locked Re: WSJT-X 2.5.0-rc1 and MAP65 3.0-rc1 H/V signals #general

Amos Sobel 4X4MF



Flex radio does tell me that my request to make their SmartSDR deliver the 2xDAXIQ stream compatible with the requirement of MAP65/Q65 have been put in their  enhancement database for sometime implementation. I will pray for that.

In the mean time please consider using the IQ  streams delivered by Flex Radio and many other SDR radios as an input to WSJT-X Q65. This is half way to your MAP65 requierment and does contain more “Flash” than the common data stream.


Amos 4X4MF



From: main@WSJTX.groups.io <main@WSJTX.groups.io> On Behalf Of Bill Somerville
Sent: Sunday, June 6, 2021 3:23 PM
To: main@WSJTX.groups.io
Subject: Re: [WSJTX] WSJT-X 2.5.0-rc1 and MAP65 3.0-rc1 H/V signals #general


Hi Amos,


in order to do polarization diversity reception I/Q samples for both polarizations must be delivered in sync to the MAP65 application. The only practical way to do that is as a multichannel (4 in this case) feed. Inside MAP65 the application connects to an audio device and receives buffers full of audio samples, with a 4-channel audio device the samples for each of the 4 channels are delivered together. That is I and Q from he vertical receiver, and I and Q from the horizontal receiver interleaved in frames that have 4 samples each. If the pair of I/Q channels are received via two separate audio devices, i.e. a pairs of interleaved stereo channels, there is no easy way to match the arrival time of the two polarizations. Only when the arrival times are exactly synchronized can polarization diversity be carried out.


One way MAP65 users do this is with the Link RF IQ+ direct conversion dual SDR, that device consists of a pair of ADCs clocked with a common clock source and then the pair of I/Q outputs at 96,000 Hz Sa/S are fed to a 4-channel external sound card which also has ADCs using a common clock source, which in turn delivers interleaved 4-channel audio to MAP65 via a USB connection.


Other options are available, and using Linrad to wrangle I/Q outputs from any pair of SDRs that are known to be synchronized is one option. Linrad delivers the pair of I/Q data streams as interleaved samples via a UDP network protocol that MAP65 supports.


The bottom line here is that polarization diversity requires synchronized sampling of the two polarization channels. I am not an expert with Linrad, but it may be possible that Linrad can combine the output of two slices of I/Q data from your FlexRadio SDR, maintaining any synchronization they might have. That would require, at least, that the FlexRadio Signature series SDRs use a common clock for all ADCs, but I believe you stated earlier that is not the case, YMMV.




On 06/06/2021 10:55, Amos Sobel 4X4MF wrote:

Please explain what do you mean by  4 channel audio device feeding an
interleaved pair of I/Q channels.
My Flex 6600 radio can deliver 4 channels of I/Q data out of 2 separate ADC
connected to 2 separate antennas. Would that suffice?
Amos 4X4MF
-----Original Message-----
From: main@WSJTX.groups.io <main@WSJTX.groups.io> On Behalf Of Bill
Sent: Sunday, June 6, 2021 12:38 PM
To: main@WSJTX.groups.io
Subject: Re: [WSJTX] WSJT-X 2.5.0-rc1 and MAP65 3.0-rc1 H/V signals #general
as discussed previously MAP65 when used for polarization diversity requires
a pair of synchronized I/Q channels which must be interleaved, that is not
possible if your starting point is two separate stereo channels containing
I/Q data. Either a 4 channel audio device feeding an interleaved pair of I/Q
channels, or Linrad is supported using an interleaved pair of I/Q channels
via UDP in Linrad's own message format.
On 06/06/2021 07:04, Amos Sobel 4X4MF wrote:
I am preparing to work EME using Q65 on 2m:
I have a CROSS H/V  long Yagi.
I have a Flex 6600 Radio which can support 2 antennas In parallel 1. 
To enable the use of Q65, do I need a 2 channel Transverter to enable 
2 instance processing of WSJT-X v2.5.0 with possible software  
combination of the H/V data?
2. Prefer a combination(X)  of the H/V signals into one circularly 
polarized signal at the antenna level and use 1 instance of Q65 with 
possible switching between H/V/X signals?
Amos 4X4MF
-----Original Message-----
From:main@WSJTX.groups.io  <main@WSJTX.groups.io>  On Behalf Of Joe
Sent: Thursday, June 3, 2021 12:31 AM
Subject: [WSJTX] WSJT-X 2.5.0-rc1 and MAP65 3.0-rc1 #general
Dear WSJT-X and MAP65 Users,
We are pleased to announce that a public Release Candidate WSJT-X
2.5.0-rc1 is ready for download by beta testers.
WSJT-X in this release is nearly identical to that in WSJT-X 2.4.0.  
Q65 decoder has been enhanced to measure and compensate for linear 
frequency drift in Q65 signals.  In addition, the Windows installation 
package now includes version 3.0 of program MAP65.
Potential interests of users in this release candidate can be sorted 
into three main categories:
1. If you are currently using MAP65 for EME, we strongly recommend 
installing WSJT-X 2.5.0-rc1.  On the Windows platform this action 
automatically installs MAP65 3.0.0-rc1 as well.  MAP65 3.0 is a major 
upgrade that incorporates the Q65 mode, complete with support for 
LiveCQ and other features enjoyed by MAP65 users for many years.
2. If you are currently using an earlier version of WSJT or WSJT-X for 
EME, or using the Q65 protocol for any purpose, WSJT-X 2.5.0-rc1 
offers a faster and more robust decoder for Q65.  If you are using 
JT65 or JT4 for EME on any band, we recommend switching to the Q65 
mode and encouraging others to do so using WSJT-X 2.5.0-rc1.
3. If you are not currently interested in Q65, EME, or MAP65, there is 
little reason for you to try WSJT-X 2.5.0-rc1.  For your present 
purposes WSJT-X 2.4.0 is just as good.
Please note that MAP65 is installed automatically only on the Windows 
platform.  Please let us know if using MAP65 in Linux or macOS would 
be important for you.
If you need more information on recent additions to the capabilities 
of WSJT-X and MAP65, these short papers may be of interest:
"Quick-Start Guide to FST4 and FST4W"
"Quick-Start Guide to Q65"
"Quick-Start Guide to WSJT-X 2.5.0 and MAP65 3.0"
"Q65 Sensitivity in MAP65 3.0"
Links for downloading WSJT-X 2.5.0 can be found on the WSJT-X Home 
Page, https://physics.princeton.edu/pulsar/k1jt/wsjtx.html
Scroll down to find "Candidate release:  WSJT-X 2.5.0-rc1".
WSJT-X and MAP65 are licensed under the terms of Version 3 of the GNU 
General Public License (GPLv3).  Development of this software is a 
cooperative project to which many amateur radio operators have
If you use our code, please have the courtesy to let us know about it.  
If you find bugs or make improvements to the code, please report them 
to us in a timely fashion.
We hope you will enjoy using this beta release of WSJT-X 2.5.0 and 
MAP65 3.0.0, and exercising the new mode Q65.  As a beta tester you 
should report on your experiences with new features, successful and 
otherwise, on one of the relevant WSJT forums.  Bugs should be 
reported by following instructions found here in the User Guide:
   -- 73 from Joe, K1JT; Bill, G4WJS; Steve, K9AN; and Nico, IV3NWV


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