Re: 7A18 option1?
I have both models- both look identical to the 7A18, except that the 7A18N has plain position knobs without the central push-to-ID buttons, and the pull tab has the "N" on it.toggle quoted messageShow quoted text
On Thursday, September 12, 2019, 09:32:29 AM PDT, Colin Herbert via Groups.Io <email@example.com> wrote:
I have two 7A18, a 7A18A and a 7A18(Option 6). I don't have a 7A18N (and wouldn't really want one). As far as I am aware 7A18 and 7A18A are significantly different in their circuitry and even have different Service Manuals. The "N" designation indicates that there is no readout including the "Identify" function. Since I have never seen a 7A18N, I don't know what the situation regarding the "Position" and "Identify" controls might be.
Neither of my Service Manuals list an Option 1, neither does TekWiki. The entry in Tekwiki shows a main photograph of a 7A18A, but labels it as a 7A18. It also states that the 7A26 and 7A24 share the same front panel as the 7A18, which isn't totally correct, as the 7A26 has a second slide-switch to change the bandwidth between "FULL" and "20MHz" and the 7A24 labels the inputs as 50 Ohm and the "VOLTS/DIV" switches have reduced ranges (8 positions from 1VOLT/DIV to 5mV/DIV, where the other plugins have 10 positions from 5VOLT/DIV to 5mV DIV).
Option 6 is the offset function, which replaces the "Identify" buttons with ten-turn pots and adds a fourth position for the "AC/GND/DC" switch, i.e. "DC OFFSET".
Perhaps if someone has a 7A18N, or a 7A18 (Option 1) and could post some photographs, it might be informative.
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Ed Breya via Groups.Io
Sent: 12 September 2019 16:53
Subject: Re: [TekScopes] 7A18 option1?
I believe this "option 1" may be to replace the standard trace position pot with an offset function, kind of like in the 7A13, but only over a limited range. I vaguely recall that I have one of these, but didn't know it was different until I started using it - the trace positioning acted differently, and advantageously for some applications. I haven't seen it in a while, but I think each channel has dual concentric pots, instead of the single pot and "ID" button.