Tektronix 2247a calibration frequency off

[schulteaaron5]

Hi, I just bought my first oscilloscope! I couldn't say no to 50 bucks for the 2247a in supposed working order, but I do have the option to return it. I haven't even had a chance to power it on yet but I know the "probe adjust" calibration frequency is off by almost 100hz! Out of 1khz! Maybe I'm using the wrong terminology, but I couldn't find any general info on this issue. I know tek scopes can be hard to fix, but I would love to get this thing up and running!

First post, go easy!

[tggzzz]

Hi, I just bought my first oscilloscope! I couldn't say no to 50 bucks for the 2247a in supposed working order, but I do have the option to return it. I haven't even had a chance to power it on yet but I know the "probe adjust" calibration frequency is off by almost 100hz! Out of 1khz! Maybe I'm using the wrong terminology, but I couldn't find any general info on this issue. I know tek scopes can be hard to fix, but I would love to get this thing up and running!

That output's frequency and amplitude are unimportant; what matters is a flat top and short edges. The only time you use that output is when you are fiddling with a "high" impedance *10 probe's frequency compensation, where you fiddle until the waveform's top looks flat, like a good square wave.

BTW, please add a country flag, via the "profile"; that way you might get more relevant information.

[schulteaaron5]

Thanks a bunch, I just booted it up and squared off the calibration signal, looks nice at flat now as you'll see in my pictures...pictures i post because now I have an interface issue, I hope its all my fault and not the scopes!

I can't get the menu to pop up, pretty sure I've tried every "reasonable" button. Also I don't get a legible "readout" on what my time division and v/div are. Turning up readout brightness just makes some scribbles appear, stuck in the center of the screen as seen in pics. Let me know if I should delete this and start a new post

Sent from my A0001 using Tapatalk

[singapol]

Try displaying two or 4 trace and see where text line is positioned.I suspect vertical knob is moved. The text line should appear at the last bottom grid position. The size of the alphabets is small/abnormal, could be some problem in the  readout section. Unable to find operator's manual only service manual so a video will have to suffice. 2447a has about 30 engineering changes from 1989 to 1993 ( see service manual).

2247a scope familiarisation video:



2247a service manual (129.4 Mb file! 370 pg.): Wait for "Processing" to change to "Get manual".

http://elektrotanya.com/tektronix_2247a.pdf/download.html