Testing the video channel on a vintage Audio Analyzer

[heavymod]

If this is in the wrong area, please let me know / move the thread.

I have a circa 1980's Audio Analyzer - unfortunately I do not have the custom CRT that you could purchase back then. I thought I could just get a bunch of adapters and hook it to a modern LCD, but that is not working.

What I am hoping to do is find out if the unit is putting out a decent video signal. I have access to an oscilloscope / DMM and will look for a CRT tomorrow. However, I have to make a decision soon on whether to keep / return it - so hoping to find out if the video signal is _clearly_ broken before I go and purchase a CRT that may/may not work with this unit.



So I want to test the pins on the monitor plug and determine if they are providing a good signal. The device turns on, fan starts, I can detect voltage on the various internal cards. Inside the computer there are 3 pins that go from the "Graphics card" to a DB-15 plug.

http://i.imgur.com/kG3yyLH.jpg
These 3 wires to go a DB15 plug on the back of the computer labeled CRT MONITOR.

When I attach my DMM ( 388-HD ) to the 3 pins that are attached to the card, I get:

PIN1: .3VAC (.06VDC ) .120 Khz
PIN2: .03VAC (.00VDC )
PIN3: .04VAC (.00VDC )

I have not tested with my oscope yet - I am going to do that this evening.


1) What would appropriate voltages be?

2) Am I able to measure these using my DMM ( I read that low HZ signals could be problematic )

3) Aside from plugging in a matching CRT, is there anyway to determine some basic level of functionality?

A manual for a similar unit ( the 201 ) which comes with a built in CRT says it operates at 50hz, which surprised me.. I figured it would be one of the 15hz types.

Any help appreciated!