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Old 21st Jul 2021, 12:07 am   #1
jamesinnewcastl
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Default Tek 7L12 Spectrum Analyser Manual Wanted - Later Version

Hi All

I've landed a Tek 7L12 Spectrum Analyser for 150 which seems to be working!

I've down loaded a manual but it is for the earlier version without the L.O. outputs (but not the one with the newer knob sadly).

Anyone have a file of, or hardcopy of the later manual please?

Cheers
James
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Old 21st Jul 2021, 9:49 am   #2
chriswood1900
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Default Re: Tek 7L12 Spectrum Analyser Manual Wanted - Later Version

Hi James
Have you seen the info on the Tek Wiki site here https://w140.com/tekwiki/wiki/7L12
it may be useful.
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Old 21st Jul 2021, 10:02 am   #3
Craig Sawyers
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Default Re: Tek 7L12 Spectrum Analyser Manual Wanted - Later Version

150 for a working 7L12 is a good price. I built mine from two parts units - there was enough parts between them to complete one functional unit.

They had been pulled from a skip, including a 7000 series mainframe that has been hit so hard that one of the side panels had a massive tear in it. Even after that sort of abuse it worked perfectly!

Yes - indeed the Tekwiki site is the go-to place for Tektronix manuals.

Craig
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Old 21st Jul 2021, 10:45 am   #4
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Default Re: Tek 7L12 Spectrum Analyser Manual Wanted - Later Version

Hi Chaps

I have already drained the Wiki site dry - the manuals there are the older ones.

I doubt there is too much difference but I noticed oddities in the set-up text possibly related to the slight differences in old and new. I am hoping the newer one will be more relevant.

The 7L12 is an amazing mess of plumbing and mysterious boxes, I was assuming something wrong with it and not looking forward to tracking any issues down. But until I get it set up I still can't be sure it is really OK.

I have an old Marconi SA which I used to make the Avatar next to my posts - I can't seem to get the same sort of 'text-Book' images from the 7L12 so I'll have to keep playing.

Cheers
James
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Old 21st Jul 2021, 11:49 am   #5
chriswood1900
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Default Re: Tek 7L12 Spectrum Analyser Manual Wanted - Later Version

According to the Vintage Tek site Tantalums are the biggest problem (aren't they always!).
This link may help https://www.youtube.com/watch?v=f02rCpkjs8Q
It also shown what you getting on a working display.
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Old 22nd Jul 2021, 10:30 am   #6
jamesinnewcastl
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Default Re: Tek 7L12 Spectrum Analyser Manual Wanted - Later Version

Hi

I'm still after the later manual. With regard to waveforms that might be displayed I found this:

https://w140.com/tekwiki/images/9/9f...1_Jan_1972.pdf

Cheers
James
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Old 26th Jul 2021, 9:13 pm   #7
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Default Re: Tek 7L12 Spectrum Analyser Manual Wanted - Later Version

Hi!

Could you post photos of front and back of your unit please?

Chris Williams

PS!

There has to be an amendment or supplement somewhere – I find it very surprising Tek would do a major change like the addition of L.O. outputs, without writing something on the subject somewhere!

I can find copies of book 070–1298-00 in both B/W and colour that cover the first version, but so far, altho' I have seen 7L12s for sale on the past, never any bookworks yet!
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Last edited by Chris55000; 26th Jul 2021 at 9:33 pm.
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Old 26th Jul 2021, 10:11 pm   #8
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Default Re: Tek 7L12 Spectrum Analyser Manual Wanted - Later Version

PS!

There is a later book in existence, but not available for free download – even Tek groups.io don't seem to have it – the book you want is 070-1298–02!

According to the w140 Wiki, Tek released the modification to production and offered it to buyers for 400 USD, sending the unit to their Beaverton office to have the work done, and the bookwork covering it didn't appear till 1987!

Chris Williams
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Old 27th Jul 2021, 12:11 pm   #9
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Default Re: Tek 7L12 Spectrum Analyser Manual Wanted - Later Version

I have a 7L12, early version without the LO outputs, and have been intending to add LO outputs for years. The information about the outputs is definitely present in the scanned manual I have, which came from Artek Media. It's well worth paying them the money for a copy. They do a great job.

The manual says Part No. 070-1298-02, first printing JUL 1972, revised MAR 1986.

The internal connectors for the LO outputs are there in my early 7L12, so adding them to the front panel shouldn't be too hard. Though squeezing the necessary adapters in is a real fiddle. There's some odd jiggery-pokery with an isolator too, if I remember correctly.

Chris
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Old 27th Jul 2021, 2:23 pm   #10
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Default Re: Tek 7L12 Spectrum Analyser Manual Wanted - Later Version

If you are going to use the TR501 or TR502 tracking generator, you need front panel LO outputs on the 7L12.

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