FM antenna curiosity

If I can't see the other half it is the monopole. So I repeat my question: Are now the FM stations which use the dipoles?

doubling notions should be packaged up in art's box and never see the light of day.

The dipoles have the directional pattern like this:

It looks like the interference of the many sources (dipoles have the two).

The two sources not in phase double the frequencies. S*

g2000yqd.googlegroups.com...

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so why when i switch my transmitter from a 'monopole' where YOU can't see the other half to a dipole does the frequency stay the same?

see the other half to a dipole does the frequency stay the same?

Your transmitter has the same but in the receiver antenna is possibility that appear the doubled frequency. Luxembourg effect was observed in 1930. Now radio people manage with eliminating it. S*

The Luxemburg effect is usually contributed to the suspected Radio Luxemburg intermodulation products caused by the _ionosphere_ nonlinearities.

Similar intermodulation effects can be obtained by the nonlinearities caused by rusty bolts in a transmitter tower.

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nope, the receiver still hears the proper transmitted frequency.

Well, that's what I suggested above, notch = trap :-)

But it's tough and can be impossible if there are useful weaker stations near the one you want to muffle. In Europe they had a pager service right at the lower end of the FM band. Whichever committee signed off on that one should be dunked into a moat for gross incompetence, until they either learn or quit their career. Anyhow, the inevitable happened, and despite being a school kid I predicted that: A barrage of complaints by FM listeners. In Germany they pay a radio tax so that makes them sort of constituents with rights. Long story short the governement had to furnish rather expensive notch filters to anyone who complained.

"Paul Keinanen" wrote news: snipped-for-privacy@4ax.com...

Are such products the hours independent? Is ionosphere all time the same. The dipole on the tip top of the mountain (the both end of the dipole were :seen") produced the doubled frequency.

The same was obtained in Warsaw tower (collapsed years ago). Now Warsaw use monopole. S*

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So you move the trap slightly to one side. A good trap can be narrow enough to only affect one or two channels if it is built with the right components, but it isn't cheap. Glass piston capacitors and glass inductors are temperature stable and have a very high 'Q'.

It's probably a severe impedance mismatch between your new antenna and the old pickup coil. You might need to create a little step-up transformer between the board and jack. I looked at a few FM chip specs and they leave it up to the designer to figure out the right input transformer. You'll probably need trial and error to figure it out.

Yes. THY receiver is tuned to the transmitted frequency. Luxembourg effect means that another receiver tuned to the doubled your frequency hears you. S*

Perhaps you should read up on what the Luxembourg Effect actually was!!

It had nothing to do with antennas!!

It was Cross Modulation in the ionosphere between Radio Luxenbourg and other radio stations, where by the modulation of Radio Luxenbourg was heard superimposed onto the second station.

Jeff

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^^^^^^^^^^^^^^^^^^

Bingo!

I just hope someone was read the riot act for making that frequency allocation. I mean, that allocation was really borderline daft ;-)

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You think that's bad? Some idiot sold two way radios to a school system, and put them on a frequency reserved for ambulance service. Every time the base tried to contact one of their ambulances, the damn school bus drivers would start yelling at them to 'Get off OUR channel". The so called frequency coordinator for the area refused to do anything about his screw up for allowing them to be licensed on that frequency.