Date   

Re: Plug for 7CT1N captive lead?

Lawrance A. Schneider
 

Thank you, larry

On Aug 25, 2019, at 3:16 PM, Dave Seiter <d.seiter@att.net> wrote:

Gaffer tape (or Gaff tape) is used in studios, sets and theaters for EVERYTHING. It's like duct tape, but holds better, tears better, feels better, etc, and tends not to leave a mess behind if you leave on too long. It can also be really pricey.
-Dave


On Sunday, August 25, 2019, 05:45:02 AM PDT, Lawrance A. Schneider <llaassllaaass@gmail.com> wrote:

Hi,

I’d never heard of ‘gaffer tape”. Why not just plane plastic electrical tape?


Larry

On Aug 25, 2019, at 5:37 AM, EJP <esmond.pitt@bigpond.com> wrote:

When I went to put on a standard soldered BNC plug I found there is no shielding in the cable, only a pretty thick set of strands for the inner conductor, so I was unable to even fix the outer cover on. So I settled for just the pin. I'm not happy with it, as it is uninsulated: gaffer tape awaits, but also a better solution, if there is one.

EJP







Re: 11801C and the T1331 error: lost factory TB calibration data.

Leo Bodnar
 

On Sun, Aug 25, 2019 at 12:48 AM, Reginald Beardsley wrote:
All I need now is an SD-32 at a sensible price.
What are you going to use it for?
I have two SD-30 that I use interchangeably that I have bought broken and fixed: one had blown termination resistors, another - faulty trigger pick-off hardline.
I don't trust *any* SD heads, even sold as guaranteed working. My approach with them: if it works - it's a bonus.
SD series had really bad manufacturing quality track record. From delaminating PCB gold plating to cracked solder to tin whiskers to missing bond wires to dying EEPROMs.
I reckon S-series will still be alive and kicking while SD-series will perish in time.
Cheers
Leo


Re: Plug for 7CT1N captive lead?

Dave Seiter
 

Gaffer tape (or Gaff tape) is used in studios, sets and theaters for EVERYTHING.  It's like duct tape, but holds better, tears better, feels better, etc, and tends not to leave a mess behind if you leave on too long.  It can also be really pricey.
-Dave

On Sunday, August 25, 2019, 05:45:02 AM PDT, Lawrance A. Schneider <llaassllaaass@gmail.com> wrote:

Hi,

I’d never heard of ‘gaffer tape”.  Why not just plane plastic electrical tape?


Larry

On Aug 25, 2019, at 5:37 AM, EJP <esmond.pitt@bigpond.com> wrote:

When I went to put on a standard soldered BNC plug I found there is no shielding in the cable, only a pretty thick set of strands for the inner conductor, so I was unable to even fix the outer cover on. So I settled for just the pin. I'm not happy with it, as it is uninsulated: gaffer tape awaits, but also a better solution, if there is one.

EJP



Re: Plug for 7CT1N captive lead?

magnustoelle
 

I have used some ordinary RG218 cable and BNC connector & left the shield unconnected on my 5CT1N. Works like a charm.
Cheers,
Magnus 

Maybe it can be seen from here:

https://lh3.googleusercontent.com/R75LyC-LMnwITr_Peqe63xXJ0AMuTkHCZ9Fmty0nHfLueZ5UShWwG662Loz0ywbX-JExDtO4VGHnT4pnw9bqz3irY2hjHZn0xLvG_tQzXp3r646Q-YYocGyrg2b-gz0D_P-i2lJIT6S6RxWq6wLmNAeebo9iUdFHLwIWAPIclRe_LKlYq81PUOn3iEYL3pi2aLXVhVKkJHg6ujGHlcjJeQCBcYrSuRhESy_wtPTadVxWtsiOfcThKFizX_S6XR1sxShzTr4mPJXgrtkjFVwmTSom575hoazShwWGJdOkg7llKCSYaRaCdWAXp93IBygo6QSoNXC0iF2iC6PA5HcrJC84iyYP0lP5S6cCZE9-uTnbffJAEWhZRyPx9xyW5kUOnAcc8EPstXfqYX0tuJXFf_1Ip1yDWEEcRBR06ryc30Yy8zEqnJdvwKx4SJoZ2tMzzCnhoe_lmeSwiUc4RbCuhOpqoQb2UAmiRIDkKd3lS1uUa0LoY4B333L-LOyWqdf2O8aeFG-c2I2kKCBuSZbcntsJ26R8swYPRXTP4v8GLq6h93JDdScTMdAlx3WGDk61gJsK0vs_bBvMPYjGDcObkwsXcsrxTo5pbC502wWVi5h7F7v4w7UKEMOQ7c6l8ooioYf3Wow3RPqX0FvCwjvh1oFd7glsocs=w1308-h982-no

Regards,

Ignacio EB4APL



El 25/08/2019 a las 19:14, EB4APL escribió:
I'm sorry, I forgot that attachments are not allowed. I will upload it
somewhere and I'll send the link.



El 25/08/2019 a las 19:11, EB4APL via Groups.Io escribió:
Could this be used? It is with me more than 40 years, probably it was
manufactured by Pomona.

Ignacio EB4APL



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---
El software de antivirus Avast ha analizado este correo electrónico en busca de virus.
https://www.avast.com/antivirus


Re: Tek 576 Curve Tracer HV Transformer winding

Miguel Work
 

Hi Peter,

Mine moves exactly one division too

Vert Offset Horiz Pol Max Peak Series Resistor
Left/Right
0.5mA 0 50v +NPN 1500v 3k (220W) off (no
component)
Turn the variable collector supply so the trace reaches to 10 div. What happens to the left end of the trace? Mine moves over 1 div.


-----Mensaje original-----
De: TekScopes@groups.io [mailto:TekScopes@groups.io] En nombre de peter bunge
Enviado el: domingo, 25 de agosto de 2019 18:34
Para: TekScopes@groups.io
Asunto: Re: [TekScopes] Tek 576 Curve Tracer HV Transformer winding

This may be of interest to the Tek Group so I am going on line again.
I got my 576 working again.
It was one of the push-on connectors on the top left board. I have had trouble with those long ago on a 465 scope. I just ran an insulated rod along them until the trace re-appeared. I will have to go around the entire curve tracer with a pair of plyers and pull off and push on each one. It solves many problems.
I would appreciate you doing a couple of tests:
Vert Offset Horiz Pol Max Peak Series Resistor
Left/Right
0.5mA 0 50v +NPN 1500v 3k (220W) off (no
component)
Turn the variable collector supply so the trace reaches to 10 div. What happens to the left end of the trace? Mine moves over 1 div.
Reset to the following with a 2N3565 (high gain NPN)
2uA 0 0.1v +NPN 10v 30 ohm Step Gen,
0.05 uA, Zero, Steps, Rep Norm, 3 steps
turn the collector to full scale as shown (1 volt). The first trace is not really dim, it is the camera.
Do you see a similar set of curves. I am most interested in the looping.
[image: 2N3565.jpg]

On Sat, Aug 24, 2019 at 3:11 PM Miguel Work <harrimansat@hotmail.com> wrote:

I have two 576, if you told me which test you need to compare, I will
do it with mine. Do you know ferrite core specs? Could be changed some
transformer HV turns for a voltage multiplier?



FERRITE CORE E 20 N27
Core Type : E
Core Size : E20/10/6
Core Material Grade : N27
For Use With : -
Effective Magnetic Path Length : 46.3mm Ae Effective Cross Section
Area : 32.1mm² Inductance Factor Al : 1.3µH Product Range : B66311
Series SVHC : No SVHC (15-Jun-2015) Accessory Type : Ferrite Core
Material Grade : N27 -----Mensaje original-----
De: TekScopes@groups.io [mailto:TekScopes@groups.io] En nombre de
peter bunge Enviado el: sábado, 24 de agosto de 2019 16:08
Para: TekScopes@groups.io
Asunto: Re: [TekScopes] Tek 576 Curve Tracer HV Transformer winding

Thanks David for your generous offer;
Where do they get the cores to make a compatible transformer that
works in the 576 circuit. This is not a 115v 60 Hz transformer.
A friend suggested a plate transformer and doublers or triplers. 225v
is also needed.
I have been looking at using a 4 kV and 225 V switching power supplies
from China and I have used some for other projects. They tend to be
noisy but can be cleaned up.
Since my 576 is still working there is no great urgency.
I also want to look at my friend's 577 and compare it to my 576. His
is smaller and lighter but may not do as much.
My 576 does weird things at lower currents (all loops) and PNP do not
seem to work the same as NPN (lack of steps) so the transformer is not
the only issue. I spent a couple of days working on it a few years ago
but could not improve it.
I need to find someone with a 576 and compare traces to see if mine is
"normal".
I need the 1500v capability which rules out some of the newer ones
which are also more expensive.
I will think about your offer.
Peter

On Fri, Aug 23, 2019 at 4:28 PM drawding@pacbell.net
<drawding@pacbell.net
wrote:

Yes. David Rawding is still here.

: )

I bought five professionally made transformers. One was donated to
Bob for his kind help. Two were used by me. Two were sold. I am
all
out.

Another run is ~ $1k for 5 more. Five is the minimum order. A bit
pricey, I know. However, they are made by a professional
transformer company. Fully enclosed and potted in silicone. If you
consider what technical wages are today and overhead and materials,
I would say it is fair pricing. However, at the hobby level, it is pricey.

If we can find five buyers (though this seems unlikely), I will
handle the details, and will sell at my cost + shipping.

Also, as you can see from this thread several people have been
successful winding their own.

One gentleman came here a year or so ago, asked a bunch of
questions, got great support from the group, ended up successfully
winding his own, and left. He was asked to put some details
together (pictures, documentation, video, etc), but apparently could not be bothered.

I hope you find a solution.

Thanks,
Dave









Re: Plug for 7CT1N captive lead?

Cliff Carrie
 

The low 100 mV / division vertical sensitivity, a very low operating frequency and the shortness of the lead are the reasons why Tek did not shield this connection.
Anything that completes the circuit to the center pin is sufficient. I suggest soldering or crimping a pin on the end of the lead, followed by several layers of gradually larger shrink tubing to provide a handle and stop the lead from falling inside the 7CT1N when retracted. A rigid plastic probe handle cut short and epoxy (JB Weld?) might also work. At a maximum voltage of 0.8 volts, there should be no safety issues.

Regards, Cliff Carrie
________________________________
From: TekScopes@groups.io <TekScopes@groups.io> on behalf of EB4APL <eb4apl@gmail.com>
Sent: Sunday, August 25, 2019 1:16 PM
To: TekScopes@groups.io <TekScopes@groups.io>
Subject: Re: [TekScopes] Plug for 7CT1N captive lead?

Maybe it can be seen from here:

https://lh3.googleusercontent.com/R75LyC-LMnwITr_Peqe63xXJ0AMuTkHCZ9Fmty0nHfLueZ5UShWwG662Loz0ywbX-JExDtO4VGHnT4pnw9bqz3irY2hjHZn0xLvG_tQzXp3r646Q-YYocGyrg2b-gz0D_P-i2lJIT6S6RxWq6wLmNAeebo9iUdFHLwIWAPIclRe_LKlYq81PUOn3iEYL3pi2aLXVhVKkJHg6ujGHlcjJeQCBcYrSuRhESy_wtPTadVxWtsiOfcThKFizX_S6XR1sxShzTr4mPJXgrtkjFVwmTSom575hoazShwWGJdOkg7llKCSYaRaCdWAXp93IBygo6QSoNXC0iF2iC6PA5HcrJC84iyYP0lP5S6cCZE9-uTnbffJAEWhZRyPx9xyW5kUOnAcc8EPstXfqYX0tuJXFf_1Ip1yDWEEcRBR06ryc30Yy8zEqnJdvwKx4SJoZ2tMzzCnhoe_lmeSwiUc4RbCuhOpqoQb2UAmiRIDkKd3lS1uUa0LoY4B333L-LOyWqdf2O8aeFG-c2I2kKCBuSZbcntsJ26R8swYPRXTP4v8GLq6h93JDdScTMdAlx3WGDk61gJsK0vs_bBvMPYjGDcObkwsXcsrxTo5pbC502wWVi5h7F7v4w7UKEMOQ7c6l8ooioYf3Wow3RPqX0FvCwjvh1oFd7glsocs=w1308-h982-no

Regards,

Ignacio EB4APL



El 25/08/2019 a las 19:14, EB4APL escribió:
I'm sorry, I forgot that attachments are not allowed. I will upload it
somewhere and I'll send the link.



El 25/08/2019 a las 19:11, EB4APL via Groups.Io escribió:
Could this be used? It is with me more than 40 years, probably it was
manufactured by Pomona.

Ignacio EB4APL



---
---
El software de antivirus Avast ha analizado este correo electrónico en busca de virus.
https://www.avast.com/antivirus


Re: Tek 576 Curve Tracer HV Transformer winding

peter bunge
 

The picture does not show.
I will attach. Note this is low voltage (1v full scale) and very low
current in base and collector.

On Sun, Aug 25, 2019 at 12:34 PM peter bunge via Groups.Io <bunge.pjp=
gmail.com@groups.io> wrote:

This may be of interest to the Tek Group so I am going on line again.
I got my 576 working again.
It was one of the push-on connectors on the top left board. I have had
trouble with those long ago on a 465 scope. I just ran an insulated rod
along them until the trace re-appeared. I will have to go around the
entire curve tracer with a pair of plyers and pull off and push on each
one. It solves many problems.
I would appreciate you doing a couple of tests:
Vert Offset Horiz Pol Max Peak Series Resistor
Left/Right
0.5mA 0 50v +NPN 1500v 3k (220W) off (no
component)
Turn the variable collector supply so the trace reaches to 10 div. What
happens to the left end of the trace? Mine moves over 1 div.
Reset to the following with a 2N3565 (high gain NPN)
2uA 0 0.1v +NPN 10v 30 ohm Step Gen,
0.05 uA, Zero, Steps, Rep Norm, 3 steps
turn the collector to full scale as shown (1 volt). The first trace is not
really dim, it is the camera.
Do you see a similar set of curves. I am most interested in the looping.
[image: 2N3565.jpg]

On Sat, Aug 24, 2019 at 3:11 PM Miguel Work <harrimansat@hotmail.com>
wrote:

I have two 576, if you told me which test you need to compare, I will do
it with mine. Do you know ferrite core specs? Could be changed some
transformer HV turns for a voltage multiplier?



FERRITE CORE E 20 N27
Core Type : E
Core Size : E20/10/6
Core Material Grade : N27
For Use With : -
Effective Magnetic Path Length : 46.3mm
Ae Effective Cross Section Area : 32.1mm²
Inductance Factor Al : 1.3µH
Product Range : B66311 Series
SVHC : No SVHC (15-Jun-2015)
Accessory Type : Ferrite Core
Material Grade : N27
-----Mensaje original-----
De: TekScopes@groups.io [mailto:TekScopes@groups.io] En nombre de peter
bunge
Enviado el: sábado, 24 de agosto de 2019 16:08
Para: TekScopes@groups.io
Asunto: Re: [TekScopes] Tek 576 Curve Tracer HV Transformer winding

Thanks David for your generous offer;
Where do they get the cores to make a compatible transformer that works
in
the 576 circuit. This is not a 115v 60 Hz transformer.
A friend suggested a plate transformer and doublers or triplers. 225v is
also needed.
I have been looking at using a 4 kV and 225 V switching power supplies
from China and I have used some for other projects. They tend to be noisy
but can be cleaned up.
Since my 576 is still working there is no great urgency.
I also want to look at my friend's 577 and compare it to my 576. His is
smaller and lighter but may not do as much.
My 576 does weird things at lower currents (all loops) and PNP do not
seem
to work the same as NPN (lack of steps) so the transformer is not the
only
issue. I spent a couple of days working on it a few years ago but could
not
improve it.
I need to find someone with a 576 and compare traces to see if mine is
"normal".
I need the 1500v capability which rules out some of the newer ones which
are also more expensive.
I will think about your offer.
Peter

On Fri, Aug 23, 2019 at 4:28 PM drawding@pacbell.net <
drawding@pacbell.net
wrote:

Yes. David Rawding is still here.

: )

I bought five professionally made transformers. One was donated to
Bob for his kind help. Two were used by me. Two were sold. I am all
out.

Another run is ~ $1k for 5 more. Five is the minimum order. A bit
pricey, I know. However, they are made by a professional transformer
company. Fully enclosed and potted in silicone. If you consider what
technical wages are today and overhead and materials, I would say it
is fair pricing. However, at the hobby level, it is pricey.

If we can find five buyers (though this seems unlikely), I will
handle the details, and will sell at my cost + shipping.

Also, as you can see from this thread several people have been
successful winding their own.

One gentleman came here a year or so ago, asked a bunch of questions,
got great support from the group, ended up successfully winding his
own, and left. He was asked to put some details together (pictures,
documentation, video, etc), but apparently could not be bothered.

I hope you find a solution.

Thanks,
Dave











Re: Tek 576 Curve Tracer HV Transformer winding

RustySparks
 

If our cores can be rewound that may make things easier? I would pay $200 for either new or rewound 453 HV XFMR done with professional quality. Doesn't make good economic sense I agree, but I would gladly pay that, both for sentimental reasons and to get the ball rolling in the first place.

-----Original Message-----
From: TekScopes@groups.io <TekScopes@groups.io> On Behalf Of Chuck Harris
Sent: Sunday, August 25, 2019 10:45 AM
To: TekScopes@groups.io
Subject: Re: [TekScopes] Tek 576 Curve Tracer HV Transformer winding

If you guys are all willing to pay in the $200-300 range, like the custom made stuff that was done for the 576, I'll start winding again.

-Chuck Harris

Dave Daniel wrote:
And 547s and 7934s ...

DaveD


On 8/25/2019 8:12 AM, RustySparks wrote:
I wonder if the same company could make a batch of HV transformers
for the 453 scope? I think several users of this group, including
myself, have 453 scopes with bad HV transformers.
Thanks,
Harry

-----Original Message-----
From: TekScopes@groups.io <TekScopes@groups.io> On Behalf Of
drawding@pacbell.net
Sent: Sunday, August 25, 2019 1:25 AM
To: TekScopes@groups.io
Subject: Re: [TekScopes] Tek 576 Curve Tracer HV Transformer winding

"Where do they get the cores to make a compatible transformer that
works in the 576 circuit. This is not a 115v 60 Hz transformer."

I believe that they make them in house. I sent them the original Tek
transformer specification. I got the specification drawing from Bob
Koller (now posted online as per this thread).

Thanks,
Dave










Re: Plug for 7CT1N captive lead?

EB4APL
 


Re: Plug for 7CT1N captive lead?

EB4APL
 

I'm sorry, I forgot that attachments are not allowed. I will upload it somewhere and I'll send the link.



El 25/08/2019 a las 19:11, EB4APL via Groups.Io escribió:
Could this be used? It is with me more than 40 years, probably it was
manufactured by Pomona.

Ignacio EB4APL



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https://www.avast.com/antivirus


Re: Plug for 7CT1N captive lead?

EB4APL
 

Could this be used? It is with me more than 40 years, probably it was
manufactured by Pomona.

Ignacio EB4APL



---
El software de antivirus Avast ha analizado este correo electrónico en busca de virus.
https://www.avast.com/antivirus


7D01 manual for serial B020000 + for $5 postage.

John Griessen
 

I think I can find some probes. Ask off list if interested. john@ecosensory.com


Re: Tek 576 Curve Tracer HV Transformer winding

peter bunge
 

This may be of interest to the Tek Group so I am going on line again.
I got my 576 working again.
It was one of the push-on connectors on the top left board. I have had
trouble with those long ago on a 465 scope. I just ran an insulated rod
along them until the trace re-appeared. I will have to go around the
entire curve tracer with a pair of plyers and pull off and push on each
one. It solves many problems.
I would appreciate you doing a couple of tests:
Vert Offset Horiz Pol Max Peak Series Resistor
Left/Right
0.5mA 0 50v +NPN 1500v 3k (220W) off (no
component)
Turn the variable collector supply so the trace reaches to 10 div. What
happens to the left end of the trace? Mine moves over 1 div.
Reset to the following with a 2N3565 (high gain NPN)
2uA 0 0.1v +NPN 10v 30 ohm Step Gen,
0.05 uA, Zero, Steps, Rep Norm, 3 steps
turn the collector to full scale as shown (1 volt). The first trace is not
really dim, it is the camera.
Do you see a similar set of curves. I am most interested in the looping.
[image: 2N3565.jpg]

On Sat, Aug 24, 2019 at 3:11 PM Miguel Work <harrimansat@hotmail.com> wrote:

I have two 576, if you told me which test you need to compare, I will do
it with mine. Do you know ferrite core specs? Could be changed some
transformer HV turns for a voltage multiplier?



FERRITE CORE E 20 N27
Core Type : E
Core Size : E20/10/6
Core Material Grade : N27
For Use With : -
Effective Magnetic Path Length : 46.3mm
Ae Effective Cross Section Area : 32.1mm²
Inductance Factor Al : 1.3µH
Product Range : B66311 Series
SVHC : No SVHC (15-Jun-2015)
Accessory Type : Ferrite Core
Material Grade : N27
-----Mensaje original-----
De: TekScopes@groups.io [mailto:TekScopes@groups.io] En nombre de peter
bunge
Enviado el: sábado, 24 de agosto de 2019 16:08
Para: TekScopes@groups.io
Asunto: Re: [TekScopes] Tek 576 Curve Tracer HV Transformer winding

Thanks David for your generous offer;
Where do they get the cores to make a compatible transformer that works in
the 576 circuit. This is not a 115v 60 Hz transformer.
A friend suggested a plate transformer and doublers or triplers. 225v is
also needed.
I have been looking at using a 4 kV and 225 V switching power supplies
from China and I have used some for other projects. They tend to be noisy
but can be cleaned up.
Since my 576 is still working there is no great urgency.
I also want to look at my friend's 577 and compare it to my 576. His is
smaller and lighter but may not do as much.
My 576 does weird things at lower currents (all loops) and PNP do not seem
to work the same as NPN (lack of steps) so the transformer is not the only
issue. I spent a couple of days working on it a few years ago but could not
improve it.
I need to find someone with a 576 and compare traces to see if mine is
"normal".
I need the 1500v capability which rules out some of the newer ones which
are also more expensive.
I will think about your offer.
Peter

On Fri, Aug 23, 2019 at 4:28 PM drawding@pacbell.net <drawding@pacbell.net
wrote:

Yes. David Rawding is still here.

: )

I bought five professionally made transformers. One was donated to
Bob for his kind help. Two were used by me. Two were sold. I am all
out.

Another run is ~ $1k for 5 more. Five is the minimum order. A bit
pricey, I know. However, they are made by a professional transformer
company. Fully enclosed and potted in silicone. If you consider what
technical wages are today and overhead and materials, I would say it
is fair pricing. However, at the hobby level, it is pricey.

If we can find five buyers (though this seems unlikely), I will
handle the details, and will sell at my cost + shipping.

Also, as you can see from this thread several people have been
successful winding their own.

One gentleman came here a year or so ago, asked a bunch of questions,
got great support from the group, ended up successfully winding his
own, and left. He was asked to put some details together (pictures,
documentation, video, etc), but apparently could not be bothered.

I hope you find a solution.

Thanks,
Dave









FG502 Troubleshooting Help Requested

@DC912
 

Hello.

My FG502 has no signal at the Output jack (but there is DC at the Output jack as described below) and no signal or voltage at the Trigger Out.

The positive (+20, +17) and negative (-20, -17) voltage rails are correct.

With reference to the Triangle Generator schematic (Diagram 1):
1. There is no triangle signal at the emitter of Q210.
2. There is no square wave signal at R255.
3. There is nothing at Trigger Out.
4. With the frequency dial at 5, the voltages at Pin 6 of U140 and U175 are +11.71 and -11.57

I removed Q140 and Q175 and they test okay.

I removed Q200 and Q202 and they test okay.

I removed Q292 and Q290 and they test okay.

I removed Q230 and both sections tested okay.

I tested all diodes in-circuit in the 3 bridges shown on the schematic and they tested okay.

At the front panel Output, with the offset switch off, the following voltages appear at the following switch positions:

Sine: -11.71, Sawtooth +10.9, Square +1.9, Pos Ramp, +11.2, Neg. Ramp +12.1, Pos. Pulse +2.3V, Neg. Pulse +2.3

I'm stumped. I would appreciate input on what the collector voltages should be at Q292 and Q290, and any ideas on where to go from here in my troubleshooting.

Thanks. Dave.


parting out 2) 7633's and a 7613 storage scope unless... $55 shipping each in US

John Griessen
 

Starting disassembly on the 7613. It has power, vertical, horiz pos., no sweep, no store.

7633 B152130 gives a flooded screen,
7633 B111088 has no power with fuse intact, and power present at the PS rectifier board input, so needs PS debug.

One of the 7633's had covers with 6 latches and RF shorting edging. no vents. Could make an RF tighter cover for any 3 bay 7xxx with proper vent holes drilled.


Re: Tektronix 585A Voltage Diagnoses Problem edited

Chuck Harris <cfharris@...>
 

Everything is referenced to the -150V supply. It must
be right, or the others will behave truly weird... like
you are seeing.

Start there.

Also, the 585A has DC filaments. If it doesn't have a plugin, it
switches off the -100V supply that is used to power the filaments
on the plugin... Or, it has an internal dummy load... can't remember
right now.

-Chuck Harris

randolphbeebe@gmail.com wrote:

Hello All,

I have a 585A scope that has me stumped.. the LV voltages are out of spec and I cannot find the problem. Here are the voltage readings;

-150 = -182
-100 = -115
225 = 263
350 = 409
500 = 587

The -150v adjustment pot does not change the voltage value at all. All the tubes were pulled and tested for shorts and emission. Not being very good at diagnosis I shotgunned all the electrolytics and filter caps although most of the tested good in circuit I found a couple of bad ones. No improvement. I have the schematic and can upload that if it helps. Can anyone suggest a way I can isolate the circuit causing me grief? The scope is clean and intact otherwise.

Thanks in advance.




Re: Tek 576 Curve Tracer HV Transformer winding

Chuck Harris <cfharris@...>
 

If you guys are all willing to pay in the $200-300 range, like
the custom made stuff that was done for the 576, I'll start
winding again.

-Chuck Harris

Dave Daniel wrote:

And 547s and 7934s ...

DaveD


On 8/25/2019 8:12 AM, RustySparks wrote:
I wonder if the same company could make a batch of HV transformers for the 453
scope? I think several users of this group, including myself, have 453 scopes with
bad HV transformers.
Thanks,
Harry

-----Original Message-----
From: TekScopes@groups.io <TekScopes@groups.io> On Behalf Of drawding@pacbell.net
Sent: Sunday, August 25, 2019 1:25 AM
To: TekScopes@groups.io
Subject: Re: [TekScopes] Tek 576 Curve Tracer HV Transformer winding

"Where do they get the cores to make a compatible transformer that works in the 576
circuit. This is not a 115v 60 Hz transformer."

I believe that they make them in house. I sent them the original Tek transformer
specification. I got the specification drawing from Bob Koller (now posted online
as per this thread).

Thanks,
Dave










Re: Plug for 7CT1N captive lead?

Lawrance A. Schneider
 

Hi,

I’d never heard of ‘gaffer tape”. Why not just plane plastic electrical tape?


Larry

On Aug 25, 2019, at 5:37 AM, EJP <esmond.pitt@bigpond.com> wrote:

When I went to put on a standard soldered BNC plug I found there is no shielding in the cable, only a pretty thick set of strands for the inner conductor, so I was unable to even fix the outer cover on. So I settled for just the pin. I'm not happy with it, as it is uninsulated: gaffer tape awaits, but also a better solution, if there is one.

EJP



Re: Tek P6xxx probe reference question

Lawrance A. Schneider
 

Hi,

Interesting! First, somehow I would not expect Tek to reduce themselves as you describe (obsolescence). Second, the meaning of the size (2.33 - 2 MHz).

Thanks, larry

On Aug 24, 2019, at 9:38 PM, John Griessen <john@ecosensory.com> wrote:

On 8/24/19 8:23 PM, Greg Muir via Groups.Io wrote:
From a little more digging it appears that the measurement Tek uses applies to the diameter of the metal part of the probe tip body itself; sort of a mystery since Tek does not indicate what they are referring to in any of their literature.
It's a planned obsolescence thing. Mentioning that the tip male prong and barrel on the body of the probe are well known standards might reduce sales. Most companies in test equipment know that they make plenty from
selling accessories.

5mm barrel and 2.5mm barrel on probe tips are a pseudo standard with Tek and it allows any low frequency parts
to swap out or substitute willy nilly.

I like some thin small probes by HP such as 10017A probes. Their probe tip barrel diameter is 2.33mm, not standard with Tek at all, and not even a perfect input capacitance match, but I use them up to 20 MHz with no big troubles.

For higher frequencies, the probe for the scope will be better.

An example of how 5mm probe tip barrel diameters allow swapping things is those funny elephant trunk-looking
tips for the P6046 diff probes, and also the nifty shorting tips that come with those probes for performance checks and cal.



Re: 577 D1

DW
 

That would make sense, thanks for the reply

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