Tektronix 492 - Garbled Text Display Problem

I am not sure what is going on with my spectrum analyzer. The frequency plot shows up properly both in analog and digitally-stored modes. However, the text does not. I have pulled all cards excepting the CPU, memory, CRT readout, Z-Axis/RF Interface, and sweep cards. The high-voltage drive and front panel are still connected, along with all of the RF components. Ideas?

Category:

Science & Technology

Tags:

• Tek
• Tektronix
• 492
• Spectrum
• Analyzer
• Network
• CRT
• Tube
• Electron
• Beam

[GeordiVsRiker]

It was the character generator board, about the last thing that I could possibly replace...

[ddivince]

There are several likely culprits for this on the Def Amp. PM me and I will point out the most common. I have all the factory sequence procedures, lots of spare parts, modules and boards. I can also do full Calibration & repairs on Tek Spec ans.

[GeordiVsRiker]

PM'ed

[ddivince]

Looks like a possible deflection Amp board problem. I worked 49X/275X Spec Ans at TEK for 5 years.

[GeordiVsRiker]

Thanks! I'm going to be working on this again next week. I swapped a couple of boards and a bunch of components with no luck. I figured that it was either the deflection amp or CRT readout and think that I eliminated the CRT readout when I socketed and replaced the ADCs and still got the faint swirly lines on the screen.

[ddivince]

@lazzer408 LOL, pretty amazing that you can diagnose what the problem wasn’t 8 months *after* the solution was posted here – congratulations ace. Your troubleshooting skills are exceeded only by your ignorance of how these analyzers work. Given your penchant for bewilderment it’s not surprising you are left to wonder about things. No need to reply, I have you on the ignore list, works great for blocking morons. Cheers.

[lazzer408]

@ddivince HAHA Sorry I had to laugh at that one. Clearly not a deflection problem. Makes me wonder what you've spent 5 years doing.