[Motorola] M4548

[Eric Lemmon]

Geoff,

You've got a good memory!  However, the transistor in the Motrac push-pull
audio amplifier stage is an M4584, not an M4548.  I went through the entire
Motrac manual, and found that the great majority of transistors were M9xxx
series, and the M45xx series were usually in audio or low-frequency stages.
I could not find an M4548 in the Motrac or Mocom-70 manuals- the latter
being of similar vintage.

For what it's worth, the Motorola part number of the M4548 is 48K134548, but
it is no longer available from Motorola Parts.

73, Eric Lemmon WB6FLY
 

-----Original Message-----
From: motorola-bounces at mailman.qth.net
[mailto:motorola-bounces at mailman.qth.net] On Behalf Of Geoff Fors
Sent: Monday, June 16, 2008 8:56 PM
To: Motorola
Subject: [Motorola] M4548

That Motorola transistor was in the Motracs as either the audio output or
one of the power supply inverter transistors.  PNP Ge if I recall correctly.

NTE may list a cross reference, however Motorola transistors are all unique
and not re-labeled generic items. The specs for Hfe and so forth in the NTE
and ECG books are their part's specs, which are usually pretty close , and
would probably be fine for any application using this kind of transistor.
Motorola did not publish the specs on the M- series transistors.  NTE and
its competitors get their cross references from customer requests and
customer input, and from doing things like curve-tracing and testing
original parts, rather than from any information from Motorola.

Geoff
WB6NVH

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