I have been planning to build a 600w linear amplifier to use on the HF bands.
Why homebuilt??
I have been asking my that question many times. If I have to order a commercial built amplifier I have to give out at least $1500-2000 USD. That will put a dent in the home budget and my XYL will notice big spending’s like that. Homebuilt projects usually consists of many many small orders! 
But I really like to undertake a project like this, there are many aspects to this project. Mechanical design, DC power supply design, RF deck, Filters and control circuitry . I have been playing around with programming PIC MCU’s and have decided to use one of those buggers for control and protection circuit.
Why use Transistors. Why not go for the ever so simple, reliable, tolerant Vaacum tube design?
I don’t like working with HV circuits. Don’t understand the theory behind the tube amplifiers. And the challenge is mostly mechanical !
Availability of parts here in Iceland is very poor, so I have to order most components online.
Design principles:
- Single chassis for now – can be modified later on if I decide to double the power output
- 600W Output.
- Manual and remote bandswitching – using the BCD interface from my Kenwood / Yaesu
- Protection: Over voltage, Over current, Over drive, High reflected power. Over Temp on PSU and RF stage. ALC back to Exciter.
- LCD display – showing vital amplifier stats. (just me playing around with the PIC)
Project timeframe is from now to the finished project. I really hope to test the amplifier around Xmas 2009… now the component collection phase starts.
