- I just got a cool HP 3200B 500MHz oscillator that's got a defective attenuator.
- A TDS 544A scope that can't trigger (or other problem ?) above 400MHz... reducing the usefulness of the scope somewhat...
- A TDS 694C that needs a keypad fixing...
- A 2467B that escaped the magic smoke.
I can tell you a little hack to increase the bandwidth of the TDS scopes, even upgrade them to higher models...
Maybe leaving them at the current model numbers but removing the bandwidth limiting capacitors on the acquisition boards would help a bit...
Did you recently run SPC too?
Also, one favour to ask, can you tell me what firmware you have on your units? I might task you to extract it for my firmware collection if they are versions I don't have..... It's easy with a GPIB interface and a command line app.
I don't think B/W is the problem here, plenty enough signal amplitude.. looks more like a tired trigger circuit and I have no idea how to fix / diagnose that... no schematics around for the 544A, well unless it leaked since 5 years ago when I worked on it. Think I found schematics from a 520 or something, something like that... better than nothing... but still only partial schematic, so don't don't know it they show the trigger circuitry...
Anyway regardless, would be cool upping the B/W if it's just a cap to remove on the front end.. even if in practice it's not going to make much of a difference since the sampling rate and sweep sweep won't increase accordingly to make use of the extra B/W....
But for repetitive signals I guess it could still be somewhat useful.
Bring it on, give me instructions !
SPC ? No I didn't do that... I ran it 10 times in a row 5 years ago after fixing the scope, to make sure it was working fine... but have not run it ever since... OK will try that, though from memory it has nothing to do with triggering, SPC only compensates for small temperature induced DC offsets in the signal path ? Just from memory...
But it's free to try so will do !
FW versions ?
OK just powered them up to check... here goes :
TDS 544A: v3.8.3e with options 13 1F M
TDS 694C: v6.4e with options 13 1F 2FWould be cool to extract the FW through GPIB, never done it ! Gimme the S/W and instructions even if you are not interested in my crusty old FW !