Topics

7A18 option1?

Dave Seiter
 

If my poor brain recalls correctly, the 7A18 option 1 is the same as 7A18N, except that the "N" version does not have trace ID, while the option 1 does, does that sound correct?  I have both as projects with missing parts, and I'm wondering if I should just focus on the option 1 unit. (they are almost identical; the only differences I can see are the pot assemblies and two resistors)
-Dave

Albert Otten
 

That seems to be correct. Option 1 is mentioned in the 1971 catalog and deletes only the readout. 7A18N in 1973 catalog which explicitly states that Identify is only operative in the 7A18.

Albert

On Thu, Sep 12, 2019 at 08:38 AM, Dave Seiter wrote:


If my poor brain recalls correctly, the 7A18 option 1 is the same as 7A18N,
except that the "N" version does not have trace ID, while the option 1 does,
does that sound correct?  I have both as projects with missing parts, and I'm
wondering if I should just focus on the option 1 unit. (they are almost
identical; the only differences I can see are the pot assemblies and two
resistors)
-Dave

Ed Breya
 

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.

Ed

Dave Daniel
 

According to the 1971 Tektronix catalog, Option 1 removes readout capability. The option listing in the catalog cites the 070-1126-00 manual. I have the -01 manual which is for the 7A18 and 7A18N. I'm guessing, as someone else previously posted, that Option 1 pre-dated and was replaced by the N version.

DaveD

On 9/12/2019 11:53 AM, Ed Breya via Groups.Io wrote:
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.

Ed

Dave Casey
 

You're thinking of Option 06.

Dave Casey

On Thu, Sep 12, 2019 at 10:53 AM Ed Breya via Groups.Io <edbreya=
yahoo.com@groups.io> wrote:

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.

Ed



David DiGiacomo
 

DC offset was option 06, not option 01.

On Thu, Sep 12, 2019 at 9:53 AM Ed Breya via Groups.Io
<edbreya=yahoo.com@groups.io> wrote:
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.

 

I have one of these 7A18 with the offset pot in place of the trace identify button. But mine has an "option 6" label on the top. It also has an additional position on the input switch. Instead of the usual "AC GND DC" it also has a "DC Offset" position added to the usual switch positions. The offset pot is 10 turns and indeed offsets a DC component of the input signal so that you can bring the trace back on screen when it has a DC offset, but you don't want to use the "AC" position and limit the low frequency response, much like the 7A13 or the 7A22 does. However it doesn't have a way to measure the offset or is it calibrated.
Bill

Colin Herbert
 

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.

Colin.

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Ed Breya via Groups.Io
Sent: 12 September 2019 16:53
To: TekScopes@groups.io
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.

Ed

 

Hi Ed,
Option 6 added the very useful Offset capability to the plugin.
Dennis Tillman W7PF

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Ed Breya via Groups.Io
Sent: Thursday, September 12, 2019 8:53 AM

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.

Ed




--
Dennis Tillman W7PF
TekScopes Moderator

Gudjon Gudjonsson
 

Hi list

On Thu, Sep 12, 2019 at 8:13 PM Dennis Tillman W7PF <@Dennis_Tillman_W7PF> wrote:
Option 6 added the very useful Offset capability to the plugin.
Dennis Tillman W7PF
Dennis. Can you please explain a bit more for what measurements this
feature is useful?
How does it compare with the 7a13 plugin?
(Sorry if I am hijacking the thread)

Regards
Gudjon

EB4APL
 

I have a 7A18 with option 1 and the front panel is identical to any other 7A18. In the options sticker it has _"OPTION 1_ without readout" checked.

Inside, on the right side it lacks the 2 PCBs with the readout circuitry and there are shields over this side of the input attenuators.

The Identify buttons are present and operative, it displaces the trace up, but not "IDENTIFY" message is shown due to the lack of readout circuitry.

If anybody is interested in pictures, I can take some and post them in the photos section.

Best regards,

Ignacio Cembreros, EB4APL


El 12/09/2019 a las 20:13, Dennis Tillman W7PF escribió:
Hi Ed,
Option 6 added the very useful Offset capability to the plugin.
Dennis Tillman W7PF

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Ed Breya via Groups.Io
Sent: Thursday, September 12, 2019 8:53 AM

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.

Ed

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Dave Seiter
 

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.
-Dave

On Thursday, September 12, 2019, 09:32:29 AM PDT, Colin Herbert via Groups.Io <colingherbert=blueyonder.co.uk@groups.io> 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.

Colin.

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Ed Breya via Groups.Io
Sent: 12 September 2019 16:53
To: TekScopes@groups.io
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.

Ed