7L18: Difference between revisions
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{{Plugin Sidebar| | |||
The Tektronix 7L18 is a spectrum analyzer plug-in [[introduced in 1978]] for [[7000-series scopes]]. | title=Tektronix 7L19| | ||
It occupies three plug-in bays in the oscilloscope. | summary=18 (60) GHz Spectrum Analyzer| | ||
image=7L18-front.jpg| | |||
caption=Tektronix 7L18| | |||
years=?| | |||
type=combined horizontal/vertical plugin| | |||
series=[[7000-series scopes]]| | |||
manuals= | |||
[[List of manuals that are needed|Manual needed]] (with schematics). | |||
[[Category:Manual needed]] | |||
}} | |||
The '''Tektronix 7L18''' is a spectrum analyzer plug-in [[introduced in 1978]] for [[7000-series scopes]]. It occupies three plug-in bays in the oscilloscope. | |||
The 7L18 covers the range from 1.5 GHz to 18 GHz with the internal mixer and 12.5 GHz to 60 GHz | |||
using external mixers. | using external mixers. | ||
Note that it will NOT do 1. | Note that it will NOT do 1.5 GHz to 18 GHz in one span, it will only max span | ||
the range selected by the BAND/HARMONIC control. | the range selected by the BAND/HARMONIC control. | ||
This range is determined by the | This range is determined by the heterodyne harmonic number and sign (sideband) and | ||
the range of the first LO, which is | the range of the first LO, which is 2 GHz to 4 GHz. | ||
The input attenuator range is | The input attenuator range is 0 dB to 60 dB in 10 dB steps and is a standard Weinschel Engineering | ||
product driven by a belt. The range is encoded for the digital dBm reference level display. | product driven by a belt. The range is encoded for the digital dBm reference level display. | ||
The signal then passes through a YIG preselector filter with a | The signal then passes through a YIG preselector filter with a 50 MHz bandwidth. | ||
After the YIG filter, the signal enters the RF input of the mixer assembly. | After the YIG filter, the signal enters the RF input of the mixer assembly. | ||
The LO is a YIG tuned oscillator covering the 2 GHz to 4 GHz range. | The LO is a YIG tuned oscillator covering the 2 GHz to 4 GHz range. Its output passes | ||
through a sampler assembly used to PLL the YIG on small resolution bandwidths. | through a sampler assembly used to PLL the YIG on small resolution bandwidths. | ||
The output of the sampler goes to the LO input on the mixer. The mixer IF output | The output of the sampler goes to the LO input on the mixer. The mixer IF output | ||
is | is 510 MHz. | ||
==Pictures== | |||
Service views: | Service views: | ||
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Image:7L18-service-rightfront.jpg|Service setup for the right front panel | Image:7L18-service-rightfront.jpg|Service setup for the right front panel | ||
</gallery> | </gallery> | ||
Boards within the digital card cage (from back to front): | Boards within the digital card cage (from back to front): | ||
Line 46: | Line 56: | ||
</gallery> | </gallery> | ||
The | The microcomputer board is built using three very old Intel chips: an Intel 4004 processor, | ||
an Intel 4002 320 bit RAM and 4 bit output port, and an Intel D4289 standard memory | an Intel 4002 320-bit RAM and 4-bit output port, and an Intel D4289 standard memory | ||
interface. The D4289 connects the 4004 to the two | interface. The D4289 connects the 4004 to the two 2K8 ROMs. Note that in an earlier | ||
version of the 7L18 there were 6 ROMs. | version of the 7L18 there were 6 ROMs. | ||
Revision as of 07:47, 4 June 2014
The Tektronix 7L18 is a spectrum analyzer plug-in introduced in 1978 for 7000-series scopes. It occupies three plug-in bays in the oscilloscope.
The 7L18 covers the range from 1.5 GHz to 18 GHz with the internal mixer and 12.5 GHz to 60 GHz using external mixers. Note that it will NOT do 1.5 GHz to 18 GHz in one span, it will only max span the range selected by the BAND/HARMONIC control. This range is determined by the heterodyne harmonic number and sign (sideband) and the range of the first LO, which is 2 GHz to 4 GHz.
The input attenuator range is 0 dB to 60 dB in 10 dB steps and is a standard Weinschel Engineering product driven by a belt. The range is encoded for the digital dBm reference level display. The signal then passes through a YIG preselector filter with a 50 MHz bandwidth. After the YIG filter, the signal enters the RF input of the mixer assembly.
The LO is a YIG tuned oscillator covering the 2 GHz to 4 GHz range. Its output passes through a sampler assembly used to PLL the YIG on small resolution bandwidths. The output of the sampler goes to the LO input on the mixer. The mixer IF output is 510 MHz.
Pictures
Service views:
-
Top view
-
Bottom view
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Service setup for the right front panel
Boards within the digital card cage (from back to front):
-
CRT Readout board
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Center Freq Readout board
-
Sweep Horiz board
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Span Atten board
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Phase Lock module, rear
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Phase Lock module, front
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Phase Lock Logic CTL
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VR Noise Filter
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Log & Video Amp
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Center Freq DVM
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Digital Storage, front
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Digital Storage, back
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Micro Computer
The microcomputer board is built using three very old Intel chips: an Intel 4004 processor, an Intel 4002 320-bit RAM and 4-bit output port, and an Intel D4289 standard memory interface. The D4289 connects the 4004 to the two 2K8 ROMs. Note that in an earlier version of the 7L18 there were 6 ROMs.
Internal views of the analog parts:
-
Internal of the LO sampler