In article KejMd.2014$uc.513@trnddc04,
says...

Hey, have a '78 model Alert Monitor, M03CNB1102B
VHF unit, silver front with black case, reset/alert/mon functions.

Questions:
Original battery type, location, voltage?
Frequency range? Will it do 146.000MHz?
Is it possible to turn down the volume on the alert tone?

In sequence:

Unknown. Best to adapt it to an external 12VDC supply.

Possibly. The VHF alert monitors were spec'd to bottom out at
150MHz. It may be possible to take one lower by increasing the value of
the padding capacitors across the receiver's oscillator and multiplier
coils. It is possible that it may go lower on its own. Never know until
you try.

Need schematic, tuning and recrystal instruction.

That could be difficult. The manual for this receiver was Motorola
part #68-81048A55. This P/N comes up as no longer in the database, which
means that it is no longer available from Motorola (considering the age
of the unit, and Motorola's feverish desire to gain profit at any cost,
I'm not surprised).

You should check in with the gang at Batlabs
(http://batboard.batlabs.com). They may be of further assistance.

Happy hunting.


--
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(Known to some as Bruce Lane, ARS KC7GR,
kyrrin (a/t) bluefeathertech[d=o=t]calm -- www.bluefeathertech.com
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