This is the old version of the FETProbe, with limited supply voltage range.

Sold at a discount, while stock lasts. For the newer V2, visit https://lectronz.com/products/-1-3-ghz-fetprobe-v2

What is it?

A 1.3 GHz active scope Probe with FET input and very low input capacitance (about 0.3 pF)

• AC coupled
• minimum frequency: 100 kHz
• attenuation: 1:10 (1:20 with 50 Ohm termination)
• supply. 5V through u.Fl
• reverse voltage protection
• output through u.Fl
• can be soldered directly to the device under test for minimal lead inductance

For powering, see our USB to SMA dongle also available as an accessory option on this page

This is a nice low-cost addition to your scope accessory arsenal for cases when the stock probes of a cheap oscilloscope just can't do the job.

Why did you make it?

I made this probe to measure oscillators with low load capacitance, when my stock oscilloscope probes would probably detune the circuit too much. There are more use cases - basically everything that can be done with an AC coupled probe with low input capacitance.

See here for a little example: https://hackaday.io/project/184924-diy-13-ghz-fet-probe/log/213125-measuring-an-sx1280s-oscillator-frequency