The results of the recent ARRL Frequency Measurement Test (April 7, 2016) were published early this morning. Once again I managed to measure the frequency of K5CM with a pretty good accuracy of -0.44 Hz.
I used a very basic setup, which consists only of my Icom IC-706 MkII tranceiver with a dipole antenna (currently near the ground, pending installation of a 4 m mast), a PC with a standard soundcard and the GB3RAL software, normally used to receive the 5290 kHz beacons.
The Icom radio has an option to display frequency with a precision of 1 Hz, instead of the 10 Hz display of other radios.
My metodology is to calibrate the whole system against stations CHU (7850 kHz) and RWM (4996 kHz), and a GPS-referenced source on 10000 kHz. I produce a first degree calibration equation, which I use to correct the display of the radio with the actual FMT signal.
This time I concentrated on the 40 m CW transmission of K5CM. The 20 m path was closed and 80 m is too noisy at my location. On 40 m, near 7055 kHz, I measured a carrier frequency of 7055773.15 Hz instead of the correct value of 7055773.59 Hz (error -0.44 Hz), which I believe is a good achievement with such a basic setup.
2016-04-03
Σεμινάριο VHF από τον SV1BJY
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| Παρουσίαση του bandplan των 2 m |
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| Πως μπορώ να κάνω επαφές στα 2000 km ? |
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| Το εκλεκτό ακροατήριο της διάλεξης |
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| Ο ομιλητής εξηγεί τις διαδικασίες του meteor scatter. |
Σήμερα είχα την χαρά να παρακολουθήσω ένα πολύ ενδιαφέρον σεμινάριο στα γραφεία της Ε.Ε.Ρ. Ομιλητης ήταν ο Γιάννης, SV1BJY και θέμα η διάδοση στα VHF και ιδίως στους 144 MHz. Αναφέρθηκαν πολλά και ενδιαφέροντα που έχει συγκεντρώσει ο ομιλητής κυρίως από την συμμετοχή του στα διάφορα VHF contest, στα οποία συμμετέχει ανελιπώς.
Καλύφθηκαν όλα σχεδόν τα θέματα εκτός από το Aurora Propagation, το οποίο βέβαια είναι άγνωστο στην χώρα μας. Από τα πλέον ενδιαφέροντα ήταν η λεπτομερής περιγραφή της σκέδασης σε μετεωρίτες. Επίσης λίγα θέματα σχετικά με τα 23 cm και αρκετές αναφορές για τις επικοινωνίες στους 10 GHz και την σχετική τεχνολογία.
UPDATE: The four photographs were uploaded locally (2018-02-03)
2016-03-23
SV1SIX beacon active again
It transmits on 50040 kHz in F1A (frequency shift Morse code), sending the following message: SV1SIX LOCATOR KM17UX ATHENS 30W ERP.
2016-03-12
Alternative site for Athens Digisonde
Today I discovered that the digisond of the National Observatory of Athens host an alternative website with different skin but with the same basic information. The address is http://noa-dps.astro.noa.gr/ and I don't know if it is a permanent service or some provisional or experimental feature.
Their main site at http://www.iono.noa.gr/ is again fully operational.
Their main site at http://www.iono.noa.gr/ is again fully operational.
2016-02-02
ADS-B broacast from a crane !
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| ADS-B plot from https://planefinder.net/ |
A strange marker shows up on ADS-B plots in the Docklands, near London City Airport. A relevant NOTAM has been issued, indicating that it is a fixed ADS-B beacon on a crane at a construction site:
Q) EGTT/QCBXX/IV/BO /AE /009/999/5130N00001E
A) EGLC
B) 16/01/28 23:59
C) 16/03/12 23:59
E) LOW POWER AUTOMATED DEPENDANT SURVEILLANCE-BROADCAST (ADS-B) TRANSMITTER OPR ON CRANE AT 513030N 0000057E (ROYAL VICTORIA DOCK). EQUIPMENT WILL NOT INTERACT WITH TCAS BUT MAY BE DETECTABLE ON TRAFFIC INFORMATION DEVICES AND DEPICT WITH CALLSIGN CRANE. PILOTS ARE REQUESTED TO IGNORE THIS TRANSMISSION DURING THIS TRIAL.
I believe it is the first time that a Mode-S/ADS-B marker is used in this way. Stay tuned for more info.
UPDATE 2016-05-17: See additional information by Pat Carty in Radio User magazine, 11 (5), May 2016, page 49, ISSN 1748-8117.
UPDATE 2016-05-17: See additional information by Pat Carty in Radio User magazine, 11 (5), May 2016, page 49, ISSN 1748-8117.
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