Friday, April 29, 2016

Omnia SDR on WSPR

Omnia SDR on WSPR

Putting your Omnia SDR on one of the digital modes!

 
Updated 4/30/2016-- Synchronizing your computer to Internet time.
 
 
One of the really neat features of the QRP SDR radios is the ability to couple these radios with several automated computer programs where the radio + computer get to make "QSO's" while you are off doing other things. WSPR a program developed by Nobel Laureate, Joe Taylor, K1JT is a really cool program where your rig listens for weak signals and then uses  automated reporting via the Internet to a central database. WSPR is an acronym for Weak Signal Propagation Reporting. My Omnia SDR operates on 60-20M and so that is a great mix for 24 hour operation. So far it has been used on 40,30 and 20M WSPR.
 
Using this program your radio can listen for a variable time, based on a synchronized Internet clock,  say 80% of the time and for 20% of the time your radio takes a turn at transmitting. Stations all over the world provide signal reports. Aside from the thrill of having your signal heard around the world, there is much to learn about propagation on the various bands and at various times of the day. The SDR waterfall let's you visually see the signals.

[Here is an important consideration --your computer clock. Note that earlier I mentioned about synchronized internet time. You might find as I did when I first started with WSPR about 6 years ago --it wasn't working. I thought I had done everything right! But the problem was my computer clock was not correct so there was the synchronization problem. Periodically I synchronize my computer clock with nist. If you do not know how to update your computer clock do an internet search for info on how to do that!]
 
A typical database display would look like what is shown below. I had a bit of a problem fitting this in one photo as there is additional data along the right hand side (not shown)  which displays actual distances for stations being heard and stations hearing your signal. The best "DX" for me was when I lived in Washington State and was heard over 11,000 miles away running 1/2 watt. QRP Rules!
 
 The later log shows all of the data --notice the trip down to ZL Land --about 6500 Miles.
 
 
 

The first problem one has in using the Omnia SDR with the WSPR program is how to interface the radio to the WSPR program. There are set up functions that must be done in the HDSDR Program as well as the WSPR program if you want to have the full functionality of not only receiving but also transmitting. If you just want to listen and report other stations then some of the additional steps and additional software is not required.
 
A long time ago when I was using the Power SDRIQ on my computer along with the SoftRock V6.3 and the M-Audio Delta 44 sound card two additional pieces were needed and these include installing software for Virtual Audio Cables (VAC) and for the establishment of Virtual Com Ports which must be in pairs (Com0Com). The VAC software at that time had to be purchased from a site in Russia but the Virtual Com Port software is a freebie download. I happen to have the VAC software so that was not an additional purchase but you may need to buy the VAC software. On the Com Ports you can set up an unlimited number of pairs and name them what you will --I chose Com Ports 4 and 5.
 
The Com Port data pair will need to be entered in both the HDSDR software as well as the WSPR software. When you down load the VAC you will have Virtual Cable 1 and Virtual Cable 2. In essence you will connect Com Port 4 to Com Port 5 and similarly Virtual Cable 1 on the HDSDR gets connected to Virtual Cable 2 on WSPR. Sounds complicated? It is and it took me several days to get it working. Caution --what you set up on HDSDR for normal SSB and other modes of operation it will be different from what is needed to do WSPR -- that is why it took me several days to get it working.
 
A photo is worth 1000 words. Look carefully at the choices for as you will see on the Sound Card menu that the Rx Output connects to Virtual Cable 1 and the Tx Input connects to Virtual Cable 2. This is different than the normal operation Omnia SDR setup where the RX out is connected to Speakers and the Tx Input is connected to the Microphone. On the WSPR setup note that the Audio Input is from Virtual Cable 1 (which is the Rx Output) and the Audio Output from the WSPR program is Virtual Cable 2 which is now the TX input. Bottom line you want the WSPR program to hear the Omnia Rx via VAC 1 and the transmitted output from the WSPR program is sent to the Omnia via VAC2.
 
Look also at the other settings in the WSPR setup. You must call the radio a TS2000 and you are using Com 4 and CAT to turn on the transmitter. Note also the other settings such as the Baud rate and the other two settings. [The HDSDR set up tutorial specifies the Kenwood TS2000 Selection.]
 
Now in the HDSDR menu under Options you must also bring up the CAT to HDSDR Menu and elect Com 5 as the Com Port (Com Pairs) and the Baud rate at 9600 and the method of keying is None (CAT) and be sure to Enable the CAT to HDSDR
 

 
 
There are some additional adjustments that need to be made. FIRST!!!! There are specific WSPR frequencies which can be selected from a drop down menu on the WSPR GUI. On 40M the listening frequency is 7.038600 KHz. and on 20M the listening frequency is 14.095600. There is an automatic transmit offset (higher in frequency). It should be mentioned that while their are stock frequencies you can "twizzle" these so that you are slightly higher or lower so as to avoid QRM.SECOND the radio must be in UPPER SIDEBAND no matter what band you choose.
 
Next is signal level. In the lower left hand corner of the WSPR GUI is a box marked Rx noise where the game play is to have the Rx Noise = 0 dB. This can be achieved by setting the AGC slider bar to mid-point and the Volume slider then can be used to set the value to attain 0 dB. I have found that with my Omnia SDR that the volume is set to a very low level almost near the left hand edge of the slider bar.
 
One additional adjustment in the WSPR setup GUI is the power level you are running. 30 dBm is one watt and 33 dBm  is two watts (well almost). When the Omnia SDR is placed into transmit the Volume/AGC bars switches over to Mic Gain and Power Output, I set the Output to the maximum right hand side and then adjust the actual power output with the microphone gain slider. I am able to set the Pout to one watt (30 dBm) or two watts (33 dBm).
 
There just a couple of more changes. The VAC likes to see a bandwidth of 44.1 KHz. On the Bandwidth tab of the HDSDR -- that is one of the selections and thus set both the Tx and Rx bandwidth to 44.1 KHz.
 
I did not see this when I ran Power SDRIQ (for about 4 years) but just now noticed that when you change bands on the WSPR Band tab -- the Omnia automatically changes bands. That is something new and averts a problem I previously  had where you had to manually set both of them --at times reports were given as being on 40M when the radio was actually on 20M. I even got a nasty note from a DX ham that I reported him on a specific band (my error) and that frequency was not allowed in his country --so simple errors can be a headache for others. The HDSDR has a bit of a safeguard with the frequency selections.
 
Have fun.
 
73's
Pete N6QW


Sunday, April 24, 2016

Our Hobby Takes on a New Look!

Our Changing  Hobby...


Added schematic for the linear amp switching circuit. 4/24/2016
Added Photo of the Omnia SDR working with the Raspberry Pi2 4/26/2016

In 1959 when I was first licensed, a modest station occupied a large part of the operating desk. Typically a first station might be a Hallicrafter's S-38E receiver (also known as a Widow Maker because it was operated directly off of the power mains). If you got the plug in the socket the wrong way and upon touching the radio you very likely got a hefty dose of 110 VAC. The idea was to be cost effective, thus no power transformer, although the price of that jewel in 1959 is like paying upwards of $400 today.
 
To match that radio were a variety of transmitter kits from companies no longer in business today like Heathkit, WRL, Eico and even Ameco . Of course many rolled their own from plans found in QST or the ARRL handbook when those publications fostered home construction. Sadly today that focused has shifted. Thank God for the GQRP SPRAT and QRP Quarterly where many home construction projects abound. I should mention my first station was a converted ARC-5 receiver and the transmitter was a 6V6 crystal oscillator on a wooden chassis. The really high performance radios were simply out of my league. The Collins equipment was like a whole years salary in 1959. The high end Hallicrafters were in the same ball park. So it was that many an entry level station was by today's standards pretty marginal. In 1959 that rudimentary station operated CW only!
 
But there is a nostalgia side to some of that old gear especially when a rusty old S-38E shows up on our doorstep perhaps with a burnt out front end because of the 110 VAC findings its way into the first mixer tube when the plug was inserted in the wrong direction. Innate in all hams is the thought --"hey I can fix this and get it working again". But once you get it working again --it is still an S-38E. This is akin to putting lipstick on a pig. At closing time, no matter how much alcohol has been consumed, it is still a pig!
 
[For those who are scratching their heads -- many of the cheapo radios did not employ a power transformer but used a two wire system where one side was hot and the other neutral. If you had the hot side to ground then when you added a ground to the hot chassis you would see sparks fly. Many times that ground connection was you! Thus the term widow maker!]
 
Fast forward to 2016 and we now have the very best of all worlds with the mating of computers to our ham gear and the cash outlay in today's dollars is less than the cost of an S-38E. Yes today's radios are "digi", involve black boxes and in the background, computer number crunching; but the final results are amazing.
 
Below is one of the latest offerings from Omnia SDR (click on Omnia SDR )which I believe is the successor to the Peaberry. It is an SDR radio that can optionally be bought as a total part kit rig or one that is mostly factory assembled. For those who hate to wind toroid transformers you can even purchase a fully assembled toroid kit. Note the diminutive size of the Omnia SDR when compared to the mechanical pencil and the 15 inch monitor.
 
 
 
The Omnia SDR comes in various frequency ranges and the one I purchased covers 60, 40, 30 and 20 Meters. Other variants cover above and below those bands. Given my limited time availability, I bought the semi kit and the toroid kit. The total cost was around $180. Assembly beyond the semi-kit involves installing the band specific filters and the final RF amplifier components (BS170's like the SoftRocks).
 
The Omnia SDR has some very nice built in features including the I/Q Signal Processing right on the board and other features  include external linear amplifier switching and controlling an external antenna tuner. The Omnia SDR is supported using HDSDR (a free software program) but can be run using Power SDR or Quisk. My initial setup is with the HDSDR. Beyond the Omnia I have a shack computer running Windows 7, and the internal computer  sound card handles the receiver audio output and the microphone input. I ran a short test with a Symba USB sound dongle in place of the internal sound card and it works as well for these functions. This configuration was tested as I will be migrating the Omnia SDR to a Raspberry Pi3 and will need the Symba for those same functions.
 
To date after about three days of operation all on SSB I have made about a dozen contacts on 40 Meters with half of those running barefoot at one watt. I was even heard in Hawaii on 40 Meters running only one watt. The received audio is simply amazing and having operated an S-38E can only say it is like the difference between the dark ages and today. Below is a close up of the Omnia SDR with the only connection to the computer being the USB cable as seen in the upper right hand side of the board. The hand sketch in the photo is an electronic interface I am designing to control a linear amplifier from the Omnia SDR. I will formally post that schematic and photos of the interface board.
 
 
The Omnia SDR Company has chosen the HDSDR software as the officially supported software so that their product support can be focused around a singular software. The initial setup of the Omnia SDR rig requires the use of this software. That said, once working, the user is free to use any variant of SDR software based on their own preferences. I intend to migrate to Quisk and the Raspberry Pi3. Below is a photo of the HDSDR display.
 
 
I am truly impressed with the Omnia SDR and am looking forward to continued usage of this kit. By the time you add the Raspberry Pi3, a Lapdock Matrix 4G and the Symba USB sound card you will have invested less money than what an S-38E cost in 1959 --and all low voltage operation --no widow makers here.

 
 
 


 
 
This schematic includes two modes: one where a normally closed contact is required and the second, more common where a normally open contact is required.
 
Below is a photo of the completed circuit board.
 
 
 
 
Omnia SDR mated with a Raspberry Pi2
 
 
 
 
73's
Pete N6QW