Re: WTB 7A18A pop-out shaft coupling

Colin Herbert

I have both paper and pdf Service Manuals, the paper one being original.
Both have the part number as 111. The paper manual was revised April 1984,
but the exploded mechanical diagram shows revision Sept 1983. The pdf
version manual was revised March 1985, but its exploded mechanical diagram
also shows revision Sept 1983. Not only was the change over a short
time-frame, since your manual is dated earlier than either of mine it seems
odd that your part number should be larger.

I have come to believe that Tektronix Manuals are, by and large, the "Holy
Grail", but it seems that changes were made and only documented as
revisions. I had a similar oddity with my 4623A mainframe, which I can't get
a fully complying Manual for. Caveat Emptor, I suppose.


From: TekScopes@... [mailto:TekScopes@...]
Sent: 27 January 2016 22:35
To: TekScopes@...
Subject: RE: [TekScopes] WTB 7A18A pop-out shaft coupling

It is Item 113 in the 4329 manual revision March 1983, which is the Artek
scan I have. Weird that they would have changed it at all in that short

Dave Casey

On Wed, January 27, 2016 1:23 pm, 'Colin Herbert'
colingherbert@... [TekScopes] wrote:
I think he has the right part and part-number, according to my Service
Manual. Perhaps your manual differs; my manual has the P/N 070-4329-00. I
have one of these plug-ins, but regrettably no spares.


From: TekScopes@... [mailto:TekScopes@...]
Sent: 27 January 2016 06:51
To: TekScopes@...
Subject: Re: [TekScopes] WTB 7A18A pop-out shaft coupling

I believe you mean Item 113 on Figure 1. Item 111 is an electrical

Dave Casey

On Tue, January 26, 2016 11:43 pm, test2cal@... [TekScopes] wrote:

I need one 7A18A shaft coupling (the one that gives the variable
volts/div knob its pop-out operation). It is Item 111 on Figure 1 of the
7A18A manual, Tek PN 214-1190-02, manufactured by Tektronix (vendor
code 80009). Can anyone help?

The old one seized and had to be cut up for removal, because the
setscrews were inaccessible. This coupling is used in several 7K
amplifier and timebase plug-ins. It is found in the 7A18A, but NOT in
the 7A18, which has a different mechanism for the same function. I'm
hoping to avoid using another plug-in as a parts mule.

QService has the part, but it is costly with the shipping. There's
nothing on Ebay.

Thanks in advance for any help.
Cliff Carrie

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