Ameritron ALS-600 Retrofit

20-Nov-2015 Update: Discontinued

20-Nov-2013 Update:
Assembled and tested kits are available now.
Check Forums for updates.

01-Nov-2013 Update:
User and Assembly manuals are ready to download. I will have the kits ready soon.

About a year ago, I bought a used Ameritron ALS600 amplifier, the old version, using a rotary switch to manually change bands. RX/TX relay was very loud and had a continuous running 110VAC noisy fan.
I made new MCU controlled LPF board featuring:

  • Automatic band change based on TX frequency.
  • PIN diode QSK RX/TX switch.
  • Temperature controlled FAN for quiet operation.
  • RS-232 port for Remote LCD panel, PC control and firmware upgrade    

ALS600 v0

I Scraped the original Low pass filters board and reused all capacitors and inductors for 160M, 80M, 40M, 20M bands. I also used T106-0 cores for new 15M and 10M band inductors.
Most of the firmware has been written and tested. Frequency counter and automatic band change are functional.
RS-232 Terminal emulator has been implemented – can send commands, read status and set operating parameters in EEPROM. The fan was replaced with 12V one, temperature sensor was installed, and the temperature control loop is working. SWR protection and Power monitoring are functional.