Heathkit IO 12

[nickc]

Hello list.

New here and very much a tinkerer so hope you'll bear with me. Just
came by a Heathkit io12 scope. The previous owner already warned me
that it will generate an internal sine wave but that it doesn't seem
to see external signals.

Of course I wanted to see for myself. I wanted to look at the output
of my stereo and thought that I should be able to connect one of the
spkr wires to the vert input and gnd and set everything to ext.
input.

No luck but I'm not even sure I'm doing the right thing. Can anybody
help/

Thanks
Nick

 

[Rich Grise]

On Thu, 31 Jan 2008 13:36:36 -0800, nickc wrote:

New here and very much a tinkerer so hope you'll bear with me. Just
came by a Heathkit io12 scope. The previous owner already warned me
that it will generate an internal sine wave but that it doesn't seem
to see external signals.

Of course I wanted to see for myself. I wanted to look at the output
of my stereo and thought that I should be able to connect one of the
spkr wires to the vert input and gnd and set everything to ext.
input.

No luck but I'm not even sure I'm doing the right thing. Can anybody
help/

The guy gave you a broken 'scope. Either learn to do electronics repair,
give it back to him, or maybe put it on ebay for parts.

Good Luck!
Rich

 

[Yukio YANO]

Rich Grise wrote:

On Thu, 31 Jan 2008 13:36:36 -0800, nickc wrote:
New here and very much a tinkerer so hope you'll bear with me. Just
came by a Heathkit io12 scope. The previous owner already warned me
that it will generate an internal sine wave but that it doesn't seem
to see external signals.

I assembled an "IO12 " about 45 years ago !

I think there is a bit of mis-communication here "will generate an
internal sine wave" Really means "the Horizontal Sweep Oscillator" is
working ! SEE "You can see the Horizontal Trace"! (Everything else
seems to work, High Voltage for the Beam, Horizontal Sweep Oscillator,
Horizontal Deflection Amplifier)

The Vertical Amp is Dead if you can't Expand the Trace Vertically !

I suspect the VERTICAL DEFLECTION AMPLIFIER is dead, if you can't Center
the beam Vertically, (a P-P 12BH7), across the CRT Vertical Plates


Fixing a Scope is a bit like repairing a Broken Soldering Iron! You need
one to fix one !!

In this Day and age, I would Google "Sound Card Oscilloscope" and build
one! (just a Probe and some Resistors and Capacitors and not much
else ) except for the Software, to troubleshoot your "IO12", but then
you would now have a working "Waveform Monitor", and why would you need
the "IO12" except for Its' Calibrated, Vertical Sweep, and Gain Functions.

Yukio YANO

 

[Bob Masta]

On Fri, 01 Feb 2008 02:59:37 GMT, Yukio YANO <yano@shaw.ca> wrote:

Rich Grise wrote:
On Thu, 31 Jan 2008 13:36:36 -0800, nickc wrote:
New here and very much a tinkerer so hope you'll bear with me. Just
came by a Heathkit io12 scope. The previous owner already warned me
that it will generate an internal sine wave but that it doesn't seem
to see external signals.



I assembled an "IO12 " about 45 years ago !

I think there is a bit of mis-communication here "will generate an
internal sine wave" Really means "the Horizontal Sweep Oscillator" is
working ! SEE "You can see the Horizontal Trace"! (Everything else
seems to work, High Voltage for the Beam, Horizontal Sweep Oscillator,
Horizontal Deflection Amplifier)

The Vertical Amp is Dead if you can't Expand the Trace Vertically !

I suspect the VERTICAL DEFLECTION AMPLIFIER is dead, if you can't Center
the beam Vertically, (a P-P 12BH7), across the CRT Vertical Plates


Fixing a Scope is a bit like repairing a Broken Soldering Iron! You need
one to fix one !!

In this Day and age, I would Google "Sound Card Oscilloscope" and build
one! (just a Probe and some Resistors and Capacitors and not much
else ) except for the Software, to troubleshoot your "IO12", but then
you would now have a working "Waveform Monitor", and why would you need
the "IO12" except for Its' Calibrated, Vertical Sweep, and Gain Functions.

Yukio YANO

If you have a system that will run real-mode DOS (Win9x or earlier),

you can use a handful of resistors to build an 8-bit ADC (or DAC)
that will work with my Daqarta for DOS. You can check out
the contruction details at

www.daqarta.com/lptx.htm

You can download Daqarta for DOS at

www.daqarta.com/download.htm

Download the "Basic starter package" DQA.ZIP
and (farther down the page) the LPTX driver
LPTX.ZIP.

You can get a FREE license key for Daqarta for DOS
just by requesting it on the Contact Us form (links
on every page).

If you have a more modern machine, you can use
Daqarta for Windows (www.daqarta.com). This is
free to use for 30 sessions / 30 days, after which
it will no longer accept external input signals unless
you have a license (but the free signal generator
always works). A license is US$ 29 for personal
or hobby use, and is good for all future versions.

Best regards,


Bob Masta

DAQARTA v3.50
Data AcQuisition And Real-Time Analysis
www.daqarta.com
Scope, Spectrum, Spectrogram, FREE Signal Generator
Science with your sound card!

 

[nickc]

Thanks everybody.

The vertical gain pot does increase the amplitude but the scale switch
for the vert. input seems to be broken. Guess I'll open it up and see
what's up with that before I do anything else.