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Chuck,

The only use of the linesman glove was to put the HT anode lead somewhere that would hold it from moving, and to keep it away from me. I never implied to wear them while working in electronics, they also have a leather shell glove to protect the linesman glove from damage.

But I do use latex gloves when doing this work, I'm not relying on them to protect me, but rather to add a weak safety net, since I have them lying around, they improve grip, and add a decent layer of uncertified protection, but they tear easily.

This reply is a little dated I know, haven't been following the thread for awhile.

NielsenTelecom

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 : 32.1mm? Inductance Factor Al : 1.3?H Product Range : B66311
Series SVHC : No SVHC (15-Jun-2015) Accessory Type : Ferrite Core
Material Grade : N27 -----Mensaje original-----
De: [email protected] [mailto:[email protected]] En nombre de
peter bunge Enviado el: sábado, 24 de agosto de 2019 16:08
Para: [email protected]
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@...
<drawding@...

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

On Aug 26, 2019, at 11:48 PM, atwood.1@... wrote:

Does anyone have the winding data for the 561 HV transformer? The manual shows it to be Tektronix part 120-225. thanks

-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of garp66
Sent: 27 August 2019 04:04
To: [email protected]
Subject: [TekScopes] Tek 576 Curve Tracer wanted: Max Peak Volt / Series

& knobs & Multiplier pot bezel / fixture collar

hi,
Does anyone know about the following mechanical bits on 576 CT front

a) Max Peak Volt / Series Resistor linkage mechanism:
I am missing the dual knobs for this & the mechanical (coaxial ?) linkage

behind
the front panel to the actual rotary switch inside.
-- Does anyone have a spare linkage unit with the two outer knobs or a

b) The Multiplier Pot with its silver fine gradation knob:
my Multiplier Pot has been pushed in all the way, hanging inside the

-- How is this Pot re-afixed to the front panel ?

Is there a retention ring, bezel, collar or something ?
-- Does anyone have these bits or a detailed diagram ?

thank you,
rick

-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of garp66
Sent: 27 August 2019 04:04
To: [email protected]
Subject: [TekScopes] Tek 576 Curve Tracer wanted: Max Peak Volt / Series Resistor mechanical linkage
& knobs & Multiplier pot bezel / fixture collar

hi,
Does anyone know about the following mechanical bits on 576 CT front panel ?

a) Max Peak Volt / Series Resistor linkage mechanism:
I am missing the dual knobs for this & the mechanical (coaxial ?) linkage that extends about 2"
behind
the front panel to the actual rotary switch inside.
-- Does anyone have a spare linkage unit with the two outer knobs or a detailed diagram of this ?

b) The Multiplier Pot with its silver fine gradation knob:
my Multiplier Pot has been pushed in all the way, hanging inside the instrument !
-- How is this Pot re-afixed to the front panel ?

Is there a retention ring, bezel, collar or something ?
-- Does anyone have these bits or a detailed diagram ?

thank you,
rick

Apologies for the delay in updating, was a bit under the weather.

Months ago I initially used a 5x mag lens to investigate the solder joints
in the PS areas. Didn't see any issues.

Last week when I got back to working on this, I remembered I had a cheap
$20 usb microscope laying around.

Discovered very tiny cracks on all 3 pads on both Q946 and Q947. C907 had
crack on the component side of the board (the bottom was not cracked)
hosted pics of cracks:

IPA scrubbed, dried, applied some amtech flux and reflowed the joints.

Also swapped out C956, I was using the original mallory cap due to
ordering the incorrect cap the first time. Used a new Nichicon UHW 330uF
50V that I had on hand. I seen that C956 is listed as +10-100% and believe
this is a workable low impedance choice. If not, i'd appreciate any insight
on the matter.

Powered up, the shrinking H and V issue
and extreme intensity change fail states no longer occurs. The only fault
that I notice is that the traces just barely pulse brightness (as if you
were just barely turning the intensity knob by 1-2 degrees back and forth)
after 3-5min, they remains steady for until powered down.

Going to microscope a bit more and use a long wooden dowel to gently tap
around while the unit is running as David Hess mentioned on my project
thread on eevblog.



P.S.: Just adding a link to the project thread on eevblog in case it helps
anyone in the future etc.

Hi Chuck,

The scope has a CA plug-in right now with a type 81A adapter. I am pretty sure all is good with the plug-in because the scope responds to the vertical position and input etc. I have a couple of the Type 81A adapters, I wonder if the present one may be causing problems.

Thanks for the