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onetenor
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It is a video transmitter for FPV. I think the advertiser meant mW (milliwatts - one thousandth of a watt) not MW (megawatts - million watts!) If so, then it is probably legal on its lowest power setting.

If he really did mean MW, then its going to need thicker battery cables......!

surprise

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Pete

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No BEB, I believe it is 25mW. With so many much more powerful ones on the market I wonder just how many are sticking to the ridiculously low legal limit. This is a quarter of the power of a 2.4gHz Tx and even 200mW (which of course I tried abroad!) in a quad can easily blank out. I would expect that my 2.4gHz wireless door bell is more powerful than that.

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He's right, but the risk at these levels is miniscule. As I understand it it's when you get up to the sort of power levels of serious radio and TV transmitters (that can be measured in kW) that the real danger exists. For us at mW levels its not an issue. Bear in mind your Tx is outputing 100mW - 4 times this limit.

BEB

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I don't see any sign of a CE mark or mention of CE certification. I've a feeling that the facility to switch to illegaly high outputs would rule any certification out.

BTW can someone explain to onetenor how to post links.

Edited By Biggles' Elder Brother - Moderator on 01/08/2018 20:03:42

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Bear in mind that an fpv video transmitter would normally be operating at altitude, and the higher the transmitter, the further the signal will go. At these sort of frequencies, 25 mW *should* be ok, but fluctuations in signal level caused by rapidly changing aerial orientation is likely to cause problems.

I know someone who used to use a 10mW "walkie-talkie" type airband radio (legal) as a full-size competitive glider pilot, to let his ground crew know where to retrieve him! He never had a range problem with it.

As far as the dangers of RF are concerned, BEB is right about high powered broadcast transmitters. I worked at Holme Moss for a while in its heyday, and stray RF fields were something of which we were all very wary!

However, at fpv power levels, unless you sleep with it under your pillow, it is highly unlikely to cause any problems. There have been concerns about mobile phones - which put out quite high peak powers - when operated for long periods held to the ear, but even there, the evidence is far from conclusive.

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Pete

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Some years ago I worked for a company producing mobile phone mast head Tx and Rx amplifiers, ending up as the only person tuning up the 2x20W (2x50dbm) Tx ones which had to be out of their casings in order to do this. The outputs were fed into temporary loads which got quite hot trying to dissipate that amount of RF power.

After a while of doing this virtually all of my hair fell out which was extremely embarrassing for a long time until it re grew in three different colours, OK now.

Don`t be concerned about the miniscule output of your Tx though. My hair only falls out with worry and old age now.

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