Posts Tagged ‘SDR’

Hunting For NDBs In CLE242

Online KiwiSDR Network


CLE242 runs this weekend and is a bit different than most. This time, listeners are required to use an online remote receiver to do their beacon-hunting.


There are many parts of the world where beacons have yet to be recorded to the database and this will be a great opportunity to find and report them.

Over the past few years, the number of online SDRs has grown immensely, as has their ease of use. Although there are several online systems, my favorite is the KiwiSDR network, where one can normally find over 400 receivers available at any time. As well, every one of them has the same familiar intuitive interface ... figuring out how to tune them and make them behave the way you want only takes a few moments.

When tuning for NDBs, put your receiver in the CW mode and listen for the NDB's CW identifier, repeated every few seconds. Listen for U.S. NDB identifiers approximately 1 kHz higher or lower than the published transmitted frequency since these beacons are modulated with a 1020Hz tone approximately.

For example, 'AA' near Fargo, ND, transmits on 365 kHz and its upper sideband CW identifier is tuned at 366.025 kHz while its lower sideband CW ident can be tuned at 363.946 kHz. Its USB tone is actually 1025 Hz while its LSB tone is 1054 Hz.

Often, one sideband will be much stronger than the other so if you don't hear the first one, try listening on the other sideband.

Canadian NDBs normally have an USB tone only, usually very close to 400 Hz. They also have a long dash (keydown) following the CW identifier.

All NDBs heard in North America will be listed in the RNA database (updated daily) while those heard in Europe may be found in the REU database. Beacons heard outside of these regions will be found in the RWW database.

From CLE organizer Brian Keyte, G3SIA, come details via the The NDB List Group:

Hello all 

Our 242nd listening event starts this Friday.   The last time everyone
listened via remote receivers was 40 CLEs and over 3 years ago. Since
then the receivers have improved enormously – easier to use, better
design and a much greater choice of sites Worldwide for you to use.

If you don’t like the idea of remote listening we urge you to at least
please give it a try.  I predict that several of us who ‘have a go’ in this
CLE will be very pleased to discover a fascinating new world of NDBs.
You only need a modest PC and a slow internet connection - and the
ability to read slow Morse!   (Even a tablet is sufficient, though a bit
difficult to use without a mouse)

  Days:    Friday 22 March - Monday 25 March
  Times:  Midday on Friday to Midday on Monday, local time AT THE REMOTE RX
  QRG:    Normal LF/MF frequencies (190 - 1740 kHz)
  NDBs:   A MAXIMUM of 100 normal NDBs (not DGPS, Navtex, Amateur)
               (that’s not intended to be a target to reach!)

Choose any ONE receiver, remote from you, for all your CLE listening.
Remember that reception conditions will depend on the local time of
day/night at the receiver (no through-the-night listening for us this time?)

The ‘biggest and best’ of the remote receivers is probably still the SDR
at the University of Twente at Enschede in the east of Holland.
Several hundred listeners use it, all at the same time and all unaware
of each other.   Its PA0RDT mini-whip aerial high above the metal roof
of the building allows it to receive well on the NDB range of frequencies.
Just enter http://websdr.ewi.utwente.nl:8901/ into your browser.
In seconds you should see details of the receiver and advice on how to
use it.

If you want to choose a different location, or an easier-to-use receiver
with fewer facilities, the Kiwi receivers are also SDRs.  They are mostly
in radio enthusiasts homes and they usually only support a handful of
simultaneous users.
Go to https://sdr.hu
To display the Worldwide map use the button on the right side of the screen
- experiment with (multiple) use of the + and – buttons.
Some sites of any kind have aerials that are quite unsuitable for NDB
listening, but others are excellent.  Some of our members have been busy
recently researching them and their suggested ‘best ones’ are listed below.

For each receiver, whatever its kind, do read the helpful advice carefully
before using it.  There is no charge and you don’t register or 'log in', but
you may be invited to type your chosen identification in a 'Name’ or
‘Callsign' box.  There may be a time limit for each user (e.g. 2 hours in
any 24 hours) and ‘late comers’ may temporarily have reduced facilities.

Seeklists?   The REU/RNA/RWW Website can help a lot if you enter the
Locator of your chosen receiver in the From GSQ box there.
To avoid getting details of thousands of NDBs, initially set the DX limit
to something small and/or enter one or two nearby states or countries.


LOGS  (Please read CAREFULLY):

Please show the LOCATION details and the TYPE OF REMOTE RECEIVER
clearly  (and your own location to help us identify you).
Include on EVERY LINE of your log:

  #   the UTC date  - e.g. ‘2019-03-22' (or just '22')
       and UTC time  (the day changes at 00:00 UTC).
  #   kHz   - the nominal, published, frequency.
  #   Call Ident.

Show those main log items FIRST.  Any other, optional, details such as
the NDB's location, etc., must go LATER on the same line.
You could include any UNIDs - e.g. separately if you already have 100
identified loggings.

As this is a special CLE, any extra comments in your log on your listening
experience (whether good or not!) will certainly be of interest.

Please post your log to NDB List, preferably as a Plain Text email
(not in an attachment) using 'CLE242' and ‘FINAL’ in its title.  We will
send the usual 'Any More Logs?' email at about 21:00 UTC on Tuesday
so you can check that your log has been found OK.
(NB:  that is 3 hours later than usual)

Do make sure your log has arrived on the List by 09:00 UTC on Wednesday
27 March at the very latest.  Joachim and I hope to finish making the main
combined results later on that day or soon after.

REMINDERS:
    Only ONE remote receiver of your choice.
    Not more than 100 loggings
    Start and End at midday at the receiver.

Enjoy!
  Brian
--------------------------------------------------------------------------
From:       Brian Keyte G3SIA        ndbcle'at'gmail.com
Location:   Surrey, SE England       (CLE Coordinator)
--------------------------------------------------------------------------


To help you with your choice of a remote receiver, below are recommendations
and/or advice provided by from some of our members:



To help you with your choice of a remote receiver, below are recommendations
and/or advice provided by from some of our members:


The stations in yellow are among the ones that disable the waterfall when there are more than two users - 
they can still be used and are still excellent stations.


Advice about their own and other Kiwis have been given in emails to NDB List,
mostly in the last few days:

Roelof B:  His KiwiSDR is making all four channels available for the CLE

Tony C:  Has added his openwebrx NDB receiver to SDRHU.  3 or 4 users

Bill S:   Email to NDB List on 4 Feb  (A list of USA and CAN SDR's that may 
         be useful, compiled by Dave AB5S and posted on the Boatanchor List)

Joe N5PYK: The West Texas KiwiSDR welcomes CLE participants. 

We are grateful to all the above.


Any further advice about suitable remotes will be welcome. 
Do you fancy using something really basic for the CLE?  The Global Tuners
still exist – we used 6 of them successfully in CLE202.  There are usually
about 50 of them on-line and many are older traditional receivers that
support only one user and are seldom suitable for the NDB frequencies.
But there might still be a gem or two among them:
https://www.globaltuners.com/   (You need to sign up for a free account
and provide an email address for a password to be sent to you)


These listening events serve several purposes. They:
  • determine, worldwide, which beacons are actually in service and on-the-air so the online database can be kept up-to-date
  • determine, worldwide, which beacons are out-of-service or have gone silent since the last CLE covering this range
  • will indicate the state of propagation conditions at the various participant locations
  • will give you an indication of how well your LF/MF receiving system is working
  • give participants a fun yet challenging activity to keep their listening skills honed
Final details can be found at the NDB List website, and worldwide results, for every participant, will be posted there a few days after the event.


The NDB List Group is a great place to learn more about the 'Art of NDB DXing' or to meet other listeners in your region. There is a lot of good information available there and new members are always very welcome. As well, you can follow the results of other CLE participants from night to night as propagation is always an active topic of discussion.

You need not be an NDB List member to participate in the CLEs and all reports, no matter how small, are of much value to the organizers. 

Remember - 'First-time' logs are always VERY welcome!

Reports may be sent to the NDB List Group or e-mailed to CLE co-ordinator, Brian Keyte (G3SIA), whose address appears above. If you are a member of the group, all final results will also be e-mailed and posted there.

Please ... give the CLE a try ... then let us know what NDB's can be heard from your location! Your report can then be added to the worldwide database to help keep it up-to-date.

Have fun and good hunting!

Evaluating 9 of the Best Single Board Computers for Modern SDR Systems

This past August I had the privilege of attending and video-recording the TAPR Digital Communications Conference in Albuquerque, NM.  For several years past, this conference was recorded by Gary Pearce from HamRadioNow, but Gary has since retired from making Ham Radio videos (the series was handed off to David Goldenberg, W0DHG, who is doing a great job with new episodes).  In lieu of this fact, I spoke with Gary and with Steven Bible, the administrator of the DCC, and was permitted to take up the mantle of recording all of the forums and putting them on YouTube.

With this first forum, Scotty Cowling, WA2DFI, presents his findings for 9 of the best Single Board computers for modern SDR systems.  Among these boards are, of course, the Raspberry Pi, but several others are also discussed.  I thought this information was valuable and useful to those of us who want to do Amateur Radio projects.  This applies not only to SDR Receivers and Transceivers, but also for dozens of other projects in our hobby.

As Scotty states in the video, lots of time and research was put into this presentation because the information he gathered isn’t readily available in one place.  He spent quite a bit of time digging for the information about SBCs to present in this forum.

I hope that you enjoy watching this forum as much as I did.

 

Moving Pictures! First dabbles in Amateur TV

I am always keen to try something new and I've spent the last couple of weeks experimenting with some Amateur Television ATV and Digital ATV (warning this post is bit of ramble and information overload)

They say "a picture paints a thousand words"and I've always liked the idea of sending pictures via radio having dabbled with sending and receiving SSTV and SSDV, including pictures from High Altitude Balloons (HABs) like the Hamfest HAB flight I did back in 2015


But I've also been intrigued by "Fast scan TV" to transmit moving images. I've seen demonstrations at conferences and in online videos and joined the British Amateur Television Club BATC a few years ago but apart from reading the CQ-TV magazine I had not done anything mainly due to expense and investment I mistakenly thought I would need to make.

Recently I have seen mention of using easy and low cost equipment to get on the air on 5.6GHz (the 6 cm amateur band) using cheap modules intended to transmit “First Person Video” (FPV) back from drones.
 
These simple units can be used without any modifications to get on air. A number of operators have used them with high gain WiFi panel and/or dish antennas with a clear line of sight path to send pictures to stations using the same equipment over paths in excess of 50km, the current record is over 160km. Chris Leviston M0KPW has an excellent website describing his 5.6GHz system http://www.5-6ghz-atv.co.uk/ and there is more information at the BATC Wiki https://wiki.batc.org.uk/5.6_GHz

Inspired I ordered some kit from eBay a few weeks back, a receiver module and transmitter arrived quite quickly (no slow boat from China this time)


The equipment is powered by a 12V supply and input and output is a composite video signal and audio. It can be fed by a standard camera or video source but I dug out an old Raspberry Pi and soon had it generating and transmitting a test card with the required call sign overlay. The modules are channelised, the displayed 33 number is bank 3, channel 3 which is 5.665GHz selected by the BATC since it sits inside the amateur allocation,


Over the week I refined the Pi software, adding the Pi camera and various libraries in python to generate video with informational overlay, adding a GPS allowed calculation of the locator square when out portable. I have put it in a box (sorry no picture of that) and a switch to flip between live video and test card. I also had a bash at making some double biquad antennas. Regularly updating my twitter feed with various milestones (I recommend you follow me)

While browsing the BATC website for information I spotted that there was an ATV Academy workshop being organised by the Telford and District ARS, giving people the opportunity of finding out a bit more about ATV and people could bring along their equipment and projects for advice. So at the last minute I decided to go but because of the distance could only really go on the Saturday. But it was well worth it and a great day. I was made to feel welcome by everyone there and was able to show off my modest achievements on 5.6GHz and learned about the BATC Portsdown Transceiver and MiniTioune receiver projects, even buying the parts to build the receiver.

The academy coincided with a BATC Activity weekend and they were going up to the summit of the nearby Long Mynd to operate on the Sunday. Since I wasn't there I had planned to go to a local high point to see if I could make contact with some of the other operators and stations and got the kit ready on a cheap lighting tripod. I was going to use an old portable satellite dish with one of my double biquads at the feed point.

The satellite dish is inverted because they are offset so when the dish is vertical they are actually pointing around 20 degrees upward towards the TV satellite (in the UK). So for terrestrial use with low elevation they work better inverted. (see here for better description of offset dishes)

I did venture out but I chickened out setting up due to a combination of a surprisingly busy road, fly tipping and very hot conditions. Due to the the fly tipping in the lay-by I didn't want to be seen getting stuff out of car boot! especially as a few cars had slowed down as they passed.

Nevermind I have ordered couple of cheap high-gain mesh dish antennas so when they arrive I will get out again and arrange some skeds, hopefully roping in some of the radio club.

In addition to the 5.6GHz stuff I have also taken possession of an ADALM-PLUTO SDR from Analog Devices. It is inexpensive (£90/$100) and designed to allow educational experimenting in software defined radio. It is a SDR receiver and low-power transmitter. They had been in short supply but availability has improved.

Charles Brain G4GUO has added support for the device into the DATV Express software. I am hoping to use it for some experiments in RB-TV (Reduced bandwidth TV) so I can actually use my NoVs

I took the PLUTO along to the ATV workshop and was able to see it transmitting and being received by other peoples receivers. So last night I got out the two satellite receivers I have and with a little bit of persuasion with settings got some DVB-S DATV transmitted and received.
Anyway, that is enough for now.. but will try to keep the blog updated as I experiment some more, but follow my twitter account @nerdsville for realtime updates 73 Andrew

The KiwiSDR Online Network

Online SDRs (Software Defined Radio) continue to grow in numbers and popularity.

Listening on a receiver that is running in another state, province or country can fulfill a number of functions for you, depending on your particular interest.

The network that I have explored several times and one that works nicely with most web browsers (no software to download or 'extras' required) is the SDR.HU network of Kiwi SDRs ... just choose your receiver and away you go in a matter of seconds. It's all very slick and if you have never played with an SDR before, it affords a nice introduction to this amazing technology. Although it won't work with my ancient version of Internet Explorer running on Vista, it did fine with Firefox and even worked very well on my old I-Pad! Here is a 30-second YouTube video to give you an idea of what it looks like.



There are a huge number of choices from all over the world available on the Kiwi network. As I write this, there are presently 199 receivers online! Any particular receiver can support a maximum of four users at a time so if the one you want is full, simply check back later or go to your second choice.

Although all receivers have the same appearance online, not all will offer the same performance. Although most seem to cover 0-30MHz, I see at least one that is limited to the VHF range and several that don't go all the way to the bottom of the VLF band. The antennas used seem to favor wideband loops, both large wire styles and smaller active versions as well as active e-probes.

The best way to determine any particular receiver's operating performance is to try it out using test target signals that might indicate good performance from that location. If you're interested in BCB capability, test some of the European ones to see if they can hear any TA signals around sunrise in Europe. Many SWLs will use these receivers to compare what they are hearing at home with a receiver located closer to the suspected DX target signal. I myself found the network particularly handy for listening to my Tri-Tet-Ten transmitter on 10m CW a couple of years ago when the muf was much higher than it is nowadays. I'll be trying a few of them out this winter, listening for my 630m CW signal, at various locations.

Some of the receivers appear to offer good, low noise reception on LF, MF and the BCB but the vast majority are not DX machines oriented for this part of the spectrum ... this was the opinion of one notable BCB DXer who checked many of those in eastern NA as well as western EU. The jury is still out on the westerern NA receivers and those in the Pacific / Far East ... a worthwhile listening project when there is some spare time. Even though the receivers used on these lower frequencies did not usually offer stellar performance, they may be real workhorses within the ham bands or on the international shortwave bands.

It would be worthwhile to see some form of 'performance rating' or feedback page for each individual receiver. Although there is a 'vote' tally associated with each receiver it's not clear what this actually represents as receivers that have been online for longer periods would naturally have a higher tally.

A lot of additional information about the KiwiSDR network can be found here.

No doubt you can think of your own good reason to have a remote listen to some of the network's growing list of online receivers and put them to the test ... there may be some real treasures to be found.

SDR receivers and transceivers

There is a real gap in my knowledge as I have never once tried an SDR based receiver or transceiver. SDR dongles are very low cost, so I really have no excuse.

On the Southgate site I read news of a new SDR 5W transceiver.

See https://sunsdr.eu/product/sunsdr2-qrp/

Worldwide SDR’s Online

The University of Victoria online SDR from SDR.hu
A posting today on Yahoos' ndblist Group by Geir, LA6LU, pointed to a list of online SDR receivers at various locations around the globe. I have seen similar lists like this in the past, only to be disappointed when finding many of the receivers impossible to get operating or arriving at a dead link. This list appears to be up-to-date as a quick check of four random receivers saw all four come to life quickly!

The site is run by Andras Retzler, the author of the OpenWebRX software that enables these SDR's to be made seamlessly available online through your web browser. Since all of the sites use the same software, all receivers appear the same, thus providing a very short operational learning curve. At the time of this posting, there were 76 online SDRs, a number that fluctuates slightly throughout the day. Conveniently, the site also indicates how many users are currently using any individual receiver.

I can think of several very handy uses of such a resource, from checking your own on-air signal to confirming, in real time, a suspected DX catch that you might be hearing from your own location. You may even be interested in putting your own SDR online for others to share. It really is a very useful resource and while there, check out the rest of Andras's interesting site.

What Mode Is That?

'JT-9' - courtesy: http://www.sigidwiki.com/

A recent link posted on the ON4KST 2200/630m chat page brought up a very helpful web site.

The  Sigidwiki site lists examples of the various transmission modes being used from LF to UHF, along with examples of what these signals look like on a waterfall display.

With the proliferation of digital modes found on-the-air today, it's often fairly baffling, trying to figure out what you are hearing. The main database page contains a staggering 272 different identified modes of transmitting information, in one way or another ... no wonder it's hard to keep track!

Clicking on any of the modes will bring up more details about the mode, sometimes with links to the decoding software and further reading.

'PICCOLO' - courtesy: http://www.sigidwiki.com/


I'm sure there are more that aren't on the list (is WSPR there or did I just miss it?) but it's still an impressive and helpful collection for those that use a waterfall display on their receivers.

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