[hpsdr] preselectors

[FRANCIS CARCIA]

Hi all,
  I looked at the schematic of my Cubic prepost selector and it is quite complicated. It has an 8035 processor to select the relays controlling Silver mica caps and 3/4 inch square package adjustable inductors. The board is about 10 by 12 inches packed with 1/4 crystal can relays and control parts. This is well above the scope of out board profile. 
  A good preselector to check out is the Cubic R3030. You can download the manual from bama or premium RX. It uses pin diodes for higher bands and relays for low. Also has a CP640 grounded gate fet amplifier. The R3030 MDS is about -136 dBM.
  I think it has about 10 filters to cover 15 KHz to 30 mhz. It takes 4 bits to a local decoder to select the correct filter.  The can inductors could be replaced with torroids. The L vales are on the schematic. The board is about 4 by 6 inches.  fc
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