OE1IFM

Finally I started the project "The next generation". There is a long list of things I want to implement into the next generation beacon. 
My first action point is reduction of power consumption in gerneral and implementing functionallity to switch off certain parts of th beacon.
This is in detail:

      ·         Turn off the PA and run the driver stage directly into the antenna for QRP operation (less than 500mW)

·         Turn of the bias current generation of the driver, the DDS chip and the 30MHz master oscillator. (This keeps only the CPU unit running)

      ·         Turn off 48MHz CPU oscillator for normal operation and USB. Keep CPU running on internal RC oscillator. From there the CPU can enter
                 a sleep mode.

In addition I optimized current consumption of some units:

·         Reduce bias current of first driver stage as far as it keeps a reasonable frequency response in the range of 1MHz to 50MHz

·         Reduce losses in the 5V generation by replacing the LM7805 by a LCT1265 switch mode supply.

With a 230uA load on the 5V side the LTC1265 draws 290uA on the 12V side. This is a loss of less then 2,5mW and a total power consumption
(estimated) of 4 to 5mW in sleep mode. Which is quite acceptable for battery operation.

Here is a gallery of the mods. I will keep info posted as I proceed with the implementation.

73

Gernot, OE1IFM