Author Archive

50MHz FT8 and aircraft scatter

Playing with the new FT8 mode on 50MHz, I spotted something interesting on semi-local signals affected by aircraft scatter. On JT65A, I notice quite a few UK stations affected by aircraft scatter - you can always tell by a slight (sometimes more than slight!) slant to the main trace.

What's interesting on FT8 is that you get two separate decodes - one of the main signal and one of the reflected signal. Look at this screenshot and the signals from G0GGG


I have had quite a lot of success working UK stations on JT65A via aircraft scatter, although some overs have so much doppler that the decoder simply can't cope. Maybe FT8 will offer some more possibilities.

70MHz cumulative – and more SSTV from the ISS

Randomly, I was browsing through Facebook this morning and I noticed Paul G4RRA say that he was about to drive up to the site for the RSGB 70MHz cumulatives.

Although I only have the vertical available for 70MHz, I wondered what if anything I would be able to hear. Of course, having the Noble NR4SC readily available means that there is no fiddling around connecting up transverters. Which, on a sleepy Sunday morning might have been enough to to deter activity!


I didn't have many expectations of working very far afield, with 10W to a vertical and the first few contacts were pretty local. However, I was very pleased to find G4TSW from Devon calling CQ on the key and we were able to complete a nice contact (although I had one of those moments of not being able to send my locator properly! The keyer on the NR4SC's timing is just a little different to the others I have here and it takes a moment to adjust my sending to suit). What was particularly nice was that the operator at G4TSW was Paul, G4RRA!

Another nice contact was with Dave G4ASR in Herefordshire - this time on phone. The first time we'd worked on 70MHz in quite a while, I think.

So, enjoyable to find the 70MHz cumulative event - I must try and look out for them again. I remember years ago, Chris G8TFI and I won the series from Cleeve Hill in Gloucestershire.

More SSTV had been planned for the weekend from the International Space Station. Yesterday's activity had to be cancelled, owing to the need for a spacewalk. The amateur radio transmitters are turned off whilst such activity takes place - and you can't argue with that!

Once again, the vertical, FT8900 and MMSTV came up with some nice pictures. The high elevation passes are good, although I found a few bands of noise on the pictures as the spacecraft travelled through the null of the antenna. Some of the low angle passes worked surprisingly well, with good copy down to less that 1 degree.


The SSTV activity from the ISS generates a huge amount of interest. I noticed some of the RTL-SDR groups on Facebook having a lot of fun decoding the pictures. Good publicity for the hobby!

70MHz cumulative – and more SSTV from the ISS

Randomly, I was browsing through Facebook this morning and I noticed Paul G4RRA say that he was about to drive up to the site for the RSGB 70MHz cumulatives.

Although I only have the vertical available for 70MHz, I wondered what if anything I would be able to hear. Of course, having the Noble NR4SC readily available means that there is no fiddling around connecting up transverters. Which, on a sleepy Sunday morning might have been enough to to deter activity!


I didn't have many expectations of working very far afield, with 10W to a vertical and the first few contacts were pretty local. However, I was very pleased to find G4TSW from Devon calling CQ on the key and we were able to complete a nice contact (although I had one of those moments of not being able to send my locator properly! The keyer on the NR4SC's timing is just a little different to the others I have here and it takes a moment to adjust my sending to suit). What was particularly nice was that the operator at G4TSW was Paul, G4RRA!

Another nice contact was with Dave G4ASR in Herefordshire - this time on phone. The first time we'd worked on 70MHz in quite a while, I think.

So, enjoyable to find the 70MHz cumulative event - I must try and look out for them again. I remember years ago, Chris G8TFI and I won the series from Cleeve Hill in Gloucestershire.

More SSTV had been planned for the weekend from the International Space Station. Yesterday's activity had to be cancelled, owing to the need for a spacewalk. The amateur radio transmitters are turned off whilst such activity takes place - and you can't argue with that!

Once again, the vertical, FT8900 and MMSTV came up with some nice pictures. The high elevation passes are good, although I found a few bands of noise on the pictures as the spacecraft travelled through the null of the antenna. Some of the low angle passes worked surprisingly well, with good copy down to less that 1 degree.


The SSTV activity from the ISS generates a huge amount of interest. I noticed some of the RTL-SDR groups on Facebook having a lot of fun decoding the pictures. Good publicity for the hobby!

Raspberry Pi2 up and running; DUMP1090, Piaware, GPredict as well as browsing the web

The Raspberry Pi2 was delivered very quickly - thank you CPC! However, owing to a bit of silliness on my part I didn't get it running until today. I'd assumed - always a dangerous thing - that the Pi2 used an SD card for its storage, like the Pi. Oh no it doesn't! It uses a micro SD card. I didn't discover this until I went to plug the SD card in!

Ah well. A quick Amazon order later and a micro SD card and an adapter was on the way. Those arrived here this morning, so I quickly prepared the micro SD card.

I had a bit of fun getting decent video on my rather old monitor in the shack and was starting to think I wasn't going to find something better than VGA! However, a setting of hdmi_group=2 and hdmi_mode=16 gave me a reasonable compromise between getting a decent amount on the screen and being able to read it without green and yellow flashing in the background.!

The first bit of software I installed was the Gpredict satellite prediction program. It's nice to have the map running in the shack. That went well and only seemed to be taking a very small percentage of CPU.

Then I installed RTLSDR and tested it, without any problems. I installed DUMP1090 - the ADS-B decoder as well as the Piaware software which uploads the ADS-B spots to Flightaware. Those programs run quite happily at the same time as Gpredict and use around 7% of CPU.

I fired up the Epiphany web browser and went to Twitter - again, the CPU was quite happy.

This looks very useful. I think I'd better order it a case!

Raspberry Pi2 up and running; DUMP1090, Piaware, GPredict as well as browsing the web

The Raspberry Pi2 was delivered very quickly - thank you CPC! However, owing to a bit of silliness on my part I didn't get it running until today. I'd assumed - always a dangerous thing - that the Pi2 used an SD card for its storage, like the Pi. Oh no it doesn't! It uses a micro SD card. I didn't discover this until I went to plug the SD card in!

Ah well. A quick Amazon order later and a micro SD card and an adapter was on the way. Those arrived here this morning, so I quickly prepared the micro SD card.

I had a bit of fun getting decent video on my rather old monitor in the shack and was starting to think I wasn't going to find something better than VGA! However, a setting of hdmi_group=2 and hdmi_mode=16 gave me a reasonable compromise between getting a decent amount on the screen and being able to read it without green and yellow flashing in the background.!

The first bit of software I installed was the Gpredict satellite prediction program. It's nice to have the map running in the shack. That went well and only seemed to be taking a very small percentage of CPU.

Then I installed RTLSDR and tested it, without any problems. I installed DUMP1090 - the ADS-B decoder as well as the Piaware software which uploads the ADS-B spots to Flightaware. Those programs run quite happily at the same time as Gpredict and use around 7% of CPU.

I fired up the Epiphany web browser and went to Twitter - again, the CPU was quite happy.

This looks very useful. I think I'd better order it a case!

Raspberry Pi 2 ordered

I was excited to see the Raspberry Pi 2 announced today

One is on the way. It will be interesting to see how it works out - particularly for some of the more heavy duty apps I have tried in the past such as FLDigi.

A new version of the OS compiled for the new processor is required and can be downloaded here

More news when it arrives!

Raspberry Pi 2 ordered

I was excited to see the Raspberry Pi 2 announced today

One is on the way. It will be interesting to see how it works out - particularly for some of the more heavy duty apps I have tried in the past such as FLDigi.

A new version of the OS compiled for the new processor is required and can be downloaded here

More news when it arrives!

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  • Matt W1MST, Managing Editor