The Tektronix 7A14 is a 120 MHz current probe amplifier vertical plug-in intended to use current probes P6021 and P6022 with 7000-series scopes. The 7A14 is one of the original plug-in modules introduced at the start of the 7000 series in 1969.
In the 7A14, the ring around the input BNC connector that is used to identify ×10/×100 probes on voltage probes serves the purpose of detecting the difference between the P6021 and P6022 probes, and switching in appropriate gain and frequency compensation. The P6021 shorts this ring to ground, directly switching three relays connected to -15 V internally.
The front panel gain control screwdriver adjustment affects gain for either P6021 or P6022.
- Bandwidth with P6021 Probe: 25 Hz – 50 MHz (55 MHz in 79xx)
- Bandwidth with P6022 Probe: 250 Hz – 105 MHz (120 MHz in 79xx, 80 MHz in 76xx)
- Ranges: 1 mA/Div to 1 A/Div in 1–2–5 sequence
The 7A14 uses twelve Tek-made miniature relays that can be a service issue.
The amplifier is an 8-stage discrete differential design. The plug-in contains no integrated circuits.