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Do you have a source of the paper?

If not then I prefer the XY chart recorder outputs, since they can drive a digitising scope and (theoretically!) allow it to be stored underwater :)


On 07/08/18 15:52, Adrian wrote:

Hi Tom,

Had a look at the stripline and yes, I have a short bit of braid hanging out the end too, Fig 4-26 on Page 4-27 of the manual seems to show it just hanging loose (didn't know they were that laid back in Oregon?) so I guess that's how it's meant to be.

Just waiting for the last of the correct replacement parts to arrive from Digikey (takes a day or two longer to get to the UK) and I'll replace the tacked-in temporary bits and then see if I can run through the test/calibration procedures, but it's looking good so far! Just the chart recorder to look at now.



On 8/6/2018 10:46 PM, Tom Gardner wrote:

I have one other 'loose end' wire on the 1502 which also puzzled me, what looks like it could have been an earth connection at the rear (TD end) of the strip line, but nowhere obvious that it might have linked to.? My 1502 has a somewhat below spec rise time and I wondered if this could be linked to the missing earth connection.

Hi Tom,

Had a look at the stripline and yes, I have a short bit of braid hanging out the end too, Fig 4-26 on Page 4-27 of the manual seems to show it just hanging loose (didn't know they were that laid back in Oregon?) so I guess that's how it's meant to be.

Just waiting for the last of the correct replacement parts to arrive from Digikey (takes a day or two longer to get to the UK) and I'll replace the tacked-in temporary bits and then see if I can run through the test/calibration procedures, but it's looking good so far! Just the chart recorder to look at now.



On 8/6/2018 10:46 PM, Tom Gardner wrote:

I have one other 'loose end' wire on the 1502 which also puzzled me, what looks like it could have been an earth connection at the rear (TD end) of the strip line, but nowhere obvious that it might have linked to.? My 1502 has a somewhat below spec rise time and I wondered if this could be linked to the missing earth connection.

FWIW I have also built a "silent" compressor.
Well, I had to, after switching that monster from the DIY store on the
first time I knew I wouldn't put up with that racket.

I took a refrigeration compressor, a slightly larger one from a
commercial unit, and cut it open to clean it (it was rusted solid),
and replaced the oil with regular motor oil. You really need to
replace that oil since refrigeration oil is hygroscopic and everything
will rust like crazy if you run it in air.
I simply cut open the case with an angle grinder, and later sealed it
back up with a rubber strip and a metal band.
Mine is from 1970 or thereabouts, made in Scotland of all places. The
old cast iron ones are better than the aluminium ones, in my mind
anyway.
It fills up the tank of the noisy compressor, but has it's own
pressure switch, I just didn't have a suitable pressure vessel at the
time.

Refrigeration compressors typically don't have piston rings, so they
introduce more oil into the the air than other piston compressors. But
it tends to settle out in the tank and not cause any issue.

Some commercial silent compressors look suspiciously like
refrigeration compressors anyway, with an added sight glass for the
oil level.
I guess a scroll compressor from a modern AC unit would be neat too,
but those are usually higher powered and not really silent.

ST








On Sat, Jul 28, 2018 at 5:39 PM, Pete Lancashire <xyzzypdx@...>
wrote:

Eric I'm curious on your air compressor since the metcal seed 90 PSI
can you contact me off group and tell me how you build it thanks

I have one other 'loose end' wire on the 1502 which also puzzled me, what looks like it could have been an earth connection at the rear (TD end) of the strip line, but nowhere obvious that it might have linked to.? My 1502 has a somewhat below spec rise time and I wondered if this could be linked to the missing earth connection.

Would it fit in a 561? Is there a plugin adapter for that purpose?

On August 6, 2018 at 11:58 AM Fabio Trevisan <fabio.tr3visan@...> wrote:


Hello Jim,
The pictures did arrive correctly to me and I just posted the pictures to the Tekscopes photo section:
link is here:
/g/TekScopes/album?id=65983

As I already replied in PM to you, I'll repeat it here... This rather odd missing of the through hole plating of **ONLY** the power supply rails, to me, seems like an effort of a previous owner to isolate a short-circuit in the power rails.
Given the age of those scopes, it can very well have happened before this group even existed, and before it became common knowledge that this kind of problem is often caused by a shorted tantalum capacitor, and then the scope was tossed away for - say - 20 years.
I would suggest you take advantage that the through holes are stripped out, and try to measure ohms from each of those traces to ground, everywhere that you can follow them and, if you happen to find some spot that is showing low impedance to ground... you'd have probably found the culprit.
If you can't find any of those traces shorted to ground, I would just rebuild the through-hole vias and try to apply power to the thing.
As I mentioned earlier, I don't think the presence or absence of the DM44 is too involving, in regards to the A5 trigger board and, sure enough, it has nothing to do with this mystery of the missing vias.
The only there is between the DM44 & the A5 trigger board, is the pick-off signal from the ALT TRACE SYNC PULSE, from the emitter of Q916, shown on diagram <8> of the 464 and connected through a 20K resistor, from this transistor, to a wire and then to the DM44 through pin 2 of P3201, as shown on the DM44's service manual, diagram <3> "TIME & 1/TIME <3>" and diagram <9> "464,465 & 466 INTERFACE".
The latter is the signal that tells the DM44 the end of a sweep, to allow the DM44 to switch the delay time control voltage at the end of every sweep, between the scope's own Delay time multiplier pot, and the DM44's Delta time pot (and v-v) which, ultimately is what allows the measurement of TIME and 1/TIME.

Please let us know what else did you find on this board power rails.

KRgrds,

Fabio



On Sat, Aug 4, 2018 at 09:23 PM, Jim Olson wrote:

Hi Fabio I sent the picts in an email to you PM but comcast has changed there
email to a new system so I'm not sure if you got it or not.

Jim

On August 3, 2018 at 12:23 PM Fabio Trevisan <fabio.tr3visan@...>

wrote:

Hi Jim,

Feel free to send me the pictures (PM to fabio.tr3visan@...).
I will be glad to post it to the photos area of Tekscopes.io, and reply to

you with a link to the folder.

Rgrds,
Fabio


On Fri, Aug 3, 2018 at 03:07 PM, Jim Olson wrote:

Fabio I have the pictures but I'm not using any kind of photo posting

service

it's gotten to complicated and I don't post much to forums anyway so can I
send them to you and you can post them up?

Jim

On August 3, 2018 at 7:26 AM Fabio Trevisan <fabio.tr3visan@...>

wrote:

Hello Jim,

I owed and restored a 464 with DM44 (now given to a friend) and I don't

think there are any other "optional" boards linked to the presence (or
absence) of the DM44.

The only optional boards that apply to the 464 / 466 are:
A. The optional DC inverter board (option 7)... That one can't co-exist

with

the DM44 (the inverter uses the same windings on the main transformer that

are

used to power the DM44).

B. The composite video Sync Separator (Option 5), which bears some

relation

to the A5 sync board and could explain some changes.

I did hear once, from someone of this group, there was two versions of

the

A5 Sync board... one that used the Tunnel Diodes, and another one which

used a

Custom Tek IC to discriminate the trigger edge.

I`m not sure, but maybe this is what the -01 means...
I've never landed my eyes, however, on a schematic of the latter, or a

later

manual that included both.

But regardless of this board versioning, It seems rather odd to me that

the

connections to the J6 are disconnected, and more so, that there is no
connection between the top and bottom side THROGUHOUT the board...

Moreover, there's nothing about the DM44 vs power to the A5 Trigger

board...

The DM44 takes its power from its own power supply and it's neither fed by

the

A5 board, nor the A5 board feeds it.

Yet, the only reason I can think of for the through hole plating is

missing

throughout the board is, either a mass murderer technician stripped them

off

by careless unsoldering, or yet, that it's a prototype board...

If it's the latter case, it could explain many things...
Maybe you can take a picture, post somewhere and link it here.

KRgrds,

Fabio

On Thu, Aug 2, 2018 at 11:40 PM, Jim Olson wrote:

I have a question about the A5 trigger generator sweep logic board
differences. I have two 466's with out the DM44 with the same trigger

board

670-3324-00 boards. I have a 464 with a DM44 with the 670-3324-01

board

and it

is vastly different from the 466 boards. All the DC voltage traces

from

J-6

are disconnected all the through holes are unsoldered so there is no
interconnection from top to bottom through out the board. There

appears to

be

no cable connection to the board from the DM44 to supply these?
The DM44 manual parts list's don't show that part number used for the

464/466

with the DM44 it shows the later 466 board and I can not find the

optional

boards listed in the service manuals listed in the DM44 one.
The installation sheets for installing the DM44's don't list different

or

optional boards used like the service manuals do?
So whats up with this bunch of missing info here!

Jim O

If you mean right by the three coloured connectors mounted on the rear of the PSU board, then there should be a 1cm bare single core wire from the chassis' tag to the 0V PCB trace on those connectors.

Hi Fabio I sent the picts in an email to you PM but comcast has changed there
email to a new system so I'm not sure if you got it or not.

Jim

On August 3, 2018 at 12:23 PM Fabio Trevisan <fabio.tr3visan@...>

wrote:

Hi Jim,

Feel free to send me the pictures (PM to fabio.tr3visan@...).
I will be glad to post it to the photos area of Tekscopes.io, and reply to

you with a link to the folder.

Rgrds,
Fabio


On Fri, Aug 3, 2018 at 03:07 PM, Jim Olson wrote:

Fabio I have the pictures but I'm not using any kind of photo posting

service

it's gotten to complicated and I don't post much to forums anyway so can I
send them to you and you can post them up?

Jim

On August 3, 2018 at 7:26 AM Fabio Trevisan <fabio.tr3visan@...>

wrote:

Hello Jim,

I owed and restored a 464 with DM44 (now given to a friend) and I don't

think there are any other "optional" boards linked to the presence (or
absence) of the DM44.

The only optional boards that apply to the 464 / 466 are:
A. The optional DC inverter board (option 7)... That one can't co-exist

with

the DM44 (the inverter uses the same windings on the main transformer that

are

used to power the DM44).

B. The composite video Sync Separator (Option 5), which bears some

relation

to the A5 sync board and could explain some changes.

I did hear once, from someone of this group, there was two versions of

the

A5 Sync board... one that used the Tunnel Diodes, and another one which

used a

Custom Tek IC to discriminate the trigger edge.

I`m not sure, but maybe this is what the -01 means...
I've never landed my eyes, however, on a schematic of the latter, or a

later

manual that included both.

But regardless of this board versioning, It seems rather odd to me that

the

connections to the J6 are disconnected, and more so, that there is no
connection between the top and bottom side THROGUHOUT the board...

Moreover, there's nothing about the DM44 vs power to the A5 Trigger

board...

The DM44 takes its power from its own power supply and it's neither fed by

the

A5 board, nor the A5 board feeds it.

Yet, the only reason I can think of for the through hole plating is

missing

throughout the board is, either a mass murderer technician stripped them

off

by careless unsoldering, or yet, that it's a prototype board...

If it's the latter case, it could explain many things...
Maybe you can take a picture, post somewhere and link it here.

KRgrds,

Fabio

On Thu, Aug 2, 2018 at 11:40 PM, Jim Olson wrote:

I have a question about the A5 trigger generator sweep logic board
differences. I have two 466's with out the DM44 with the same trigger

board

670-3324-00 boards. I have a 464 with a DM44 with the 670-3324-01

board

and it

is vastly different from the 466 boards. All the DC voltage traces

from

J-6

are disconnected all the through holes are unsoldered so there is no
interconnection from top to bottom through out the board. There

appears to

be

no cable connection to the board from the DM44 to supply these?
The DM44 manual parts list's don't show that part number used for the

464/466

with the DM44 it shows the later 466 board and I can not find the

optional

boards listed in the service manuals listed in the DM44 one.
The installation sheets for installing the DM44's don't list different

or

optional boards used like the service manuals do?
So whats up with this bunch of missing info here!

Jim O