Topics

311-1404-00 concentric potentiometer for (R)7603: Intensity and Readout control

Gregor Lasser
 

Hi,

I am currently restoring an R7603 that had a badly bent intensity/readout
potentiometer. With lots of careful bending I was able to get the
potentiometer back to work to the point where I could rotate the beam
intensity control more or less independently of the readout intensity, but
at this point the inner readout intensity axis of the potentiometer became
loose. My attempts to fix this by reshaping the "head" of the axis were not
successful. Otherwise the scope seems to be in good shape, I fixed a few
minor things and coarse alignment of the vertical amplifier brought the beam
and readout back to the center of the screen.

Does anyone have a spare 311-1404-00 concentric potentiometer/switch
assembly for (R)7603, or has a parts 7603 front panel they are willing to
sell? I looked up the typical soureces but they seem to be sold out on that
part.

Greetings,
Gregor

Colin Herbert
 

Hi Gregor,
I have a 311-1430-00 pull which is a dual concentric 5k/50k. I haven't
checked it yet. I guess it's the wrong values, but who knows. I am in
London, UK, so it would be a small task to post it within the UK. Postage to
the US might be a little trickier, but if it isn't anything like you want,
then that doesn't matter.
Colin.

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Gregor
Lasser
Sent: 08 March 2020 18:23
To: TekScopes@groups.io
Subject: [TekScopes] 311-1404-00 concentric potentiometer for (R)7603:
Intensity and Readout control

Hi,

I am currently restoring an R7603 that had a badly bent intensity/readout
potentiometer. With lots of careful bending I was able to get the
potentiometer back to work to the point where I could rotate the beam
intensity control more or less independently of the readout intensity, but
at this point the inner readout intensity axis of the potentiometer became
loose. My attempts to fix this by reshaping the "head" of the axis were not
successful. Otherwise the scope seems to be in good shape, I fixed a few
minor things and coarse alignment of the vertical amplifier brought the beam
and readout back to the center of the screen.

Does anyone have a spare 311-1404-00 concentric potentiometer/switch
assembly for (R)7603, or has a parts 7603 front panel they are willing to
sell? I looked up the typical soureces but they seem to be sold out on that
part.

Greetings,
Gregor

Gudjon Gudjonsson
 

Hi Gregor

I have the same problem with my 7603 and I just replaced it with a
resistor and I
don't see any downside of a constant intensity readout. I may have missed
something important :)

Regards
Gudjon

Gregor Lasser
 

Hi Colin,
Thanks for your fast reply! The original one is 5k/5k with a build in
switch. I will measure all dimensions tonight to see what I actually need.

Greetings,
Gregor

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Colin
Herbert via Groups.Io
Sent: Sunday, March 08, 2020 1:19 PM
To: TekScopes@groups.io
Subject: Re: [TekScopes] 311-1404-00 concentric potentiometer for (R)7603:
Intensity and Readout control

Hi Gregor,
I have a 311-1430-00 pull which is a dual concentric 5k/50k. I haven't
checked it yet. I guess it's the wrong values, but who knows. I am in
London, UK, so it would be a small task to post it within the UK. Postage to
the US might be a little trickier, but if it isn't anything like you want,
then that doesn't matter.
Colin.

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Gregor
Lasser
Sent: 08 March 2020 18:23
To: TekScopes@groups.io
Subject: [TekScopes] 311-1404-00 concentric potentiometer for (R)7603:
Intensity and Readout control

Hi,

I am currently restoring an R7603 that had a badly bent intensity/readout
potentiometer. With lots of careful bending I was able to get the
potentiometer back to work to the point where I could rotate the beam
intensity control more or less independently of the readout intensity, but
at this point the inner readout intensity axis of the potentiometer became
loose. My attempts to fix this by reshaping the "head" of the axis were not
successful. Otherwise the scope seems to be in good shape, I fixed a few
minor things and coarse alignment of the vertical amplifier brought the beam
and readout back to the center of the screen.

Does anyone have a spare 311-1404-00 concentric potentiometer/switch
assembly for (R)7603, or has a parts 7603 front panel they are willing to
sell? I looked up the typical soureces but they seem to be sold out on that
part.

Greetings,
Gregor

Gregor Lasser
 

Hi Gudjon,

Sure, that is better than no readout, and practically what I have now (I managed to fiddle with the broken off center piece to get the inner potentiometer for the readout adjusted for an ok value.

I just like to be able to turn down the intensity of readout and beam when I have the scope running for longer time as a measure to preserve the CRT.

Greetings,
Gregor

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Gudjon Gudjonsson
Sent: Sunday, March 08, 2020 1:28 PM
To: TekScopes <TekScopes@groups.io>
Subject: Re: [TekScopes] 311-1404-00 concentric potentiometer for (R)7603: Intensity and Readout control

Hi Gregor

I have the same problem with my 7603 and I just replaced it with a resistor and I don't see any downside of a constant intensity readout. I may have missed something important :)

Regards
Gudjon

John Brown
 

Bad news come in pairs, threes, something.

Just did my search on the 311-1404-00 and this thread was second hit!! I'm in need of the same item for a 7613.

Anybody find one laying around looking lonely?

John