E-bay item ??

[Glen Zook]

As an "aside", the Heath IO-10 oscilloscope was sold
by Motorola Communications & Electronics (the two way
division of Motorola back in the 1960s and 1970s)
assembled as their model T1015.  The front panel is
lettered differently as well as having the Motorola
model number and a printed Motorola logo.  On the side
of the case is a large metal Motorola logo.

Also, the reticle on the scope tube is calibrated for
reading FM deviation.  The right hand side has
calibration for +/- 5 KHz of deviation and the left
hand side has +/- 15 KHz of deviation.  When an
oscilloscope is used with a Foster-Seeley type of
discriminator it is possible to read deviation very
accurately by coming directly off of the discriminator
output.  The end points of the deviation are
calibrated by using known offset frequencies from the
actual i.f. frequency.

The older Motorola test sets actually had three
crystals built in for this purpose.  They were 455 KHz
for the center and 450 and 460 KHz for the end points.
 This was for two purposes:  The first was the check
the "Permakay" i.f. filters that were used in Motorola
equipment well into the 1970s to insure that they were
still symetrical and to set the discriminator to
exactly 455 KHz.  The other use was to set the end
points for deviation measurements.

You ask how I know this?  I have owned a T1015 since I
worked for Motorola directly my senior year in college
(1966).  The case was slightly damaged when the unit
was sent new to a customer and was returned for
credit.  Motorola never returned a piece of test
equipment to the manufacturer, but just went ahead and
replaced it.  The parts department gave it to me (and,
over the year that I worked there, several other
pretty nice items).

For a general purpose oscilloscope, it is pretty good.
 By the way, when you read FM deviation you are only
reading DC voltage, the discriminator has already
demodulated the 455 KHz (or whatever) i.f.

Glen, K9STH

__________________________________________________
Do You Yahoo!?
Make a great connection at Yahoo! Personals.
http://personals.yahoo.com

-----------------------------------------------------------
This list is a public service of the City of Tempe, Arizona
-----------------------------------------------------------

Subscription control - http://www.tempe.gov/lists/control.asp?list=HEATH
To post - HEATH at LISTSERV.TEMPE.GOV
Archives - http://interactive.tempe.gov/archives/HEATH.html