GU8FBO (Guernsey) JT65a Terrestrial (Heard not worked)

I decoded Richard at 22:29z and again at 22:31z.  A few minutes later I also decoded G8BCG @ -20.  This entire summer I've been using a HackRF "SDR" radio and WSJT-X to monitor for 50 Mhz Openings @ 50.276 Mhz on JT65 & JT9.

I've also decoded about a week or two ago SV9CVY.

Today's opening was a bit unusual in that Europe seldom is open this late in the day to EM47.  It was neat to capture this while I was sitting there.  The first Decode I thought was bogus, then the second one came in.  Truth is I've not had any bogus decodes using WSJT-X.  I'm not using the 1.7-devel version which seems to decode a lot deeper into the noise.

HackRF One - EXTIO DLL - HDSDR (WORKS!)

I've been searching for an EXTIO DLL for the HackRF One that will work with HDSDR for years now.

https://github.com/jocover/ExtIO_HackRF

Finally came across this today!  AND BONUS!  IT WORKS!

I contacted the author and asked him to add some smaller sample rates of 4 and 2 MSPS.  He did that and posted the new release in just about 1-2 hours.  This is useful for weak-signal stuff I most do.  It allows the ability to get HDSDR's "Resolution Bandwidth" down to 7.6 hz when MSPS is @ 2.  Which in my experience shows weak CW signals up very well!

A little about how I use HDSDR. 

I use the 9 MHz IF OUTPUT from my Yaesu FTDX-5000 as the input source to whatever SDR I'm using to feed HDSDR.   I've been using a TCXO based Nooelec RTL and an OCXO upconverter I built myself.  Even with all that 'stability' the TCXO RTL drifts all the time.  Which is a total pain in the butt for CW over the coarse of a day.

After swapping out the EXTIO for RTL in my HDSDR install I fired it up with HackRF.   Although the HackRF has advertised a low range of 30 MHz or my experience has been that it works just fine down as far as 3.5 MHz in it's stock config.  Mine is about 1.5 years old now with recent firmware installed.

Anyway I setup HDSDR initially to use 9,000,000 hz.  HDSDR has a nifty option to display the VFO frequency of the Yaesu FTDX-5000 as it's frequency regardless of what input you're really using (9 MHz in my case).

There is also a way to automatically remove the DC Spike that would show up in the middle of the display if left as noted above.  To accomplish this I set the OPTIONS > RF Front-end Frequency "IF frequency" to 9098000 and the Global Offset to 98067.  This pushes the DC Spike well below my normal viewing area, and then the 'Auto RX DC Removal' notches it down to nothing.

In this way the DC spike goes away but everything stays lined up PERFECTLY for CW.

I also connected a GPSDO I've had around for a long time that I use with my Apache Labs "Hermes" SDR.  Tee GPSDO emits a super stable 10 MHz signal that Hermes and now the HackRF lock onto.  

In a 24 hour test just completed there was 0 hz drift noted on the HackRF.  Which is what I had expected (and hoped for).  This has been my experience with the GPSDO and Hermes so I didn't expect any difference.

------------

So all of this Eliminates use of an RTL (which are drifty little bastards, but VERY VERY useful I've used them for over 5 years now with very good success), and because the RTL's are limited to 24 MHz I have always used an Upconverter which has the potential to add noise from it's OSC, and add drift to the resulting signal input to the RTL.

I'm using the HackRF because it's what I have currently and because this EXTIO is now FINALLY available.

I plan to also buy and test the AirSpy and SDRPlay at some point since I've read they hear better than the HackRF.  BUT at this point I think I can actually relax after years of muxing around with RTL's that drift like crazy and spending way to much to make a $8 device do something it doesn't really wanna do LOL.

Time will tell, but for now I'm setting my upconverters and RTL's to the side to collect some MUCH NEEDED DUST.

HF Upconverter - Assembly and Initial Testing

SUCCESS!

After a few days or working on my new HF Upconverter I got it working!  I'd been waiting for some Buck type DC-DC converters.  So I could connect the OCXO (3.3vdc) up to the 13.8vdc from my primary Astron RS-35M.  One of the Buck converters drops 13.8vdc to 12.0 vdc, then a second one drops it again from 12vdc to 3.3vdc.  They seem to be working fine.  The 12vdc is variable.  The 3.3vdc is not which is kind of a bummer, but it's at idle on my Fluke meter 3.29vdc. (probably close enough although if I'm going to the trouble of an OCXO I'd like the PS's to be adjustable).  I'll probably hunt around for a Buck DC-DC 12-3.3vdc that is adjustable.  These things are CHEAP on ebay.  Total spent on both was around $15.00 combined including shipping.  Which beats spending hours building them at this point.

I am running the OCXO HF upconverter right now as I type this, and it seems to be rock solid so far.  No FM Bcast interference (which I didn't think I'd have with all the shielding).

I have a fair amount of work to do yet on this.  However, the fact that the SBL-1+ Mixer and the OCXO work as expected is definitely encouraging.

I am listening right now to 14 Mhz Morse Code on the FTDX-5000 and also on SDR# at 109 Mhz.  (remember the FTDX-5000 uses a 9Mhz IF Output that I'm tapped into, so the actual VFO frequency is irrelevant since all signals are sent out in the 9 Mhz realm.

Anyway...I just wanted to post that as simple as this is right now and working as well as it is, I can't wait to add the Lo and Hi pass filters to my Homebrew HF Upconverter that is accurate to within 200ppb (that's parts per BILLION)!  NO DRIFTING has been noted in my testing thus far.

Tomorrow I'll start it up from cold, and see if there is any noticeable.  I'll also post some updated pictures of where the project is now.

Things are subject to change until I setting on a mixer.  While the SBL-1+ works fine I'm curious how well the the other two I ordered from Minicircuits will work.  The are supposed to be better, and certainly should be at 4-7x the cost of the SBL-1+ (which was only $9.95).

This is FUN STUFF!

100 Mhz OCXO 200ppb For Home Brew Upconverter

I still have some work to do on this.  The closest (bottom left) (pin 1) large pad get +1.15-2.15vdc via resistor network voltage divider that bridges over from the large pad behind it  (pin 14) that is the +3.3vdc Power Supply pin.

The SMA is the 100Mhz @ 200ppb output from the OCXO which comes off pin 8.

The resistor network I was talking about is a voltage divider in the standard configuration of R1 and R2 except that I've slightly modified it to include a 1-turn 1000 Ohm Potentiometer which should allow fine tuning the OCXO by as much as -500hz and +500hz.  Hopefully this won't be needed much as that the point of having the OCXO to start with, but it simplifies retouching tuning quite a bit and seemed simple enough to add (as long as my design holds up!).

There will be a KNOB on the front of this which allows easy access for tuning the OCXO to mate up with the signals on the 9 Mhz output of the FTDX-5000.  INSTEAD OF having to go into HDSDR software's option menu and extio menu to adjust things (WHICH DRIVES ME NUTS!).

I hadn't realized that I had to provide a Vcc for pin 1 initially, and at first when I discovered this I didn't really like the idea.  Still not sure I do frankly, BUT since it adds a feature I hadn't thought of to start with I figured why not make it something I can make use of, instead of simply setting pin 1's voltage to 1.65vdc which SHOULD place the OCXO at 0pmm/0hz offset from 100 Mhz.

This "feature" provides a much as 1 full Khz adjustment (I think, according to the doc's I've read).

Nice Power Line Noise Visualization - HackRF, SDR#, VAC, and Spectrum Lab

I wanted to get a real nice noise signature of the Power Line Noise issue here.  What I ended up doing was to use a Windows 7 machine (for a change).  I used the following:

• SDR# 'sdrsharp'
• HackRF One
• Spectrum Lab

The newer SDR# includes and Audio FFT however, I'm unable to resolve how to alter the bandwidth of it down to < 1 Khz in audio frequency.  It seems STUCK at 0-18Khz or so.  This is too wide to be able to really see the 60hz spike and it's harmonics of 120hz 180hz, and so no.  They just don't even register in it's FFT for some reason.  SOOO....

Since the built-in Audio FFT doesn't resolve down to < 1Khz I setup trusty Virtual Audio Cable (I use line 2 for this, because other software I use uses Line 1 already).  So this pipes the AM audio out of SDR# via Virtual Audio Cable (Line 2) and then I setup Spectrum Lab to listen on that same VAC line.

Turns out this is PERFECT.  It's as good, but even better in that there's a TON I can inside Spectrum Lab, like line graphs, alerts, etc...for monitoring over long periods of time.

So here's a screen shot of Spectrum Lab (v2.78b25) setup to use VAC Line 2 (noted above) as well as SDR# below it.  

Look how simple it is to ID the 60 hz audio and it's harmonics.  Um....schweet.

(click to see larger)

I tried using GNURADIO and it's Audio Source, but damned if I can't figure it out on Windows.  It's fairly simple on Linux, but Windows is a different animal with GNURADIO.  Kinda of a let down.  It'd be nice to create flow graphs from my fancier/faster Windows machine that I could port over to my Linux machine and vice-versa but that's not happening.

Here's a few more views of that Spectrum Lab can do:

Thoughts on the next bit of test equipment I'd like

Now that I'm just waiting for some small handheld antenna's in the VHF/UHF range to arrive.  I've been thinking how nice it would be to use an Android device that has RF Analyzer installed on it.  This is a VERY COOL app that'll run on Android and connect to RTL SDR, or HackRF One (I have both and have tested it with both, and it seems to work excellent).  

Here is a video of what I'm talking about.  

It's just a quick view of how well this works.  What I'm doing is using a small whip antenna that is good for 50, 144, 432 Mhz on a HackRF connected to my Android phone and running RF Analyzer @ 44.25 Mhz listening to AM Mode and the source of my nearby Power Line noise.

With the combination of being able to take video's, and photo's and being able to use the GPS and RF Analyzer all in one device (well two if you include the RTL or HackRF)...pairing all these tools up to be used as a portable RF noise sniffer, and recording device seems like the next logical step.

• RF analyzer paired up with a portable Arrow antenna and a HackRF to visualize the noise, as well as listen to it!  (YES the RF Analyzer app now can demod the audio, AM, FM, WBFM, SSB etc).
• Photos and video from the Android Camera (gps linked)
• On board GPS

On thing I've noticed about the HackRF is that holding it snug against the back of my Galaxy S3 increases the noise floor a fair amount.  So it's well know (I think) that the HackRF's case which is crap for RF shielding.  So I'll probably build a little Copper Clad PCB box to wrap around it or use some copper tape!  LOL

Anyway I'm envisioning all of this equipment mounted to the back of the VHF/UHF antenna, and while on site at a known noisy location all of this combined could help document a problem area.

The biggest issue I've had in the past with Power Noise tracking is the part where you need to document things each time.  With enough detail to be useful in debugging a problem.  Using all of this combined would make is as simple as waving your arms around with the gear doing all of the recording and minimal interaction required on the part of the user at the time.

This is also important from a safety standpoint.  For example you could actually be looking where you're about to plant your feet, or on coming cars, or big dogs, or downed power lines :-)  All kind of important!

The last time I'd used RF Analyzer it didn't include demodulation of the audio.  NOW it does and it CLEARLY works wonderfully!  Especially in AM mode which is helpful in power line noise hunting.

More to follow on this as soon as I've been able to video the operation of this...shouldn't be too long, I'm just waiting for my other android to charge up :-)