# Cal Test Electronics CT4066 25 MHz Differential Probe

# Cal Test Electronics CT4066 25 MHz Differential Probe

## Key Features At A Glance

-   25 MHz bandwidth (-3 dB) at 50x and 200x attenuation; 15 MHz at 20x
-   Up to ±700 V (DC + AC peak) input at 200x attenuation
-   Switchable attenuation: 20x / 50x / 200x
-   ±2% accuracy (based on DMM with 10 MΩ input impedance)
-   Active design: 4 MΩ // 1.2 pF differential input impedance
-   AC CMRR of 80 dB @ 60 Hz
-   Meets IEC 61010-1:2010 CAT II safety standard; Pollution Degree 2
-   Power indicator LED; compatible with oscilloscopes from all major manufacturers

The CT4066 is an active differential probe with a high input impedance and low input capacitance. With a 25 MHz bandwidth, it handles a wide variety of measurements ranging up to ±700 V (DC + AC peak), and it is compatible with oscilloscopes from all major manufacturers.

A differential probe measures the voltage difference between two points in a circuit, isolating the signal of interest from ground and rejecting the common-mode voltage shared by both inputs. The CT4066 is built for this work across its measurement span, with three switchable attenuation factors that trade bandwidth against maximum input voltage so the same probe covers low-level and higher-voltage differential measurements.

ValueTronics stocks and holds its own inventory in a 20,000 sq ft secure warehouse at 1675 Cambridge Drive in Elgin, Illinois.

## Accessories Supplied

-   Differential Probe
-   (2) Pincer clips
-   (2) Alligator clips
-   (2) Sheathed 4 mm banana plug test leads, silicone jacketed
-   (1) Insulated BNC cable
-   (1) 9 V power adapter

## Product Core & Specifications

Specification

Value

Electrical Characteristics

Bandwidth

25 MHz (50x and 200x attenuation); 15 MHz (20x attenuation)

Rise Time

14 ns for 50x and 200x; 23.4 ns for 20x

Attenuation

20x, 50x, 200x

Accuracy

±2% \*

AC CMRR

80 dB @ 60 Hz; 60 dB @ 100 Hz; 50 dB @ 1 MHz

Maximum Input Voltage (20x) (DC + AC peak)

±70 V

Maximum Input Voltage (50x) (DC + AC peak)

±175 V

Maximum Input Voltage (200x) (DC + AC peak)

±700 V

Absolute Maximum Rated Input Voltage (each side to ground)

600 Vrms

Input Impedance (Differential)

4 MΩ // 1.2 pF

Input Impedance (each side to ground)

2 MΩ // 2.3 pF

Output Voltage Swing

±8 V (driving 1 MΩ oscilloscope input)

Offset (typical)

±5 mV

Noise (typical)

2 mVrms

Source Impedance

50 Ω

Power Supply

9 V power adapter (included)

Mechanical Characteristics

Weight

250 g

Dimensions

195 x 55 x 30 mm

BNC Cable Length

100 cm

Input Leads Length

55 cm each

Environmental Characteristics

Operating Temp/Humidity

0°C to 50°C / 10% to 85% RH

Storage Temp/Humidity

\-30°C to 70°C / 10% to 90% RH

Pollution Degree

Pollution Degree 2

Safety Specifications

Safety

IEC 61010-1 CAT II

> **Important:** Maximum input voltage depends on the attenuation setting: ±70 V at 20x, ±175 V at 50x, and ±700 V at 200x (DC + AC peak). Absolute maximum rated input voltage is 600 Vrms each side to ground.

> **Important:** Accuracy (±2%) is based on a DMM with 10 MΩ input impedance.

> **Important:** Meets IEC 61010-1:2010 CAT II safety standard.

> **Important:** All specifications apply to the unit after a temperature stabilization time of 20 minutes over an ambient temperature range of 25 °C ± 5 °C.

## About this New unit

This is a brand-new, factory-sealed unit, supplied exactly as it arrives from the manufacturer and backed by the full manufacturer warranty. For the exact configuration, available options, included accessories, or current lead time for your application, our Test Architects can confirm the details before you order.

ValueTronics supplies both new and used test and measurement equipment. New units ship factory-sealed, exactly as received from the manufacturer; every used unit is inspected and functionally verified in-house at our 20,000 sq ft secure facility in Elgin, Illinois before it ships. Our Test Architects can help you select the condition, calibration, and configuration that fit your application.

**Please review the Manufacturer's Data Sheet to verify published specifications. Feedback on this webpage is always welcome — please reach out to your Test Architect at any time for questions or concerns. Thank you, we truly appreciate you being our customer.**

## Details

- **Price:** 420.0 USD
- **Vendor:** Cal Test Electronics
- **Type:** Diff Probe
- **Tags:** Accessories, Cal Test Electronics, Differential, Manufacturers, Other Equipment, Probe, product_manual_group_1, Product_new

## Variants

| Variant | Price | Available |
|---------|-------|-----------|
| Default Title | 420.00 USD | In stock |

## Images

- Cal Test Electronics CT4066 25 MHz Differential Probe

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> Source: [ValueTronics](https://valuetronics.com/products/ct4066-cal-test-differential-probe-new)
> Updated: 2026-06-20