J
John Crighton
- Jan 1, 1970
- 0
Hello All and Arpit,
A young fellow by the name of Arpit posted a message
about how he was looking for a used oscilloscope a few
weeks ago and commented on how expensive they were
from places like Oatley.
I came across this picture of my first CRO.
http://www.thevalvepage.com/testeq/emi/scope/emiscope.htm
I was a teenager when I bought a similer used EMI oscilloscope in
the late 60's for $15 in Adelaide. About a weeks wages as an
apprentice back then.
The coloured knobs on the CRO in this picture are not original.
Arpit, maybe spending a couple of hundred dollars in to-days
money is not too bad for a nice, not too old, BWD CRO or
something similar that is repairable with ready available parts.
A lot of the, not so old, Tektronix CROs have special ICs that
are no longer available or pricey second hand from overseas.
Maybe that BWD CRO that Trevor offered you is not a bad
deal looking at it from the point of view of spending a weeks
wages as a young fellow.
Getting back to that old EMI CRO in the picture like the
one I had decades ago.
With just a horizontal trace under the plastic graticule
bar, the meter read Zero Volts.
If a sine wave was displayed.
To read Peak to Peak volts the trace was shifted up
so the negative peak lined up with the graticule bar
and the negative Peak voltage on the meter was noted.
A similar shift was made for the positive Peak and the
two readings added. Crude but usable for measuring
a limited range of P-P volts.
There wasn't a proper time base scale. Still, I had a
lot of fun and learned a bit.
I gave that CRO away in the mid 70s, I hope that fellow
passed it on. I wonder if it is under a bench somewhere
collecting dust. Heh Heh heh....
Keep looking Arpit, something will turn up.
Old boat anchors like this one are quite common
and cheap.
http://www.thevalvepage.com/testeq/tek/545a/545a.htm
Probably a bit too big physically from your parents
point of view but I will keep an eye out for you anyway
should one turn up at a ham Trash and Treasure for
$20 or so, where most of the CRO works.
Speaking of Trash and Treasures. The Wireless Institute
of Australia are having one at Wigram Street, Parramatta
this Sunday (Noon 28/9/03). Get your parents to give
you a ride down there Arpit. You might find some "lucky
things." That is what my mum calls my electronic junk.
Regards
John Crighton
Hornsby
A young fellow by the name of Arpit posted a message
about how he was looking for a used oscilloscope a few
weeks ago and commented on how expensive they were
from places like Oatley.
I came across this picture of my first CRO.
http://www.thevalvepage.com/testeq/emi/scope/emiscope.htm
I was a teenager when I bought a similer used EMI oscilloscope in
the late 60's for $15 in Adelaide. About a weeks wages as an
apprentice back then.
The coloured knobs on the CRO in this picture are not original.
Arpit, maybe spending a couple of hundred dollars in to-days
money is not too bad for a nice, not too old, BWD CRO or
something similar that is repairable with ready available parts.
A lot of the, not so old, Tektronix CROs have special ICs that
are no longer available or pricey second hand from overseas.
Maybe that BWD CRO that Trevor offered you is not a bad
deal looking at it from the point of view of spending a weeks
wages as a young fellow.
Getting back to that old EMI CRO in the picture like the
one I had decades ago.
With just a horizontal trace under the plastic graticule
bar, the meter read Zero Volts.
If a sine wave was displayed.
To read Peak to Peak volts the trace was shifted up
so the negative peak lined up with the graticule bar
and the negative Peak voltage on the meter was noted.
A similar shift was made for the positive Peak and the
two readings added. Crude but usable for measuring
a limited range of P-P volts.
There wasn't a proper time base scale. Still, I had a
lot of fun and learned a bit.
I gave that CRO away in the mid 70s, I hope that fellow
passed it on. I wonder if it is under a bench somewhere
collecting dust. Heh Heh heh....
Keep looking Arpit, something will turn up.
Old boat anchors like this one are quite common
and cheap.
http://www.thevalvepage.com/testeq/tek/545a/545a.htm
Probably a bit too big physically from your parents
point of view but I will keep an eye out for you anyway
should one turn up at a ham Trash and Treasure for
$20 or so, where most of the CRO works.
Speaking of Trash and Treasures. The Wireless Institute
of Australia are having one at Wigram Street, Parramatta
this Sunday (Noon 28/9/03). Get your parents to give
you a ride down there Arpit. You might find some "lucky
things." That is what my mum calls my electronic junk.
Regards
John Crighton
Hornsby
