Antenna = the radiator of radio waves. Otherwise known as Aerial.
FM = Frequency Modulation
Interference = causing reception problems to other radio users
Main transmitter - the broadcast transmitter, as opposed to link transmitters.
Reception issues = receiver interference, noise, weak signal, etc
RDS = Radio Data System
Stereo = 2-channel sound
Transmitter - creates the modulated radio waves. Otherwise known as TX
DJs and Presenters' jargon
Cans = headphones (old fashioned)
Crash = to talk over the main part of a record (rather than the intro, ending or an instrumental part of the record.
Dedication = a record played on-air for someone, often requested by another listener
Jingle = a station ID
Mix = to smoothly fade one record into another, synchronising the beats. A number of records mixed together is called a Megamix.
Mixer = audio equipment used to mix audio sources together.
Power-play = a record which features prominently on a station's playlist
Promo - a station's "internal advert"
Records = can mean vinyl records, or used to mean music tracks of any physical format (esp. CD singles)
Request = a record which a listener has requested to be played on-air
Talkover = an instrumental record used as the background for announcements etc
Theme tune = the opening record of a station, or of a DJ's show.
Track = a single music recording, of whatever format.
Radio enthusiasts' jargon
Airchecks = recordings of radio stations
Anorak - a fan of pirate/free radio, or maybe of radio in general
DTI - The "radio police", now known as Ofcom.
DXing = long-distance communication, reception or transmission, using radio waves
QRM = Man made interference from domestic/industrial electrical equipment
QRN = Natural interference from ionospheric sources
Ex-pirate = a station or DJ/presenter who started on pirate radio, before going legal
ILR = Independent Local Radio, a licenced independent radio station
Marine Offences Act - the law banning offshore radio
Mail drop = a postal address at which a station may be contacted
Pirates = unlicenced broadcasters
Relay service = a station which re-broadcasts other stations
RF Feedback = interference to the studio equipment, caused by proximity to the station's transmitter
RSL = Restricted Service Licence, a short-term or low-power licence used by smaller and part-time stations
Super pirate = a very large pirate, generally with long broadcasting hours, high power and professional sounding programmes
FM - not technically a "band", but often used to refer to 87.5 - 108 MHz
Web radio - OK, so it's not technically radio or a band, but it is an increasingly popular method of broadcasting!
Wireless Waffle - loads of great stuff about pirate radio and everything wireless