ATV Controller for Comtech Modules

Supplement to article published in CQ-TV 204 (November 2004)

This circuit was designed to control transmit and receive modules made by a company called Comtech.

These modules were originally only manufactured for demonstration purposes, so come without pre/de-emphasis and only with basic control of frequencies.

I designed the controller board to meet my own requirements but have since incorporated features required by other TV Amateurs, main features are:

• Rotary tuning
• 125KHz channel spacing
• Four VFOs each for transmit and receive
• Bar graph "S" meter
• Simultaneous control over transmit and receive
• PTT with onboard transmit power switching, PA and antenna change over sequencing
• 13 or 23cm operation with the same software*
• Auto-net function*
• Receive only function*
  *By menu selection

The latest firmware comes with these enhancements:

• Scan between limits
• VFO scan
• Linked VFOs
• 7 VFOs

A 16 character by 2 line LCD displays transmit and receive frequencies or "S" meter and menu functions, provision has been made for standard or backlit type displays.

Pictures

System with prototype controller PCB

Control PCB - Assembled Kit

Kits

The controller is currently not available as a kit, if you are interested in one please email me to register your interest. It is practical to either produce your own circuit board or build the unit on a piece of stripboard.

Downloads

Construction and user instructions. Applicable to kit PCBs V3.X only, revision 6-12-03

PCB design can be down loaded here.

Drilling template for buttons etc. When printing from Acrobat ensure that page scaling is set to "none" and check the printed 100mm scale with a ruler before using as a template.

Assembler for the latest version V3.1 can be down loaded here, use MPLAB from Microchip, build a project and assemble.

A simple but effective programmer can be found at http://www.qsl.net/dl4yhf/ , have a look in the help file for suitable hardware.

Email me