36:08
Subject: [Elecraft] KAT3 (not KAT3A) issue - older K3 take note

>TL;DR: Got a KAT3 in your K3? Next time you have your K3 open, pull out
>KAT3 and preemptively remove L10 and C10, and replace with a jumper. You
>don't need them and they are probably messing you up at times.
>
>(Are there any other older K3 issues like this? Tell me!)
>
>I have an early model K3 that still has all of its original modules. I was
>having an issue where the power output was sometimes dropping to just a few
>watts.
>
>Running the TX calibration would sometimes fail completely with weird error
>messages, but if I could get it to run it would get through most of the way
>but always fail on 52MHz due to high SWR (over 2). With a dummy load or a
>matched antenna, SWR was over 2 also in normal operation.
>
>Of course, this low power situation would magically correct itself after
>some poking around, though the 52MHz high SWR was consistent.
>
>I finally decided that I wanted to do some 6m operating and I used the KAT3
>to get matched to the load. I would just operate until something finally
>decided to fail fully.
>
>It did. After a few hours C10 on the KAT3 blew, LOUDLY and smokily.
>Undoubtedly due to some crazy high voltages presented by the tuner.
>
>After some sleuthing in the Elecraft reflector I found the C10/L10 filter
>issue being well discussed. Pulling them out and jumpering solved all my
>issues. With the K3, anyway. :)
>
>This filter was not included in the KAT3A. If you have one of those, you're
>good. If you want to know more about the history of this filter it's easy
>enough to find in the email archives. :)
>
>Hope this helps - jeff wk6i
>








--
Jeff Stai ~ WK6I ~ wk6i.jeff@...
RTTY op at W7RN
Twisted Oak Winery ~ http://www.twistedoak.com/


Re: [Elecraft] KAT3 (not KAT3A) issue - older K3 take note

Alan Baker - G4GNX
 

There's a whole stack of mods done over the years. They were on the Elecraft website in pdf format. If you can't find them, I have all of them here and have performed most of them on an older K3.

73,

Alan. G4GNX

------ Original Message ------
From: "Jeff Stai" <wk6i.jeff@gmail.com>
To: Elecraft-K3@groups.io; "Elecraft Mailer" <elecraft@mailman.qth.net>
Sent: 14/06/2021 22:36:08
Subject: [Elecraft] KAT3 (not KAT3A) issue - older K3 take note

TL;DR: Got a KAT3 in your K3? Next time you have your K3 open, pull out
KAT3 and preemptively remove L10 and C10, and replace with a jumper. You
don't need them and they are probably messing you up at times.

(Are there any other older K3 issues like this? Tell me!)

I have an early model K3 that still has all of its original modules. I was
having an issue where the power output was sometimes dropping to just a few
watts.

Running the TX calibration would sometimes fail completely with weird error
messages, but if I could get it to run it would get through most of the way
but always fail on 52MHz due to high SWR (over 2). With a dummy load or a
matched antenna, SWR was over 2 also in normal operation.

Of course, this low power situation would magically correct itself after
some poking around, though the 52MHz high SWR was consistent.

I finally decided that I wanted to do some 6m operating and I used the KAT3
to get matched to the load. I would just operate until something finally
decided to fail fully.

It did. After a few hours C10 on the KAT3 blew, LOUDLY and smokily.
Undoubtedly due to some crazy high voltages presented by the tuner.

After some sleuthing in the Elecraft reflector I found the C10/L10 filter
issue being well discussed. Pulling them out and jumpering solved all my
issues. With the K3, anyway. :)

This filter was not included in the KAT3A. If you have one of those, you're
good. If you want to know more about the history of this filter it's easy
enough to find in the email archives. :)

Hope this helps - jeff wk6i


KAT3 (not KAT3A) issue - older K3 take note

jeff stai wk6i
 

TL;DR: Got a KAT3 in your K3? Next time you have your K3 open, pull out KAT3 and preemptively remove L10 and C10, and replace with a jumper. You don't need them and they are probably messing you up at times.

(Are there any other older K3 issues like this? Tell me!)

I have an early model K3 that still has all of its original modules. I was having an issue where the power output was sometimes dropping to just a few watts.

Running the TX calibration would sometimes fail completely with weird error messages, but if I could get it to run it would get through most of the way but always fail on 52MHz due to high SWR (over 2). With a dummy load or a matched antenna, SWR was over 2 also in normal operation.

Of course, this low power situation would magically correct itself after some poking around, though the 52MHz high SWR was consistent.

I finally decided that I wanted to do some 6m operating and I used the KAT3 to get matched to the load. I would just operate until something finally decided to fail fully. 

It did. After a few hours C10 on the KAT3 blew, LOUDLY and smokily. Undoubtedly due to some crazy high voltages presented by the tuner. 

After some sleuthing in the Elecraft reflector I found the C10/L10 filter issue being well discussed. Pulling them out and jumpering solved all my issues. With the K3, anyway. :)

This filter was not included in the KAT3A. If you have one of those, you're good. If you want to know more about the history of this filter it's easy enough to find in the email archives. :)

Hope this helps - jeff wk6i

--
Jeff Stai ~ WK6I ~ wk6i.jeff@...
RTTY op at W7RN
Twisted Oak Winery ~ http://www.twistedoak.com/


Re: To much output power?

Larry
 

I have an LP-100A here as well that i bought just a couple months back.  I see the same differences you are seeing but to me it has to do with the SWR it's seeing.  I also run my K3 at 85W out.  My best band is 30M with an inverted V ant.  I typically see an SWR of 1:13:1 on that band and the LP100A shows close to 90W out with the K3 running 85W.  If i go up to 20M where i have a 4 El yagi  that's about 130 ft from the shack, i typically see around 100W out on the LP-100A  with 85 watts out of the K3.

Other bands like 15, 10, 40M i still run the K3 at 85W but the output showing on the LP-100A varies due to the SWR of the antenna.

Right or not that's the way it is.

Larry W0OGH


On 6/14/2021 10:09 AM, Russ Tobolic via groups.io wrote:

After reading this thread I decided to finally look into the power output issues I have had over the last year or so in which the readings on my LP100 were always 10 -15 W higher than the display on the K3. I had been setting the output on the K3 to 85W to to get 100 on the LP100. Reading WE6R's comment on early failures of D36 and D37, I replaced them both on my vintage 2008 ser. #732 with new BAS70's. However when I run the TX gain calibration I now always get a ERR TXG at 14.2MHz as shown:

 

Elecraft K3 Utility Version 1.20.1.15

OS Version 10.0 Build 19042

K3 MCU version 05.57 on COM4 at 38400 bit/s

Starting 5 watt calibration

Calibrating at 1.900 MHz

Calibrating at 3.750 MHz

Calibrating at 5.336 MHz

Calibrating at 7.150 MHz

Calibrating at 10.125 MHz

Calibrating at 14.200 MHz

TX Gain calibration failed because transmit power did not reach the expected value

5 watt calibration failed

Elapsed time: 30 seconds

 

I also noted that during the test run at 5W, the LP100 would always indicate around 6.1W, but that may be because I haven't calibrated the internal wattmeter. I read elsewhere where someone having similar problems on 12M readjusted some trimmers in the BP filter and it fixed the problem at least temporarily. Before I start “tweaking” things are is there something else I should be looking at?

 

Russ, N3CO


Re: To much output power?

Colin Smithers
 

Russ,

 

The K3 displaying 85W but outputting 100W is in line with my experience after measuring three K3s using a lab standard power meter.

 

I can’t comment beyond that.

 

73, Colin Smithers G4CWH

 

From: Elecraft-K3@groups.io <Elecraft-K3@groups.io> On Behalf Of Russ Tobolic via groups.io
Sent: Monday, June 14, 2021 6:10 PM
To: Elecraft-K3@groups.io
Subject: Re: [Elecraft-K3] To much output power?

 

After reading this thread I decided to finally look into the power output issues I have had over the last year or so in which the readings on my LP100 were always 10 -15 W higher than the display on the K3. I had been setting the output on the K3 to 85W to to get 100 on the LP100. Reading WE6R's comment on early failures of D36 and D37, I replaced them both on my vintage 2008 ser. #732 with new BAS70's. However when I run the TX gain calibration I now always get a ERR TXG at 14.2MHz as shown:

 

Elecraft K3 Utility Version 1.20.1.15

OS Version 10.0 Build 19042

K3 MCU version 05.57 on COM4 at 38400 bit/s

Starting 5 watt calibration

Calibrating at 1.900 MHz

Calibrating at 3.750 MHz

Calibrating at 5.336 MHz

Calibrating at 7.150 MHz

Calibrating at 10.125 MHz

Calibrating at 14.200 MHz

TX Gain calibration failed because transmit power did not reach the expected value

5 watt calibration failed

Elapsed time: 30 seconds

 

I also noted that during the test run at 5W, the LP100 would always indicate around 6.1W, but that may be because I haven't calibrated the internal wattmeter. I read elsewhere where someone having similar problems on 12M readjusted some trimmers in the BP filter and it fixed the problem at least temporarily. Before I start “tweaking” things are is there something else I should be looking at?

 

Russ, N3CO


Re: USB rig control

Joe Subich, W4TV
 

On 2021-06-13 7:07 PM, W2XJ wrote:
There is no carrier in the ATSC signal, just a low level pilot.
I said, "Analog UHF TV" ... in case you have forgotten analog TV
that is NTSC (not ATSC) and was vestigial sideband *with carrier*.

73,

... Joe, W4TV


On 2021-06-13 7:07 PM, W2XJ wrote:
There is no carrier in the ATSC signal, just a low level pilot.

On June 13, 2021 6:30 PM Colin Smithers <colin@crsmithers.com> wrote:


It can only re-appear if carrier is present for the wanted sideband to mix with in the non-linear amplifier.

In an SSB transmitter with good carrier suppression it is not possible to regenerate the unwanted sideband through poor IMD in the final stages. In my experience the K3 has negligible carrier content. Given that, It would require an inappropriate TX filter or TX filter adjustment for the unwanted sideband to truly be present.

I think in TV transmitters there is still carrier present.

73, Colin G4CWH

-----Original Message-----
From: Elecraft-K3@groups.io <Elecraft-K3@groups.io> On Behalf Of Joe Subich, W4TV via groups.io
Sent: Sunday, June 13, 2021 10:13 PM
To: Elecraft-K3@groups.io
Subject: Re: [Elecraft-K3] USB rig control


On 2021-06-13 4:45 PM, Lou W7HV via groups.io wrote:
Subsequent distortion in the rig or external amplifier can broaden
> that signal but can't create and add back the opposite side band.

Au contraire! IMD in amplifier stages *will* regenerate the missing
sideband. I saw with my own eyes (spectrum analyzer) in the days of
analog UHF TV ... in "high efficiency" Klystrode/IOT amplifiers. It
was necessary to do significant precorrection (early "Pure Signal")
to prevent the lower sideband from exceeding the "spectral mask"
requirements for protecting the next lower channel.

73,

... Joe, W4TV


On 2021-06-13 4:45 PM, Lou W7HV via groups.io wrote:
I am not a well known engineer and certainly not a respected engineer.  It is my understanding that normal superhets produce SSB by mixing audio with the LO up to the IF where the unwanted sideband is stripped off by the same xtal filters used for RX.  This is fixed and doesn't change with TX band or frequency because mixing to the TX frequency occurs after that.  Subsequent distortion in the rig or external amplifier can broaden that signal but can't create and add back the opposite side band.  So, based on that, I would think if someone is hearing the opposite sideband, there's a problem with the rig unrelated to being used outside the ham bands.

Direct conversion rigs are another matter.

Perhaps a well known and respected engineer will weight in.


Re: To much output power?

Russ Tobolic
 

After reading this thread I decided to finally look into the power output issues I have had over the last year or so in which the readings on my LP100 were always 10 -15 W higher than the display on the K3. I had been setting the output on the K3 to 85W to to get 100 on the LP100. Reading WE6R's comment on early failures of D36 and D37, I replaced them both on my vintage 2008 ser. #732 with new BAS70's. However when I run the TX gain calibration I now always get a ERR TXG at 14.2MHz as shown:

 

Elecraft K3 Utility Version 1.20.1.15

OS Version 10.0 Build 19042

K3 MCU version 05.57 on COM4 at 38400 bit/s

Starting 5 watt calibration

Calibrating at 1.900 MHz

Calibrating at 3.750 MHz

Calibrating at 5.336 MHz

Calibrating at 7.150 MHz

Calibrating at 10.125 MHz

Calibrating at 14.200 MHz

TX Gain calibration failed because transmit power did not reach the expected value

5 watt calibration failed

Elapsed time: 30 seconds

 

I also noted that during the test run at 5W, the LP100 would always indicate around 6.1W, but that may be because I haven't calibrated the internal wattmeter. I read elsewhere where someone having similar problems on 12M readjusted some trimmers in the BP filter and it fixed the problem at least temporarily. Before I start “tweaking” things are is there something else I should be looking at?

 

Russ, N3CO


Re: USB rig control

W2XJ
 

There is no carrier in the ATSC signal, just a low level pilot.

On June 13, 2021 6:30 PM Colin Smithers <colin@crsmithers.com> wrote:


It can only re-appear if carrier is present for the wanted sideband to mix with in the non-linear amplifier.

In an SSB transmitter with good carrier suppression it is not possible to regenerate the unwanted sideband through poor IMD in the final stages. In my experience the K3 has negligible carrier content. Given that, It would require an inappropriate TX filter or TX filter adjustment for the unwanted sideband to truly be present.

I think in TV transmitters there is still carrier present.

73, Colin G4CWH

-----Original Message-----
From: Elecraft-K3@groups.io <Elecraft-K3@groups.io> On Behalf Of Joe Subich, W4TV via groups.io
Sent: Sunday, June 13, 2021 10:13 PM
To: Elecraft-K3@groups.io
Subject: Re: [Elecraft-K3] USB rig control


On 2021-06-13 4:45 PM, Lou W7HV via groups.io wrote:
Subsequent distortion in the rig or external amplifier can broaden
> that signal but can't create and add back the opposite side band.

Au contraire! IMD in amplifier stages *will* regenerate the missing
sideband. I saw with my own eyes (spectrum analyzer) in the days of
analog UHF TV ... in "high efficiency" Klystrode/IOT amplifiers. It
was necessary to do significant precorrection (early "Pure Signal")
to prevent the lower sideband from exceeding the "spectral mask"
requirements for protecting the next lower channel.

73,

... Joe, W4TV


On 2021-06-13 4:45 PM, Lou W7HV via groups.io wrote:
I am not a well known engineer and certainly not a respected engineer.  It is my understanding that normal superhets produce SSB by mixing audio with the LO up to the IF where the unwanted sideband is stripped off by the same xtal filters used for RX.  This is fixed and doesn't change with TX band or frequency because mixing to the TX frequency occurs after that.  Subsequent distortion in the rig or external amplifier can broaden that signal but can't create and add back the opposite side band.  So, based on that, I would think if someone is hearing the opposite sideband, there's a problem with the rig unrelated to being used outside the ham bands.

Direct conversion rigs are another matter.

Perhaps a well known and respected engineer will weight in.









Re: K3 for POTA

Wes Stewart
 

A couple of weeks ago I talked to VK3XXY from 03:58Z to 05:25Z on 20M SSB. Turns out we are both car guys and I own an Aussie-built (Holden) Pontiac G8 GT, so that was quite a conversation piece.  Condx were fantastic with steady S9 signals.

Wes  N7WS


On Sat, Jun 12, 2021 at 07:52 AM, mikerodgerske5gbc wrote:
Does anyone ragchew anymore on hf?
 
One day every few clicks of the VFO it was pota. 
Pota Sota FT8 5/9next. 
 
Of course ft8 can be a indicator of band propogation to somewhere but my buddy got France on ft8 with his wire on the ground so there’s that. 
 
Certainly not what I got into the hobby for. Oh well. I’m sort of wondering why I just bought another radio. 
 
Well I like them since I got hooked as a teenager in 1975. 
 
Don’t take it personally, just a view from my side of the fence. 
 
73
Mike R
KE5GBC 
 
 

7!
Absolutely Awesome 

On Jun 12, 2021, at 9:14 AM, Vic Owen - KB7GL <kb7gl@...> wrote:

Scott —

I agree…the K3 was my primary rig until I got the FTdx101MP. I considered getting the 100W amp for my KX3, but that baby is pricey and it still wouldn’t be as good as the K3. Size and weight difference would be minimal between the K3 and the combo. This gives me a way to keep the K3 on “active duty”…I just won’t be humping it up any mountains for SOTA!
--
Vic - KB7GL


Re: USB rig control

Joe Subich, W4TV
 

On 2021-06-13 7:24 PM, Lou W7HV via groups.io wrote:
I think that's a tough one to pull off, even for Yaesu.
It's simple 3rd order IMD. If the carrier is at 10 MHz and the
audio is at 10.003 MHz ... 2*10.000-10.003 = 9.997 MHz. Instant
LSB.

Without a carrier it is more difficult, but say one has 200 Hz
and 2400 Hz audio present at the same time: 2*10.0002-10.0024 =
9.998 MHz. It's not a perfect LSB but it is a lot of energy
in the LSB spectrum. Remember, Sherwood measures 3rd order
IMD of many of the rigs with 12V finals in the -25 dBc range
(-31 to -34 dB pep) and fifth order no better than -30 dBc.

-30 dBc is *one watt* of IMD power with a 1KW amp (1 mW for
a 100 W transceiver) *assuming* the 1KW amplifier is *totally*
clean (and many of the LDMOS amps are as bad as a 12V rig).

73,

... Joe, W4TV


On 2021-06-13 7:24 PM, Lou W7HV via groups.io wrote:
As an unknown and disrespected engineer, I'll add the following.  The TX side band consists of ~3kHz band of RF frequencies.  Even if the carrier was present, there's no audio signal to mix with it to produce the other sideband.  The carrier would have to mix with the TX signal to recreate the audio signal, and that audio signal would then have to mix with the carrier again to produce two sidebands at the TX frequency, including the undesired one. I think that's a tough one to pull off, even for Yaesu. ;-)


Re: USB rig control

Lou W7HV
 

As an unknown and disrespected engineer, I'll add the following.  The TX side band consists of ~3kHz band of RF frequencies.  Even if the carrier was present, there's no audio signal to mix with it to produce the other sideband.  The carrier would have to mix with the TX signal to recreate the audio signal, and that audio signal would then have to mix with the carrier again to produce two sidebands at the TX frequency, including the undesired one. I think that's a tough one to pull off, even for Yaesu. ;-)


Re: USB rig control

Joe Subich, W4TV
 

On 2021-06-13 6:30 PM, Colin Smithers wrote:

I think in TV transmitters there is still carrier present.
Yes, analog TV transmitters (NTSC) were vestigial sideband
(carrier and upper sideband with a remnant lower sideband).

*However* the IMD products in an SSB transmitter will spread
out on both sides. Given that the male voice has significant
energy in the 200-600 Hz and 1600-2700 Hz formats, the IMD
energy to +/-5.2 KHz (3rd order), +/-7.5 KHz (5th order),
+/- 9.5 KHz (7th order) and more (9th and higher) will be
significant, particularly with heavy clipping.

With many of the "12V" final rigs, the 3rd order IMD is only
-25dBc and 7th can be as bad as -40 dBc (see Sherwood's recent
writings/measurements). Icom and Yaesu are particularly
notorious but the K3/K3s is no saint.

73,

... Joe, W4TV


On 2021-06-13 6:30 PM, Colin Smithers wrote:
It can only re-appear if carrier is present for the wanted sideband to mix with in the non-linear amplifier.
In an SSB transmitter with good carrier suppression it is not possible to regenerate the unwanted sideband through poor IMD in the final stages. In my experience the K3 has negligible carrier content. Given that, It would require an inappropriate TX filter or TX filter adjustment for the unwanted sideband to truly be present.
I think in TV transmitters there is still carrier present.
73, Colin G4CWH
-----Original Message-----
From: Elecraft-K3@groups.io <Elecraft-K3@groups.io> On Behalf Of Joe Subich, W4TV via groups.io
Sent: Sunday, June 13, 2021 10:13 PM
To: Elecraft-K3@groups.io
Subject: Re: [Elecraft-K3] USB rig control
On 2021-06-13 4:45 PM, Lou W7HV via groups.io wrote:
Subsequent distortion in the rig or external amplifier can broaden
> that signal but can't create and add back the opposite side band.
Au contraire! IMD in amplifier stages *will* regenerate the missing
sideband. I saw with my own eyes (spectrum analyzer) in the days of
analog UHF TV ... in "high efficiency" Klystrode/IOT amplifiers. It
was necessary to do significant precorrection (early "Pure Signal")
to prevent the lower sideband from exceeding the "spectral mask"
requirements for protecting the next lower channel.
73,
... Joe, W4TV
On 2021-06-13 4:45 PM, Lou W7HV via groups.io wrote:
I am not a well known engineer and certainly not a respected engineer.  It is my understanding that normal superhets produce SSB by mixing audio with the LO up to the IF where the unwanted sideband is stripped off by the same xtal filters used for RX.  This is fixed and doesn't change with TX band or frequency because mixing to the TX frequency occurs after that.  Subsequent distortion in the rig or external amplifier can broaden that signal but can't create and add back the opposite side band.  So, based on that, I would think if someone is hearing the opposite sideband, there's a problem with the rig unrelated to being used outside the ham bands.

Direct conversion rigs are another matter.

Perhaps a well known and respected engineer will weight in.


Re: USB rig control

Chuck Hill K0MV
 

Colin and Lou are correct.

Well I'm not well known in these circles, but in some circles I am.  And I am an "RF engineer" if that means competent in this area.

3rd order IM distortion goes by 2*f1 - f2 = fout, and 2*f2 - f1=fout.  f1 and f2 are in the SSB transmitted signal.  So 3rd order IM distortion in the amplifier chain produces frequency products near the transmitted signal.  The 3rd order IM products would be both above and below the SSB signal, not just the opposite sideband.

In the analog TV days the US standard (NTSC) transmitted video vestigal sideband which had the USB, the lower frequency portion of the LSB (to improve SNR), and some carrier.  3rd order IM products involving the carrier would regenerate the LSB.  That would QRM the next TV channel down.

A good reference for this is "RF Design Guide" by Peter Vizmuller c1995 Artech House, page 188.  A description of good debugging techniques too.

73,
Chuck K0MV

On 6/13/21 4:30 PM, Colin Smithers wrote:
It can only re-appear if carrier is present for the wanted sideband to mix with in the non-linear amplifier.

In an SSB transmitter with good carrier suppression it is not possible to regenerate the unwanted sideband through poor IMD in the final stages. In my experience the K3 has negligible carrier content. Given that, It would require an inappropriate TX filter or TX filter adjustment for the unwanted sideband to truly be present.

I think in TV transmitters there is still carrier present.

73, Colin G4CWH

-----Original Message-----
From: Elecraft-K3@groups.io <Elecraft-K3@groups.io> On Behalf Of Joe Subich, W4TV via groups.io
Sent: Sunday, June 13, 2021 10:13 PM
To: Elecraft-K3@groups.io
Subject: Re: [Elecraft-K3] USB rig control


On 2021-06-13 4:45 PM, Lou W7HV via groups.io wrote:
Subsequent distortion in the rig or external amplifier can broaden
> that signal but can't create and add back the opposite side band.

Au contraire! IMD in amplifier stages *will* regenerate the missing
sideband. I saw with my own eyes (spectrum analyzer) in the days of
analog UHF TV ... in "high efficiency" Klystrode/IOT amplifiers. It
was necessary to do significant precorrection (early "Pure Signal")
to prevent the lower sideband from exceeding the "spectral mask"
requirements for protecting the next lower channel.

73,

... Joe, W4TV


On 2021-06-13 4:45 PM, Lou W7HV via groups.io wrote:
I am not a well known engineer and certainly not a respected engineer.  It is my understanding that normal superhets produce SSB by mixing audio with the LO up to the IF where the unwanted sideband is stripped off by the same xtal filters used for RX.  This is fixed and doesn't change with TX band or frequency because mixing to the TX frequency occurs after that.  Subsequent distortion in the rig or external amplifier can broaden that signal but can't create and add back the opposite side band.  So, based on that, I would think if someone is hearing the opposite sideband, there's a problem with the rig unrelated to being used outside the ham bands.

Direct conversion rigs are another matter.

Perhaps a well known and respected engineer will weight in.









Re: USB rig control

Colin Smithers
 

It can only re-appear if carrier is present for the wanted sideband to mix with in the non-linear amplifier.

In an SSB transmitter with good carrier suppression it is not possible to regenerate the unwanted sideband through poor IMD in the final stages. In my experience the K3 has negligible carrier content. Given that, It would require an inappropriate TX filter or TX filter adjustment for the unwanted sideband to truly be present.

I think in TV transmitters there is still carrier present.

73, Colin G4CWH

-----Original Message-----
From: Elecraft-K3@groups.io <Elecraft-K3@groups.io> On Behalf Of Joe Subich, W4TV via groups.io
Sent: Sunday, June 13, 2021 10:13 PM
To: Elecraft-K3@groups.io
Subject: Re: [Elecraft-K3] USB rig control


On 2021-06-13 4:45 PM, Lou W7HV via groups.io wrote:
Subsequent distortion in the rig or external amplifier can broaden
> that signal but can't create and add back the opposite side band.

Au contraire! IMD in amplifier stages *will* regenerate the missing
sideband. I saw with my own eyes (spectrum analyzer) in the days of
analog UHF TV ... in "high efficiency" Klystrode/IOT amplifiers. It
was necessary to do significant precorrection (early "Pure Signal")
to prevent the lower sideband from exceeding the "spectral mask"
requirements for protecting the next lower channel.

73,

... Joe, W4TV


On 2021-06-13 4:45 PM, Lou W7HV via groups.io wrote:
I am not a well known engineer and certainly not a respected engineer.  It is my understanding that normal superhets produce SSB by mixing audio with the LO up to the IF where the unwanted sideband is stripped off by the same xtal filters used for RX.  This is fixed and doesn't change with TX band or frequency because mixing to the TX frequency occurs after that.  Subsequent distortion in the rig or external amplifier can broaden that signal but can't create and add back the opposite side band.  So, based on that, I would think if someone is hearing the opposite sideband, there's a problem with the rig unrelated to being used outside the ham bands.

Direct conversion rigs are another matter.

Perhaps a well known and respected engineer will weight in.


Re: USB rig control

Joe Subich, W4TV
 

On 2021-06-13 4:45 PM, Lou W7HV via groups.io wrote:
Subsequent distortion in the rig or external amplifier can broaden that signal but can't create and add back the opposite side band.
Au contraire! IMD in amplifier stages *will* regenerate the missing
sideband. I saw with my own eyes (spectrum analyzer) in the days of
analog UHF TV ... in "high efficiency" Klystrode/IOT amplifiers. It
was necessary to do significant precorrection (early "Pure Signal")
to prevent the lower sideband from exceeding the "spectral mask"
requirements for protecting the next lower channel.

73,

... Joe, W4TV


On 2021-06-13 4:45 PM, Lou W7HV via groups.io wrote:
I am not a well known engineer and certainly not a respected engineer.  It is my understanding that normal superhets produce SSB by mixing audio with the LO up to the IF where the unwanted sideband is stripped off by the same xtal filters used for RX.  This is fixed and doesn't change with TX band or frequency because mixing to the TX frequency occurs after that.  Subsequent distortion in the rig or external amplifier can broaden that signal but can't create and add back the opposite side band.  So, based on that, I would think if someone is hearing the opposite sideband, there's a problem with the rig unrelated to being used outside the ham bands.
Direct conversion rigs are another matter.
Perhaps a well known and respected engineer will weight in.

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