2205

The Tektronix 2205 is a 20 MHz dual-trace analog oscilloscope introduced in 1989. There is a also a 40 MHz version, the 2205-40. A 2205 equipped with option 07 (internal DC inverter) can be powered ≥3 hours from an 1104A battery.

Manuals – Specifications – Links – Pictures

Key Specifications

Risetime	17.5 ns @ 20 MHz, 23.3n @ 15Mhz
Bandwidth	20 MHz (≥5 MHz with ×10 vertical magnification)
Deflection	5 mV/Div to 5 V/Div, 1–2–5; 50 V/Div with ×10 Probe; variable ≥2.5:1
Input impedance	1 MΩ // 25±2 pF
Maximum safe input	400 V (DC + peak AC) or 800 Vp-p AC to ≤10 kHz
Trigger sensitivity	0.3 Div or 40 mV @ 5 MHz, 1 Div or 200 mV @ 5 MHz
Sweep	0.5 s/Div to 0.1us/Div, 1−2−5; ×10 Mag. down to 10 ns/Div; variable ≥2.5 : 1
Z input	5 V causes noticeable modulation (positive decreases intensity), DC to 5 MHz; max. 400 V (DC + peak AC) or 800 Vp-p AC to ≤10 kHz
CRT	1.8 kV cathode voltage, no post-deflection acceleration, Tube, 8 X 100mm² Display, P31 154-0929-00
Weight	6.2 kg (13.7 lb)
Power	95–128 or 185–250 VAC, 48–440 Hz, max. 40 W
X-Y mode	X bandwidth 2 MHz; phase shift ±3° from DC to 50 kHz
Calibrator	0.5 V ±5% into 1 MΩ Load; 1 kHz ±20%

Options (See also 2225)

• 1T - Adds Transit Case
• 22 - Adds 24 Oscilloscope Test Leads
• 23 - Adds P6119 1×/10× probe with accessories (2 each)
• 24 - Adds P6103 10X Probe W/Accessories (2 each)

Accessories

• 103-0275-00 Oscilloscope Test Leads (2 each)

Optional Accessories (See also 2225)

• Oscilloscope Test Leads (Pack of 24)

Prices

• 1990: $695 (~$1,600 in 2023 dollars)

Internals

Each of the two inputs first goes through attenuators, then discrete dual-JFET source-follower buffer stage, then an Intersil CA3102 differential amplifier chip to provide some gain and convert from single-ended to a differential signal.

The vertical output amplifier driving the CRT is discrete and has an interesting design that conserves power (and minimizes heat). When the output is slewing at low rates, the output transistors have a constant, relatively low current passing through them. At higher slew rates, to provide enough current to charge and discharge the parasitic and CRT plate capacitances, the output stage operates in more of a push-pull mode.

The 2205 has a switch-mode power supply that produces low voltage and CRT voltages using transformer T901, which operates at about 60 kHz. Interestingly, there is a also a mains-frequency step-down and isolation transformer (T901) in the power path before the SMPS.

Pictures

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