Receiving RadioSondes or not in my case

I was inspired by this recent Hackaday ( post to try my hand at receiving RadioSonde messages. A RadioSonde is the box of electronics (Temperature, Pressure monitors etc , GPS receiver, Processor and UHF transmitter) that sits below a weather balloon. Apparently they don’t go and collect them either so they are up for grabs and experimentation.

At the minute though I am failing to decode the messages sent by the UKs Vaisala RS41 RadioSondes. I am using a piece of software called SondeMonitor and the RTL USB dongle with SDRSharp. Last night I received 4 perfect (I think) signals, one shown below not being decoded ūüôĀ

Further testing will commence shortly as they lift of at 11:15 and become audible at 11:30ish. Wish me luck.


Arduino Beginners Course

It’s beginning to look a lot like Christmas!

This week I have received a number of parcels from the great electronics store in the East. The contents of which is the majority of the parts required for the Arduino beginners course. I’m now only waiting for three items. The photo below shows the contents.

And a less cluttered photo showing:

  • Jumper wires to be split into kits
  • A breadboard
  • The all important NodeMCU (ESP8266 or ESP12-E)
  • NodeMCU base
  • USB cable (yes I know you have one already, but at 29p each!)
  • Two speakers (one in each kit)
  • And a bag of LEDs to be split up.

As most of the items have arrived so quickly, I may be able to bring the course date forward slightly.



Wsprlite antenna testing – Rex G4RAE 6371 km

This week we have been testing Rex’s 1/2 G5RV,¬† East / West, height less than 20ft.

The wsprlite classic was set to transmit late on Saturday afternoon, a tuner and MFJ analyser were used to tune to the 40m band. Rex confirmed that stations receiving the signal reflected the spread of QSO’s he had made over many years.

Note the time of the signal being received in America.

above indicates the variable propagation; note that from Jan 7th at 21.00 the propagation is rising and is more stable.

and finally a map of the received signals taken from



Outside Amateur Radio

Last week Mike G0JMD spoke about a few radio related topics that while not directly amateur related  provided some good talking points.

He talked about how he first came across Amatuer Radio while in the army.

Other subjects included scanners, CB and ADSB recieving.

Mike showed some of the kit he has used over the years and talked of others that he had which caused some interesting discussions and memories from other members.

Thanks Mike for a good evening.

WSPR lite antenna testing update Average distance: 2195 km

map of stations hearing M0hfh from our club 40m dipole for the last 24 hour period

The Dx10 table note the max distance 3683 km

Dx10 graph  indicates changing propagation sunrise today Bristol  8.14am

Pick a time for your long range Transmission to win the club competition!!

Think we need more data and a plan for that. comments appreciated.




WSRPlite antenna test resumes

After a small setback (a flat battery) we have resumed transmission using a mains power supply. I have included the DX10 table showing the  best 10 (in terms of range) . The DX10 table gives you a snapshot of the system performance. However it does more as it identifies the time ranges for the spots so that you can identify the best times for DX openings.

DX10: M0HFH – 7 MHz – 200mW

Distance (km) Call Spots count Last seen
2720 EA8BFK 4 2017-12-20 21:42 to 2017-12-21 10:06
2047 OF5C 4 2017-12-21 07:50 to 10:08
1817 OH8NW 2 2017-12-21 07:36 to 10:06
1644 HA7MAC 2 2017-12-21 04:46 to 05:16
1546 SM0BYO 1 2017-12-21 09:46
1538 SM5EPO 3 2017-12-21 08:04 to 09:02
1480 HG5ACZ 2 2017-12-20 22:54 to 2017-12-21 01:20
1405 SM4JST/RX1 9 2017-12-21 05:06 to 09:02
1398 OE3BUB 3 2017-12-21 01:06 to 05:06
1384 OE6PWD 1 2017-12-20 23:04
Average distance: 1698 km


the map below shows the spots in a more visual form and comes from

using filters M0hfh on 40m for the last 24 hours



Wsprlite test of the club 40m dipole under way

Today at around I connected my wsprlite antenna analysis system to the club 40m Dipole after completing the 40m low pass filter. It is now transmitting at 200mw and here is the first image from the spots map. The test will continue for 3 days, i will publish data as the test progresses.

for info on the system :-

Arduino workshops

Last week was the second week with Paul m0zmb  showing  some of his experiments using the Arduino open source electronics platform.  We looked at a full colour LCD display from Tony G0WMB and my (John m0hfh) experiments to link the Arduino and a AD9850 dds module to give a variable sine wave output with a variable frequency from a few kilohertz to 30mhz; a very useful VFO. We stayed later than we should  to test the output using the club radio on 3.5mhz and 7.2mhz  and the circuit achieved our first goal, and a signal was detected at approximatly 4m distance using very crude wire antennas.