Tag: 2018

HF fun with the 18 MHz beam

The addition of a beam on HF never ceases to bring a smile to ones face, the addition of a linear amplifier is often enough to create a pile-up.

If you look around at some of the amateur radio publications you will often see people complaining about the conditions or the lack of propagation. Undoubtedly we are at the bottom of the sunspot cycle, and HF propagation is much more of a challenge than sunspot maximum, but you would be forgiven for thinking  HF was dead.

Home for the weekend

The truth is even in this solar minimum it’s still possible to work DX, all be it you will need to try a little harder. If possible I try to use a beam, and the addition of a linear but you still need to be able to hear the lower powered stations.

The transceiver was a newly purchased Icom 7300, second hand but in excellent condition. The radio performed flawlessly and often had to cope with multiple stations calling simultaneously.

At times it was hard to work out what JA I was working at any given time!

 

Last weekend team SNBCG decided to have a weekend of radio fun on 144 MHz MS and 18 MHz HF. I operated the HF station, while George M1GEO operated MS.

The beam is a DK7ZB design, you can read about the construction project in this article.

FT8 was the favoured mode, giving me the best chance to work some DX.

Over the course of the next few hrs I decoded a large volume of exotic calls, not all working me but it did demonstrate what is possible with a reasonable setup.

 

25 USA, 42 JA (Japan), not forgetting to mention XE (Mexico), BD (China), FR (Reunion Island) and ZS (South Africa)

As traditional with field days, they often finish in VU.

Mysterious HF Number Stations

Much has been written about number stations over the years, although little is known for fact.

We do know they often broadcast on a schedule, so with a little planning, it is quite easy to receive them for yourself. Online SDR receivers take this to a new level, and now with TDoA, we are able to learn something about the geolocation of the transmitters.

It’s probably no surprise to learn many are now being geolocated to the area of Russia and Poland.

I remember the first time I ever stumbled upon a mysterious signal reading out numbers, this was BG (Before Google) so it was hard to identify or read about the history of these stations.

Needless to say, I started to log the station’s frequency and content, and would often find the same stations time and time again.

BBC Radio 4 program first aired in 2005.

Priyom.org provide an excellent service, collating lots of information in one place. They also link to various SDR around the world, providing you with a unique insight into this mysterious world.

The strange thing is they are still around today, despite us having the internet and 101 ways to encrypt and send messages these days. The attraction of HF is it leaves no digital footprint, and messages can be broadcast to 1 or many recipients over 1,000 of miles.

The Conet Project spent many years recording these strange stations and later selling these as audio recordings on CD’s

You can listen to many of these stations on my SDR, I have been added them to the frequency dial to help identification. Over the coming months, I want to collect some recordings and add them to this page.

The BBC has published a few articles on the subject one is “The Ghostly Radio Station that no one claims to run” and you can listen to the UVB Buzzer below.

Why not check out the geolocated maps, and view the site in Google street view.

UVB-76 Buzzer (Geolocated) or maybe (Geolocated)

6802 kHz (CW)

7600 kHz (Voice)

10343 kHz (CW)

Suffolk Red Field Weekend

Suffolk Red hosted a field weekend from their field day site at the Suffolk Aviation Heritage site near Ipswich. The weather was set fine, with temperatures close to 30C and with the option to camp out for the weekend.

George M1GEO, Chris G8OCV and I set up the operating tent and populated it with the following equipment.

HF – Icom 7610 and 1.3K Linear from expert

VHF – Icom 7100 and 300w VHF amplifier from Linear amp UK

RACAL push up mast

Power – Honda 2KW generator

The object was to try something new, so I opted for 9e LFA on the Racal push up mast and tried to work as many EU stations as I could on both phone and FT8. VHF seemed quite lively, and with good take off into Europe I was soon working into France, Germany, Denmark and Belgium.

LMR 400 coax was used to keep the losses down, and the masthead amp compensated for any RX losses.

Masthead amplifier for 144 MHz was originally published in the RSGB magazine RADCOM plus issue 1 designed by Ian White GM3SEK. The details are published on his website, detailed as the DG8 low cost, high-performance preamp for 144 MHz.

Over the course of the weekend I completed 50 QSO in 25 squares, the map is shown below. If you are new, or even not so new to FT8 you may find this operating guide helpful.

Some 144 MHz FT8 highlights include.
DL3GAK at 662KM
F4CYH at 673 KM
OZ1BEF at 693 KM
OZ1BP at 698 KM

Solar Powered WSPR Transmitter

A while ago I completed the QRP labs WSPR transmitter, you can read about that project in this article. I wondered how easy it would be to set this up in the garden, solar and battery powered.

The QRP labs unit transmits around 200mW, and the idea was to have this running 24×7 transmitting around 80% of the time and band hopping. I have the multi-band option, with BP filters for 3.5, 5, 7, 14 and 21 MHz.

Searching eBay I found a low costs solar charge controller and solar panel. I also needed a voltage regulator to drop the 12v to 5v for the QRP labs unit.

The items I selected are not “high quality” it was more proof of concept. The charge controller is in fact so high quality even China didn’t put their name on it.

The charge controller is marked as follows.

10A Advance Pulse Width Modulation (PWM) Charge controller:

  • Automatic 12v/24v recognition (need 2 panels to run 24v systems)
  • Fully 4 stage PWM charge management
  • Day/night recognition
  • Dual mosfet reverse current protection
  • Protection from over-charging, deep-discharging and reverse connection from both solar panel and battery
  • Protection from short circuit and over current
  • LED indicator to show charging/fault/battery status/load status etc
  • LED digital display to show the load work mode and status
  • Self-consumption: 10mA or less
  • Working temperature: -35C to 60C
  • Working Humidity : 10% to 90% RH
  • Size: 14 x 7.5 x 3cm
  • Weight: 180 g
  • Terminals for wire up to 6mm2

The solar panel is marked 10w

The QRP labs kit was connected to the GPS module, battery and a random bit of wire and placed in a plastic bag. I left it running 24×7 for 8 days and then checked the battery voltage.

The voltage showed 12.7 volts, I consider that to be a success.

70 MHz Cumulatives

Using the club call M0SNB June saw another chance to operate 70 MHz outdoors in the RSGB contest, with perfect weather at 24c. The contest site at the Secret Nuclear Bunker was used, at some 110m ASL it has good take off in most directions.

Using the homebrew 6e 70 Mhz beam, and the solid-state amplifier to deliver 160w worked a treat, with our best DX EI2FG @ 568 KM.

The antenna uses the latest in “push fit” technology. You can read more about the antenna in this article.

Over the course of the 2Hrs operating, I worked GW, GM, GI, GC and GD.

Here is the QSO map for the afternoon.

Summer 2018 has arrived (almost)

At last, the warmer weather has arrived, today gave me the first opportunity to operate outdoors without a coat.

It was a pleasant sunny afternoon so I decided to operate outdoors and make the most of the nice weather. Using the Icom 7100 and 65Ah leisure battery and a white stick for 145 MHz and slim jim for 70 MHz allowed me to work a number of local stations.

The 70 MHz Slim Jim is mounted on the fibreglass pole on the right.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

The metal mast on the right had been given to me by Richard G4DDP and it was its first chance to try it out in the field. Its very heavy duty, and I think would have originally been designed to take a speaker at a gig, now upscaled to amateur radio.

On 145 MHz I worked M0FAQ Martin in Braintree, M0WJL Gordon in Corringham.

On 70 MHz I worked 2E0HPA/M Andy in Tadlow, G4YBI Paul Rainham, M0XTA Selim, G0ENN Southend.

Here you can see the Icom 7100 setup and operating on 70 MHz

The Icom 7100 all packed up in its travel box.

 

© 2015 Dave, M0TAZ