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Old March 8th 05, 04:22 AM
 
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Michael Black wrote:

The average "police band" receiver from the analog era wasn't

particularly
great. They'd have a relatively wide IF passband, and many designs

were
just reworked from FM broadcast band designs. They likely had more

than
ample sensitivity, especially given that VHF is line of sight only.


Yea, if it's an analog portable type, they were pretty
marginal...Selectivity was the main problem. In a busy
city, you couldn't listen to the police, unless you wanted
to hear 2-3 channels at once. Those were usually 460 mhz,
with 25 kc channel separation. I couldn't hardly use one
here in Houston. Now, anything that is a "scanner" will
usually be ok. Either xtal, or synth, pll, etc...They all
had the selectivity needed to listen to tight channel spacing.
Also, the sensitivity was so-so...Usually FM images too...
I once had the top of the line patrolman radio...The big
puppy with two TV style whips, AM/FM/SW/AIR/VHF/UHF, etc...Was
a decent radio I suppose for a portable, but not anything a
serious police listener would want to use, unless they were in
a dinky small town, with few channels. I used to cuss the
things here in busy Houston. Really pitiful....My first actual
scanner was like night and day...Most of the scanners are
called "pro-whatever" instead of patrolman...Some of the first
xtal versions might have been called "patrolman" though, light
years ago...MK