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Unusual VarAC Contacts Method Using Beacons

✇Ham Radio with K0PIR – Icom 7300 and 7610 SDR Transceivers
By: K0PIR
3 October 2023 at 20:25

Ham Radio With K0PIR

Hey guys, I've been busy on another project, but have been able to keep up on my VarAC activity. Last weekend there was a RTTY contest and it made operating very challenging. While operating VarAC I discovered some things, see...

The post Unusual VarAC Contacts Method Using Beacons appeared first on Ham Radio with K0PIR - Icom 7300 and 7610 SDR Transceivers and now Elecraft!.

Release DVPI Version 1.03 (scirpt update)

✇KD8CEC Amateur Radio
By: noreply@blogger.com (KD8CEC)
13 July 2021 at 05:54

 Release DVPI Version 1.03

There have been some changes to the DMR node recently.

This version changes only those related to the recently changed DMR node. If you normally use Version 1.0 or Version 0.95, no upgrade is required.

DVPi uses the USRP Client protocol. When you install and use DVSwitch, you must read and comply with the license that appears. The user is responsible for the license for the use of DVPi.


1.Download Link

https://github.com/phdlee/dvpi/releases/tag/v1.03

https://github.com/phdlee/dvpi/releases/download/v1.03/dvpi_103.zip

https://github.com/phdlee/dvpi/releases/download/v1.03/dvpimanager_103.zip


2.What was added in Version 1.03 (from Version 1.0)

 -To reduce user confusion, the MMDVM password change function has been removed.

  If the DMR's BM password has been changed, it can be changed on the DVSwitch Settings Change screen.

- It is not a function you use. Changed the TX/RX frequency of MMDVM to the same frequency. This is because the new DMR rule may not work if the frequency is different.



3.How to Install

  There is a detailed explanation about more detailed installation method and H/W configuration on my blog. 

  The following explains how to download and configure to use DVPi. Please refer to another post for more details.


3.1 Download

  Download the dvpi_103.zip and dvpimanager_103.zip files from the download link.

   Unzip the downloaded files (dvpi_103.zip, dvpimanager_103.zip)


3.2 Write the dvpi_103.img file to the SD card.

  Formatting the SD card is not mandatory. When I apply the image file to the SD card, sometimes an error occurs, so I format it first.


Apply the dvpi_103.img file to the SD card with Win32Disk Imager.






After completion, remove the SD card and insert it into the Raspberry Pi of the DVPi.


Connect power to the DVPi. (power on DVPi)

Sometimes, depending on the LCD, the screen is turned upside down, You can reverse the top and bottom of the screen in DVPi Manager.


At the time of the first boot, because there is no setting, it is not possible to log in.



3.3 Find DVPi IP Address
The Raspberry Pi image used in DVPi is automatically assigned an IP (using DHCP Server).
You can use the DVPi Manager to find out the IP of the DVPi.


Run DVPi Manager -> Click the 'Find DVPi' Button


Click the 'Find' Button
(If multiple LAN cards are installed in your computer, you must select the IP address of your computer before clicking the 'Find' button)

I have 3 DVPi and they are all found. Once you have found the IP of the DVPi you can use ssh.
DVPi can be accessed with ssh id: pi, password: dvpi


3.4 Installing DVSwitch and Setting up DVSwitch
(DVSwitch installation is only necessary to embed DVSwitch into DVPi)

Execute DVPi Manager -> Input DVPi IP Address -> Click the 'Connect' Button

Click the 'Easy setup of installed DV Switch'



To embed DVSwitch into DVPi, you only need to execute 4 commands. The four commands are explained in the center of the screen.

Rutn the SSH Client as putty
Login ID : pi, Passwor d: dvpi


Execute the commands described in DVPi Manager one by one.
It is convenient to use copy and paste.


In the case of putty, you can copy and paste multiple lines at once.





Execute 'sudo apt-get install -y dvswitch'


If all 4 commands were executed, your DVPi would have DVSwitch installed.
Setting up DVSwitch is easy with just a few entries.


Enter your callsign and DMR ID,
Unique ID is your Hotspot number that is unique. Any number you don't use is fine.


Choose Brand Meister Host, It is recommended to choose a server in your country.
(The US1 server that was set as the default until DVPi Version 1.0 is no longer operated)


If you have changed your password in Brand Meister, you must change the password field to your password.


The BM password can be changed here.

Enter the changed password.

Enter the Location field, the rest is not required, but it is strongly recommended to enter latitude and longitude.
Click the 'Apply All Setting' button.


The screen below is displayed and the operation takes about 1 minute.

When all settings are completed, the following message is displayed.

After rebooting DVPi, you should be connected to the DVSwitch server as shown below.



You can also check your Hotspot list if you log in to Brand Meister. I set the unique number 37 and it was displayed as follows.


3.5 flip the screen upside down

(This is only necessary if the screen is upside down like me. If your screen appears normally, this step is not necessary.)

Click the 'DVPi Basic Setup'

Click the '3.5 LCD 180 (upside down)' Button click




After rebooting, it will display normally as shown below.




3.6 Using DVPi
(For detailed usage and hardware configuration, please refer to other posts)

I will configure the DVPi to Dual Mode.  Since it's in Single Mode now, only VFOA works.
Since VFOB copies the settings of VFOA as it is, it is necessary to test whether VFOA works well.

Change TG



Reception is good. You have to test the transmission. If you are using D-Star, I recommend testing up to D-Star.



3.7 Dual Mode Settings

Connect to DVPi via SSH Client


Execute the setdvs2.sh command.
  (./setdvs2.sh new unique number, The unique number is the new Hotspot number.
  ex ./setdvs2.sh 38)


You can ignore the following error messages during script execution. (This is because it is a command to delete if it is already installed)

When all execution is completed, it asks if you want to reboot as follows.
No reboot required. This is because DVPi Manager will cause the DVPi to reboot.


Run DVPI manager

Click the 'DVPi Basic Setup'


After selecting Dual VFO as shown below, click the 'Apply All Setting' button.
(You may select 'Use Voice' if you wish to use the voice guidance function of DVPi)


When all settings are completed, DVPi automatically reboots.


After rebooting, DVPi operates in Dual Mode.


How to use DVPi's Dual Mode is described in detail in another post.




I tried changing the TG of VFO B.


3.8 DVPi's Hardware Settings
DVPi does not require any hardware other than the Raspberry Pi, sound card and LCD.
But for convenience, you can add things like buttons that you need.
How to add hardware to the DVPi is detailed in another post.

Run DVPi Manager

Click the 'Settings to use rotary encoder, PTT, and VOX functions' Button

In my case, I chose all of the below because I had a rotary encoder and buttons.
(If the direction of the rotary encoder is opposite, the numbers in the red square box below are interchanged)


When the activation selection for hardware is finished, click the 'Apply All Setting' button.



If the DVPi is equipped with a rotary encoder, it is possible to check who is in the TG as shown below.


4. conclusion

DVPi has quite a few features. In this post, I only set the settings for some of the features that are absolutely necessary for me.

You can find various features in different posts.






Release DVPI Version 1.0

✇KD8CEC Amateur Radio
By: noreply@blogger.com (KD8CEC)
2 January 2021 at 12:07

 

Release DVPI Version 1.0

Version 1.0 and Version 0.95 are the same. If you are using Version 0.95 you do not need to update to Version 1.0. 

DVPiManager has some features added. If you want to use features added in Versio 1.0, you only need to download dvpimanager.

DVPi uses the USRP Client protocol. When you install and use DVSwitch, you must read and comply with the license that appears. The user is responsible for the license for the use of DVPi.


1.Download Link

https://github.com/phdlee/dvpi/releases/tag/v1.0

https://github.com/phdlee/dvpi/releases/download/v1.0/dvpi_1.0.zip

https://github.com/phdlee/dvpi/releases/download/v1.0/dvpimanager_1.0.zip


2.What was added in Version 1.0 (from Version 0.95)

2.1 DVPi Manager 1.0 has added the ability to change the DMR password.

  Of course, you can change the DMR password using the DVSwitch Setup function in DVPiManager. But it will be a pretty long process.

If you have changed the DMR password in https://brandmeister.network/, you can easily change the DMR password in DVPiManager.



Enter the password you changed at brandmeister in the password field.

If you are using DVPi in DualMode, select both MMDVM_Bridge#1 and MMDVM_Bridge#2. If not, just choose MMDVM_Bridge#1.

Then click the'Change Password' button. Restart DVPi and your new password will take effect.


2.2 DVPi update function

If you are using DVPi 0.95 you do not need to update to Version 1.0. Just download DVPiManager 1.0.

But if you want your DVPi to appear as Version 1.0, click the Update button.



It automatically downloads and updates DVPi executable files from the web.

When all updates have been completed, the following message is displayed.

If you restart DVPi, Version 1.0 will be displayed. 

If the update fails, you can download the DVPi executable file below.

https://github.com/phdlee/dvpi/releases/download/v1.0/dvpi_up.zip


3. Getting started with DVPi

Posts on DVPi :  http://www.hamskey.com/search/label/dvpi

DVPi works without additional circuitry. You can configure additional circuits when you want to be more convenient.


Thank you for using DVPi.

Next time, I'll post a new kind of article.

Ian KD8CEC









Release DVPi Version 0.88 - Dual Mode, D-Star, Function Key 2

✇KD8CEC Amateur Radio
By: noreply@blogger.com (KD8CEC)
29 September 2020 at 14:43

 Release DVPi Version 0.88 - Dual Mode, D-Star, Function Key 2

DVPi uses the USRP Client protocol.

When you install and use DVSwitch, you must read and comply with the license that appears.

Version 0.88 is a test version. If you want a stable version, please wait for Version 1.0.


1.How to install

Download : https://github.com/phdlee/dvpi/releases/tag/V0.88

Please check the previous installation documentation for detailed installation instructions. This post only describes what was added in Version 0.88.

http://www.hamskey.com/2020/08/release-dvpi-07-1installing-on-micro-sd.html


2. What was added in Version 0.88

2.1  D-Star protocol 

    You can use D-Star only by checking whether to 'Enable D-Star' in DVPi Manager.

   


Touch the 'More' button -> Touch the 'Mode (displayed DMR or DStar)' Button


The video below shows the activation of D-Star during the initial installation of DVPi.


If you are already using D-Star, you will not be able to use it on two at the same time. If you want to use D-Star in DVPi, you need to log off in another device. If anyone has solved this problem, please tell me.


2.2 Dual Mode

You can use two VFOs in the same way as a conventional VHF/UHF transceiver.

You can use two DVSwitch servers or DVLink. Or, if you operate DVPi as Standalone, you can create session 2 by copying the existing installed DVSwitch in DVPi.

If you are using DVPi stand alone, just run the setdvs2.sh command to copy the DVSwitch installed in DVPi and add a new session.


Unique ID values must be entered differently from existing values. 

Example)

 Session 1 Unique ID is 51


Sesssion 2 Unique ID is 58

In order to distinguish Hotspot in DMR network, you must use different Unique ID.


Select Dual VFO in DVPi Manager.


It will operate in Dual Mode as shown below.

Important Point: If you use DVPi stand alone, D-Star only works on VFO A.

The video below shows how to create Session 2 by copying the DVSwitch installed in DVPi and operate DVPi as Dual Mode.



2.3 Function Switch 2

  Function Switch2 can be used as Mode change or VFO change according to your selection.

Example of using Function Switch2 as a mode change switch




3.conclusion

The host.brandmeister.network server is not serviced, and the entire Talkgroup status can no longer be retrieved. So, the underline of DVPi's Talkgroup Button is disabled.

I'm trying to restore that functionality in Version 0.9. If we connect to brandmester.network directly, it will generate quite a lot of traffic. This is a problem for us as well, but it could also cause problems on the brandmeister.network server.

So I am thinking of building a separate server to minimize traffic. 

Until version 1.0, we plan to stabilize without adding features.

Thank you for using and testing.

We are always grateful to the DVSwitch team for implementing most of the features.

Ian KD8CEC




Improvements to use the FT8 protocol on the Cortex-M base

✇KD8CEC Amateur Radio
By: noreply@blogger.com (KD8CEC)
29 May 2019 at 08:01

Improvements to use the FT8 protocol on the Cortex-M base

Several experiments are underway to use FT8 on the Cortex-M base. The previous experiment can be seen in the link below.
http://www.hamskey.com/2019/05/ft8-wsjt-x-20-protocol-decoding-in.html




1.Previous experiment
 1.1 Implement FT8 protocol to operate on Cortex-M base
 Refrence :
  https://physics.princeton.edu/pulsar/k1jt/wsjtx.html
  https://physics.princeton.edu/pulsar/k1jt/wsjtx-2.1.0-rc5.tgz
  https://github.com/kgoba/ft8_lib
  https://github.com/phdlee/ft8_lib (forked from kgoba/ft8_lib and modified)

  and gcc fortran compiler

 1.2 Adjust Sampling Frequency and FFT size to use FPU of MCU
   http://www.hamskey.com/2019/05/ft8-wsjt-x-20-protocol-decoding-in.html

 1.3 Previous experiment results
  The FT8 protocol should be completed decoding and ready for next transmission within 15 seconds. The encoding for FT8 transmission is very simple and time consuming, so Ignore it.
  For normal communication, it is still necessary to reduce the time by about 2 to 3 seconds.

2. Parallel processing using DMA and FPU for speed improvement
 The experimental conditions are the same as before.

 2.1 Structure for FT8 decoding
  Approximately eight steps are required to decode FT8 in Wsjt-X 2.0. I divided the time consuming part into four large parts.
Power Data (frequency domain data per time unit)

The FT8 requires 12.65sec of transmission time, but I added 900msec to account for the time error. (This time may change later)

After receiving the data for about 13.5 seconds, the FFT process is performed.
It is the longest part of decoding the FT8 signal. (3.5sec)

I adjusted the sampling rate and the FFT unit to use this part in the Cortex-M's built-in FPU. As a result, I reduced the time by about 2 seconds.
http://www.hamskey.com/2019/05/ft8-wsjt-x-20-protocol-decoding-in.html


 2.2 Modified Structure for FT8 decoding

Power Data (frequency domain data per time unit)

I changed the structure so that I could process the FFT together while receiving the signal.

Receiving data is handled by DMA, while Main Core is processing FFT while DMA is receiving data. Note that the FFT processing must end within the DMA 1 cycle.
To understand Cortex-M's events, handlers, and pending times, I recommend the following book: https://www.amazon.com/Definitive-Guide-Cortex-Cortex-M0-Processors/dp/0128032774


This method reduces most of the time required for FFT.


3. Hash callsign (Recent callsign)
 In Wsjt-x 2.0, a non-standard callsign was added to extend the FT8 protocol. This is the best way to add functionality without changing the length of the protocol.

non-standard callsign has 58bit Length
1234567890123456789012345678901234567890123456789012345678
1111111111111111111111111111111111111111111111111111111111
=> Dec 288230376151711743

Non-standard callsign can only use the following 38 characters.
 0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ/

38^11 = 238572050223552512
58bit can transmit up to 11 characters.

Below is the processing structure of Non standard Callsign added in Wsjt-x 2.0.

In this experiment, I added the above structure to make it compatible with Wsjt-x 2.0


4. Experiment
 The experimental conditions are the same as before.
I used one UART as the MCU's output device for debugging.

 4.1 Processing speed improvement test
Ready


Start Receive and FFT -> Calculate power
In the screen below, each time two "." Are output, the FFT operation is performed by parallel processing.


complete decoding


620ms + 887ms = 1507msec


Almost came close to the goal. But there is a problem.
The less the number of decoded messages, the longer it takes.
Up to 1 sec can be increased.
That is, the time to decode the message is variable. 800msec ~ 1500msec


 4.2 non standard callsign test
non standard protocol ('CQ OZ/LA6OP') is decode and displayed normally on the screen below.

'OZ / LA6OP' will be stored in the hash10, has12, and hash22 repositories respectively.


The stored hash code is being converted normally.
(IZ4... <OZ/LA6OP> >


Below is another example of a non standard call


Below is another example of a non standard call


Test Video for this article


5. Conclusion
Perhaps the next experiment may be delayed.
My main project (for business) has started and I am going to be very busy with this semester class lecture.
My seasonal courses are matlab related classes. Maybe I could use this project for my class.
Whenever it is time, I will worry for improvement.

Thanks for reading.
Ian KD8CEC




FT8 (Wsjt-x 2.0) protocol decoding in Cortex-M for experiment

✇KD8CEC Amateur Radio
By: noreply@blogger.com (KD8CEC)
18 May 2019 at 14:50

FT8 (Wsjt-x 2.0) protocol decoding in Cortex-M for experiment

I implemented FT8 signal decoding on the STM32F746G-Disc board for Expermental.
I want to test whether Cortex-M based FT8 communication is possible. I used Wsjt-x 2.0 and some source code to enable FT8 decoding on the Cortex-M7 base.
I received the FT8 signal directly to the microphones (mems) on the STM32F746G-Disc board.

1.Implementation and experiment preparation
I have used web sdr for the experiment and can do real time testing.

The decoding comparison used Wsjt-x 2.05 (for FT4)

The red square in the picture below is the microphone for receiving the FT8 signal.

2.Experiment

First Decoding :
Compared to Wsjt-x 2.0, decoding is delayed about 2 seconds.

Second Decoding : Wsjt-x has already been decoded.

Cortex-M was decoded about 2 seconds later.


Test Video

3.conclusion
Several improvements have been made to the Cortex-M, but it is still difficult to use.
If 2 seconds are delayed, the next signal transmission has already begun.

The STM32F746 is 216Mhz and I have been successful in overclocking near 300Mhz a few years ago. (300Mhz is not accurate)

But I will not solve this problem with Overclock. I will keep the CPU speed below 216Mhz for stability.

The part that needs the most time to decode the FT8 protocol is the FFT processing part.


FT8 : Tone spacing = 6.25Hz * 8FSK = 50Hz

FFT Size : 3840 = 1920 * 2
             1920 = 12000(bitrate) / 6.25Hz (Tone spacing)
In this way, the FFT Bin unit will be 6.25 Hz.

I modified the Bitrate to slightly reduce the FFT Size while maintaining 6.25Hz. I also modified the Kiss-FFT library to work with Cortex-M.

I am going to make a few more improvements to fit Cortex-M. As a result of the improvement, if it is available in Cortex-M, I will make it public.

Thank you for reading

Release EU1KY AA Firmware CEC Version 0.53

✇KD8CEC Amateur Radio
By: noreply@blogger.com (KD8CEC)
4 May 2019 at 13:54

Release EU1KY AA Firmware CEC Version 0.53 

This version is a development version and may be unstable, and some of the features included in this version may be removed from V1.0, Stabilized version V0.40 has been released, and stabilized version is posted separately.




1. Added or improved in V0.53

  Please see the link below for revisions and improvements until Version 0.40
  (Do not download the firmware from the above page. old version)
  http://www.hamskey.com/2019/03/released-eu1ky-antenna-analyzer-version.html

  Please see the link below for revisions and improvements until Version 0.34
  (Do not download the firmware from the above page. old version)
  http://www.hamskey.com/2019/03/released-eu1ky-antenna-analyzer-version.html

  Please see the link below for revisions and improvements until Version 0.21
  (Do not download the firmware from the above page. old version)
  http://www.hamskey.com/2019/03/release-firmware-cec-version-021-for.html


1.1 Audio DSP function added

This is an Audio DSP that uses a microphone attached to the STM32F746 board.


It is a function to filter the sound frequency range coming from the radio.


Band Pass Filter (50Hz, 100Hz, 150Hz)


User Filter (Variable Bandwidth)

Please refer to LInk below for how to use 'Audio DSP'
http://www.hamskey.com/2019/05/how-to-use-audio-dsp-on-antenna.html





1.2 The frequency of WSPR has been expanded.
At the request of the tester, 630M, 2190M, 4m, 2m have been added.
Please use WSPR only for added band. (630, 2190, 4, 2)
In the added band, only WSPR works normally.


In the 2m band, the Si5351 clock must be stable. I recommend using 27Mhz TCXO for wspr on 2m.
You can use any oscillator in any band except 2m.

Videos related to WSPR will be posted soon.

1.3 I have changed the GUI of 'Single Frequency' and 'Tune SWR'


Single Frequency


Tune SWR

1.4 I changed the GUI of S21-Gain to increase the size of the Auto button.


1.5 Other minor updates
  - Apply default settings to users who are new to WSPR
  - Fixed an issue where fonts would go out of range in the LCR meter.

video of brief introduction to Version 5.0.

My development board configuration values and calibration test


2. Download Firmware
https://drive.google.com/file/d/12jHjQ6NNFlgPCNg6xkl4IH6zr334eHpA/view


3. Conclusion
I would appreciate it if you test and give feedback.
If there is no problem after 1 week ~ 2 weeks test, version name will be changed to stable version.

If you want a stable version, please use the link below. 
stabilized version : http://www.hamskey.com/2019/03/eu1ky-antenna-analyzer-cec-stabilized.html

The current stable version is V0.40.

Thank you for your test.
Ian KD8CEC





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