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Tentativo di ricezione eco dell’asteroide 2012 TC4

Questi giorni si avvicinerà alla Terra l’asteroide 2012 TC4 ad una distanza veramente minima per un oggetto spaziale, domani alle 7:42 ita il picco di massimo avvicinamento.

Animazione asteroide - NASA

Con quasi le stesse modalità del sistema meteor scatter sto provando a ricevere sulla frequenza del GRAVES l’eco dell’asteroide che transiterà a circa 42000 Km da noi. L’esito della prova è alquanto incerto poiché l’asteroide ha un diametro di “soli” 20 metri e passerà prevalentemente nell’emisfero sud quindi un pò fuori dalla finestra del trasmettitore.

Alla solita pagina http://www.ik0vve.net/?page_id=745 è possibile, rumori vari permettendo, visualizzare alcuni grafici adattati per l’evento.
Il primo grafico in alto è lo spettro radio a 143.050 MHz, frequenza di trasmissione del GRAVES, il 24h meteor strip è stato adattato per una maggiore visualizzazione. Ogni strip è di sole 4 ore e non 24 e la larghezza di banda è di 5 kHz. Tutto questo dovrebbe far vedere, in caso di eco, una linea curva che dalle frequenze più alte scende fino a scomparire sotto lo zero.

Vedremo domani se e cosa il sistema avrà registrato.WhatsApp Image 2017-10-11 at 14.58.14

 

NDB: photo of ZRA antenna

During last holidays in Croatia I made a photo about a Marconi-T antenna in the village of Kakma, here the photo:

ZAR NDB

The antenna consists of a pair of towers about 20 meters high with a 2 wires Marconi-T antenna. Under the vertical wires is there a little house where the transmitter is positioned. It’s curious that the antenna is very close to the road and a lot of near trees surround it, it’s not located at the top of the hill but probably for its work is enough efficient.

The coordinates are 43° 59′ 50” N – 15° 29′ 47” E, transmission frequency is: 330 kHz. It’s a middle power NDB with a nominal range of 50 NM. More informations on Zadar airport web site: http://www.zadar-airport.hr/en/radio-navigation

Google maps: https://www.google.com/maps/@43.9973652,15.4968233,378m/data=!3m1!1e3?hl=en-EN

MF tests with the sunlight

This morning, until about 1 o’clock pm local time, I tried to increase the transmission power from 50W to about 180W to see if the homemade radial matcher commutator can resist or smoke…
Well, it endured! During the tests i’ve been looking on wspr.net page and with a nice surprice I’ve seen that my signal was captured not only 246 km far from my TX by IK6BAK but also from DJ0ABR station even 800 and more km far! I think that DJ0ABR has a very low noise at the receiver front end.

I’ll be on the air tonight for a first “hi power” transmission. Stay tuned!

Timestamp Call MHz SNR Drift Grid Pwr Reporter RGrid km az
 2017-10-05 11:20   IK0VVE   0.475757   -23   0   JN61km   0.2   IK6BAK   JN63kr   246   0 
 2017-10-05 11:10   IK0VVE   0.475757   -23   0   JN61km   0.2   IK6BAK   JN63kr   246   0 
 2017-10-05 11:00   IK0VVE   0.475757   -24   0   JN61km   0.2   IK6BAK   JN63kr   246   0 
 2017-10-05 10:50   IK0VVE   0.475757   -23   0   JN61km   0.2   IK6BAK   JN63kr   246   0 
 2017-10-05 10:40   IK0VVE   0.475757   -23   0   JN61km   0.2   IK6BAK   JN63kr   246   0 
 2017-10-05 10:30   IK0VVE   0.475757   -24   0   JN61km   0.2   IK6BAK   JN63kr   246   0 
 2017-10-05 10:20   IK0VVE   0.475757   -25   0   JN61km   0.2   IK6BAK   JN63kr   246   0 
 2017-10-05 10:10   IK0VVE   0.475757   -24   0   JN61km   0.2   IK6BAK   JN63kr   246   0 
 2017-10-05 10:00   IK0VVE   0.475757   -23   0   JN61km   0.2   IK6BAK   JN63kr   246   0 
 2017-10-05 10:00   IK0VVE   0.475757   -28   0   JN61km   0.2   DJ0ABR   JN68nt   811   1 
 2017-10-05 09:50   IK0VVE   0.475757   -24   0   JN61km   0.2   IK6BAK   JN63kr   246   0 
 2017-10-05 09:40   IK0VVE   0.475757   -23   0   JN61km   0.2   IK6BAK   JN63kr   246   0 
 2017-10-05 09:30   IK0VVE   0.475757   -24   0   JN61km   0.2   IK6BAK   JN63kr   246   0 

MF TX season started!

Last night I’ve been transmitting for the first time after the summer period. A new look to the the TX antenna was made to simplify the shape and get more gain. Now the hat is about 16 meters long and the vertical side is about 9 meters high.WhatsApp Image 2017-10-03 at 16.33.33

The 6 wires of vertical slope are almost invisible on the left.

This are the stations that copied my signal in a couple of hours of transmission:031017vveMF

But a new “masterpiece” was build to remote tune the antenna in addition to the remote control of the variometer by a stepper motor, I’ve build a multi rotary switch to commutate the coils of antenna transformer without going out to the balcony changing the correct tip where to connect the antenna to get the right impedence. Soon a photo on these pages.

Log for stations over 1000 Km (61 different station overall):

Timestamp Call MHz SNR Drift Grid Pwr Reporter RGrid km az
 2017-10-03 20:40   IK0VVE   0.475757   -28   0   JN61km   0.2   EA8BFK   IL38bo   2809   248 
 2017-10-03 20:40   IK0VVE   0.475757   -21   0   JN61km   0.2   SM2DJK   KP03au   2526   8 
 2017-10-03 19:40   IK0VVE   0.475756   -24   0   JN61km   0.2   OH2EAT   KP20xw   2333   18 
 2017-10-03 20:40   IK0VVE   0.475741   -14   0   JN61km   0.2   SM3LNM   JP82qg   2327   6 
 2017-10-03 20:40   IK0VVE   0.475758   -22   0   JN61km   0.2   EI8JK   IO51do   2046   311 
 2017-10-03 20:30   IK0VVE   0.475746   -24   0   JN61km   0.2   LA8AV   JO59cs   2038   356 
 2017-10-03 20:30   IK0VVE   0.475757   -27   0   JN61km   0.2   LA6LU   JO59eq   2027   356 
 2017-10-03 19:20   IK0VVE   0.475757   -22   0   JN61km   0.2   LA3EQ   JO28xj   1938   348 
 2017-10-03 20:40   IK0VVE   0.475757   -27   0   JN61km   0.2   G0LUJ/1   IO83ls   1802   324 
 2017-10-03 19:10   IK0VVE   0.475757   -28   0   JN61km   0.2   G0LUJ/2   IO83ls   1802   324 
 2017-10-03 19:10   IK0VVE   0.475757   -24   0   JN61km   0.2   G0MJI   IO83ni   1763   324 
 2017-10-03 20:40   IK0VVE   0.475757   -24   0   JN61km   0.2   G4CPD   IO94hc   1751   328 
 2017-10-03 19:20   IK0VVE   0.475758   -23   0   JN61km   0.2   GW3UCJ   IO81cr   1698   318 
 2017-10-03 20:40   IK0VVE   0.475757   -22   0   JN61km   0.2   EA7HPM   IM67xj   1684   260 
 2017-10-03 20:40   IK0VVE   0.475758   -15   0   JN61km   0.2   G8HUH   IO81mg   1622   317 
 2017-10-03 20:40   IK0VVE   0.475757   -20   0   JN61km   0.2   G4ETG   IO92uc   1541   324 
 2017-10-03 20:40   IK0VVE   0.475758   -15   0   JN61km   0.2   G4ZFQ   IO90ir   1492   318 
 2017-10-03 20:40   IK0VVE   0.475761   -16   0   JN61km   0.2   G7UHT   IO90jr   1487   318 
 2017-10-03 19:10   IK0VVE   0.475757   -19   0   JN61km   0.2   G6AVK   JO01ho   1457   324 
 2017-10-03 20:40   IK0VVE   0.475754   -22   0   JN61km   0.2   DF2FF   JO44th   1442   352 
 2017-10-03 20:00   IK0VVE   0.475757   -14   0   JN61km   0.2   PA0A   JO33de   1387   341 
 2017-10-03 20:40   IK0VVE   0.475757   -23   0   JN61km   0.2   PA0SLT   JO33kg   1381   343 
 2017-10-03 20:40   IK0VVE   0.475757   -16   0   JN61km   0.2   PD0SBS   JO33le   1371   343 
 2017-10-03 19:20   IK0VVE   0.475757   -26   0   JN61km   0.2   PA2GP   JO33hb   1366   342 
 2017-10-03 20:40   IK0VVE   0.475762   -22   0   JN61km   0.2   PA7EY   JO22jj   1354   336 
 2017-10-03 19:20   IK0VVE   0.475757   -19   0   JN61km   0.2   SP5XSB   KO02ld   1330   25 
 2017-10-03 19:30   IK0VVE   0.475758   -30   0   JN61km   0.2   PA0EHG   JO22hb   1328   335 
 2017-10-03 20:40   IK0VVE   0.475757   -19   0   JN61km   0.2   DL0HT   JO43jb   1319   348 
 2017-10-03 19:20   IK0VVE   0.475759   -12   0   JN61km   0.2   PA0RDT   JO11tm   1316   331 
 2017-10-03 20:40   IK0VVE   0.475759   -24   0   JN61km   0.2   DL/PA0EHG   JO32sq   1305   344 
 2017-10-03 20:40   IK0VVE   0.475757   -13   0   JN61km   0.2   DJ2FS   JO62wx   1276   3 
 2017-10-03 20:40   IK0VVE   0.475757   -24   0   JN61km   0.2   PI4THT   JO32kf   1274   341 
 2017-10-03 20:30   IK0VVE   0.475757   -20   0   JN61km   0.2   PE1IWT   JO32kf   1274   341 
 2017-10-03 20:40   IK0VVE   0.475759   -19   0   JN61km   0.2   EB1LO   IN82sk   1270   280 
 2017-10-03 20:40   IK0VVE   0.475756   -26   0   JN61km   0.2   PA0MLC   JO31aw   1269   338 
 2017-10-03 20:40   IK0VVE   0.475759   -18   0   JN61km   0.2   DF5FH   JO42um   1246   350 
 2017-10-03 20:40   IK0VVE   0.475757   -16   0   JN61km   0.2   EA2HB   IN93ah   1232   284 
 2017-10-03 20:40   IK0VVE   0.475756   -23   0   JN61km   0.2   DL6OW-R   JO31kk   1194   340 
 2017-10-03 19:10   IK0VVE   0.475760   -16   0   JN61km   0.2   ON8IM   JO20ls   1194   332 
 2017-10-03 20:30   IK0VVE   0.475758   -25   0   JN61km   0.2   DC5AL-R   JO31lk   1191   340 
 2017-10-03 20:20   IK0VVE   0.475760   -23   0   JN61km   0.2   DC0DX   JO31lk   1191   340 
 2017-10-03 20:30   IK0VVE   0.475756   -14   0   JN61km   0.2   DF2JP   JO31hh   1188   338 
 2017-10-03 20:40   IK0VVE   0.475757   -10   0   JN61km   0.2   ON7ZO   JO20ei   1180   329 
 2017-10-03 20:40   IK0VVE   0.475758   -28   0   JN61km   0.2   DL4EAI   JO31je   1171   339 
 2017-10-03 20:40   IK0VVE   0.475759   -26   0   JN61km   0.2   EA5DOM-1   IM98xn   1146   258 
 2017-10-03 19:20   IK0VVE   0.475758   -28   0   JN61km   0.2   EA5AU   IM99tl   1142   263 
 2017-10-03 20:40   IK0VVE   0.475754   -13   0   JN61km   0.2   DL6II   JO30nx   1140   339 
 2017-10-03 20:40   IK0VVE   0.475759   -11   0   JN61km   0.2   F1AFJ   JN06ht   1139   305

Perseidi 2017, report un pò in ritardo

Solo ora sono riuscito a terminare la stesura del report sulle Perseidi 2017. Purtroppo ancora ho problemi nel far lavorare assieme SpectrumLab con RMob con la conseguenza che i dati degli eventi non si distribuiscono per ore ma sono raggruppati in grossi “ammassi”, solo grazie all’indispensabile e preziosissimo aiuto del mio amico e collega Luca Francescutti siamo riusciti a venirne a capo.
Quello che segue è il grafico relativo al periodo delle Perseidi partendo dal giorno 8 Agosto per avere un riferimento di come erano gli eventi di fondo prima di questo sciame. Certo è che l’attività era già alta probabilmente a causa di alcuni sciami minori come le Delta Acquaridi.

Perseidi2017

Dalla tabella a lato si può chiaramente vedere che i giorni di maggiore attività sono stati il 12 ed il 13 Agosto anche se il giorno 11 ci regalava già parecchi echi.

Per questo sciame ho effettuato dei cambiamenti sul sistema di ricezione, non ho usato la chiavetta RTL ma l’Elad FDM-S1 con filtro passabanda centrato sulla frequenza del GRAVES. La cosa che però ha elevato moltissimo il numero di echi ricevuti è il cambio di polarizzazione della 8 elementi LPDA passando da orizzontale a verticale. Confrontando con i dati dello scorso anno (non sono in rete) abbiamo numeri notevolmente più alti. Anche dal precedente post con video in timelapse è possibile vedere l’enorme quantità di echi catturati arrivando per il giorno 12 a ben 2109 con due picchi di 127 echi in due ore diverse della mattinata. 

Dalle immagini catturate ci sono stati degli echi veramente interessanti e lunghi. Di seguito un secondo grafico sull’andamento continuo nei sette giorni.

Perseidi7giorni

 

Di seguito link ad altri amici sulle Perseidi 2017:

IK0OZK Renato
IU3IOU Giorgio
I55387FI Daniele
Massimo

My Perseid 2017 time lapse video

NEO M8N U-Blox GPS receiver

WhatsApp Image 2017-04-06 at 23.20.40Finally I’ve had some free time to play with my new GPS receiver, a NEO M8N.

This nice and cheap object arrived to me over a little PCB where other components are positioned for an easier and fast utilization. The rx-tx  serial data are 3.3 V level, so a converter is needed for a correct work. I’ve used a USB converter that provides the 5 Volt DC for the 3.3 Volt board regulator.

To configure the NEO M8N I’ve used U-Center, the software is freely available at U-Blox website.

At first start the power LED was on and after a while also the TimePulse LED began to blink.

Despite I used it in an indoor ambient has been quickly possible to receive a lot of satellites.

ucenter

This GPS receiver will be used to discipline my VLF to MF receivers thanks to the possibility to change the TimePulse period configuring it by U-Center software. I’ve tried to change the frequency measuring it by an oscilloscope. Here follows some images of the test.

WhatsApp Image 2017-04-06 at 23.53.51

 

A first test at 136 kHz with a low duty cycle. I’ve tried it at the maximum frequency of 10 MHz and the result seems to be good looking also to its linearity.

WhatsApp Image 2017-04-07 at 00.05.22

Lately other tests with 50% duty cycle at some interesting frequency:

WhatsApp Image 2017-04-07 at 00.08.31 WhatsApp Image 2017-04-07 at 00.18.34 WhatsApp Image 2017-04-07 at 00.20.42

To set a decimal frequency we need to change the frequency setup to period setup, so it will be possible to write a very sharp frequency till to nHz’s. For example I’ve tried to set 8270.005 Hz, whose period is 120.918911 us (microSeconds). Minimum frequency reached is 0.01 Hz with a possible accuracy of 0.1 nHz (nanoHz)!

First reception on 8270 Hz

Finally, thanks to Stefan DK7FC, I’ve my first “human” signal on 8 kHz band.
Stefan was active for all the last week-end on the band to give me a chance to receive his signal, and pixel after pixel the signal apeared in this way:
WhatsApp Image 2017-02-20 at 08.32.03A well marked peak exactly on 8270.005 Hz shows the integration of the signal after many hours of transmission.

The distance between Stefan and me is about 940 Km, not bat at all! Stefan helped me to fine “tune” Spectrum Lab software to optimize the system for the best performance. As antenna I’ve used my loop oriented towards Heidelberg.

I think that other works, for a better receiving, could be done.

Almost ready for VLF again

Ready again to receive VLF with my new loop. At the moment the antenna is located on the roof under the TX WhatsApp Image 2017-02-02 at 18.02.02antenna for MF-LF.

The preamplifier circuit comes from the easyloop of VLF.IT with an OP27 and few others components.

The antenna is composed by 32 turns of 0.15 mm dia. for a total lenght of over 200 meters. No screen has been applied around the wires.

Power supplied from a 12 V battery the signal goes down to the station by a little dual coaxial cable for submergible cameras (video+PS).

Just before the input to the audio board I’ve used a 50:600 Ohm home made trafo to optimize the signal.

This solution give me less noise and more signal.

Next step will be to insert the GPS to one of the audio channel to discipline by Spectrum Lab the audio board and get a stable and precise frequency.

Under here an image of this afternoon.

I still have an unknown noise on 10KHz.

capt170202164045 

630m pirate?

Tonight I’ve decided to try QRSS on MF and while I was transmitting I’ve seen on DK7FC grabbers a strange signal between mine and IK1HGI’s. The call was C7MW which prefix is allocated to the World Meteorological Organization. With Stefan’s RDF spectrogram is possible to see on the next picture that signal comes from E/W direction.

RDF3

Any news?