Solidifying the Amplifier and Control Design

I have been on a track romancing the PIC32. It is a wonderful idea but not practical for me since it is a steep learning curve. I have changed directions in a natural path for me. That is to go with parts that the average builder can put on a board, go with a processor that I fully understand and go with a programming language that I have proficiency. The schematic for the Control Module for the amp currently has 3 schematics: Processor, RF Path and Dual USB. It is a work in progress but pretty complete.

File Attachment: SCH PROCESSOR 10 08 2011.pdf (19 KB)

The plug-in processor is a 40–pin PIC18F46K22. Shown on this page are flat cable control plug-ins for the Amp Module and the Filter Module. We have 16 high current outputs that control the amps gain, filter band, RF modules, transceiver selection and antenna selection. These are all 12V relay type controls. The Amp Module receives control for the bias adjustment, current measurements and temperature measurements. There are two SPI ports and an interface for two USB channels. Analog signals monitoring RF Power In, RF Power Out and Power Reflected and FT817 Cat Interface are read by the processor on this schematic. A In-Circuit Debug connector is also on this schematic.

File Attachment: SCH RF PATH 10 09 2011.pdf (25 KB)

The RF Path schematic shows the two transceiver connections on the left. On the far right is the two antenna selections. T1 is an RF Tap for detection of carrier and frequency measurement. T2 measures the RF Power In, T3 measures the RF Power Out and reflected power. The T/R relays, K2 routes the drive signal to the amp module. The RF Ouput from the amp goes through the Low Pass Filter and returns to flow through T3, K3 and K4 to the antenna connection of choice.

File Attachment: SCH DUAL USB 10 09 2011.pdf (17 KB)

The Dual USB circuit diagram shows to USB channels. One channel connects to a device that speaks KenWood Cat commands. This could be the PC control program that I provide or a 3rd  party program. The other channel connects to a graphics control panel. Currently we are looking at the 3.2 inch QVGA (320×240 color) with a 4–wire resistive touch screen. We will need a lower cost solution than the off-the-shelf Microchip solution.

File Attachment: SCH AMP 10 09 2011.pdf (28 KB)

This schematic shows the amplifier and control connector. This is a separate independent module that mount near the heat sink and is cabled to the Control Module via SMA and flat cable connections.

I am currently on a quest to get a prototype of the Amplifier Module in the shop. Thanks for those who stepped up with the down payment on the project. A couple more such down payments will get my head above water to proceed with the prototype Amp Module.


To sign up, send me an email and I will put you on the list. I want to get this project started and need your help to support it.

73, K5OOR –  Virgil

HF Projects


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