Quote:
Originally Posted by Dave757
The PB on the set you mentioned was for Police Band (the US one), which operated in the general area of 40 - 50Mhz.
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On multiband radios I have seen 'PB' (combined with AIR) was high VHF up to maybe 176MHz (going up to the start of TV Band III or usually a bit above)
here is one example:
http://www.radiomuseum.org/r/audioso...o_tk_322f.html
They could cover a bit into Band III TV, one I had (from the 1990s) just about went far up enough to hear RTE1 TV sound here in the south of Ireland on 181.25 (before ASO in 2012).
Strong Band III TV signals could also breakthrough on frequencies 21.4 MHz lower , so images of sufficiently strong Band III signals up to nearly 200 MHz could appear.
Demodulation is actually Wide-FM (as for 87.5-108 MHz) in this band , on these low cost receivers the local oscillator would never be stable at VHF for Narrow-Band FM or AM, the price that is paid for this is mainly (1) no selectivity of close NBFM communications channels (2) volume has to be turned up on the NBFM signals (compared to FM Band II broadcast)
The FM demodulation will also (crudely) receive AM signals (such as in Airband) by tuning to the "edge of the carrier".