144 MHz beacon
Corsica has an interesting geographical situation in the Mediterreanan sea, and the idea to build a 2m beacon came to me in early 1991. I engaged all the administrative steps at the REF and former ART to get a callsign and frequency. The given frequency was 144.8925 MHz.
Following his nomination at the REF in charge of the beacons, Michel F6HTJ asked me if i couldn't reactivate this project. During a local ham meeting, the decision was taken to do something.
In january 2002, as the 2m bandplan changed, a new frequency request has been done and the new frequency was 144.485 MHz. The new callsign was TK5ZMK.
On the technical side :
The beacon has been build around an old Philips M294 repeater, in which i only kept the power supply and the transmitter.
The oscilator is a TCXO built after a DF9LN design with a xtal oscilating directly on the working frequency of 144.485 MHz. A small amplifier between this oscilator and the amplifier of the original M294 amplifier with a MMIC was build, et voilŕ !
The keyer was already done in 1992 for my first project. It's based around a simple design after a description done in an old REF magazine in november 1983 by F6FBB, F1GQS, F1CDC. I wrote a small BASIC software to easily program the 8 possible messages.
The beacon has been build rather rapidly, but we had to find a site that would observe following conditions :
- Main powered
- Site not or almost not used by other radioamateur activities to reduce interferences.
- Site not too far from my home QTH to allow easy checking and repair.
The solution was found only in 2006 when we finaly could get a small building on top of a hill south of Ajaccio, called "Coti-Chiavari". But meanwhile, i had to suffer a lot of jokes about the beacon laying for years under ..... my bed ! ;-)) ...
Thus, it is only on april 23 2006 that the installation on site was carried out. With the help of TK1BI and TK1CX some works have been done on the building and the beacon could start.
Toussaint TK1BI proved to be an excellent painter and Thierry TK1CX made all the metal work. Myself, i installed the antenna and the beacon.
Callsign : TK5ZMK
Locator : JN41JS
Frequency : 144,485 MHz.
Modulation : F1D
Power : 10 W
Antenna : big wheel (3dB gain).
Somes pictures : (Click on them to enlarge.)
|The 2m beacon||The antennas||Best received report|
1296 MHz beacon
A 23cm beacon has been installed by Jean-Claude F5BUU and Jean-Pierre F1AAM in july 2006 during their SHF expedition.
It has been built by Jean-Pierre F1AAM. The 108.07666 MHz signal coming from a temperature controled oscillator goes through a CW coder and is keyed in A1A, than goes into a X12 multiplier and is finaly amplified by a hybrd amplifier.
Some pictures (Click to enlarge)
|The 23cm beacon||Both beacons||First breakdown !|
Callsign : TK5ZMV
Locator : JN41JS
Frequency : 1296,920 MHz.
Modulation : A1A
Power : 5 W
Antenna : 19 el F9FT dir. NW
Health report :
25/10/06 : 23cm hybrid PA failure, printed board burned. Repaired 30/10/06
29/10/06 : Main power failure due to thunderbolt. Repaired 30/10/06
27/04/07 : 23cm beacon stopped : PA power supply failure.
22/06/07 : 23cm beacon started : temporary PA power supply.
24/10/07 : Both beacon stopped : 2m PA out of service + 23 cm PA power supply change.
01/11/07 : Both beacon restarted after repair.
29/04/10 : VHF beacon repaired. New PA, changed keying to A1A. Antenna repaired.