The 516F-2 power supply can be used with many of the Collins transmitters and transceivers. The 516F-2 runs from a 115 volts AC 50/60 Hz power source to provide the high voltage DC, low voltage DC, variable DC bias, and an AC filament supply. The provided voltage from the 516F-2 is connected to the associated equipment by a 60 inch long gray cable. 

As was the case with many of these power supplies they were often modified to include a speaker as is the case here. Another modification was to change out the 5U4GB and the 5R4GYA full wave rectifier tubes with solid state components. Collins engineers actually recommended this solid-state conversion in SIL 1-76. This SIL 1-76 is not an official service bulletin but it does show the concern that Collins engineers had with the rectifier tubes arcing over. Another advantage of adding this solid state modification is the reduction in filament current by removing the two rectifier tubes. Not only does this make life a little easier on the transformer, it also reduces the heat that the transformer absorbed due to its location near these two tubes.

Even if this solid state modification is done correctly it can still be a source of heated debate amongst owners of the 516F-2. There is two reasons that come to mind, one is that it may be possible that there will be B+ on the plates before the filaments are at operating temperature, and the second reason is that you are taking a tube rig and turning it into some thing more modern and with less tubes.

The size of the 516F-2 is 10 inches wide by 7 3/4 inches high by 12 inches deep and weighs in at 28 pounds.  

The photograph on the left is a picture of the side of the 516F-2 power supply. The photograph on the right is a close up of the back rear corner of the 516F-2. Here we can see a Collins logo stamped onto to the chassis of the power supply, as well as the serial number, model number and tube identification markings. Also take notice of the brown paper tubes that are used to protect the operator from accidentally touching the high voltages that are present on the solid state modification that we talked about in the above text.

The photograph on the left is a close up of the solid state modification that replaces the 5U4GB and the 5R4GYA full wave rectifier tubes. The photograph on the right is of the rear of the unit with all modifications and their associated hardware installed.

A special thanks to Steve Fitzgerald(N4KQR) who personally hand delivered this item.