FT990 high audio noise

friedemann (f.) heyer heyer@nortel.ca
Mon, 10 Jun 1996 08:54:00 -0400


Hi everybody, (I wonder If I ever come through with this message)

I like the FT990 very much, the only thing I'm dissapointed about is the
relatively loud audio noise which highers the noise floor of the transceiver
specially on calm bands which is really a pitty because you can't work what
you can't hear. So my question : Does anybody know if there is a possibility
in a small design change to lower this noise. I read something that it comes
out of the IF- not RF-stages so maybe one could use other transistors with
lower noise or different bias currents (Arbeitspunkte ??? (sorry))
Maybe there is a known workaround to lower the noise floor.

(The use of the switched capacitor filter makes it even worse as it lowers
the usable audio bandwith and understandibility)


Thank you in advance and 73

Friedemann, still DG9GM, hard practicing CW