That makes sense................I will try those measurements with the
series load. This explains quite a bit............thanks.

Pete

"Telamon" wrote in message
...
In article ,
"Pete KE9OA" wrote:

I just got through characterizing this unit. MDS = .15uV across the
entire
tuning range. Not bad. Overload point = 120mV.
Icom R75..............................................M DS = .07 to .1uV
across tuning range. Overload point = 110mV
Palstar R30 MDS = .06 to .1uV
across tuning range Overload point = 500mV
KE9OA MW receiver (to be marketed someday MDS = .1uV
Overload point = 100mV

I am beginning to think that many of the radio manufacturers are
measuring
their overload points using the hard measuring technique, whereby instead
of
hooking up the RF Generator directly to the antenna input of the Rx, they
are first running the generator through a 50 Ohm through load ( I do have
some of these types of loads).

Snip

Most RF generators are calibrated to a 50 ohm load. This load must be
resistive in order to actually "burn power" against the generators
output source impedance. Not having this resistive load means the
generator output will be higher than calibrated. The generator is
probably designed to be 50 ohms so if you connected it to a 100 ohm
resistor you would have something like two times the indicated swing of
the generator. The front end of most radios are reactive and their
resistive component is large so I expect that the best thing to do is
use a 50 ohm resistor across the receivers input terminals.

--
Telamon
Ventura, California