10 GHz - 1Watt PA, made from 14 GHz surplus stuff sold by ON7UN

by DF2CK

  • matching is done with the ceramic of SMD capacitors, be sure to carefully cut off the solder ends
  • at the input and output I used the ceramic of 1 nF caps, all others are 1 pF (all 1206, but 0805 will work also)
  • the area between both transistors is the most sensitive
  • do not to short circuit the coupling strip between both transistors as K30M will smoke off for sure!
  • the usual methode of moving small copper strips did not work good for me

  • if you have own experience on that issue and you want to share it with others please mail it to me..

  • by PE1KXH

  • use 0805 or 1206 capacitors with low values (10pF or less) with white ceramic (NPO material , low RF losses)
  • capacitors are glued with "Velpon" ( a dutch brand) glue, don't use cyanoacrilate like "one second glue"
  • tune for minimum smoke and maximum power with a woodenstick, use evantually a ceramic trimming stick for
     determing the spots where a capacitor can be placed. ( fast scan for sensitive places)
  • a spectrumanalyser for this tuning is prefered above a wideband powermeter, oscilations can be seen on a analyser
      I used a HP141T with 18 GHz oplugin and a hp8620 sweeper with 8-12 ghz plugin as signalsource

  • this bias circuit by DB6NT
    is used (slightly modified)..

    MGFK25V4045 Data sheet

    MGFK30V4045 Data sheet

    here is what you can do with the rest, tnx DJ6JJ