"Ken Taylor" wrote in message
...
Allen Crawford wrote:
I recently purchased a pro97 scanner in near new condition over the
internet
through ebay. The item was
listed as having very low audio such as one has to place the speaker
next to
his ear to hear the broadcast so I took a chance and bought it for 45
dollars. I got it in yesterday and it is totally new! packaging, all
accessories, books and not a scratch on it. Well. I unpack it and
install
freshly charged (new) batteries and
I go to playing with it..first..a weather channel..sure enough, very low
volume even when cranked to the fullest
it is still at the same volume level. I went ahead and took out the
four
back cover screws and examined the area
where the volume pot is soldered and took some readings. center tap is
about 2.1kohm and 200 k ohm on the non grounded side. (this is without
power
applied)
in the area of the volume/squelch pot, are 3 tiny pots
and 3 test points...(this is all from memory as the scanner
is closed up now). I was hoping for a misplaced speaker magnet or
something
simpler and the circuits are ungodly
miniature and even the audio amp chip is about the size of an op amp on
most
regular size circuits. The doggone thing is so new looking, that it may
be
swapped with a
newer one from radio shack (by swapping backplates) but I don't dare
attempt
the dishonest. Anyway, any suggestions to resolve my dillemma...could
it be
possible that I have a defective volume pot? No amount of regulation
seems
to affect the audio at all. The channel
beep come through loud and clear but it seems that either
the preamp from the radio is set too low or the pot is
defective/soldered
wrong. Of course, the possibility of
a bad IC has crossed my mind as well. Any suggestions?
No warranty so all I have is either a repairman or my good wits and some
knowledge to help correct the problem. Btw, the sqelch seems to work
OK.

Your input would be greally appreciated,

Allen


Is the beep affected by the volume pot? I have the Pro-96 and the volume
control is awfully hair-trigger - goes from nothing to too damn loud in
the first few degrees of movement and then there's not much left for the
rest of the adjustment. It may be a 'design feature', though yours
suggests an actual fault of some sort. Can you get to the volume pot and
listen with an earpiece on the various pins to ground?

Cheers.

Ken

Ken,

the "beeptone" is virtually unaffected by the volume
control and remains constant from the near off position to
max volume. I only wish I could get to the contacts
while the unit is powered up but it is sandwiched with
a lower speaker/display/keypad board and they will
not operate when separated. so all my experimentation must be done with the
component side only:-(\

regards,


Allen