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Multiple Mercury Receivers

I am testing the new Mercury/Ozy code to support multiple receivers on a single Mercury card.

I have changed the architecture so that I now have a server application talking to OZY over the USB bus and talking to client applications over UDP sockets.

A client application can connect to the server requesting a specific receiver. The server currently only allows 1 client connection for each receiver.

This is the first attempt to run 3 copies of ghpsdr. Needs some debugging as the spectrum display is not correct, but the basic concept is there.

Split Transmit

Trying to design a usable UI as the capabilities get more complex is not easy!

I have added the split rx/tx full/half duplex capability. This is using VFO-A for receive and VFO-B for transmit. Now that VFO-B is used for this I have changed the sub receiver to maintain it's own receive frequency.

In the image above the main receiver is receiving on 14.195200 MHz, the sub receiver is receiving on 14.219700 MHz and the transmitter is transmitting on 14.241900 MHz. All running full duplex! Of course, the transmit frequency does not have to be in the displayed passband, but then it would not be visible!

I am also adding transverter support for the split frequency mode mainly to support working cross band on the satellites.

Note that this is currently working with a version of the firmware that is not yet generally released.

Next major UI design issue will be how to support multiple receivers both within one Mercury card and with multiple mercury cards.

AO-51 Mode-S

Click for full size image

I hooked up my Mode-S down converter and quad patch antenna as I saw that AO-51 was running in Mode-S for the next few days.

Here you can see the Doppler shift as AO-51 approaches my QTH. Running at 4 frames per second for the display update so the waterfall represents 50 seconds. I need to add an interface (CAT?) to allow another program to control the frequency. On a subsequent pass I used the sub-rx to track the doppler manually, leaving the main rx on centre frequency of 2401.200.

The antenna was simply sitting on the window ledge of the shack close to a wireless router, hence the strong qrm.

ISS

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Here is a screen dump of part of an ISS pass (using a Microwave Modules 2Mtr Transverter) showing the bursts of AX.25 packets.

You can see the doppler shift from high to low frequency as it passes over. I slowed the display update rate to 5 samples per second, so the Waterfall represents about 40 seconds.

The 3 strong signals showing up on the Bandscope at around 20MHz (136MHz) are from Gatwick Airport which is close to my location.

Video of sub rx

The main rx audio is panned to the left and the sub rx audio is panned to the right.



The video was created using recordmydesktop running on Ubuntu 9.04.

iPhone video running on Simulator

Can't work out how to get the audio working on the iPhone simulator!

Now have the band buttons working correctly.

Sub RX

Added Sub RX for tuning second receiver (DttSP thread) across the passband.

Note the TX controls beginning to appear - coming soon.

Audio streaming to iPhone

I now have the audio streaming from ghpsdr to the iPhone. I am sending it at 8K samples per second and sounds OK. Did a very simple implementation of taking 1 in 6 of the 48K samples being fed back to Mercury. Also just sending one channel.

Now it needs the ability to change band, filters and mode for a fully functional internet radio.

I should get a development board for the iPhone next week which will let me dock the iPhone and get access to line-in and line-out. I intend to look at taking the I/Q data from a softrock receiver and processing it directly on the iPhone. Should make a great little portable receiver.

iPhone

I now have the iPhone working well displaying the spectrum from ghpsdr.

I have also added a button to configure the application.

Next step is to look at adding the audio stream.

More iPhone

I have now got the iPhone working when I can see real time spectrum from ghpsdr using a tcp socket to get the data.

I also added the ability to change frequency by dragging on the iPhone display.

Now to try to get the audio streaming to the iPhone as well ;-)

iPhone teaser ...

I got a little side tracked this week playing with the iPhone SDK. I wanted to see if I could get something working that will, at a minimum, display the spectrum for the currently selected frequency so that I could monitor HPSDR remotely using my iPhone.

This is some prototype code running on the iPhone Simulator (it does run on my iPhone as well). It is updating the display 15 times per second. The data is currently 2 seconds of spectrum samples (30*4096 samples) that I captured using ghpsdr and wrote them to a file that are repeated while the application runs.

Next step is to add the ability to ghpsdr to write them to a socket connection and add the code to the iPhone to make a socket connection to ghpsdr.

Better startup ...

The code now will detect that ozy is not powered on or plugged in and allow the user to retry.




It will then run initozy if required.

Added first cut at support for transverters

The svn store now has the first cut of code to support transverters:

svn://206.216.146.154/svn/repos_sdr_hpsdr/trunk/N6LYT/ghpsdr

Major updates to ghpsdr

Made some changes to cleanup the GUI and added support for clock source selection.

The version of DttSP has been replaced with a ported version of the current Windows DttSP code in preparation for the development of the transmit code to support Penelope.

Layout changes for ghpsdr

rev 1022 of ghpsdr now contains some layout changes along with some changes to the band stack.

Click on picture for full size

GTK+ GUI running on Mac

I finally managed to get ghpsdr compiled and running on the Mac. There are some USB performance problems that need to be resolved, but it is running. Required changes to the semaphores (I had forgotten that the mac did not like unnamed semaphores) and the libusb_open_vid_pid does not claim the interface as it does on the Linux version.

I will try to update the repository in the next couple of days.

Click on image to see full size

192K and display updates 30 times per second

I tried running at 192K with the display rate for the Panadapter/Waterfall running at 30 updates per second. Uses about 60% of the cpu (3.4GHz Intel dual core), but still no pops on the audio using the pre-2.7 Mercury/Ozy code that Phil will release when they have resolved a couple of problems. Now I can read the CW ;-)

Click on image to see full size

VLF Radio Time Signals

I was looking at me radio controlled clock and wondered what the signals looked like that they use. First time I have tried Mercury on VLF frequencies.

You can see the 3 time signal stations MSF on 60kHz in Rugby, England, HBG on 75 kHz in Prangins, Switzerland and DCF77 on 77.5KHz in Mainflingen, Germany.

ghpsdr - the video

Testing a new version of the Ozy/Mercury FPGA code. Seems to resolved my problems of lost audio when switching to 96k or 192k. Still get the occasional burst of frames from ozy where the sync has been lost.