IC202 makeover

I decided to upgrade my old IC202 with some new features,  a long time ago I already added a new frontend based upon a BF891 and SBL-1 but I now wanted to have a digital readout to have a better and more accurate frequency  reading.


An overview of the new features is listed below:

  • Improved frontend with BF981 and SBL-1 (already in place)
  • VFO using Si570 chip
  • Controlled by ATMEGA328P (board from PA0KLT, firmware by PA3BWE)
  • New final stage, adjustable from 0 – 30 Watt
  • Frequency tuning resolution (selectable) 1, 2, 5, 10, 20, 50, 100, 200, 500 and 1000Hz
  • Software RIT
  • Calibrated S-meter (S-points and dBm’s)
  • On-board sequencer to control external amplifier / coax-relay
  • Separate PS for PA and IC202/controller
  • 13.5 Volt output on back
  • LO-output to calibrate VFO using external counter

I found an old Tektronix meter and used the cabinet for the new IC202. The power supply is an overkill but it can handle the internal PA of about 30Watt. Firmware is written in Basic (BASCOM) giving flexibility to program all the functionality I needed.

SAM_1435 Front side of the new IC202, the only two ‘old’ parts are the VFO knob and the microphone entry, the rest is new.

SAM_1434 Backside shows the antenna connector and a ref out to calibrate the VFO. This is done using an external counter which reading is entered in the menu of the IC202. Unit also has  a 12 volt output to feed my keyer or other 12 V devices.

SAM_1430 Detailed view of frontside and ‘original’ IC202 board. The box contains the VFO and microcontroller board.

SAM_1418 View from top, left is frontpanel, right is backside. The new frontend is in the middle box.

SAM_1431 Detail of the coax relay, switches between RX and TX.

SAM_1428 Extra PA of ~ 30W, from standalone VHF linear.

Things to do :

  • Add audio in/out for connection with PC