Date   
Re: PG506 mod

Albert Otten
 

Yes Christoph, there is a (partial!) circuit diagram showing the modification. But I think I had better protect you from destroying more than you improve if you try to update your unit. As a hobbyist there is no need to set the PG506 at High Amplitude for long periods, so what is the problem? If the High Amplitude is functioning properly then simply leave it the way it is. If it's not functioning properly then you have to find the cause before attempting any modifications.
The document I mentioned is Manual Change Information. I doubt there ever was a user modification kit for this. May I also recall that David (IIRC) commented some time ago that for understanding how things work the High Amplitude diagram is one of Tek's most terribly drawn diagrams.

Albert

========
Thanks. My serial # is B031278 (doesn't have this mod yet).
Is this mod documented with a circuit diagram? Would it be worth adding it?
What was the purpose? Just reliability? Or performance also?

--
Christoph

Re: PG506 mod

Christoph
 

Thanks. My serial # is B031278 (doesn't have this mod yet).
Is this mod documented with a circuit diagram? Would it be worth adding it?
What was the purpose? Just reliability? Or performance also?

--
Christoph

Re: Help to find CRT part number

petepdx1955
 

How about another picture of the face ? the one posted is very very small.


Can you find any marking on the gun/deflection assembly ?


Take a few more pictures of the P/N label at different angles, do you have a polarizing filter ?


Wet the label it may help raise the ink or create a better contrast.


154 is the p/n prefix for all CRT's, it is the middle 4 digits that you want.


-pete

Re: Help to find CRT part number

 

The part number is on the label - starts 154-

-----Original Message-----
From: TekScopes@... [mailto:TekScopes@...]
Sent: 23 February 2016 13:10
To: TekScopes@...
Subject: [TekScopes] Help to find CRT part number

Hi folks,
I have uploaded an album named unknown CRT These are pictures a CRT I came
across down here for sale.
He has two of them and he says the CRT's are new, but I am not sure I can
believe him.
Is it possible to find out the exact part number from the pictures?
I wonder if it could be used in a 7854.
Thank you in advance,
Roger






------------------------------------
Posted by: @rodd
------------------------------------


------------------------------------

Yahoo Groups Links

Re: Help to find CRT part number

 

Applying my definition of what "new" means, this CRT isn't, not even NOS. It may have been "pulled from a new i.e. unused 'scope" but I doubt it. Some dust near the rim at the front seems not too carefully removed. OTOH, the HV lead and connector look clean The socket pins are bent. Not cared for with love...

If you can provide us with the Part no. (partially visible: "154-0..."), we can find out what \scope model(s) it would fit.
AFAIK, the 7854 uses pins, not sockets for the plate connections and their distance (pins for L-R, T-B plates) is larger.

Raymond

Re: New file uploaded to TekScopes

Albert Otten
 

That 3 kB jpg picture is useless.
Albert

======
You can access this file at the URL:
https://groups.yahoo.com/neo/groups/TekScopes/files/Unknown%20CRT/CRT1.jpg https://groups.yahoo.com/neo/groups/TekScopes/files/Unknown%20CRT/CRT1.jpg

rogerio414 <rodd@... mailto:rodd@...>

Help to find CRT part number

 

Hi folks,
I have uploaded an album named unknown CRT
These are pictures a CRT I came across down here for sale.
He has two of them and he says the CRT's are new, but I am not sure I can believe him.
Is it possible to find out the exact part number from the pictures?
I wonder if it could be used in a 7854.
Thank you in advance,
Roger

New file uploaded to TekScopes

TekScopes@...
 

Hello,


This email message is a notification to let you know that
a file has been uploaded to the Files area of the TekScopes
group.


File : /Unknown CRT/CRT3.jpg
Uploaded by : rogerio414 <@rodd>
Description :


You can access this file at the URL:
https://groups.yahoo.com/neo/groups/TekScopes/files/Unknown%20CRT/CRT3.jpg


To learn more about file sharing for your group, please visit:
https://help.yahoo.com/kb/index?page=content&y=PROD_GRPS&locale=en_US&id=SLN15398


Regards,


rogerio414 <@rodd>

New file uploaded to TekScopes

TekScopes@...
 

Hello,


This email message is a notification to let you know that
a file has been uploaded to the Files area of the TekScopes
group.


File : /Unknown CRT/CRT2.jpg
Uploaded by : rogerio414 <@rodd>
Description :


You can access this file at the URL:
https://groups.yahoo.com/neo/groups/TekScopes/files/Unknown%20CRT/CRT2.jpg


To learn more about file sharing for your group, please visit:
https://help.yahoo.com/kb/index?page=content&y=PROD_GRPS&locale=en_US&id=SLN15398


Regards,


rogerio414 <@rodd>

New file uploaded to TekScopes

TekScopes@...
 

Hello,


This email message is a notification to let you know that
a file has been uploaded to the Files area of the TekScopes
group.


File : /Unknown CRT/CRT1.jpg
Uploaded by : rogerio414 <@rodd>
Description :


You can access this file at the URL:
https://groups.yahoo.com/neo/groups/TekScopes/files/Unknown%20CRT/CRT1.jpg


To learn more about file sharing for your group, please visit:
https://help.yahoo.com/kb/index?page=content&y=PROD_GRPS&locale=en_US&id=SLN15398


Regards,


rogerio414 <@rodd>

Re: PG506 mod

 

Albert,
Thanks for checking out those things.

Raymond

Re: PG506 mod

Albert Otten
 

These heatsink and transistor changes are in the High Amplitude circuitry.
Albert


---In TekScopes@..., <christophkukulies@...> wrote :

Thanks, guys. I now understand that this is stock and only depends on serial number.
Will post mine later.

Nonetheless I'm wondering why the risetime of the standard pulse was noticeably better on the unit with the large heat sink (don't know whether it has sth. to do with it, though)


--
Christoph

Re: PG506 mod

Albert Otten
 

Model changes M30099 EFF SN031980-up (dated 6 DEC 1976):
ADD:
214-1291-00 HEATSINK, XSTR: (Installed on Q745)
215-2569-00 HEATSINK, XSTR: (Installed on Q758)
214-2572-00 HEATSINK

Further Q755 removed, Q758 added, among other changes.

Albert

Re: PG506 mod

Christoph
 

Thanks, guys. I now understand that this is stock and only depends on serial number.
Will post mine later.

Nonetheless I'm wondering why the risetime of the standard pulse was noticeably better on the unit with the large heat sink (don't know whether it has sth. to do with it, though)


--
Christoph

Re: PG506 mod

 

I think the early PG506 service manual scan that we have from Artek
for serial number B039999 and below does cover it insofar as there is
a note on the schematic itself. Some of the parts like Q755 look to
be drawn with a different weight or color but it is difficult to tell
from the grayscale scan.

On 23 Feb 2016 02:35:45 -0800, you wrote:

Christoph,
I have two PG506 Service Manuals: One for S/N B039999 and below, the other for S/N B040000 and up.

"Low" does not have the heat sink that you mention and uses the two-relay output filter.
"High" does not have it either and has a thoroughly changed PCB

My S/N B0103XX does not contain the "new" heat sink mod and is exactly as per the "Low" manual.
My S/N B0332XX contains the mod. I don't have a manual for that exact sample.

The "High" model contains a strongly modified PCB.

And then there's the PG506A...

Looking at my two units, There are several differences, apart from just the different heat sink configuration for both power transistors in the area. Without further studying it, I would consider the better cooling arrangement of the heat sink mod for the two power transistors (both changed to TO-39 packaged ones, one on the heat sink, the other getting a "star" heat spreader) to be the most urgent change. Personally, I might consider doing that and skipping the others.
I have to admit the whole set of mods does not look very neat, rather botched together.

Raymond

[Non-text portions of this message have been removed]

Re: PG506 mod

 

My PG506, serial number B035309, is built in exactly the same way with
the transistor mounted to the aluminum heat sink. If you look below
the transistor in your photograph, you can see some air wired parts as
well.

The early PG506s are serial number B039999 and below but the parts
list shows that the later ones are missing Q755 among other changes.
The schematic in the Artek scan of the manual has a note "EFF SN
B031979 & BELOW" but it is not clearly apparent from the Artek scan
what the differences are. It looks to me like the original schematic
had some color elements which were lost when it was scanned.

The schematic from the late PG506 may be closer as it does not show
Q755 at all.

So I think what you are seeing here is that the late version of the
early PG506 is closer to the late PG506 than the early PG506.

On 23 Feb 2016 00:58:40 -0800, you wrote:

Raymond,

I believe you missed the change I mean, because it looks as if it must be there: it's the aluminum heat sink, mounted with the two philips screws, which are normally there anyway for some other mounting purposes and are abused to hold the heat sink.

Then this floating TO-39 transistor mounted horizontally against that heatsink.

It looks to my like a circuit change to lower leading edge rise time of the standard signal on output since I observed that the risetim of that unit was shorter than that of a comparison unit.

Also the cylindrical heat sink with the hole in the middle is also not standard.

Re: PG506 mod

 

Christoph,
I have two PG506 Service Manuals: One for S/N B039999 and below, the other for S/N B040000 and up.

"Low" does not have the heat sink that you mention and uses the two-relay output filter.
"High" does not have it either and has a thoroughly changed PCB

My S/N B0103XX does not contain the "new" heat sink mod and is exactly as per the "Low" manual.
My S/N B0332XX contains the mod. I don't have a manual for that exact sample.

The "High" model contains a strongly modified PCB.

And then there's the PG506A...

Looking at my two units, There are several differences, apart from just the different heat sink configuration for both power transistors in the area. Without further studying it, I would consider the better cooling arrangement of the heat sink mod for the two power transistors (both changed to TO-39 packaged ones, one on the heat sink, the other getting a "star" heat spreader) to be the most urgent change. Personally, I might consider doing that and skipping the others.
I have to admit the whole set of mods does not look very neat, rather botched together.

Raymond

Applications for 012-0841--00 and 012-0842-00 Cables?

Egge Siert
 

Hi to All,


Both 50R? cables are fitted with a BNC Male on one end and a BNC Female on the other end. They look like a extended (12ft) 012-0104-00 (Type 134 Accessoire). Does anybody known why these are made or to which instrument they belong?


Greetings,


Egge Siert

TekProbe Interface Cables

Egge Siert
 

Hi to All,


Can the 012-1605-00/01 TekProbe Interface Cables be used as direct replacements for the earlier 012-1372-00 Models? Anybody?


Greetings,


Egge Siert

Re: PG506 mod

Albert Otten
 

Hi Christoph,

The application/position of heat sinks differs considerably between earlier and later versions of the PG506. So what is your serial number?
A look at
http://www.amplifier.cd/Test_Equipment/Tektronix/Tektronix_500/PG506.htm
might help.

Albert