Pls help me repair HP 54642A OSC

[chihaxinh]

Hi, Everyone!

I have one HP 54642A OSC - and i have a big trouble when i measurement frequency., pls see table below

Sign Gen   - HP 55642A measurement
100 HZ      - 150 Hz
1KHz         - 1.5 KHZ
100KHZ     - 150 KHZ
1 MHZ   - 1,5 MHZ

I have error about Measurement Frequency = Real frequency * 1,5 

OSC have 2 type input impedance - 50R and 1Meg ! I think hybird atten have trouble , other function it's OK ( RMS , Peak - Peak ..etc mearsurement option )

Below it's picture about carlib information ( Fail in high frequency )








Pls help me repair OSC ! Sory for my english , i speaking english not well !

Best regards !
Nam Nguyen Hai

[Smith]

Both devices probably have oscilator in and outputs. You could connect the signal gen oscillator out to the osciloscope oscilator input or the other way around. Measurements should be spot on. This eliminates any possible oscillator trouble.

I assume both oscillators to be 10MHz.

BTW does the selftest show any errors?

[chihaxinh]

Dear Smith

I runing seft test OK , you can see picture. Wave form it's signal from triger output .



When i runing User Carlib , i see function allway return to menu ( not running ), you can see video in link below.

http://www.4shared.com/video/ipt3Jolvba/video-1431620725.html




Pls help me fix OSC

Thank you so much !
Best regards
Nam Nguyen Hai