A Brazilian Fredbox 2m AM transceiver

Hamilton, PU2XLB, has built a Fredbox 2m AM transceiver using the G4BYE adaptation of my original schematic. The G4BYE version has an LM386 audio rather than a simple stage driving a crystal earpiece. Hamilton, PU2XLB, has managed a 10km QSO already. He also has a Youtube video of it in action on RX.

VHF AM Yahoo group

This is a picture of G4BYE's version of my own Fredbox 2m AM transceiver design - a neat unit his is complete with proper PCB.

Many blog readers are already members of the Yahoo VHFam group. To join visit http://groups.yahoo.com/group/VHFam/ and follow the joining instructions.

At last VHF AM operation has got a mention in the latest UK VHF bandplans with the agreed "centre of AM activity" being notified in the footnotes as 144.55MHz. This spot in the European all-modes area is also used by some other users - I hear SSTV here sometimes - so it is NOT an exclusive spot, rather somewhere to look for 2m AM activity in the first instance. There's some AM activity on 145.8 still in Scotland but it would be good if users there would move to 144.55 so this became a UK-wide spot on which AM activity is likely to be found. Users can also be found on 70.26MHz on 4m.

VHF AM gear can be very simple to make and AM is an ideal mode for QRP building and experimenting. There's plenty of ex-PMR AM gear still to be found for next to nothing, ripe for use on 2m/4m AM.