Coherent IQ Streams for Adaptive EME

USB headsets to digital audio workstation software...
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Conrad_PA5Y
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Re: Coherent IQ Streams for Adaptive EME

Postby Conrad_PA5Y » Sun Apr 29, 2018 2:32 pm

Not without doing some reading. I don't have any spare time today
AB2EZ
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Re: Coherent IQ Streams for Adaptive EME

Postby AB2EZ » Sun Apr 29, 2018 3:37 pm

Conrad
et al.

I am very much enjoying reading and following this discussion.

Thank you
Stu
AB2EZ
Ton_PA0TBR
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Re: Coherent IQ Streams for Adaptive EME

Postby Ton_PA0TBR » Sun Apr 29, 2018 7:11 pm

Hi Bryan,

Conrad said that he is using the EXT1 and RX2 inputs.

Receiver 1 is disconnected from the LPF by relay K36 when EXT1 is selected.
The HPF can be bypassed in the Ant/Filters - HPF/LPF menu

73,
Ton PA0TBR
Last edited by Ton_PA0TBR on Mon Apr 30, 2018 9:01 pm, edited 1 time in total.
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w-u-2-o
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Re: Coherent IQ Streams for Adaptive EME

Postby w-u-2-o » Mon Apr 30, 2018 1:04 pm

Sorry for the delay in responding. I was 100% otherwise occupied yesterday with no time for the internet.

Thanks for posting those screen shots, Conrad, and I'm so glad to see that everything is as expected with VMB. In particular, it is good to see that gains are now nearly all near 0dB with just the 10dB checkbox selected in MAP65. This is much closer to what I expected.

A few ideas for you:

1. Go back into the Virtual IO and Virtual AUX IO control panels and double the buffer sizes to see if this will rid you of the red indicators in VMB. A restart will be required.

2. No need to have MUTE activated on any channel.

3. You can probably eliminate any amplitude differential by using this tool with VMB:

https://forum.vb-audio.com/viewtopic.php?f=8&t=394

4. Defeat the preselectors and check your phase offset and amplitude offset. It would be interesting for us all to know how it changes with the preselector bypassed. Bypassing the preselector should make it near 0 for both phase and amplitude, but I guess we'll see!

To really make this work right, the plumbing inside of PowerSDR (or Thetis) needs to allow the "diversity" phase/amplitude control be effective when using the radio this way.

73,

Scott
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Conrad_PA5Y
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Re: Coherent IQ Streams for Adaptive EME

Postby Conrad_PA5Y » Mon Apr 30, 2018 1:43 pm

Hello Scott, I will have limited time tonight and also the moon rise is getting very late and lunar conditions are worsening. What I can maybe do is come up with a test signal and a variable delay line in 1 leg. I would like to do this so that I can get meaningful and repeatable measurements.

Just to be clear what must I do to bypass the pre-selector for RX1?

I think that I can maybe test that on Wednesday evening although not off the moon, it will be too late before moonrise.

I am pretty certain that we can make this work without a massive amount of development. Trimming the amplitude and phase for the inputs will be useful. You can imagine that the chances of having 2 mast mounted LNAs, 2 band-pass filters, RX cables from the mast with perfectly matched phase is unlikely. I spent a lot of time on this and I have a small but acceptable error. To be honest it is not hugely important, not as important as seeing the signal at max combined amplitude.

Then we get to the real sticky wicket, how to TX on the correct frequency and return to 144.125 on RX. We have CAT tools that are tied to MAP65 but I am not sure about this yet. We will need Split, will we maintain coherent operation?

One thing at a time...

73

Conrad PA5Y
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w-u-2-o
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Re: Coherent IQ Streams for Adaptive EME

Postby w-u-2-o » Mon Apr 30, 2018 4:10 pm

Conrad_PA5Y wrote:Just to be clear what must I do to bypass the pre-selector for RX1?
Follow the hot-link in item 4 in my post above, then see item 5.

73,

Scott
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Conrad_PA5Y
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Re: Coherent IQ Streams for Adaptive EME

Postby Conrad_PA5Y » Mon Apr 30, 2018 8:49 pm

Sorry when I was speed reading in a coffee break I did not notice that it was hyperlink. Will do so and also report back Wednesday evening all being well.

73

Conrad PA5Y
W4WMT
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Re: Coherent IQ Streams for Adaptive EME

Postby W4WMT » Sat May 12, 2018 9:08 pm

Hi Conrad,

Does your 40 degree error seem to be constant for all signals on the band, or does it seem to depend on the polar angle of the incoming signal? The reason I ask is that there is a chance that the I & Q channels for RX2 are reversed in the code, which would be giving us the complement of the true phase angle. What do you think?

73, Bryan W4WMT
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Conrad_PA5Y
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Re: Coherent IQ Streams for Adaptive EME

Postby Conrad_PA5Y » Sun May 13, 2018 1:26 pm

Hello Brian.

Things are little hectic right now. I am involved with renovating a property on the same site as the current house, I should have moved this weekend but there are delays, also 6m has woken up!

I will try this week probably not until Friday, Monday busy, Tuesday Contest, Wednesday picking up new furniture for the new shack, Thursday contest - quite a week!

Project is not dead at all just on hold.

Best Regards

Conrad PA5Y
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R3YA
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Re: Coherent IQ Streams for Adaptive EME

Postby R3YA » Wed Aug 07, 2019 5:42 am

Conrad_PA5Y wrote:Then we get to the real sticky wicket, how to TX on the correct frequency and return to 144.125 on RX. We have CAT tools that are tied to MAP65 but I am not sure about this yet. We will need Split, will we maintain coherent operation?

Hello friends!

I repeated all the actions of Conrad, now my system receives two channels (tranceiver is home made from EU1SW theme).
But the question arose about signal transmission.
How to teach to transmit a transceiver at a receiving frequency? I am using split now. But I have to tune in manually. Maybe there is a CAT from MAP65?

Al, R3YA team of RA3EME.
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Re: Coherent IQ Streams for Adaptive EME

Postby W9IP » Sun Oct 18, 2020 11:13 pm

Thanks to the help of Conrad, Scott, and Bryan, I have been able to route two I/Q streams from OpenHPSDR mRX PS (3.4.9) to Map65. I’m not yet sure whether the streams are coherent, but there are two of them and that’s a start.
I mostly followed the setup described above. I had to add ASIO4ALL and of course go through VoiceMeeter Banana. ASIO4ALL is basically transparent and VoiceMeeter Banana just mystifies me.
Assuming that the two IQ streams are coherent, the only think lacking is actual audio output that I can listen to. I wonder whether anyone has a suggestion how to route audio from OpenHPSDR to speakers while it is also sending I/Q to Map65. My setup for VAC1 is below. I understand that VAC2 is not available for RX1.
HPSDR dual IQ setup.jpg
HPSDR dual IQ setup.jpg (53.6 KiB) Viewed 6694 times

Thanks for any suggestions-
Michael, W9IP
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w-u-2-o
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Re: Coherent IQ Streams for Adaptive EME

Postby w-u-2-o » Mon Oct 19, 2020 1:27 am

W9IP wrote: wonder whether anyone has a suggestion how to route audio from OpenHPSDR to speakers while it is also sending I/Q to Map65.
AFAIK you cannot listen to IQ output via VAC. You will have to use the speaker or headphone output from the ANAN hardware to listen.
W9IP
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Re: Coherent IQ Streams for Adaptive EME

Postby W9IP » Mon Oct 19, 2020 9:40 am

Thanks, Scott.
So, the Direct I/Q, Output to VAC box in OpenHPSDR means "instead of audio", not "in addition to audio."
Nuts.
73,
W9IP
W9IP
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Re: Coherent IQ Streams for Adaptive EME

Postby W9IP » Mon Oct 19, 2020 9:56 am

I forgot to add... My SDR is mounted 250 meters away. I suppose I need to do some sort of audio-over-ip in order to use the headphone jack.
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w-u-2-o
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Re: Coherent IQ Streams for Adaptive EME

Postby w-u-2-o » Mon Oct 19, 2020 11:15 am

You could do something like this: http://www.crazy-audio.com/projects/raspberry-pi-for-audio-distribution/

Or, if you don't need RX2, you can assign RX2 to the same ADC as RX1 and use it independently to listen. Its output is on VAC2. Assign that to the third virtual channel on Voicemeeter Potato and route it to your speakers in Voicemeeter.

Or Bryan could write some more code ;) Voicemeeter can accept up to an 8 channel connection on a single interface, two of those could be plain audio.
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Re: Coherent IQ Streams for Adaptive EME

Postby W9IP » Mon Oct 19, 2020 1:41 pm

Isn't RX2 the second source of RF for my XPOL? Maybe I don't fully understand what a "receiver" is in OpenHPSDR. I thought that it was everything from the 2nd RX SMA connector all the way to the speaker or VAC.
W9IP
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w-u-2-o
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Re: Coherent IQ Streams for Adaptive EME

Postby w-u-2-o » Mon Oct 19, 2020 2:25 pm

Sorry, I didn't realize you were running the cross polarization setup. Yes, that uses up the other receiver.

An RTSP/RTP streamer setup is looking more and more like your solution. You don't have to use a Pi, you can repurpose any old PC you have to do that, Linux or Windows, there are open source solutions for all platforms. You could receive and listen to the stream using something like VLC.

As for what comprises a "receiver", the lines get a little blurry. See: https://apache-labs.com/community/viewtopic.php?f=6&t=2644
W4WMT
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Re: Coherent IQ Streams for Adaptive EME

Postby W4WMT » Mon Oct 19, 2020 5:41 pm

W9IP wrote:.....I had to add ASIO4ALL and of course go through VoiceMeeter Banana. ASIO4ALL is basically transparent and VoiceMeeter Banana just mystifies me. .......
Michael, W9IP


I understand why VoiceMeeter is needed, i.e. to patch PowerSDR & MAP65 together. But why ASIO4ALL?

73
W9IP
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Re: Coherent IQ Streams for Adaptive EME

Postby W9IP » Mon Oct 19, 2020 6:33 pm

Hi, Brian - I'm not sure either. I tried every permutation with just VMB I could think of without resorting to ASIO and had no success. Added ASIO and it worked pretty quickly. Now that I know that it can work, I'll try to go back and try again. No need for extra software.
W9IP

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