Originally Posted by JnglMassiv
It would be cool is someone with access to a calibrated service monitor and a bunch of common radios would do this type of thing without having to rely on antennas and distant signals.
Unfortunately, I can't tell you exactly what the sensitivity of the 396XT and PSR500 is, but I have done bench testing comparisons of the 996xt and the PSR600 with a calibrated Aeroflex service monitor.
In all these tests, the 996xt was the clear winner by at least 1-2dBm on all bands.
Raw receiver sensitivity is not the most important aspect of any receiver.
A difference of only 1-2dBm, when signal levels are down around -118dBm, really isn't that noticeable.
Interference rejection and strong adjacent signal handling is by far the most important factor in these scanners.. This factor is even more critical when monitoring P25 signals since in many cases it is interference rather than weak signals that is degrading reception. Unfortunately, due to the characteristics of P25, it is never obvious that this is the real problem and people often assume that putting a 'bigger' antenna up will solve the problem when in fact, it can make the interference and reception much worse.
A case in point..
If you live within a few miles of a high powered FM broadcast transmitter and you own a PSR600 which is connected to a discone scanner antenna, you will find that reception on the 108-170Mhz band is severely degraded, if not impossible. You may even find you have to turn the attenuator on just to get the squelch to close, due to the noise!
A 996xt scanner connected to the same antenna will not suffer any interference from the FM transmitter at all and even very weak signals will be received with no problems..
The same holds true on the UHF bands. If the receiver doesn't have good bandpass and IF filtering, your reception will suffer when there are multiple strong, nearby signals. Problem is, on digital at least, it won't always be obvious that it is even happening.
I have the 396xt and am currently trying to get hold of a PSR500.
When the GRE scanner arrives, I will do some sensitivity and interference rejection measurements.
I too am curious to see if the handheld scanners match the performance of their mobile/base siblings.
And by this measure, I'm afraid the Uniden was still a clear winner.