17 May 2019
Portugal castle - NOT amateur radio
16 May 2019
Rally
Sunday 19 MAY : DUNSTABLE DOWNS NATIONAL AMATEUR RADIO CAR BOOT SALE
Stockwood Park, Luton LU1 4BQ. All the usual facilities. www.ddrcbootsale.org.
A list of rallies can be found at http://rsgb.org/main/news/rall
Stockwood Park, Luton LU1 4BQ. All the usual facilities. www.ddrcbootsale.org.
A list of rallies can be found at http://rsgb.org/main/news/rall
Portugal - NOT amateur radio
This has been a busy few days, but we have seen and learned a lot.
For days we have been looking for bee eaters. Today my wife and I saw 4!
Right wing extremists - NOT amateur radio
The upcoming European elections will be test for the far right parties in many EU countries. Although fairly centralist politically myself, there is no denying that politics in many countries is moving further right.
Many of those who vote right wing are disaffected people who think (falsely) that right wing parties will bring back halcyon days without immigrants and the EU. In my view all EU nations have changed forever and people are being misguided.
The UK and USA have been integrating immigrant people for a very long time. It is important that people coming into a country learn the language and integrate. It is very unlikely those who do not try to fully integrate will feel welcomed.
If right wing parties do well in the EU elections the EU could change radically in the years ahead.
See https://www.bbc.com/news/world-europe-48264638
Many of those who vote right wing are disaffected people who think (falsely) that right wing parties will bring back halcyon days without immigrants and the EU. In my view all EU nations have changed forever and people are being misguided.
The UK and USA have been integrating immigrant people for a very long time. It is important that people coming into a country learn the language and integrate. It is very unlikely those who do not try to fully integrate will feel welcomed.
If right wing parties do well in the EU elections the EU could change radically in the years ahead.
See https://www.bbc.com/news/world-europe-48264638
Even lower!
Stefan DK7FC has been doing experiments at even lower frequencies! This was posted a few days ago. His attachment has NOT been included.
"Hello SLF freinds,
Just a note from a recent experiment at 270.1 Hz.
On sunday morning, 2019-05-12_10:34,+150m, i've done a carrier transmission on my ground loop antenna again. I did not expect more than, hopefully, a detectable spectrum peak in 57.6 km distance, i.e. at my tree site. The tree receiver site was listening and recording data using vlf-rx tools.
One E field antenna and two orthogonal loops were listening. The loops have been improved recently! They consist out of a single circular turn of 1.2 m diameter using 10mm diameter copper tube (about 25 mm^2). It is a closed loop, non-resonated, with an impedance matching transformer. This transformer previously had 1:100 turns. Now it (they) has 2:240 turns, i.e. two turns primary (out of 14mm^2, AWG6). This improved the sensitivity below 2 kHz significantly ( abt. 4...5 dB).
Furthermore the TX antenna length and angle has been improved, resulting in about +3 dB more signal strength on the RX site!
In a previous experiment at 270.1 Hz, some month ago, there was no result at all, not the weakest trace, despite excessive tweaking of all parameters. So the question was, will the improvements result in a detectable signal now?
Several things went wrong in that experiment. I forgot a bag containing important equipment such as the power supply for the netbook that generates the carrier signal. Also the output power was not as high as planned, just about 380 W, giving 2.2 A antenna current (I measured 64.7 V at 1 A DC). Anyway i managed to improvise so the experiment was started, but with some hours of delay which meant i higher QRN background level. Then, on the WLAN link to the tree, there were several interruptions of the stream (i'll move to 5 GHz very soon!). I even got some QRM from my battery charger for some short time periods (forgot to disable the charger remotely). So there were several factors that could have been improved or avoided. And the middle of May is not the ideal time anyway.
Well, 270.1 Hz, that's the 1110 km band! The far field begins at 177 km distance, i.e. i am clearly in the near field here. Thus, from a 'magnetic' TX antenna, we would expect that the signal is mainly detectable on the H field, i.e. the loop antennas.
The first interesting results is that this expection is actually confirmed. There is nothing detectable on the E field but the carrier S/N in the H fields is close to 10 dB in the first run. Mixing the H fields and tweaking the filters rises the carrier S/N to 10.7 dB, see attachment.
So far not really an undoubtly detection but it is a candidate for optimism! With a few less problems during the experiment there is a chance for 14 dB SNR. Also, there is quite much sideband QRM arround 300 Hz which makes 270 Hz a bit harder to work on.
73, Stefan"
"Hello SLF freinds,
Just a note from a recent experiment at 270.1 Hz.
On sunday morning, 2019-05-12_10:34,+150m, i've done a carrier transmission on my ground loop antenna again. I did not expect more than, hopefully, a detectable spectrum peak in 57.6 km distance, i.e. at my tree site. The tree receiver site was listening and recording data using vlf-rx tools.
One E field antenna and two orthogonal loops were listening. The loops have been improved recently! They consist out of a single circular turn of 1.2 m diameter using 10mm diameter copper tube (about 25 mm^2). It is a closed loop, non-resonated, with an impedance matching transformer. This transformer previously had 1:100 turns. Now it (they) has 2:240 turns, i.e. two turns primary (out of 14mm^2, AWG6). This improved the sensitivity below 2 kHz significantly ( abt. 4...5 dB).
Furthermore the TX antenna length and angle has been improved, resulting in about +3 dB more signal strength on the RX site!
In a previous experiment at 270.1 Hz, some month ago, there was no result at all, not the weakest trace, despite excessive tweaking of all parameters. So the question was, will the improvements result in a detectable signal now?
Several things went wrong in that experiment. I forgot a bag containing important equipment such as the power supply for the netbook that generates the carrier signal. Also the output power was not as high as planned, just about 380 W, giving 2.2 A antenna current (I measured 64.7 V at 1 A DC). Anyway i managed to improvise so the experiment was started, but with some hours of delay which meant i higher QRN background level. Then, on the WLAN link to the tree, there were several interruptions of the stream (i'll move to 5 GHz very soon!). I even got some QRM from my battery charger for some short time periods (forgot to disable the charger remotely). So there were several factors that could have been improved or avoided. And the middle of May is not the ideal time anyway.
Well, 270.1 Hz, that's the 1110 km band! The far field begins at 177 km distance, i.e. i am clearly in the near field here. Thus, from a 'magnetic' TX antenna, we would expect that the signal is mainly detectable on the H field, i.e. the loop antennas.
The first interesting results is that this expection is actually confirmed. There is nothing detectable on the E field but the carrier S/N in the H fields is close to 10 dB in the first run. Mixing the H fields and tweaking the filters rises the carrier S/N to 10.7 dB, see attachment.
So far not really an undoubtly detection but it is a candidate for optimism! With a few less problems during the experiment there is a chance for 14 dB SNR. Also, there is quite much sideband QRM arround 300 Hz which makes 270 Hz a bit harder to work on.
73, Stefan"
15 May 2019
Portugal Birds - NOT amateur radio
See https://en.wikipedia.org/wiki/European_bee-eater
Chapel of Bones - NOT amateur radio
Dayton
17-19 MAY : DAYTON HAMVENTION
Greene County Fairgrounds and Expo Center, Dayton, Ohio.
A list of rallies can be found at http://rsgb.org/main/news/rall
Greene County Fairgrounds and Expo Center, Dayton, Ohio.
A list of rallies can be found at http://rsgb.org/main/news/rall
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