We need a 144 MHz beacon in the western part of Denmark, and a good an cheap way to solve this, is using the RFzero board as exciter and control board.
Next thing is to make a 100 to 150 MHz low power Low Pass filter, and this is possible by using one of the small PCB’s from RFzero.
Above filter is not suitable for power above 0.5W, so I searched for a better solution, and found a nice small low pass filter on Ebay.
Output form RFzero on 144 MHz is only 20 mW, so I have to build a small Power Amplifier based on a power block from Mitsubishi.
I was quite sure that I had a 30W block on the shelf, bu I was not able to find it. So I purchased an new one, and decided to buy a Mitsubishi RA60H1317M.
It’s a 60W type, but will be limited to 5-25W depending on future QTH.
28.08.2021: OZ7CE Christian is willing to try to put my beacon up in he’s tower, and test whether it’s making noise on the repeaters living in the same tower.
This will be quite a challenge, as there is several repeaters for 434MHz, one for 145MHz, one for 70MHz, and one for 50MHz.
To ensure a good an clean signal, I have decided to use a very narrow band pass filter, and a narrow notch filter.
I was lucky to have them sponsored from OZ5KM Kjeld, and Peter Opfinder.
Here is final test of Band Pass filter in combination with a notch filter.
I have to ensure not to disturb a APRS gear at 144.800 MHz and repeater on 145.175 MHz.
After adjustments signal on 145,175 MHz is 60db down, at 144.800MHz it’s about 50db down.
November 2021: Complete setup was handed over to OZ7CE Christian, waiting for good weather for the tower work.
Antennas will be 3 x 3 element DK7ZB mounted 30-40 meter AGL / 167-177 meter ASL.
See also https://www.beaconspot.uk for further information about OZ1FYR.