Low power MW transmitter?

[paulsherwin]

Originally Posted by mark pirate

I also have an fm transmitter that is ce marked, it's intended use is for connecting an mp3 player to an fm radio, i am surprised that these are legal & am transmitters are not.

Manufacturers can make conformant AM transmitters and have them CE certified, but I'm not aware that anybody has done this, presumably because the market is too small. Very low powered AM transmitters were legalized at the same time that the FM rules were changed. It's on the Ofcom website somewhere but I don't have the link.

[ms660]

"It's called Amateur Radio (till a few years ago officially called "Wireless Experimenters" in Ireland). Closest frequencies to AM are 137KHz and 1.8MHz. Though 500KHz or near it might get added.

You can't put music on it though"

Is that licensed? or a free for all...The point I was trying to make was how about an experimenters freq. for any body but pointing out the fact that would soon get abused.
Cheers.

[neon indicator]

Very strictly licensed, more so in some countries. You have to study and pass exam(s). Thought I don't think passing a Morse exam is needed anymore anywhere. Not needed Ireland or UK.

What it is that they are "strict" about varies a bit, in US I think they are allowed to patch into phone system. Not in UK or Ireland.

There are different limits on power and sometimes modulation (no wideband transmission on 10MHz, only 1W ERP on 137kHz, though that might need a 2kW power amp). Most bands it's the Power Amplifier (11W to 800W RMS depending on band) rather than EIRP that is limited. Most countries don't allow encrypted transmission. Some don't allow you to "invent" a new digital mode.

You can't use the service commercially, most countries don't allow 3rd party messages except for Emergency or State agencies in Emergency. You can't play your MP3 collection or rebroadcast a commercial station.

[neon indicator]

Originally Posted by paulsherwin

Manufacturers can make conformant AM transmitters and have them CE certified, but I'm not aware that anybody has done this, presumably because the market is too small. Very low powered AM transmitters were legalized at the same time that the FM rules were changed. It's on the Ofcom website somewhere but I don't have the link.

But is that just Ofcom or all / most EU countries?

Beware of Radio gear with CE /!\ on it. It may not be legal all EU states. Ireland legalised 5.8GHz video senders later than 5.8GHz WiFi for example. In the past CB with CE mark legal in Ireland probably wasn't in UK. The UK FM CB 27MHz + kit is only legal in Ireland with a WPAS licence (Community Broadcast, you pay for 1 channel TX and everyone else can only listen, it's between "regular" European CB Band which starts at 26.ish MHz and ends just below the Amateur band 28MHz to 29.7MHz).


It's not too hard to get a CE mark. It's feasible for a small outfit to produce AM micropower TX and get it approved. There is sadly no ongoing testing. So some unscrupulous companies get CE mark for CFL lamp or PC PSU and then later leave out the filtering components to save money. In UK Ofcom will do nothing. However the UK Trading Standards people WILL take action up to seizing all existing stock and all imports, they are excellent.

[mark pirate]

I do think that a lot of cheap Chinese tat has dubious CE labels, after all, anyone can put a little sticker on an item.

I have had so called CE stamped wallwarts, which are frankly dangerous,
One of which decided to come apart when being removed from a socket, exposing the user to live parts

As for my fm transmitters, one clearly has the CE mark moulded in to the plastic case, the other one just had a CE sticker on the battery lid (now lost).

Mark

[Boom]

I have a 1/4 Watt green laser which has a CE mark. Somehow I doubt it is pucker.

[Brian R Pateman]

Too far off topic now and we've covered this ground many times and it always ends the same way.

This has therefore ceased to transmit.