The Martello Tower Group is an amateur radio group which was originally formed in the late 1980s under the name ClackPak.

Over the years ClackPak has run an AX25 amateur radio packet radio mailbox along with a number of nodes and gateways which linked Clacton-on-Sea with Kent and central London and from there via a wormhole direct to New York.

At the same time, ClackPak organised some successful amateur radio rallies which helped the initial funding of the two local repeaters, GB3TE and GB3CL on 145.775MHz and 433.225MHz respectively.

In more recent times the group has set up an SSTV repeater (MB7TV), an FSTV repeater/beacon and the first licenced amateur radio to internet gateway in the UK (MB7UIV).

ClackPak was reborn in May 2009 as the Martello Tower Group with ambitious plans for other groundbreaking radio projects in the Tendring area including a 28MHz repeater.

The Martello Tower Group also compete in various RSGB amateur radio contests and the group callsign G0PKT has been active on both 50MHz and 144MHz SSB since the reforming of the group.