The MT1000 will hold 32 different PL/DPL setups

The hot deal is to use the guts of an MT1000 enhanced MVA to control the radio, giving you an LED display of channel and push button control of PL/CSQ and channel.

The radio is a little tough to disassemble, and is highly integrated; but the only two signals that need to be found inside the radio (discriminator and PL/CSQ) turn out to be fairly easy to get to once the radio is apart.

An Overview of the NTN5613 Enhanced MVA

This unit (also called a Convertacom) is probably familiar to most readers, but if not, suffice it to say that it is a mobile unit into which you dock an MT1000. The MVA charges the battery, will operate the radio with a dead battery, and causes the radio to connect to an external antenna and a really LOUD external speaker.

The MVA also takes over the controls of the radio, allowing channel selection, scan on/off, PL on/off, etc by connecting the radio via the "shorthorn" bus on pin 11 to a small computer in the MVA.

The NTN5612A is the "basic" MVA and has no radio controls. It is of no use to this modification.

The NTN5613A  is the "enhanced" MVA. It is the same as a 5612, except that it has an added microprocessor, control panel, and display.

It just so happens that the microprocessor and control panel will operate stand-alone without the rest of the MVA !
( We don't need a battery or charger )

We had the parts laying around so.......

We sold 100 MVA's to an Australian concern who was going to gut them and only use the mechanical docking mechanism and chassis of the MVA. So, before we shipped them, we stripped the microprocessors and display/control panels out of them.

The initial experiment (right) has an MT running on the bench, powered by the 9.6V supply from the MICOR station, and a small regulator chip to get 5V for the computer. The main PC board of the MVA got junked or cannibalized for parts.

We brought discriminator audio and PL/COR detect out for interface to the MICOR chassis. All other required signals and interfaces are available on the universal connector on the top of the radio.

Ultimately, we will mount a computer and display in the transmitter and receiver covers along with an MT. They will display channel ( 1-16 ) and will indicate when signal is coming into the receiver and will give an indicator of when the transmitter (exciter) is keyed.

We have several MT's which either have broken switches or channel selectors and which are not useful as walkies anymore, but which are perfectly useable when controlled by the computer.

One note: The MT's WILL go down into the 440 band, and the VHF radio WILL go down into 2-meters.

Experimental hookup from the universal connector to the Enhanced Computer board

We'll keep this sub-article updated as this experiment progresses.