Tektronix 556 Dual Beam Oscilloscope Testing: Vertical Bandwidth

This was originally posted in December, 2017

Tektronix 556 Dual Beam Oscilloscope Testing: Vertical Bandwidth

I have been doing some basic testing of my Tektronix 556 Dual Beam Oscilloscope, and I have documented some parts of this process. I have also captured images of the traces, which I will share here.

Test Setup: Tektronix 556, 1A2 plug-in, Timebase A, Tektronix SG 503 Generator, and Tektronix TG 501 Time Mark Generator

I found the -3db vertical bandwidth of the 1a2/556 to be 65 Mhz, which is to be expected for the 50 Mhz rated 1A2.

The scope triggered out to 113 MHz, and displayed 100Mhz pulse (sine wave in this case) without problems.

TM 500 Module with plug ins

Tek 556 with 1A2 Vertical 50 KHz BW Test

Tek 556 with 1A2 Vertical 5 MHz BW Test

Tek 556 with 1A2 Vertical 20 MHz BW Test

Tek 556 with 1A2 Vertical 40 MHz BW Test

Tek 556 with 1A2 Vertical 50 MHz BW Test

Tek 556 with 1A2 Vertical 65MHz BW Limit

65 MHz is the -3db point (vertical bandwidth) for the system. The 1A2 plug-in was specified to have a -3db bandwidth of 50 MHz.

Next, I increased the generator frequency to find out when the 556 and 1A2 would stop triggering.

Tek 556 Timebase A Trigger Limit Test 75 MHz Sine Wave

Tek 556 Timebase A Trigger Limit Test 100 MHz Sine Wave

Tek 556 Timebase A Trigger Limit Test 113 MHz Limit

The upper limit turned out to be 113 MHz. Any higher and the scope lost trigger and did not display a sine wave.

Next I investigated the pulse response:

Tek 556 Timebase A 1 mS Pulse (1 kHz)

Tek 556 Timebase A 1 uS Pulse (1 MHz)

Tek 556 Timebase A 100 nS Pulse (10MHz)

Tek 556 Timebase A 10 nS Pulse (100MHz)

The scope displayed 10 nS pulses with no problems.

Shaun Merrigan

Tektronix 556 Dual Beam Oscilloscope Testing: Vertical Bandwidth

Tektronix 556 Dual Beam Oscilloscope Testing: Vertical Bandwidth

Discover more from Shaun Merrigan

Shaun Merrigan