1L5

Tektronix 1L5
1 MHz Spectrum Analyzer Tektronix 1L5 Compatible with 500-series scopes Produced from 1967 to 1975 Manuals Tektronix 1L5 Manual Tektronix 1L5 Factory Calibration Procedure, September 1967 (All manuals in PDF format unless noted otherwise)

Manuals – Specifications – Links – Pictures

The Tektronix 1L5 is a low-frequency spectrum analyzer for 500-series scopes. It is very similar to the 3L5.

Its center frequency is set on a trio of rotary switches and can range from 50 Hz to 990 kHz. Minimum resolution bandwidth is 10 Hz. It has a 1 MΩ input resistance.

Type 1L5 was sold from 1967 until the end of the classic plug-in scope line. Not particularly accurate in either frequency, bandwidth, or amplitude, it was no match for HP's 141T/8556A/8552B combination in performance, but it was a small fraction of the price.

Although Type 1L5 can operate in any 500-series scope*, it is most useful by far in the Type 549 storage mainframe which allows slow sweeps needed to match the narrower resolution bandwidths.

In conjunction with the 015-0107-00 Swept Frequency Converter (tracking generator), the 1L5 can also measure frequency response.

* 531/535/541/545 need a wiring mod to alleviate vertical amp instability.

Key Specifications

please add

Links

Documents Referencing 1L5

Pictures

External

Front panel
Rear

Internal

top
right
left
bottom

Pre-production unit

Preproduction 1L5 (serial A01)
Preproduction 1L5 (serial A01)
Preproduction 1L5 (serial A01)

Measurements, Diagrams

1L5 works fine in 549
Measured frequency response of 3 MHz filter from P90 to P280 with Q290 removed to disable 3.1 MHz oscillator, but powered up. 10 dB/div.
Measured frequency response of 3 MHz filter. 1 dB/div.
Block Diagram
Attenuators and Input
Center Frequency Switching
Swept Frequency Generator
Variable Resolution Amplifier
Dispersion Warning Light
Output Amplifier
Calibrator
Interconnecting Plug and Power Distribution