Topband: Moon and the Ionosphere : YO3FFF

cris blak cyo3fff at
Fri Mar 16 07:23:01 EST 2007


This could also be done with exisiting low frequency BC beacons that are 
there every day - for example, a W6 listening to an Asian beacon every 
day at the same time for a year as you suggested.

I'm not aware of the active beacons on 160m (in the last 10 years I was a "2m DX guy" HI). If someone can point me to a WEB page or to send me a file with this information, I'll appreciate that.

Carl, yes and no. I agree to use the existing beacons but I think there RF power is very low for transcontinental experiment! Is like the Transatlantic beacon experiment on 2m...Is there any beacon who use at least 100W CW?

To keep the experiment 
simple and controlled, I believe it is preferrable to have a path that 
stays away from the higher latitudes to minimize geomagnetic field 
effects (just another variable to contaminate the data you're after).

Right. I'm not after something particular, just for the community. If people who like TP want to elucidate the "Moon dilemma" than should set-up an experiment. I'm one of those who is interested of this dilemma:)

I'm not a propagation specialist. That why I ask the guys with more experience on this field to contribute to this test in order to establish the path and the test method.

You are right regarding the high latitude path. Should be avoided.

Now for anybody who is interested of this experiment.

For the reception site I propose the following equipment to measure the signal strength of a particular beacon:

- a stable RX from the amplitude/temperature point of view; should be calibrated at lease 3 times/day (in the morning, at the mid day and in the evening/night) the best will be to inject a known calibrated signal together with the received signal - this should be done automatically; the BW of the receiver should be as low as possible (less than 500Hz, preferable 10Hz - this could be achieved with PC software); the dynamics of the receiver should be greater than 80dB; the noise floor should be at least -125dBm; AGC should be OFF; if AGC is ON than the AGC voltage should measured in order to achieve a linear response at the output of the receiver.
- a PC software to measure the detected signal of the beacon; a good example should be Radio SkyPipe; The best will be an audio spectrum analyzer like Spectran but the recorded file will be huge! the advantage of an time/frequency recording is the doppler information but is not mandatory for this experiment;
- a PC, preferable a laptop in order to minimize the power consumption and the possible interference with the radio.
- antenna - this is a point to be discussed; is it better to use a directional antenna or not. is it better to use vertical or horizontal polarization (or both); is it better to use a vertical low angle or a high angle antenna?
IMHO one should use at least two antennas; one directional antenna toward the beacon and another one omni directional but with low vertical angle. Each antenna will feed a separate receiver (so 2 RX is needed!) than the tow signals will be logged.
- power back-up.

This is on short.

I'm looking for your opinion.

73 de YO3FFF

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