Yaesu FT-847 Separate receive connectors for 432 and 144MHz
In many instances using a separate receive antenna connection is an advantage, e.g. high power and pre-amp usage, squezing every last dB of nF out of the system, or just plain saving on external relays.
I have installed separate SMA antenna receive connectors as pictured below:
Here you see coaxial connections to the receive circuit (marked V and U), with the cables unplugged, and a small area in front scraped clean for soldering. Also visible is a sligth enlargeing of the rear air grille to receive one of the SMA connectors. Note also that the 144 antenna connector has been replaced with an N-connector - something Yaesu should have done from the factory!
Now the 144 receive connector has been mounted and soldered in place.
and the 432 as well. The original connection from the Tx/Rx switching circuit has been restored, and everything works as before, with the exception that you now have the option of using a separate receive connection, with a gain of almost 1dB noise figure! Finish off by securing the SMA connectors with judicial usage of Lock-Tite or Epoxy.