When I transmit, I get distorted audio while using the amplifier 1500w. These are my settings. Am I doing something wrong?
When I disconnect the sampler cable and run the amp the signal is clean.
Distortion during Pure Signal
Distortion during Pure Signal
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- puresignal settings.png (3.3 MiB) Viewed 5585 times
Jay N2GQ
Re: Distortion during Pure Signal
When you say "I get distorted audio", how do you know this? If you are listening with MON, it will sound distorted to you because you are hearing the raw DAC data and when PS is enabled that DAC data is, of course, pre-distorted!
Or is somebody reporting this to you on the air?
What ANAN, what amp, and what coupler/sampler are you using?
It seems like you are badly overdriving your amp. 106W out of the ANAN into the amp? And look at how badly the blue line is going horizontal up at the top right corner of the AmpView display. Back the drive off some.
I'm going to guess that you are using the metering on your amp to make adjustments, which is perfectly reasonable, of course. But a lot of amp metering does not respond correctly when using two tone, and this can fool you badly. I have this exact problem with my Elecraft KPA1500. One way to fix this is to change your two tone settings from the standard 700 and 1900Hz to 70 and 190Hz. While this is not the "official", de facto standard for measuring IMD, it nevertheless works extremely well for making amp's and metering behave, and it works perfectly fine for obtaining a PureSignal correction and getting a good idea of what your IMD is. It also has another benefit, which is that it does not "sing the song of our people" on the air
Other things to consider after changing the tone pair and reducing drive:
- Set your TX DUP display scaling to be 0 to -70dBm, this will net you a much better view of your transmitted signal and anything under -70 is a "don't care".
- Uncheck Low Res on the AmpView display.
- Enable Quick Attenuate Response.
- Try disabling MAP and enabling STBL.
Examples of improper and proper behavior of amp metering at my station are shown below. Right click and "Open image in new tab" for full resolution.
The first image shows how my KPA1500 responds using the 70 & 190Hz non-standard two tone configuration. As can be seen, the (calibrated) drive is 35 and the KPA1500 is reporting 37W in (close enough) and 1585W output (this is into a dummy load). Note the Thetis power output of 45W (uncalibrated). The AmpView display shows a nice, smooth curve with very little leveling off up at the top. IMD is better than -50dBc.
The second image shows how my KPA1500 responds using the 700 & 1900Hz standard two tone configuration. Again the calibrated drive is 35 but the KPA1500 is only reporting 21W in and 1261W out. Meanwhile the uncalibrated Thetis power meter still shows the same as in the previous case, 44W (close enough), i.e. it is unaffected by the tone pair selection. The AmpView curve remains identical, albeit with the characteristic dotted line you get with the standard tone pair which is normal.
In both cases I'm confident that the actual power output of the amp is 1500+W.
Try changing to 70 & 190 and turn that drive down!
Or is somebody reporting this to you on the air?
What ANAN, what amp, and what coupler/sampler are you using?
It seems like you are badly overdriving your amp. 106W out of the ANAN into the amp? And look at how badly the blue line is going horizontal up at the top right corner of the AmpView display. Back the drive off some.
I'm going to guess that you are using the metering on your amp to make adjustments, which is perfectly reasonable, of course. But a lot of amp metering does not respond correctly when using two tone, and this can fool you badly. I have this exact problem with my Elecraft KPA1500. One way to fix this is to change your two tone settings from the standard 700 and 1900Hz to 70 and 190Hz. While this is not the "official", de facto standard for measuring IMD, it nevertheless works extremely well for making amp's and metering behave, and it works perfectly fine for obtaining a PureSignal correction and getting a good idea of what your IMD is. It also has another benefit, which is that it does not "sing the song of our people" on the air
Other things to consider after changing the tone pair and reducing drive:
- Set your TX DUP display scaling to be 0 to -70dBm, this will net you a much better view of your transmitted signal and anything under -70 is a "don't care".
- Uncheck Low Res on the AmpView display.
- Enable Quick Attenuate Response.
- Try disabling MAP and enabling STBL.
Examples of improper and proper behavior of amp metering at my station are shown below. Right click and "Open image in new tab" for full resolution.
The first image shows how my KPA1500 responds using the 70 & 190Hz non-standard two tone configuration. As can be seen, the (calibrated) drive is 35 and the KPA1500 is reporting 37W in (close enough) and 1585W output (this is into a dummy load). Note the Thetis power output of 45W (uncalibrated). The AmpView display shows a nice, smooth curve with very little leveling off up at the top. IMD is better than -50dBc.
The second image shows how my KPA1500 responds using the 700 & 1900Hz standard two tone configuration. Again the calibrated drive is 35 but the KPA1500 is only reporting 21W in and 1261W out. Meanwhile the uncalibrated Thetis power meter still shows the same as in the previous case, 44W (close enough), i.e. it is unaffected by the tone pair selection. The AmpView curve remains identical, albeit with the characteristic dotted line you get with the standard tone pair which is normal.
In both cases I'm confident that the actual power output of the amp is 1500+W.
Try changing to 70 & 190 and turn that drive down!
- 70&190.JPG (923.27 KiB) Viewed 5563 times
- 700&1900.JPG (925.64 KiB) Viewed 5563 times
Re: Distortion during Pure Signal
[quote="w-u-2-o"]When you say "I get distorted audio", how do you know this? If you are listening with MON, it will sound distorted to you because you are hearing the raw DAC data and when PS is enabled that DAC data is, of course, pre-distorted!
Or is somebody reporting this to you on the air?
What ANAN, what amp, and what coupler/sampler are you using?
--------------------------------------------------------------------------------------------------
Hi
Yes, the reports are on the air reported to me.
My radio: Anan-7000del mkIII, Ameritron al-82 and a Clean Rf sampler.
And yes the radio although I set the output power calibration it seems like it does not stay at the 100 watt setting. The meter I use is from the Ameritron tuner.
Love your display awesome.
Or is somebody reporting this to you on the air?
What ANAN, what amp, and what coupler/sampler are you using?
--------------------------------------------------------------------------------------------------
Hi
Yes, the reports are on the air reported to me.
My radio: Anan-7000del mkIII, Ameritron al-82 and a Clean Rf sampler.
And yes the radio although I set the output power calibration it seems like it does not stay at the 100 watt setting. The meter I use is from the Ameritron tuner.
Love your display awesome.
Jay N2GQ
Re: Distortion during Pure Signal
The adjustable CleanRF samplers are not recommended as it is all too easy to accidentally adjust them to dangerous feedback output levels that can damage the ANAN. Be careful with it!
Have you tried changing to the 70 & 190Hz combination?
There should be no problem with the power calibration. Use TUN to measure that, not two tone.
Have you tried changing to the 70 & 190Hz combination?
There should be no problem with the power calibration. Use TUN to measure that, not two tone.
Re: Distortion during Pure Signal
w-u-2-o wrote:The adjustable CleanRF samplers are not recommended as it is all too easy to accidentally adjust them to dangerous feedback output levels that can damage the ANAN. Be careful with it!
Have you tried changing to the 70 & 190Hz combination?
There should be no problem with the power calibration. Use TUN to measure that, not two tone.
Hi
Yes I changed the tones much more mellow
and the map setting as well as the other settings you recommended. Still had the same distortion.So I started bypassing antenna switches and still had the distortion. More like rf feedback at this point only there when running the amp. So I reinstalled everything on the desk the way it was and my friend said the signal was crystal clear. So I'm thinking a bad jumper and the amp view also changed. I also recalibrated the pa gain and that too was normal this morning. I hope it's a bad jumper.
And Tyler from Clean RF says hello.
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- puresignal settings 2.png (2.32 MiB) Viewed 5459 times
Jay N2GQ
Re: Distortion during Pure Signal
HI Scott,
Finally got the distortion sorted. I had to work all my ground in the station everything now goes to a common point. Used a morgan line arrestor for the rotor at my hexbeam. In my case seems like a lot of the rf energy was on the control cable for rotator. But anyway, the radio is working just fine and thank you for the advice and help. By the way my friend likes your mixer or eq console on the extreme right, he wants to know what program or plug-in you are using.
Finally got the distortion sorted. I had to work all my ground in the station everything now goes to a common point. Used a morgan line arrestor for the rotor at my hexbeam. In my case seems like a lot of the rf energy was on the control cable for rotator. But anyway, the radio is working just fine and thank you for the advice and help. By the way my friend likes your mixer or eq console on the extreme right, he wants to know what program or plug-in you are using.
Jay N2GQ
Re: Distortion during Pure Signal
Glad you got it all sorted! 
PureSignal tells no lies!
Please tell Tyler I also say "Hi!"
[thread drift]
My audio software setup is perhaps more complex than it needs to be.
Presonus Studio 192 Mobile interface <---->Voicemeeter<---->Reaper DAW
Thetis<------------------------------------------------------->Potato<------------------------------->Digi mode stuff like WSJT-X
Voicemeeter just acts like an ASIO patch panel, and all mixing and routing is done in Reaper.
I don't really need to do it that way. It probably adds a little latency. I could just do all mixing and routing in Potato, but I've been using Reaper a long time, since back before we had CFC and all the other wonderful audio processing in Thetis, and I'm used to the way it works. There is no processing being done in Reaper. Just mixing and routing
[/thread drift]
PureSignal tells no lies!
Please tell Tyler I also say "Hi!"
[thread drift]
My audio software setup is perhaps more complex than it needs to be.
Presonus Studio 192 Mobile interface <---->Voicemeeter<---->Reaper DAW
Thetis<------------------------------------------------------->Potato<------------------------------->Digi mode stuff like WSJT-X
Voicemeeter just acts like an ASIO patch panel, and all mixing and routing is done in Reaper.
I don't really need to do it that way. It probably adds a little latency. I could just do all mixing and routing in Potato, but I've been using Reaper a long time, since back before we had CFC and all the other wonderful audio processing in Thetis, and I'm used to the way it works. There is no processing being done in Reaper. Just mixing and routing
[/thread drift]
Re: Distortion during Pure Signal
w-u-2-o wrote:Glad you got it all sorted!
PureSignal tells no lies!
Please tell Tyler I also say "Hi!"
[thread drift]
My audio software setup is perhaps more complex than it needs to be.
Presonus Studio 192 Mobile interface <---->Voicemeeter<---->Reaper DAW
Thetis<------------------------------------------------------->Potato<------------------------------->Digi mode stuff like WSJT-X
Voicemeeter just acts like an ASIO patch panel, and all mixing and routing is done in Reaper.
I don't really need to do it that way. It probably adds a little latency. I could just do all mixing and routing in Potato, but I've been using Reaper a long time, since back before we had CFC and all the other wonderful audio processing in Thetis, and I'm used to the way it works. There is no processing being done in Reaper. Just mixing and routing
[/thread drift]
Okay will pass the hello as well and let my friend no what you are using he likes your setup. And once again thank you.
Jay N2GQ