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* [ | {{Instrument Sidebar | ||
* [ | |class=Spectrum Analyzer | ||
|manufacturer=Tektronix | |||
|model=492 | |||
|summary=21 GHz Spectrum Analyzer | |||
|image=Tek 492 3.jpg | |||
|caption=Tektronix 492 | |||
|introduced=1980 | |||
|discontinued=1993 | |||
|designers=Larry Lockwood;Steve Morton;Linley Gumm;Robert Alm;Bob Bales;Carlos Beeck;Bill Benedict;Craig Bryant;Russell Brown;Wes Hayward;David Leatherwood;Gordon Long;Dave Morton;Bill Peterson;David Shores;Steve Skidmore;Dennis Smith;Phil Snow;Leighton Whitset;Norman Witt; | |||
|manuals= | |||
'''492/492P''' | |||
* [[Media:070-2729-00.pdf|Tektronix 492(P) Operators Handbook]] | |||
* [[Media:070-2726-02.pdf|Tektronix 492(P) Operator Manual -02]] (OCR) | |||
* [[Media:070-2726-03.pdf|Tektronix 492(P) Operator Manual -03]] (OCR) | |||
[[Category:Spectrum | * [[Media:070-2727-03.pdf|Tektronix 492(P) (SN B029999 & below) Service Volume 1]] | ||
* [[Media:070-3783-01.pdf|Tektronix 492(P) Service Manual – Volume 1]] | |||
* [[Media:070-3784-01.pdf|Tektronix 492(P) Service Manual – Volume 2]] | |||
* [[Media:070-3401-00.pdf|Tektronix 492P Programmers Manual]] (OCR) | |||
'''492A/492AP/492BP''' | |||
* [[Media:070-5562-01.pdf|Tektronix 492A(P) Operators Manual -01]] | |||
* [[Media:070-5562-00.pdf|Tektronix 492A(P) Operators Manual -00]] | |||
* [[Media:070-5566-01.pdf|Tektronix 492A(P) Service Manual Vol.2]] | |||
* [[Media:070-5564-01.pdf|Tektronix 492AP/492BP Programmers Manual]] | |||
'''Modifications''' | |||
* [[Media:050-1467-01.pdf|Product modification – Variable Resolution Module Replacement]] | |||
'''Specifications''' | |||
* [[Media:Tek_492_Catalog_Spec_1980.pdf|Tektronix 492 Introduction Spec]] (OCR) | |||
* [[Media:Tek_490-Series_Final Spec_1991.pdf| Tektronix 492 Final Spec]] (OCR) | |||
}} | |||
The '''Tektronix 492''' is a spectrum analyzer with a frequency range of 10 kHz to 21 GHz in coax, and up to 325 GHz with external waveguide mixers (492PGM N/A). The '''P''' suffix designation indicates GPIB '''P'''rogrammability. | |||
During the lifespan of the instrument, the specifications and included options were altered several times. A major upgrade was the introduction of the '''492A''' in 1987 which added marker functionality and resolution bandwidths and the '''492BP''' in 1989 which added a counter and increased the displayed dynamic range. The '''492PGM''' is a cost reduced version introduced in 1990. Also see [[49X Series Comparison]]. | |||
Regarding the 492, [[Linley Gumm]] says, | |||
<blockquote> | |||
Given how complicated it was, many people contributed to the design. I currently have a list of 20 people. | |||
The problem is that I’m sure that I am missing several people and I hate to submit a list without them. | |||
The 492 was designed at the request of the military. They asked for a modern replacement of the [[491]]. | |||
It was required that it provide coaxial input coverage of the lower microwave bands (~18 GHz), | |||
be very rugged, be a one person carry and fit through a submarine hatch. | |||
There was a lot more than that of course. | |||
When the 492 program started I was the project leader of the [[7L18]] and was still working to finish it off. | |||
The 7L18 was the first instrument at Tektronix to use a microprocessor. | |||
We had worked long and hard to learn how to electronically switch and control all the elements that were controlled by physical switch closures in the earlier instruments. | |||
Understand that to position the frequency of a YIG filter correctly with respect to the frequency of a YIG oscillator | |||
one must generate very quiet DC voltages accurate to roughly 1 part in 20,000 (i.e. 1 MHz in 18 GHz), so new control techniques were required. | |||
Plus the TEK-made YIG filter designed for the 7L18 was therefore ready for use in the 492. | |||
We had also learned quite a number of things not to do and this was also used to anchor the 492 program. | |||
I say this to note that most of the long lasting, “classic”, Tektronix products were often the second, but more often the third generation product by the same design group. | |||
The 492 was definitely a second generation product in its use of microwave components and a microprocessor based control system; | |||
perhaps a third if you lump the [[7L12]], [[7L13]] (microwave systems) and the [[7L5]] (electronic bus control system) together as a first generation. | |||
[[Larry Lockwood]] led the first part of the program. He defined the RF and microwave frequency conversion architecture of the 492. | |||
As the program progressed, [[Steve Morton]] became the project manager of the initial 492 program. | |||
Recognize that beyond that initial project, follow-on design work went on for years as new features were added. | |||
Further, after their initial design work in the initial portion of the project, designers often went on to do rather different subsystems in the follow-ons. | |||
I worked on the 492 as a circuit designer in the initial design and in several other roles later, none of which were leadership roles. | |||
The other people I can recall having worked on the 492 at some point in its life were: | |||
[[Robert Alm]], | |||
[[Bob Bales]], | |||
[[Carlos Beeck]], | |||
[[Bill Benedict]], | |||
[[Craig Bryant]], | |||
[[Russell Brown]], | |||
[[Wes Hayward]], | |||
[[David Leatherwood]], | |||
[[Gordon Long]], | |||
[[Dave Morton]], | |||
[[Bill Peterson]], | |||
[[David Shores]], | |||
[[Steve Skidmore]], | |||
[[Dennis Smith]], | |||
[[Phil Snow]], | |||
[[Leighton Whitset]], and | |||
[[Norman Witt]]. | |||
Be aware my spelling is often “inventive”. There are at least two other names I can’t bring to mind. | |||
</blockquote> | |||
{{BeginSpecs}} | |||
{{Spec | Frequency | | |||
* Coaxial Input Bands: 10 kHz to 21 GHz | |||
* External Waveguide mixers: 10 kHz to 325 GHz (applies to 492BP not 492PGM) }} | |||
{{Spec | Frequency Span | 492BP: 100 Hz/div to 10 GHz/div; 492PGM: 200 MHz to 1 GHz; both in 1, 2, 5 sequence; plus 0 Hz and MAX }} | |||
{{Spec | Resolution Bandwidth (-6 dB bandwidth) | 492BP: 100 Hz to 3 MHz; 492PGM: 1 kHz to 3 MHz; both in decade steps }} | |||
{{Spec | RF Input | 50 Ω, max. +30 dBm (1 W) CW; / 75 W peak pulse (1 µs, 0.1% duty factor) }} | |||
{{Spec | RF Attenuator | 0 dB to 60 dB, 10 dB steps }} | |||
{{Spec | Reference Level | -117 dBm to +30 dBm }} | |||
{{Spec | Sweep Speed | 10 sec/div to 20 µs/div, 1−2−5 }} | |||
{{Spec | Video Bandwidth | 492BP: 0.3 Hz to 30 kHz; 492PGM: 3 Hz to 30 kHz }} | |||
{{Spec | Memory | NVRAM for up to 9 waveform displays, up to 10 front panel setups, plus 8 K for programming macros | |||
}} | |||
{{Spec | Triggering Modes | Free Run, Line, Video, Single, External }} | |||
{{Spec | Displayed Average Noise | −30 dBm to −131 dBm }} | |||
{{Spec | Display Dynamic Range | 492BP: 90 dB; 492PGM: 80 dB }} | |||
{{Spec | Calibrator (Cal out) | 50 Ω, -20 dBm ±0.3 dB at 100 MHz }} | |||
{{Spec | Weight | 492BP: 21.8 kg (47 lbs) 492PGM: 21.3 kg (46 lbs) }} | |||
{{Spec | Power | 90 − 132 V<sub>AC</sub>, 48 to 440 Hz; 180 – 250 V<sub>AC</sub>, 48 to 440 Hz. At 115 V<sub>AC</sub>, 60 Hz, 210 W max }} | |||
{{EndSpecs}} | |||
==Options== | |||
* Opt. 01: Internal Preselection. (Limits the first band to 1.8 GHz instead 4.2 GHz). Later became standard | |||
* Opt. 02: Digital Storage. Later became standard | |||
* Opt. 03: Frequency Stabilization & 100 Hz Resolution. Later became standard | |||
* Opt. 07: 75 Ω dBmV input and calibration in addition to the normal 50 Ω dBm input and calibration. (Not combinable with Opt. 21 and 22; no external mixer capability). Include 42-inch 75 Ω BNC-BNC coax cable and BNC male to “F” female adapter. | |||
* Opt. 21: (492BP) High performance 18 to 40 GHz WM490 Series Waveguide Mixer Set | |||
* Opt. 22: (492BP) Same as Opt. 21 plus WM490U (40-60 GHz) Waveguide Mixer | |||
* Opt. 23: GRASP software, PC2A interface, and GPIB cable | |||
* Opt. 27: Epson LT-386SX, GRASP software, PC2A interface, and GPIB cable | |||
* Opt. 28: Compaq Deskpro 386S, Model 40, GRASP software, PC2A interface, and GPIB cable | |||
* Opt. 39: Non-lithium (Silver) batteries for battery-backed memory | |||
* Opt. 41: Digital Microwave Radio Measurement Enhancement package | |||
* Opt. 42: Replaces MARKER/VIDEO input port on the rear panel with a 110 MHz IF output port that provides a 3 dB signal bandwidth ≥ 4.5 MHz | |||
* Opt. 45: (all except 492PGM) MATE/CIIL language interface | |||
==Links== | |||
* [http://www.ko4bb.com/Test_Equipment/Tek7L18-492-494_compared.php Comparison of 492] with [[494]] and [[7L18]] | |||
* [http://www.ke5fx.com/49x_notes.pdf 49x Service notes @ John Miles KE5FX] | |||
* [http://www.ke5fx.com/gpib/readme.htm KE5FX GPIB toolkit] | |||
* [http://softsolder.com/2009/07/31/tektronix-492-spectrum-analyzer-backplane-pin-spacing/ ROM replacement] | |||
* [https://www.circuitben.net/node/4 Tek 492 DIY USB interface project] | |||
* [[016-0631-01|Waveguide Mixers for 492 and 7L18]] | |||
* [https://www.youtube.com/watch?v=tKC24SpHTSY YouTube: Tektronix 492 and 496 Portable Spectrum Analyzers] | |||
* [[067-1137-99|067-1137-99 GPIB to accessory controller]] | |||
{{Documents|Link=492}} | |||
==Connections== | |||
Front panel inputs/outputs are: | |||
* RF INPUT (50 Ω [[N connector]]) – Input for RF signals to 21 GHz. If input signal has a DC component, use a blocking capacitor | |||
* CAL OUT ([[BNC connector]]) – Provides 100 MHz, –20 dBm signal and a comb of frequency markers 100 MHz apart | |||
* 1ST LO OUTPUT ([[SMA connector]]) – Output of the 1st local oscillator, must be terminated into 50 Ω when not connected. | |||
* 2ND LO OUTPUT ([[SMA connector]]) – Output of the 2nd local oscillator, must be terminated into 50 Ω when not connected. | |||
* EXTERNAL MIXER RF INPUT ([[TNC connector]], 50 Ω) | |||
* Camera Power | |||
Rear panel inputs/outputs are: | |||
* PROBE POWER – Provides operating voltages (+5 V, -15 V, +15 V; 100 mA max each) for active probes | |||
* HORIZ/TRIG (input, [[BNC connector|BNC]]) – In External Triggering mode, AC coupled input for trigger signals; when TIME/DIV selection is EXT, DC coupled input for horizontal sweep voltages | |||
* MARKER/VIDEO (B053575+, output, [[BNC connector|BNC]]) – interfaces the 492/492P with a TV Sideband Adapter, such as the Tek [[1405]], so a marker from the adapter is displayed on the internal video. External video applied to this connector will also be displayed if pin 1 of the ACCESSORIES connector is grounded. | |||
** Opt. 42 replaces MARKER/VIDEO with 110 MHz IF (output, [[BNC connector|BNC]]) – 3 dB signal bandwidth ≥ 4.5 MHz | |||
* EXT PRESELECTOR (B053574 and below) (output, [[BNC connector|BNC]]) – variable voltage (approx -0.2 V to +10 V) proportional to center frequency, for preselector bands of Opt. 01 instruments, to drive an external preselector | |||
* HORIZ (output, [[BNC connector|BNC]]) – 0.5 V/div horizontal signal | |||
* VERT (output, [[BNC connector|BNC]]) – Video signal with 0.5 V/Div | |||
* PEN LIFT (output, [[BNC connector|BNC]]) – TTL compatible signal to lift the pen of a chart recorder during sweep retrace. In Opt. 42 instruments this port may also be used for inputting external video if pin 1 of the ACCESSORY connector is grounded. | |||
* 10 MHz IF (output, [[BNC connector|BNC]]) – Output of the 10 MHz IF | |||
* J104 ACCESSORY (B053575+ only), female [[DB25 connector]] – Provides bidirectional access to the instrument bus. | |||
* IEEE STD 488 PORT [[GPIB interface]] – Added to all "P" suffixed instruments | |||
==Pictures== | |||
===492=== | |||
<gallery> | |||
Tek 492 trace open.jpg | |||
Tek 492 top internal.jpg|Internal top view | |||
</gallery> | |||
===492A=== | |||
<gallery> | |||
Tek 492 3.jpg | |||
Tek 492 2.jpg | |||
Tek 492 4.jpg | |||
Tek 492 5.jpg | |||
Tek 492 6.jpg | |||
Tek 492 7.jpg | |||
Tek 492 8.jpg | |||
</gallery> | |||
===492BP=== | |||
<gallery> | |||
492BP_ebay_1.jpg | |||
492BP_ebay_2.jpg | |||
492BP_ebay_3.jpg | |||
492BP_ebay_4.jpg | |||
492BP_ebay_5.jpg | |||
</gallery> | |||
===492PGM=== | |||
<gallery> | |||
492PGM_front.jpg | |||
</gallery> | |||
[[Category:Spectrum analyzers]] | |||
[[Category:Manual needed]] |