FM Sender 15 cm Reichweite illegal?
Ich habe mir einen FM Sender gebaut, wollte einfach Mal schauen ob ich das kann:), ja kann ich anscheinend, aber ich würde gerne wissen ob dieser geht. Darf ich ihn Mal für 1minute einschalten und Testen? Nach Berechnung hat der ungefähr 15cm reichweite mit ca 101mhz Frequenz. Ich habe halt schon gehört dass das Illegal wäre, aber ich wohne hier sehr ländlich, Oberwellen erzeugt er bestimmt… Bin halt erst 15 und will jetzt nicht, dass das BNA vor der Tür steht. Der Sender ist Firma Eigenbau und könnte deshalb eben sehr störanfällig sein…
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Officially: NO WAY – completely illegal!
If you go to the basement, then in this case no one will complain – except for all radio listeners with you in the house(halt).
In addition, it would be useful if you use a “artificial antenna” as an antenna – i.e. a 50 ohm final resistance in a metal housing that lies on the transmitter mass. This also limits the range enormously and would thus almost limit it to an adjacent radio.
If you have serious interest in (legal) construction of stations and receivers, the amateur radio service would be the right thing for you. On the way to the test and after, of course, one learns how to build harmonic arms transmitters 😉
https://www.darc.de/einsteiger/darc-online-lehrgang/
Thank you.
It’s not legal. Legal are only industrially manufactured FM transmitters with a transmission power of 50 nanowatts, which have a corresponding CE marking.
But here the principle “Where no plaintiff, because no judge.” If the transmitter actually has only a range of 15cm, you don’t disturb anyone, so nobody complains and there is no risk of persecution.
You should only make sure that you actually only have such a small range (also applies to possible secondary broadcasts), and not perhaps ignorantly blow out with a watt and the whole village is happy with your test shows, a radio service is disturbed or the like, then the BNA can really come fast.
(Or if you’re lucky too – I’ve been running a pirate transmitter for half a year in my youth for several hours a week, reach about 1km, and I’ve never done anything. That was really pure luck.)
OK Thank you
15 centimeter range?
My FM transmitter for car radios continues.
How does any BNA want to know if it can’t even leave your room.
That’s why I built him so that he really has very little scope, but harmonics still exist and could be farther?
Can they… Your harmonics even interfere with the radio of firefighting, police and retaliation. Therefore – as advised: cellar, artificial antenna and finished.
@dvdfan: This is exactly the voice of the unconscious: “How will any…”.
This is quite simple: non-compared transmitters frequently emit harmonics and secondary waves on a multiple of the basic frequency, which are frequently stronger by a zigfold than the basic wave. And that is precisely why it is forbidden as a non-licensed private person to independently build and operate transmission systems. This is the perfect example for the “why”. But it’s hard to get into the heads these days.
@alpha489: You’ve built this thing now and you’ve seen it work. It is worth remembering that you can think about it and what the consequences might be here. And right: After you’re even in the radio band, you can easily expect someone to report to you, you can count on the BNetzA – which you can also pay in this case because that was a willing action and hasn’t happened due to innocuous disturbances of a device. The costs are generally over 10,000€.
Take the insights from the construction of the transmitter and leave the thing now. As long as no one was there, no one will come. But don’t play around with such risks in the future – would be my tip!
How far the transmitter really goes can’t be said because the 15cm can also only be because the receiver is so insensitive. I can easily get 30km – and more with a 100mW view. So much about performance. The location is far more important!
But each switching power supply (handylader, LED light source) has any interference in the FM range.
Your harmonics will not come much further than the actual transmission power.
Not quite: With the mini-transmitters, you can only position them if they interfere… and then this happens at frequencies that are not allowed for them – i.e. on harmonics. In this case, one does not seek the basic frequency but the source of the interference frequency. And you can place them relatively easily.
I mean not only radios, but everything, from the car key, babyphone, everything that works with radio. That’s the dilemma. There has been more and more radio technology, and according to what I read, for the sake of the economy, the authorisation requirement has been abolished by public authorities and only the manufacturer or dealer has to ensure that the standards have been complied with and a disturbance of the official frequencies is prevented. Unfortunately, this resulted in more and more sources of interference for police and others. Such a hobby radio station can be located comparatively easily, thousands of mini transmitters from babyphone to car keys is almost impossible to isolate the disturber.
This has nothing to do with the authorisation requirement, because that would be the display of approved devices that are released for operation with this procedure. But this duty is only for the unlicensed private man, not for amateur radio: If they have radiation outputs above 10W, they must still display their fixed installations via self-explaint.
The China devices also have nothing to do with self-construction transmitters; however, it is true that every depp is now missing these things – even department stores sell radios for which operation a radio license is required – air radio or amateur radio. As far as this is concerned, it has become a wild West.
However, it is no longer a secret that since the abolition of the authorisation requirement for telephones and devices, which are working with radio, the number of disturbances in the radio have increased drastically, so much the police and fire department themselves get problems. The problem is not illegal, but legal devices. Reason is because every trader can be cheap Made in Chna Import a CE and not worry about the disorders which babyphone and other stuff cause lack of compliance with standards, just as little as politics.
Thank you.)
Thank you for the good answer