Multi-Tx DF  - An overview for those with previous experience of radio direction finding. 1.  Introduction This format of DF was devised to allow competitors with a wide range of skills and physical abilities to compete alongside each other. It uses a number of Txs (say 10) supervised by one person.  Unlike other events the operator doesn’t hide but roams the site looking after the equipment and helping beginners when necessary. The principle of the event is that powerful Txs lead you to areas where less powerful Txs may be heard, the term parent is used below to indicate this action. 2.  Types of Transmitter Maxi Tx –  Normal power, automatic timing and Morse, identified  by operator’s callsign and a single letter repeated several times, should be audible at the start (up to 40Km away); intended to bring competitors to the site where other types of Tx may be found. A Maxi may act as a parent to several Minis or Micros. Mini Tx – Lower power (range about 1 Km), automatic Morse and timings. Several Minis share a single frequency, transmitting for one minute each in sequence. A Mini may act as parent to a Micro. Micro Tx – very low power (range about 200 metres), continuous ‘beeping’ signal.  If more than one is on a single frequency different beep speeds are used. 3.  Scoring This is uses numbered tickets located close to each transmitter, when a competitor finds the Tx the highest value left is taken. The non-linear sequence of numbers (e.g. 40, 32, 26, 23, ...17, 15....3, 2, 1) makes it a game of strategy and discourages competitors from following each other. Tickets must be posted into named boxes located at the Maxi Tx before the end of the competition. The winner is the person with the highest total score.  If a competitor finds Minis or Micros but no Maxi and thus can’t hand in tickets, they are ranked after all those who do find the Maxi. A recent addition to the scoring system is Jokers which double your score at a particular Tx. These increase the reward for  individual hunting and help with training. 4.  Difficulty The Micros, being on continuously, are easy to find offering beginners encouragement, while old hands have to include them in their strategy for maximising their points score.  It is easy to miss a Micro if you forget to check all the frequencies when you are near its parent Tx. Usually the ticket location will be marked by an A4 sheet of paper.The Maxi must also be relatively easy to find because all tickets must be posted there.  The length of transmissions is increased near the end to help all complete the event.The Minis provide the difficulty required to occupy the experienced competitor.  The brief transmissions make it essential to have a good ‘sense circuit’ in your receiver.  Having the tickets located in a camouflaged container can make them extremely frustrating to find!  This ‘frustration time’ is however an essential ingredient slowing competitors down and preventing it from becoming a running race. 5.  Introducing Beginners The operator may chose to invite beginners to come directly to the site  (the location is kept secret from the other competitors).   Being surrounded by transmitters there is plenty of scope for instruction.  Once basic principles have been grasped the beginner can be given an envelope which  shows the parent station for each Micro. This allows them access to the weak Micros while encouraging them to listen to the more difficult Minis.