7L5: Difference between revisions

Revision as of 05:18, 12 October 2023

Tektronix 7L5

5 MHz Spectrum Analyzer

Compatible with 7000-series scopes

Produced from 1976 to 1989

Manuals

Tektronix 7L5 Operators Manual -00 (OCR)
Tektronix 7L5 Operators Manual -01 (OCR)
Tektronix 7L5 Service Manual (OCR)
Tektronix 7L5 Options Manual (OCR) (1982 version; options 32 and 33 only covered as 1983 addendum page)

Calibration

Tektronix 7L5 Factory Calibration Procedure

Application Notes

Alternate copies

(All manuals in PDF format unless noted otherwise)

Manuals – Specifications – Links – Pictures

The Tektronix 7L5 is a low frequency (10 Hz – 5 MHz) spectrum analyzer plug-in for 7000-series scopes. It has built-in digital storage, so it will work fine in non-storage mainframes such as the large-screen 7603. It also features digital scale and marker level/frequency (6 digits) readout, and a "max hold" function.

According to the 070-2184-01 manual, instruments with a serial number below Β070000 are missing the B − (Save A) feature and the corresponding button on the front panel. The military version is called PL-1391/U and is also lacking the B − (Save A) feature.

Fendall Winston was Project Leader for the 7L5 and along with Craig Bryant and Steve Morton provided much of the electrical design. Bill Benedict and Don Kirkpatrick did the digital circuitry. Steve Skidmore coordinated mechanical design, with Carlos Beeck doing the optoelectronic switch-in-a-knob. Morris Engelson provided overall engineering direction for the program.

Key Specifications

Input frequency	10 Hz – 5 MHz
Drift	< 5 Hz/h
Resolution bandwidth	10 Hz – 30 kHz in ×3 / ×10 steps
Sweep rate	10 s/Div to 0.1 ms/Div in 1−2−5 sequence plus Auto
Residual FM	< 40 Hz_p-p (< 1 Hz from 50 Hz/Div to 2 kHz/Div)
Outputs	Horizontal, Video, Calibrator
Input impedance	L1 input module: 50 Ω L2 input module: 75 Ω L3 input module: 50 Ω, 600 Ω or 1 MΩ selectable (75 Ω, 600 Ω or 1 MΩ for the L3-1)
Log Sweep Option	250 Hz to 222.25 kHz by digitally combining three decade sweeps (250 Hz—2.25 kHz, 2.25 kHz—22.25 kHz, 22.25 kHz—222.25 kHz), 2.5 s sweep time

Options

No.	Log sweep display	Tracking generator	LED Readout
21	•
25		•
28			•
30	•	•
31	•		•
32		•	•
33	•	•	•

Links

7L5 page @ amplifier.cd with internal photos
7L5 in operation @ youtube
L1-GC

Documents Referencing 7L5

Document	Class	Title	Authors	Year	Links
Tekscope 1975 V7 N3.pdf	Article	A 5 MHz Digitally-Controlled Spectrum Analyzer		1975	7L5
TekWeek (partial) October 10, 1975.pdf	Article	Spectrum analyzers require high technology	Thor Hallen • Dave Friedley	1975	Spectrum Analyzers • Pentrix • 7L5 • 5L4 • 7L12 • 7L13 • 1401 • 491 • 1405 • 1502 • 1503
AX-3535.pdf	Application Note	Crystal Device Measurements Using the Spectrum Analyzer	Morris Engelson	1977	7L5 • 7L13 • TR502
Tekscope 1977 V9 N3.pdf	Article	Digital Storage for a Microwave Spectrum Analyzer	Dennis Smith • Don Kirkpatrick	1977	7L18 • 7L5 • 155-0157-00 • 155-0158-00
Tekscope 1977 V9 N2.pdf	Article	Measuring Harmonic Distortion with a Spectrum Analyzer	Ken Matheson	1977	FG504 • 7L5 • 5L4N
Tekscope 1978 V10 N3.pdf	Article	Spectrum Analyzer Applications in Baseband Measurements	Morris Engelson	1978	7L5 • L3 • 013-0182-00
AX-3406-1.pdf	Application Note	EMI Applications Using the Spectrum Analyzer	Morris Engelson	1979	7L5 • L1

Prices

Year	1976	1980	1988
Catalog price	$4,500	$7,075	$12,500
In 2023 Dollars	$24,300	$26,400	$32,400

According to an internal memo, in 1979 annual sales were estimated at 454 units.

Pictures

7L5 Opt. 33 in 7633 mainframe
7L5 Opt. 32
7L5 Opt. 25
7L5 in 7844
7L5 Opt. 25 without B - (Save A)
Front Panel of 7L5
Back side of 7L5 front panel
Complete IF Assembly of 7L5
Complete IF Assembly of 7L5
RF Module (Vertical Control Board and 1st LO assembly) of 7L5
Sweep board of 7L5
7L5 A and B oscillator control board front side
7L5 A and B oscillator control board back side
Front side of Tune Reference A board
Back side of Tune Reference A board
Front side of Tune Reference B board
Back side of Tune Reference B board
Front side of A oscillator board
Back side of A oscillator board
Front side of B oscillator board
Back side of B oscillator board
Later revision of 7L5 digital storage and average board - front side
Later revision of 7L5 digital storage and average board - back side
Tektronix 7L5 Transverse Interface Board
Tektronix 7L5 Transverse Interface Board
Top view of L3 plugin assembly
Bottom view of L3 plugin assembly
7L5 prepared for servicing the sweep and reference boards

7L5 Opt.25 tracking generator plug-in

For internal pictures see the repair section.

Components

Some Parts Used in the 7L5

Part	Part Number(s)	Class	Description	Used in
151-0261-00	151-0261-00	Discrete component	dual PNP transistor	AM501 • AM502 • CG5001 • CG551AP • FG501 • FG502 • FG503 • OF150 • OF151 • OF152 • OF235 • OS261 • RM502A • R1140 • R5030 • R5031 • R7912 • 067-0679-00 • 067-0807-00 • 1101 • 1140A • 1141 • 1142 • 1350 • 145 • 1450 • 1480 • 1481 • 1482 • 1485 • 1501 • 1801 • 1900 • 1910 • 1980 • 213 • 26A1 • 26A2 • 2620 • 285 • 3A9 • 3A10 • 3S1 • 3S2 • 3S5 • 3S6 • 432 • 434 • 4501 • 454 • 4601 • 4602 • 4610 • 4612 • 4620 • 4632 • 4634 • 4701 • 475 • 492 • 492A • 492AP • 494 • 494P • 496 • 496P • 5A13N • 5A20N • 5A21N • 5A22N • 5A26 • 5L4N • 502A • 5030 • 5031 • 576 • 690SR • 7A22 • 7A29 • 7B51 • 7B71 • 7J20 • 7L5 • 7S11 • 7S12 • 7912AD
155-0014-01	155-0014-00 • 155-0014-01	Monolithic integrated circuit	analog-to-decimal converter	7000 series readout system • 7854 • 7934 • 7J20 • 7L5 • P7001
155-0035-00	155-0035-00 • 155-0116-00	Monolithic integrated circuit	quad op-amp	3110 • 3S7 • 3T7 • 492 • 492A • 492AP • 492P • 494 • 494P • 496 • 496P • 4010 • 4011 • 4012 • 4013 • 7L5 • 7L12 • 7L13 • 7L14 • 7L18 • 7S11 • 7T11 • 7S12 • S-6 • 1461 • 4602 • P7001 • 613 • 653
155-0056-00	155-0056-00 • 155-0056-01	Monolithic integrated circuit	sweep control	26G1 • 26G2 • 26G3 • 314 • 4701 • 5B10N • 5B12N • 5S14N • 7L5 • 7L12 • 7L13 • 7L14 • 7L18 • 7S14 • RG501 • Telequipment D63 • Telequipment DM63
155-0108-00	155-0108-00	Hybrid integrated circuit	non-linear shaper	7L5
155-0110-00	155-0110-00	Monolithic integrated circuit	custom legend generator	7L5
155-0117-00	155-0117-00	Monolithic integrated circuit	readout control	7L5
155-0118-00	155-0118-00	Monolithic integrated circuit	vertical control	7L5
155-0157-00	155-0157-00	Monolithic integrated circuit	digital storage vertical control	7L5 • 7L14 • 7L18 • 491 • 492 • 492A • 492BP • 492PGM • 494 • 494A • 495 • 496 • 497P
155-0158-00	155-0158-00	Monolithic integrated circuit	digital storage horizontal control	7L5 • 7L14 • 7L18 • 491 • 492 • 492A • 492BP • 492PGM • 494 • 494A • 495 • 496 • 497P
155-0198-00	155-0198-00	Monolithic integrated circuit	readout control	7L5
155-0199-00	155-0199-00	Monolithic integrated circuit	vertical control	7L5
VTL2C4	307-0476-00	Discrete component	LED-LDR optocoupler	7L5

@@ Line 8: / Line 8: @@
 |introduced=1976
 |discontinued=1989
+|designers=Fendall Winston;Craig Bryant;Steve Morton;Bill Benedict;Don Kirkpatrick;Steve Skidmore;Carlos Beeck;Morris Engelson
 |manuals=
 * [[Media:070-1734-00.pdf|Tektronix 7L5 Operators Manual -00]] (OCR)
@@ Line 34: / Line 35: @@
 According to the 070-2184-01 manual, instruments with a serial number below Β070000 are missing the ''B − (Save A)'' feature and the corresponding button on the front panel. The military version is called PL-1391/U and is also lacking the ''B − (Save A)'' feature.
+<blockquote>
+Fendall Winston was Project Leader for the 7L5 and along with Craig Bryant and Steve Morton provided much of the electrical design. Bill Benedict and Don Kirkpatrick did the digital circuitry. Steve Skidmore coordinated mechanical design, with Carlos Beeck doing the optoelectronic switch-in-a-knob. Morris Engelson provided overall engineering direction for the program.
+</blockquote>
 {{BeginSpecs}}