The Ultimate 3 (Again)

Well,

You may remember back here that I showed you an Ultimate 3 kit.

Mikael, SA6BSS was kind enough to get intouch and let me know that my QRSS beacon was outside of the QRSS band!

So now I have RTFM and actually calibrated the unit properly, here's my QRSS signal on 30M viewed on his Grabber today:

I think I've fixed it now!

The Ultimate 3

Well,

Quite some time ago, I built myself an Ultimate 3 QRSS/WSPR beacon kit from QRP Labs.

Now this is a fab and groovy kit from the infamous Mr Hans Summers.

The completed kit is currently sat atop of my FT-817 and is configured to send WSPR beacon and a QRSS beacon both on the 30M band.

The output of the unit looks like this:

and is 13.12V peak to peak.

That's a power output of 420.2 mW or 26.3 dBm.

So, I've left this running for 24 hours connected to a simple 30M dipole in the garden, and here's the WSPR map of the resultant reception of my signal:

Never fails to amaze.

And here is my very beautiful Bonnie Dog:

Local conditions.

QRSS Beacon

Well,

Earlier on today I dug out an old QRSS beacon that I made for 30M. I plugged it into my 30M dipole and switched it on.

I've just found this on the internet:

This is from the live grabber belonging to LA5GOA, here I have annotated the image to highlight my callsign in the grabber:

The beacon is running about 6V Peak to Peak which is around 100mW. Clearly I need to turn the power down.

Local conditions.

Can we do it with Less - Part II

Well,

Following my musings last time about how far not much RF can travel, I took another look at the site of W3PM here:

http://www.knology.net/~gmarcus/

This is where I found the inspiration for my WSPR beacon back here:

http://g0mgx.blogspot.co.uk/2012/05/back-to-real-homebrewing.html

So I took a look at the latest software for the project - noting that my callsign appears in the credits! - then just reprogrammed my project with the latest code after changing the appropriate bits like callsign and locator et cetera.

I then calibrated the output for an accurate 100mW - I also calculated the loss in the coax between the output and the antenna - I make that about 1dB.

So, I have 100mW or 20bBm out of the box, 1dB loss in the coax = 19dBm or about 80mW into the antenna.

Remembering that propagation conditions are quite poor at the moment, here are the results of an overnight run:

Simply stunning, egh?

Can we do it with less?

Well,

My 30M QRSS Arduino based beacon is still on the air; and I am receiving reports via e-mail from time to time. The most recent was from Andre, DL8WX; he is in JO30WE 716.75 km (445.390 miles), bearing 112.3 degrees from me and said "I found ur beacon last night with a strong signal on 10140.02 kHz for the first time!". The beacon project build is here:

http://g0mgx.blogspot.co.uk/2013/06/qrssing-again.html

Last night, I left my FT-DX-3000 WSPRing on 40M using the dipole I made here:

http://g0mgx.blogspot.co.uk/2013/04/well-further-to-my-musings-last-time.html

and here's the result:

Before I left it alone I measured the power out exactly using my Arduino based power meter from here:

http://g0mgx.blogspot.co.uk/2012/11/the-power-is-with-me.html

and the list of stations heard/hearing looks like this:

So, you have to wonder, if this is achievable with 40dbM (10dBW or 10 watts), what could we achieve with far less power?

Given that the most recent 50mW QRSS beacon project is Arduino based, I could write some software to generate WSPR using that, I would need a GPS to give me an accurate time source, there's also exactly that in a (not quite finished) project from here:

http://g0mgx.blogspot.co.uk/2012/05/more-wspring-and-qrssing.html

or even this Hans Summers project from here will do it exactly as I describe above (GPS and WSPR):

http://g0mgx.blogspot.co.uk/2012/07/qrssing-again.html

So, time to fiddle!

As a slight aside, I'm going to Malta for a week soon and I have 9H3JM for use there; as my FT-450 is in Doha I have bought myself an FT-817 to take with me. This radio is capable of outputting much lower power levels than the other radios I have here, so perhaps the easiest option for some really low power WSPR is to use that?

Lets see.

I Never Fail to be Amazed

Well,

Just been rummaging through recent email in my inbox and a digest from the QRSS Knights has caught my eye. There are a set of reports from Joze, S52AB who is in locator JN75ou.

Here's the image that one of his reports are based on (Joze has done the annotation, not me):

So the distance from IO93ga (me) to JN75ou (him) is 1439.44 km or 894.470 miles at a bearing of 116.9 degrees, so my 50mW is making it all the way to Slovenia.

Would you Adam and Eve it?

QRSSing Again, Again

Well,

Been fiddling a little more here, and stuck the Arduino QRSS beacon inside a box - it's currently being powered by an old bench PSU that I made many years ago - this PSU has a really nice toroidal  transformer inside it.

Here's the box on the shelf in the shack:

Anyhow, PA2OHH, has a really neat on-line grabber for QRSS monitoring on 30M here:

http://www.qsl.net/pa2ohh/grabber.htm

tnx Onno!

And here is a screen grab that I've annotated to aid reading:

So, my Arduino QRSS beacon, which has a p-to-p output of about 4.8V (that's about 60mW- calculated by p-to-p squared / 400) is being decoded in PA2 land (actually in square JO33df) which is about 520km.

I'm lower in frequency than I thought, although I didn't check the frequency after I put the gubbins in the box - so a little tweak up a smidgen and all should be well.

Here's another shot from PA2OHH after I have altered the TX frequency, you can now see my call around 14.0140.135 (ish):

And this one is an image Onno sent to me as a report of my sigs:

As a quick experiment, I decided to test the characteristics of the low pass filter on the output of the QRSS beacon, here's what I find using the tracking generator in the new Spectrum Analyser thingamabob:

So the filter is passing up to 10.something MHz with little or no attenuation and the first harmonic is going to be almost 50dB down - all good!

All in all, not bad, egh?

QRSSing Again

Well,

You may remember way back when I did some mucking about with QRSS (that's really low power slow morse):

http://g0mgx.blogspot.co.uk/2010/12/qrss-beacon.html

I've found another kit from Hans Summers:

www.hanssummers.com

This time it's an Arduino shield - so I can write and fiddle with the software to drive this myself.

Here's the kit as delivered:

it's very simple to make:

and here is the finished thing sat on top of it's Arduino host:

So, a bit of simple software to get the board to send my callsign in FSK QRSS mode, and we now need to align the beacon to be somewhere between 10.140.000 and 10.140.100 - that's quite a narrow band to aim at.

The easiest way seems to be to use the Argo software - it's a kind of spectrum monitoring thingamabob where you can set the offsets associated with the radio connected. So I tuned by FT5000 to 10.139.000 USB (because the carrier offset in USB is 1000Hz) and then entered that as the offset in the Argo software. I then adjusted the beacon to be at what looks like 10.140.060:

I dont really understand why I can see more faded images of the beacon in other parts of the spectrum, but the main beacon seems to be around 10.140.060/065. You can see the end of an "X" and then the start of my call again with a "G" then a "0".

Looking at the output of the beacon on my new Spectrum Analyser thingy, we see this:

The Analyser cant go to an accurate enough frequency, but it confirms that the RF peak is at 10.140 - so I am certainly in the right ballpark and my maths isn't out of bonk.

It looks good and clean on the 'scope too:

Might just take this back with me to A71 land and see what we can see. In the meantime I'll connect this to an antenna and see if anyone can spot me!

Fun, egh?

QRSSing Again

Well, a while ago I stumbled upon a kit of parts here:

http://www.hanssummers.com/qrsskitmm.html

I thought it looked rather fun. The kit arrived the other day and it's a very simple bit of equipment all based around a single processor. The link above will give you details of all the different modes et cetera that the kit can produce, but here's the finished version of mine:

It's in a ridiculously large box which mainly contains fresh air, but I had the enclosure here anyhow so figured I may as well use it. I've built a power supply out of bits from the junk box.

The first time I plugged it in I had the electrolytic capacitor the wrong way round in the power supply; it exploded with quite a bang! So I replaced that and all is now well.

Cat's not impressed as normal:

All good fun though, egh?

It's been ages.....

Work, work and more work. That's all there is to it at the moment; finaly, however, I now have some time to:

1. Catch up with my Blog;
2. Play some Radio!

The WSPR and QRSS beacon I was begining to develop here:

http://g0mgx.blogspot.co.uk/2012/05/back-to-real-homebrewing.html

is finaly complete!

The output amplifier that I was fiddling with ended up as an Analogue Devices AD8008, which I ended up mounting on a kind of break out board that I had:

You can see how this helps with the "ugly" construction and the use of SMD devices. I can't remember where I got this break out type board from, but it certainly came in useful here!

Many, many moons ago I built myself an QRP ATU, and now I have it permanently hooked up between this beacon and a cheap vertical HF antenna I have slung up against the side of the house. So the setup looks like this:

The WSPR and QRSS beacon is written in C for Arduino:

www.arduino.cc

and I've made quite a few changes to the source code which can be found here in anyone is interested:

http://www.qsl.net/g0mgx/files/Mega_DDS_60_v2_1_G0MGX_eeprom.ino

I've got this hooked up to a GPS module which is sitting in the window of the shack, this is providing the timing data to the WSPR and QRSS beacon. Currently I've got it running on 30M and will be doing some checks for reports in the near future. It's utputting a stagering 20mW!!!!

I've also started (well nearly finided) re-writting the code for my recent DDS project in Arduino; I was never quite happy with the way that ended up, so using my new found C skills I have written (from scratch) the DDS control software.

The original project is here:

http://g0mgx.blogspot.co.uk/2012/02/dds-running-well.html

The functionality is the same as before, it's just that it works better and I have a much better understanding of how it works.

The source code for this is here:

http://www.qsl.net/g0mgx/files/G0MGX_DDS_FINAL.ino

I can claim some originality in this one!

Here's the inside of the replacement DDS, you can see that it's now Arduino based:

Please excuse the clothes pegs; they are just holding bits in place whilst the glue dries. I'll post again about this piece of work once completed. It's kind of soak testing right now as there is a calibration routine included to adjust the DDS for any misalignment in the frequency output due to clock inaccuracies.

All good though, egh?

More WSPRing and QRSSing

Well,

After my last ramblings here:

http://g0mgx.blogspot.co.uk/2012/05/back-to-real-homebrewing.html

I've been doing some travelling with work, so progress is not so good. However, I have entered into a dialogue with a number of folk over my observation that the amplitude of the DSS reduces as the frequency increases. Some suggestions to overcome this mainly include AGC type circuitry or utilising pin 12 of the AD9851 to feedback a voltage to set the output amplitude based on a sample of the output (recursion see recursion). The most interesting feedback that I got, however, was not that the amplitude was dropping with an increase in frequency, but that my scope wasn't reading the signals correctly. The theory being that as the frequency increases my scope sensitivity drops off....

I ended up plotting this graph:

This is implying that my scope starts to take a dive, accuracy wise, after about 1MHz, this is the blue line with the y-axis indicating how many dB my scope is "deaf" by. The yellow line is the same signal but through the on-board low pass filter from the DDS module. This seems to imply that the LPF is rather badly designed also. If this theory is correct I need to subtract my scope deafness from the drop in signal out of the LPF. If at this stage we remember that 6dB is half voltage, this is not insignificant!

All rather confusing? My scope is a 100MHz rated fluke which I thought was supposed to be a good quality instrument. So, is this behaviour typical or is my scope a pile of dingos kidneys? I wonder...

I've made a bit of progress boxing the WSPR and QRSS beacon project:

So far, I have tried a number of output amplifiers, the first based on the circuit in my original QRSS beacon, from back in December 2010:

http://g0mgx.blogspot.co.uk/2010/12/qrss-beacon.html

This gives me a nice clean 4v P-to-P voltage out, but I wanted more than that, so either I add another stage or do something else.

I have also tried an output amp based on the Analogue Devices AD8008, this works OK also. I'm off on my travels again tomorrow, so I'll pick this up again when I get back.

All good fun though, egh?

Back to real homebrewing!

You may recall my discovery back here:

http://g0mgx.blogspot.co.uk/2012/04/well-this-looks-just-great.html

So, Ive managed to make some progress. I've modified the software from W3PM from here:

http://www.knology.net/~gmarcus/

and have managed to get the GPS module working and also the DDS drive routines....

The code is written in C for the Arduino; and it's now interfaced to a four-line LCD, the AD9851 DDS module and the GPS receiver. The GPS module isn't in the picture as it's hanging out the window so it has visibility to the sky.

I've started to box the project, and have also built an RF amp to get me a staggering 100mW out...

Progress has been quite good today, I need to think about how I can get the RF levels the same on each band because as the frequency increases, so the amplitude out of the DDS and hence out of the RF amplifier decreases. I'm really not sure how to tackle that one, so I may have to ask for some help here.

Yesterday myself and Vince G0ORC went over to the "Dambusters Rally":

http://www.qsl.net/gb4tcm/dambusters.html

The rally was really good, albeit a bit small, but there was loads of really good radio junk to rummage about in. I picked up all sorts of stuff including this meter which I am rather proud of:

I've cleaned it up, mounted it on some wood, and stuck it in the corner of the shack with some amps flowing through it...

The next step will be to put some lighting inside...

Looks god though, agree?