Re: 1A5 with FET input

Dave Wise

For what it's worth, I compared the 1967 and 1969 cal procedures, and there's not enough difference to prove a major circuit change at 90000.
I don't know why they mentioned it.

Dave Wise

-----Original Message-----
From: [] On Behalf Of Albert Otten
Sent: Friday, September 27, 2019 8:59 AM
Subject: Re: [TekScopes] 1A5 with FET input

On Fri, Sep 27, 2019 at 05:22 PM, bobkrassa wrote:

I have a late model 1A5 sn B092783 that I am planning to use for the first
time, and wonder if it has FETs. It has the nuvistor sockets but no
nuvistors. Perhaps the long ago seller kept them. But the factory
calibration changed with sn 90,000, hence my question. Before i get out the
magnifying glass I thought I would ask-

Can anyone provide a copy of the input schematic for the FET version and/or a
picture of the main board for that? Or even post a late sn manual to Tekwiki?

Thanks and 73s

Bob Krassa ACØJL

Those schematics are in tek-1a5.pdf and it seems that the 1a5 always had the fet input. There are 2 7586 nuvistors in the output stage, V164/264.


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