7L18: Difference between revisions

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image=7L18-front.jpg|
image=7L18-front.jpg|
caption=Tektronix 7L18|
caption=Tektronix 7L18|
years=?|
years=1978 - ? |
type=combined horizontal/vertical plugin|
type=combined horizontal/vertical plugin|
series=[[7000-series scopes]]|
series=[[7000-series scopes]]|
Line 70: Line 70:
[[Category:Spectrum Analyzers]]
[[Category:Spectrum Analyzers]]
[[Category:Specifications needed]]
[[Category:Specifications needed]]
[[Category:Introduced in 1978]]

Revision as of 14:45, 16 August 2014

{{{manufacturer}}} combined horizontal/vertical plugin
18 (60) GHz Spectrum Analyzer
Tektronix 7L18

Compatible with [[7000-series scopes]]

Produced from {{{introduced}}} to {{{discontinued}}}

Manuals

Manual needed (with schematics).

(All manuals in PDF format unless noted otherwise)
[[Category:Introduced in {{{introduced}}}]]
Manuals – Specifications – Links – Pictures

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:

Boards within the digital card cage (from back to front):

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: