Is my antenna setup blowing up my x-mitter?

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Nico
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Is my antenna setup blowing up my x-mitter?

Post by Nico »

Hello, Within the past year I seem to have gone through 2 relatively low end Stereo PLL transmitters broadcasting at around 0.25W. The second was a better build quality than the first by far. I could tell right away since it had two output transformers instead of just one like the old one. They both worked great for the first few months. I could get about 1000-1200 meters of coverage pretty crystal clear when I fired them up.
This last failure has me a bit baffled. The output transformers seem to be very microphonic when I tap on them like old tubes would get when they went bad. My radios all lock on to the frequency, but even with no audio going to the transmitter I get what sounds almost like some white noise mixed with feedback, very nasty sound.

I have been reading about antennas and see on this site that using a standard TV antenna is not recommended. I built this antenna myself using an old TV antenna and just using one row of the elements, effectively creating a dipole antenna. Also, I believe my coax wire is a bit too long, and actually almost makes a complete loop at one point.

I must admit, I do know a good share about electronics, but get pretty lost when it comes to transmitters and the like. But from what I have been reading, it would seem like my antenna is causing signal to get reflected back to the transmitter output and causing my transistors to fail eventually. It must not be a bad reflection cause as I said before, they seem to work well for about 4 or so months before starting to fail.

I also must admit that both of these transmitters were e-bay purchases and were really in no sort of finished package, they are just a PCB with all the components.

Since I am making a post, and it looks like I am going to need to purchase some new equipment. Would the PCI MAX card with a moderately priced di-pole antenna that is designed to be driven be a good setup to use and still cover the 1000-1200m that I was covering with this 0.25W transmitter?

Thanks so much in advance...

Nico
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pcs
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Post by pcs »

NIco,

pci max 2006+ is sold out at the moment. New version 2007+ is just around the corner.

Several versions will be available, exact power ratings are not yet known but it will
go way above what you used to have.
A few new antennas will be accompanying product release as well so you'll have plenty
to choose from.

This new 2007+ model will feature temperature protection. The output stage will also be
robustly over-dimensioned with solid power margin to make sure it never dies even when
abused.

I am sure you will find it wastly superior to your previous transmitters.

Check back in about 3-5 weeks.
Best regards,
Marko - PCS Electronics
--------------------------------------------------------
Turn your PC into a FM radio station!
http://www.pcs-electronics.com
fax +386 4 2316 128
oneintown
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Post by oneintown »

Hello there

I need someone to rell help me - a novice at least to say.
Already I have a broadcasting station on air, mere using a cheap di pole antenna with a 30watts transmitter.
The coverage has been just about two mile.
This I believe that its because of three things, one- my location( the antenna is on 3 storey town hse.
Well my problem now is. I managed to approach a supplier who supplied me 500 watts Booster with a 30 watts Transmitter.
The main problem is, the 4 bay Di-pole came with my order, but do not know how to arrange or put the antenna togeher.
It came with 4 short cable with connectors on it and one long cable i believe that this one will be connected to TX/booster.
Please can you help me on how to put this 4 bar dipole antenna together, as am confused with the cabling
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pcs
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Post by pcs »

Whoever sold it to you should help you.
Best regards,
Marko - PCS Electronics
--------------------------------------------------------
Turn your PC into a FM radio station!
http://www.pcs-electronics.com
fax +386 4 2316 128
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