AM 'Pantry' Transmitters

[Old Sparky]

Over on UKVRRRDF there is a thread, closed by Paul Stenning, from a member in, I think, Slovenia, asking which aerial is best to use with these devices. I don't wish to break any forum rules. as i know these devices are unlicensable in the UK, and don't posess one, but I wonder if anyone knows what the regulations are regarding these transmitters in other European Countries. Just out of curiosity!

[Joe]

They are illegal throughout the EU. As for places like Norway that are geographically in Europe but not EU members I don't know.

- Joe

[Yorkie]

The short answer is:

However low the transmit power is, be it below 100mW or not, all such equipment is unlawful anywhere in the EU, whether commercially built or home-brew.

Because it's a horrible morning - dull, and raining, I'm minded to prattle on in my cosy warm study, pecking away at my keyboard at some length for the few who might be interested, unless a moderator thinks it's a topic best not elaborated upon and should be filed under 'Burn before Reading', which I'd quite understand.

Regardless of how the law stands, to be pragmatic about this, it just isn’t on Ofcom’s radar – they’ve never had a complaint and they don’t want to know about such equipment. I can state that with confidence as I was in protracted discussions with Ofcom in 2010 and still have all the correspondence.

Fact is, how many neighbours listen to MW radio? If they do, and happened to hear a re-transmitted FM station from a MW pantry transmitter next door, how would they know, (unlikely), and what problems would it cause them (it wouldn’t). When I queried the legality of such equipment (in attempting to make the case for it being made licence free), I asked what Ofcom's approach to enforcement was, here’s what they said:

Quote:

We encounter many non-compliant devices on the market in the UK, we have to prioritise our work so as to maximize the effectiveness of our team and offer the best level of protection of the radio spectrum...

End quote.

Whilst not wishing to denigrate the UK VRF in any way (of which I'm a member and occasional poster), given the strict moderation policy - where even a misspelt word or 'grocers' apostrophe’ can incur the opprobrium of the moderators - it's always surprised me that the discussion - indeed encouragement - of building 'micro-transmitters' is permitted, but that of course is entirely a matter for the owner of that forum. I can understand why the particular thread was closed because the commonsense answer is ‘don’t use an aerial that risks transmitting signals beyond the bounds of your property’. Normally of course, an aerial is designed to maximise rather than minimise the range of transmission (or reception), but in the case of so called ‘Pantry Transmitters’ the aim is to restrict the range.

Under “what are or are not permissible topics for discussion”, the VRF rules do permit the discussion of illegal ‘micro transmitters’ (AKA ‘Pantry Transmitters’), stating thus:

Quote:

“For this forum, broadcast transmitters are defined as those having an output in excess of 100mW e.i.r.p. on any waveband currently or previously used for radio or television broadcasting. Most 'Gizmo' and 'iTrip' type units intended to enable transmission over a few metres are less than this threshold”.

End quote.

(Incidentally, 'i-trips’ and similar devices for use in cars are legal and have no parallel to MW ‘micro transmitters’ which are not legal so the two should not be confused).

The BVWS too, has published designs for such home-brew transmitters.

In support of both the VRF and BVWS, I understand the keen interest and usefulness of these devices to us, and would assert that even if such topics were not discussed, people would experiment come what may, using internet sources etc, and it has to be said that several well qualified and competent designers have built and tested numerous 'pantry transmitters', details of which have appeared on the forum and in the Bulletin, so it could be argued that in so doing, this has minimised the risks of causing problems and has raised the standard of competence of others who wish to dabble.

Notwithstanding that, Ofcom have clearly stated that such equipment – be it home brew or commercially constructed is illegal per se, throughout the EU. And how many builders and experimenters have test equipment to ensure that the output is below 100mW? Very few would be my guess. With a suitable aerial the Spitfire is designed (and permitted in the USA by the FCC) as a Community Broadcast Station:

Here’s what the advert for the Spitfire says:

Quote:

Local Community Broadcast Station:

So you want to run a "Low Power AM" Local Community Radio Station, and need a 100mw FCC compliant AM Medium Wave transmitter. (US ONLY).

The Spitfire low power (100mw) AM modulator is designed for just that purpose. It is a small mains powered unit, which connects to any mono or stereo source and provides a high-quality AM output, which may be tuned across the MW band.

End quote.

The FCC in the States does take enforcement action on unapproved equipment and back in 2010, a forum member elsewhere drew attention to a prosecution in the USA:

Quote:

Re: SSTRAN low power AM transmitter
________________________________
A recent story from Radio World Newspaper about this transmitter:

"Mann’s Antique Radio Collector Fined for Uncertified AM Transmitters"

The FCC fined Richard Mann $7,000 for marketing uncertified AM transmitters.

The Spectrum Enforcement Division of the FCC’s Enforcement Bureau responded to a complaint in 2006 that Mann’s Antique Radio Collector was marketing fully assembled, uncertified AM transmitters — specifically, the SSTRAN model AMT3000 AM transmitter.

In a response to the agency, Mann stated he’d bought the transmitters as kits from a third party and assembled them at home. Antique Radio Collector advertised the assembled transmitters for sale online at www.oldtimeradio.com and said it has sold 46 completed units since December 2003.

Here’s the full story:

www.rwonline.com/pages/s.0102/t.9952.html
(Note the size of the fine).

In answer to a query I sent to Ofcom enforcement department back in 2010 asking about the legality of the Spitfire for use in the UK, here is their reply:

Quote:

The Spitfire product is the type of product (radio equipment) that is covered by the Radio Equipment and Telecommunications Terminal Equipment (R&TTE) Regulations. Such a product may only be lawfully placed on the market or put into service if it meets the requirements of the regulations, has a Declaration of Conformity and is legitimately ‘CE’ marked (see the following link for further details). The FCC approval scheme is not applicable in Europe.

The device does not meet the requirements of those directives.

End quote.

I believe that as a result of Ofcom contacted the supplier, that company’s website now makes clear that the equipment it sells is not licensable within the EU:

Quote from the vendor:

EU R&TTE directive and EMC Directive 2004/108/EC - in order to purchase this item, you must agree that:-

1. You intend to re-export the item to an address outside the European Union. Under no circumstances will this item be resold or put into service within the European Union.

Or:

2. The item will only be used within a completely RF screened and shielded metal enclosure or environment for testing, evaluation, experimental or laboratory purposes and any other use that does not radiate electro-magnetic waves into free space. I am not an unqualified end user and I have RF engineering and electromagnetic compatibility skills at my disposal.

End quote.

Source: http://www.vcomp.co.uk/spitfire/spitfire.htm

(I won’t comment on whether that transfers the vendor's responsibilities to the buyer’s).

In a similar vein, Quasar Electronics - a reputable UK supplier of kits, including low power transmitters - makes it clear that such equipment is not licensable within the EU, and that they will not accept orders for such devices from EU customers:

Quote:

FM Transmitters:

* Please note that products marked with an asterisk are NOT FOR SALE in the UK or EU.
Please do not order these items if you live in the EU. They will be removed from your order and refunded accordingly.

Radio Transmitters, Telephone Devices & the law:

It is legal to buy, sell, posses, and build electronic bugging, surveillance and radio transmitting equipment in the UK. It is however ILLEGAL to operate such equipment under a number of areas of law.

Firstly, it is against the law to transmit a radio signal without an appropriate license or with equipment that is not approved for use in the UK by Ofcom. All of the surveillance and radio transmitters that we sell (both room and telephone bugs) have NOT been approved by the Ofcom. Ofcom will NOT grant licenses for this type of equipment.

End quote.

(Their use of red text – not mine).

Source: http://www.quasarelectronics.com/fm-transmitters.htm

http://www.quasarelectronics.co.uk/Item/...ransmitter

The bottom line is that as with all things in life, 'you ride at your own risk'.

Well done if you read right down to here - I wouldn't have!

Quote of the day:

He draweth out the thread of his verbosity finer than the staple of his argument.

William Shakespeare, "Love's Labour's Lost", Act 5 scene 1

[Kalee20]

And how many builders and experimenters have test equipment to ensure that the output is below 100mW? Very few would be my guess.

Probably right in that not many experimenters will have equipment to measure RF power. However, most, I hope, would possess DC voltmeters and ammeters.

If the DC power taken by the output stage is less than 100mW, you can be sure that the RF output is less than this. It was how the amateur radio license restricted transmitted power - you just ensure the DC power is below the threshold, and you are compliant. The RF is less than this, depending on how efficient the set-up is, but can never be greater.

[Yorkie]

True - many own 'scopes too, but the ownership of test gear isn't always an indication of the knowledge and ability to use it. That said, as I mentioned earlier, there are those around who do have the knowledge and are only too willing to assist others wishing to experiment on either side of the law without causing a nuisance or drawing attention to themselves.

In my dealings with Ofcom it became clear that they are disinterested in this and I think that to paraphrase the US Military (in a different vein!) the motto is "don't ask - don't tell" and Ofcom will keep on not minding. I got the impression that Ofcom just see us a tiny band of harmless eccentric 'men in sheds' furtling with bits of wire and soldering irons - at worst, spraying a tiny bit of MW RF over their own curtains. I'm content with that perception!

As to amateur radio, most amateurs these days use solid state 'plug 'n play' commercial transceivers which generally have a maximum output of 100 Watts SSB - well below the legal limit of 400 Watts PEP. Most modern PA stages progressively reduce the output if it isn't into a well-matched antenna system, and with feeder losses etc, I dare say that there will be a lot less than 100Watts at the feed point of the antenna anyway. Few amateurs will have the means of accurately checking their RF output (Bird through-line Wattmeter etc) and just rely on what the makers' spec says.

Ironically, the last bastion of technically and practically minded radio amateurs seems to reside in the QRP community. Ironically, the reason they are keen to measure their power isn’t to ensure that it’s within the legal limit, but to ensure that it doesn’t exceed their self-imposed output power of a maximum of 10 Watts to be considered ‘QRP’ (Low Power). As to how far a few mW will travel when into an efficient antenna system, the QRP community has the ‘Million Miles Per Watt award’. The Wold record, set on January 2, 2005, is 13.4 million miles per Watt, from a beacon with a transmit power of 40 millionth of a Watt! But admittedly the amateur who copied the signal used rather more than a coat-hanger for an antenna!

Quote:

Bill Tippett, W4ZV, of New London, NC correctly copied code word OMAHA from the N2XE beacon transmitting with a peak carrier power of .0000406 watts at 3.5455 MHz on the 80 meter Amateur Radio band. Bill confirmed reception of the beacon at 2328Z, January 2, 2005. The precise distance between the two stations is 546.8 miles, establishing Bill's record reception distance at 13,467,980 miles per watt. Tippett used a Ten Tec Orion Transceiver with a 1,000 foot Beverage antenna (named after Dr. Harold Beverage who invented it in the 1920s).

Unquote.

Source: http://www.eham.net/articles/9982

(My younger son is very pleased with his 'Spitfire' that he uses with his two Ekco A22s - saved me a job of building him something!).

[Old Sparky]

All the above makes interesting reading, and answers my question. I knew that AM 'Pantry' transmitters were illegal in the UK, but whether the Slovenian member of UKVRRR is aware that they are also illegal there I've no idea. He probably doesn't know about this forum so won't read the above. As to VHF(FM) microtransmitters, as most members will know, these are legal in the UK. I have a Logic3 FM Tx, bought in WH Smiths 3 or 4 years ago. When connected to the 'Aux out' sockets on my DAB radio, it will transmit the signal to a portable radio in my kitchen. less than 5 metres distant.
It carries a CE 0678 mark, and can be powered from a PC via a USB socket, or from 2 AAA batteries

[Kalee20]

Yes, if it does not cause a nuisance then I'm glad to hear that Ofcom will not see the technical illegality of pantry transmitters as something to pursue.

My own MW pantry transmitter runs 24/7 and although range does not go very far (garden use is limited), I also took the precaution of searching around with a SW receiver in case it happened to radiate harmonics much more efficiently. It didn't, so I can sleep at nights.

[Refugee]

If anyone is that keen to discuss pantry transmitters with the guy from Slovenia there might be some value in sending him a PM inviting him over here.
The mods appear to have overlooked the fact that Ofcom rules do not apply over in Slovenia anyway as it is outside the UK.

[Yorkie]

The mods appear to have overlooked the fact that Ofcom rules do not apply over in Slovenia anyway as it is outside the UK.

They're not Ofcom rules - they're the EU RTT&E Directive which apply throughout the EU, of which Slovenia is a member state. However, Slovenia will have its own regulatory enforcement regime. It's worth saying that all public bodies must comply with the 'principle of proportionality' which means that any restrictions or enforcement actions must be proportionate to the real or perceived problem they seek to minimise or obviate. In this context, Ofcom's main concern is the prevention of interference to spectrum users such as the emergency services, air traffic control and the military.

Hence, Ofcom's disinterest in micro-transmitters.

Were they to seek to enforce the regulations simply for the sake of it when there are no problems being caused and no risks to anyone, that would not be a proportionate response - it would be a waste of resources. Ofcom are a bit more astute than that.

[Ian - g4jqt]

I too can confirm that tiny MW transmitters are not on Ofcom's radar. While setting up a medium wave RSL recently, a senior member of Ofcom was there to check my installation. (That's not something they normally bother with, not an actual visit, but he knew the station operator, it was on his way to work and he did some measurements out of interest, which saved me doing the calculations for the official submission. So, Ofcom don't usually even bother with a 1 watt AM RSL with a range of a few miles unless there is a reported technical or programming problem.)

I informally asked him about their position on small 'pantry' transmitters, and he more or less said they don't want to know: "There are more important things to worry about". But yes, he agreed they are technically illegal. And we then discussed the legality of using a signal generator modulated with tone or music to transmit a few yards across a workshop. We just laughed; you see, it starts to get silly when you consider what will radiate.

The ones I make run off a PP3 with a total current of about 7mA, so that's about 60mW DC input, probably about 20 mW RF output. Take into account the grossly inefficient antenna of only about 1 metre of wire and no earth, and you're radiating a few tens of micro watts. Presumably this "100mW limit" that's been mentioned is ERP isn't it? On MW that would need at least a couple of watts RF output and/or a pretty good antenna.

If only all those SMPS radiated so little! They cause MUCH more grief.

UK commercial stations on AM can malfunction for weeks before anyone notices and reports it. Even then Ofcom don't drop everything to deal with the matter unless it's causing interference to some other service.

In the medium to long term, MW (and probably LW) will just go fallow and are likely to be nominated as officially unmonitored.

Ian