The Phasing Transceiver on 73kHz

摘要

Portable operation seemed to require attention and to this end, battery power was decided on; a 12V jelly battery worked well. Because of this, the regulators in the receiver and VFO were lowered to 9V. Without these, chaos breaks loose. As sideband switching now takes place at the oscillator drive, in the receiver, the original sideband switch is not needed; the USB pin should be connected to the sideband switch pin by a hidden wire under the board. On the exciter where the VFO amplifier and RF phasing network used to be, there is just room for the divider piggy-back board to be mounted, see Fig 3. The output transformer and converter are not fitted and their space left blank. As mentioned in part one, the tuned circuit is now fitted on the power amp board. Here a small piece of thick aluminium bolted to the chassis forms a heat sink for the PA stage TDA2003.