The Tektronix 3L5 is a 50 Hz — 1 MHz spectrum analyzer plug-in for 560-series scopes.
It is very similar to the 1L5 and can be used to measure the spectrum of signals. In conjunction with the 015-0107-00 "Swept Frequency Generator" (tracking generator), the 3L5 can also be used to make scalar frequency response measurements.
75 Ω Version
There is also a 75 Ω version of the 3L5. Its input is on the rear, via a coaxial connector. A lever on the front panel switches between two frequency ranges:
- 10 kHz - 1 MHz
- 18.010 MHz - 19 MHz