UK - Transmitting WSPR on almost any frequency without the need for a license ?

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G8JNJ
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UK - Transmitting WSPR on almost any frequency without the need for a license ?

Hi all,

If you live in the UK, the Wireles Telegraphy act Exemptions make interesting reading -especially for WSPR users……

My understanding (and I have discussed this on the phone at length with OFCOM – The UK Licensing body) is that you can transmit on any frequency up to 960MHz.

The three main provisos are:-

1. Keep transmissions below a defined transmit field strength (requires a very low transmitter power in the region of µW or a very inefficient antenna)

2. Operate within specifically defined frequency ranges (to avoid allocations associated with safety of life e.g. distress beacons and aeronautical navigation and communication).

3. Not cause interference to other services or users.

Note that if you do choose to operate under this exemption it is entirely at your own risk and you do need to understand all the legal requirements.

To quote a summary of the exemption:-

'These Regulations provide for the exemption from the provisions of section 1(1) of the Wireless Telegraphy Act 1949 of stations or apparatus for wireless telegraphy operated under suppressed radiation conditions on specified frequencies for testing or development purposes (which are defined to include the modifying, servicing or repairing of such stations or apparatus and scientific research, training, instruction or experimentation in radio theory or practice). Accordingly, it will not be necessary to hold a licence to establish, install and use such stations or apparatus.

The Regulations do not apply to apparatus which is exempt from the licensing requirement under certain other instruments (regulation 3).

Regulation 5 provides for the terms, provisions and limitations of exemption. It requires that the apparatus must not cause undue interference with any wireless telegraphy. The Schedule sets out in detail certain minimum requirements concerning suppressed radiation.

Regulation 6 requires that the station or apparatus must be available for inspection and that its use must cease, or its operation must be restricted, on the demand of a person authorised in that behalf by the Secretary of State. Regulation 7 requires a person using the station or apparatus to conduct measurements to ascertain whether minimum requirements concerning suppressed radiation are being complied with. Failure to comply with regulation 6 or 7 is an offence under section 3 of the Wireless Telegraphy Act 1949.'

The full exemption document can be found at this link:-

Note there is a typo in the document Limit for maximum field strength (dB.013 V/m) should read Limit for maximum field strength (dBµV/m)- I got very excited before OFCOM confirmed it was an error :-)

http://www.legislation.gov.uk/uksi/1989/1842/schedule/made

And here is the schedule (format permitting)

The columns in order left to right should read

Frequency Band (MHz)
Limit for maximum field strength(dB uV/m)
Distance at which measurement taken(m)
Power into 0dB antenna required to produce Maximum field strength (Watts)
Equivalent transmitter power (dBW)
Equivalent transmitter power (dBm)

0.150 – 0.2835 34 100 0.0000006500 -61.9 -31.9
0.5265 – 1.605 34 100 0.0000006500 -61.9 -31.9
1.605 – 2.1735 48 100 0.0000170000 -47.7 -17.7
2.1905 – 3.950 48 100 0.0000170000 -47.7 -17.7
22.00 – 29.999 34 100 0.0000006500 -61.9 -31.9
30.00 – 70.50 30 30 0.0000000240 -76.2 -46.2
71.50 – 74.60 30 30 0.0000000240 -76.2 -46.2
75.40 – 80.00 30 30 0.0000000240 -76.2 -46.2
84.00 – 108.00 30 30 0.0000000240 -76.2 -46.2
137.00 – 143.00 30 30 0.0000000240 -76.2 -46.2
144.00 – 146.00 30 30 0.0000000240 -76.2 -46.2
148.00 – 153.00 30 30 0.0000000240 -76.2 -46.2
156.8375 – 225.00 30 30 0.0000000240 -76.2 -46.2
400.00 – 405.50 30 30 0.0000000240 -76.2 -46.2
406.50 – 450.00 30 30 0.0000000240 -76.2 -46.2
453.00 – 464.00 30 30 0.0000000240 -76.2 -46.2
467.00 – 960.00 30 30 0.0000000240 -76.2 -46.2

Any takers ?

Regards,