The lower the number the better the radio can hear.
The difference in sensitivity and overload rejection
between radios determins how far you can hear
and how strong the signals will sound. uV (or microvolt)
measurements are used to give you an idea how weak a
signal you can pick up. dB measurements are used to
indicate gain or loss on antenna systems. every 3 dB
is twice as strong a signal. (1 watt + 3 dB = 2 watts)
The lower the uV on the radio specs AND the higher the
dB on the antenna system, the better the reception. My
PRO-92 hears just about the same as my BC780 on 800 MHz.
It is not as good at rejecting interference from cell towers.Here is an interesting chart showing uV & dB side by side.
This gives a look at how much signal you really stand to
loose if the receiver specs are bad.
dBm uV
-127 0.1000
-126 0.1120
-125 0.1260
-124 0.1410
-123 0.1580
-122 0.1780
-121 0.2000
-120 0.2240
-119 0.2510
-118 0.2820
-117 0.3160
-116 0.3550
-115 0.3980
-114 0.4470
-113 0.5010
-112 0.5620
-111 0.6310
-110 0.7080
-109 0.7940
-108 0.8910
-107 1.0000
A receiver with 0.31 uV sensitivity would receive 8 dB better
then a receiver with 0.79 uV sensitivity. Or to put it another
way, you would need an antenna system with 8 dB more gain to
make up for the less sensitive receiver. Hope that answers your
question. :-}
Phil