[Premium-Rx] Noise Power Ratio Testing of Radio Receivers

[Michael O'Beirne]

Gents

The comment attributed to Ulrich Rohde was in voiced some years before in
one of Pat Hawker's Technical Topics pieces. I can't place in which issue.

I well recall at the time thinking along parallel lines in relation to the
then eagerness  to achieve the maximum carrier suppression for SSB but
ignoring (or forgetting) that the transmitter's IP3  products were at vastly
higher levels and would completely mask any residual carrier.

As for PAs, I still stand by traditional valved ones.  Angus McKenzie's
spectrum shots in his review of the Trio TS83S in the old "Amateur Radio"
are absolutely stunning, the level falling by 75dB within about +/- 3.5 kHz.
It used a pair of 6146 valves.

73s
 Michael
G8MOB