>I live in a 15 floor building, on top of which there is a 30 meter mast, and my building - by Warsaw >standards - is "small". (I set a QRP world record in 2005 from such a building on 3.5mhz)
Do you have access to this 30m mast ? Would it be possible to hang a vertical slope wire from top
of the mast to top terrace on floor 15th ?
>Thus to hang a dipole on such a building would not be expensive and to mount a 1w TX at the dipole >center point would make beacon construction simple.
A dipole is not an option on MF. If the power limitation is 1w radiated power, you will have to use
many watts on Tx to get 1w radiated, specially with a low efficient antenna
What I'm using here with great success is a 11m vertical with two 6m "arms" as top load
Then in the base of the antenna a coil about 3mH to get it in resonance. The ground line of PA
runs to ground using a water pipe inside the building. This is not "ground" but the extension of
the vertical antenna. So the antena is really a vertical formed by 80m + feed + coil + 11m + topload
If you build something similar at your building tower it should provide similar results
My QRP tests ended by injecting 1mW to the antenna and then I got my signal decoded using
Opera32 at 300Km by EB3FRN. All this on 630m band
Your mileage may vary ....as US guys say ;-)
73 de Luis
EA5DOM
