Dear OM's

I'm looking for some help concerning a defective driver pcb for a
yig oscillator inside the mentioned device above.

see link: (http://www.mikrocontroller.net/topic/215840#2149959)

I'm looking for the proper value of the destroyed resistor ( 50 ohm) in
the lower corner as well as for the value of the capacitor.

Have any of you a link to the service schematic of the mentioned driver,
or could send me a copy of it.

Any help would be appreciated.


vy73

Markus
alias
DL8MBY

On Apr 18, 3:58*am, Markus Wolfgart wrote:
Dear OM's

I'm looking for some help concerning a defective driver pcb for a
yig oscillator inside the mentioned device above.

see link: (http://www.mikrocontroller.net/topic/215840#2149959)

I'm looking for the proper value of the destroyed resistor ( 50 ohm) in
the lower corner as well as for the value of the capacitor.

Have any of you a link to the service schematic of the mentioned driver,
or could send me a copy of it.

Any help would be appreciated.

vy73

Markus
alias
DL8MBY

So, is that a board that is actually part of the YTO assembly, A11?
There is a remote possibility I can find a schematic...if nobody else
has one handy. I do worry, though, WHY it burned up: is there a
shorted coil in the YTO? I assume you have the 09562-90062.pdf
service manual that you can get from the Agilent website.
Unfortunately, it's pretty thin on component-level schematics. Even
in instrument manuals with more detailed schematics, it's common to
treat the YTO as a "black box."

Cheers,
Tom

On Apr 18, 3:58*am, Markus Wolfgart wrote:
Dear OM's

I'm looking for some help concerning a defective driver pcb for a
yig oscillator inside the mentioned device above.

see link: (http://www.mikrocontroller.net/topic/215840#2149959)

I'm looking for the proper value of the destroyed resistor ( 50 ohm) in
the lower corner as well as for the value of the capacitor.

Have any of you a link to the service schematic of the mentioned driver,
or could send me a copy of it.

Any help would be appreciated.

vy73

Markus
alias
DL8MBY

A bit more on this: tantalum caps have a bad habit of shorting out.
I can see from your posted pictures of the board that the burned axial
lead component is in series from pin 8 of the connector, which from
the partial schematic someone else posted to the thread is the +15V
supply. I can't quite trace out where the other end of the burned
component goes, but if it goes to that burned tantalum, then it's
reasonable to suspect that the capacitor shorted and drew enough
current through the axial lead component to burn up both itself and
the axial lead part, and that may be the extent of the problem. If
the axial lead part really was a resistor, it was probably a pretty
low value, as you suggest, and the value is probably not at all
critical. Is there any chance it was instead a low-value inductor?
You might trace out where that +15V power is used. It may help to
know that the 1826-1149 is an OP-07 op amp. If the tantalum is a
power supply filter cap (pretty likely), you'll of course want to use
one rated at least 25V on a 15V bus; 35V would be even better. These
days you could likely just use a ceramic to replace it...we have a lot
less trouble with ceramic shorting than with tantalums.

Cheers,
Tom

"Markus Wolfgart" wrote in message
...
Dear OM's

I'm looking for some help concerning a defective driver pcb for a
yig oscillator inside the mentioned device above.

see link: (http://www.mikrocontroller.net/topic/215840#2149959)

I'm looking for the proper value of the destroyed resistor ( 50 ohm) in
the lower corner as well as for the value of the capacitor.

Have any of you a link to the service schematic of the mentioned driver,
or could send me a copy of it.

Any help would be appreciated.


vy73

Markus
alias
DL8MBY


I agree with K7ITM that tants have a habit of burning out like the one in
your photo. And I agree it looks like the tant and series R or L are just
filtering a power supply coming onto the board.

From the photos, it looks like the square pad of the blown tant is connected
to a ground plane inside the board. After removing the cap, you could buzz
it out to check. But I think I see a + adjacent to the square pad on the
top copper in your 01k photo. I wonder if there is an error in the PCB
layout or the schematic. You might want to check if pin 8 is really +15V
or -15V by measuring the voltage on the unplugged cable.

On Apr 18, 4:56*pm, "Andrew Holme" wrote:
"Markus Wolfgart" wrote in message

...



Dear OM's

I'm looking for some help concerning a defective driver pcb for a
yig oscillator inside the mentioned device above.

see link: (http://www.mikrocontroller.net/topic/215840#2149959)

I'm looking for the proper value of the destroyed resistor ( 50 ohm) in
the lower corner as well as for the value of the capacitor.

Have any of you a link to the service schematic of the mentioned driver,
or could send me a copy of it.

Any help would be appreciated.

vy73

Markus
alias
DL8MBY

I agree with K7ITM that tants have a habit of burning out like the one in
your photo. *And I agree it looks like the tant and series R or L are just
filtering a power supply coming onto the board.

From the photos, it looks like the square pad of the blown tant is connected
to a ground plane inside the board. *After removing the cap, you could buzz
it out to check. *But I think I see a + adjacent to the square pad on the
top copper in your 01k photo. *I wonder if there is an error in the PCB
layout or the schematic. *You might want to check if pin 8 is really +15V
or -15V by measuring the voltage on the unplugged cable.

Yeah, I kind of wondered about the connections to the cap too. Since
we don't have the board, it's hard to tell. It does look like a 4-
layer board, and in that case the interior layers may be ground and
power (with the power possibly split between +15 and -15, or
such...). I fully agree with Andrew: ohm/buzz out the connections to
reverse-engineer as much of the schematic as you need. It's a pretty
simple board, and shouldn't be difficult. If there's a code on the
two transistors, I can probably tell you what they are (assuming they
aren't labeled 2N3904 or whatever). Typical would be 4-nnn (for an
NPN) or 3-nnn (for a PNP) -- abbreviations for the full HP part
number, which would be 1854-xxxx or 1853-xxxx. The full numbers were
a bit hard to put on small parts back then.

Cheers,
Tom

Dear om Andrew dear om Tom,

many thanks for your prompt replay.

Today before breakfast I start to fiddle out the connections from the
pcb to the parts on it.
I'm not ready yet but probably this evening.

But its true as you noticed that all tree caps are routed to the inner
layer (only three of them) with the pos. pol.

The neighbour of the burned resistor seems to be a coil
(vio/red/green/silver/space/brown) colour marking (72uH? I have to check
the meaning of silver labelling factor 0,1?).

The burned resistor is not directly connected to the destroyed cap but
to one of the others 10u25V or 39u10V.

As you mentioned the OPA labelled as PMI9017 - is this part comparable
to a OP07 (or OP27) ?
I have unfortunately no luck to find any doc in the web but some hints
that PIM parts were manufactured for AD in the 80 years and later on AD
take over this company.

I hope to fine more details this evening.

Many thanks for your help.
I will keep you informed on my progress.

Would be great to reanimate this HP8562B for ham purpose.

vy73 + tnx

Markus
DL8MBY





Am 18.04.2011 12:58, schrieb Markus Wolfgart:
Dear OM's

I'm looking for some help concerning a defective driver pcb for a
yig oscillator inside the mentioned device above.

see link: (http://www.mikrocontroller.net/topic/215840#2149959)

I'm looking for the proper value of the destroyed resistor ( 50 ohm) in
the lower corner as well as for the value of the capacitor.

Have any of you a link to the service schematic of the mentioned driver,
or could send me a copy of it.

Any help would be appreciated.


vy73

Markus
alias
DL8MBY

On Apr 18, 11:56*pm, Markus Wolfgart wrote:
Dear om Andrew dear om Tom,

many thanks for your prompt replay.

Today before breakfast I start to fiddle out the connections from the
pcb to the parts on it.
I'm not ready yet but probably this evening.

But its true as you noticed that all tree caps are routed to the inner
layer (only three of them) with the pos. pol.

The neighbour of the burned resistor seems to be a coil
(vio/red/green/silver/space/brown) colour marking (72uH? I have to check
the meaning of silver labelling factor 0,1?).

The burned resistor is not directly connected to the destroyed cap but
to one of the others 10u25V or 39u10V.

As you mentioned the OPA labelled as PMI9017 - is this part comparable
to a OP07 (or OP27) ?
I have unfortunately no luck to find any doc in the web but some hints
that PIM parts were manufactured for AD in the 80 years and later on AD
take over this company.

I hope to fine more details this evening.

Many thanks for your help.
I will keep you informed on my progress.

Would be great to reanimate this HP8562B for ham purpose.

vy73 + tnx

Markus
DL8MBY

Am 18.04.2011 12:58, schrieb Markus Wolfgart:

Dear OM's

I'm looking for some help concerning a defective driver pcb for a
yig oscillator inside the mentioned device above.

see link: (http://www.mikrocontroller.net/topic/215840#2149959)

I'm looking for the proper value of the destroyed resistor ( 50 ohm) in
the lower corner as well as for the value of the capacitor.

Have any of you a link to the service schematic of the mentioned driver,
or could send me a copy of it.

Any help would be appreciated.

vy73

Markus
alias
DL8MBY

Yes, the 1826-1149 is an OP-07, and specifically an OP-07EZ. It
appears to still be available from Analog Devices, at least in a
plastic version, and you can get a full data sheet on their web site.
The web site also suggests that OP-27 is similar, the data sheet for
the OP-97 may give you some ideas too, and the OP-07 web page at
Analog Devices suggests the AD8677 as a replacement. In short, it
should not be difficult to find both data for the OP-07 and a suitable
replacement should that be necessary. And yes, Analog Devices
acquired PMI many years ago, but carries on the "OP" line of parts
today.

Cheers,
Tom

On Apr 18, 11:56*pm, Markus Wolfgart wrote:
Dear om Andrew dear om Tom,

many thanks for your prompt replay.

Today before breakfast I start to fiddle out the connections from the
pcb to the parts on it.
I'm not ready yet but probably this evening.

But its true as you noticed that all tree caps are routed to the inner
layer (only three of them) with the pos. pol.

The neighbour of the burned resistor seems to be a coil
(vio/red/green/silver/space/brown) colour marking (72uH? I have to check
the meaning of silver labelling factor 0,1?).

The burned resistor is not directly connected to the destroyed cap but
to one of the others 10u25V or 39u10V.

As you mentioned the OPA labelled as PMI9017 - is this part comparable
to a OP07 (or OP27) ?
I have unfortunately no luck to find any doc in the web but some hints
that PIM parts were manufactured for AD in the 80 years and later on AD
take over this company.

I hope to fine more details this evening.

Many thanks for your help.
I will keep you informed on my progress.

Would be great to reanimate this HP8562B for ham purpose.

vy73 + tnx

Markus
DL8MBY

Am 18.04.2011 12:58, schrieb Markus Wolfgart:

Dear OM's

I'm looking for some help concerning a defective driver pcb for a
yig oscillator inside the mentioned device above.

see link: (http://www.mikrocontroller.net/topic/215840#2149959)

I'm looking for the proper value of the destroyed resistor ( 50 ohm) in
the lower corner as well as for the value of the capacitor.

Have any of you a link to the service schematic of the mentioned driver,
or could send me a copy of it.

Any help would be appreciated.

vy73

Markus
alias
DL8MBY

Addendum: the label on the op amp, PMI9017, is undoubtedly the date
code: 17th week of 1990. The 1826-1149 is an HP part number: all
common HP parts have a "4x4" HP number; ones special to a single
instrument or a few instruments may have a "5x5" number. Note that
the printed circuit board has a 4x4 number: 5062-0752. That suggests
to me that the YTO is used in several other instruments, though it
could also be the case that when it was made, the team _thought_ it
would be used in other places. I'd expect some of the boards in your
instrument will have 5x5 numbers beginning with 08562, showing that
they are used in the 8562. Many (most) parts with 4x4 part numbers
have one or more equivalent industry-standard part numbers; for
example a 316 ohm resistor could be purchased from any of several
different suppliers, all qualified to meet the requirements of the
particular 4x4 part number. But in some rare cases, a 4x4 number
refers to a part selected for especially good performance in some
area, and you couldn't be guaranteed to maintain performance of the
instrument with a similar non-selected "generic" part.

Cheers,
Tom

Dear Tom,

many thanks for your detailed explanation.

Today before my breakfast;-) I replaced two caps
a little choke and the destroyed resistor (I guess a value of 75Ohm)
by some parts of my ham box.
The second cap which was connected to the resistor which overheat was
shorted too but looks good from outside in contrast to the one which was
destroyed.
A quick and dirty solution for the moment until I get the proper infos.
This dirty solution was so far successful as I could see the spectrum of
the 300MHz test oscillator build in ;-)

Now I will check the docs in order to find out how to proof that the SA
is working properly.

I will keep you informed on further progress.

By the way I get some help from your good friend Barry WA4VZQ
via mail.

vy73

Markus



Am 20.04.2011 00:37, schrieb K7ITM:
On Apr 18, 11:56 pm, Markus Wolfgart wrote:
Dear om Andrew dear om Tom,

many thanks for your prompt replay.

Today before breakfast I start to fiddle out the connections from the
pcb to the parts on it.
I'm not ready yet but probably this evening.

But its true as you noticed that all tree caps are routed to the inner
layer (only three of them) with the pos. pol.

The neighbour of the burned resistor seems to be a coil
(vio/red/green/silver/space/brown) colour marking (72uH? I have to check
the meaning of silver labelling factor 0,1?).

The burned resistor is not directly connected to the destroyed cap but
to one of the others 10u25V or 39u10V.

As you mentioned the OPA labelled as PMI9017 - is this part comparable
to a OP07 (or OP27) ?
I have unfortunately no luck to find any doc in the web but some hints
that PIM parts were manufactured for AD in the 80 years and later on AD
take over this company.

I hope to fine more details this evening.

Many thanks for your help.
I will keep you informed on my progress.

Would be great to reanimate this HP8562B for ham purpose.

vy73 + tnx

Markus
DL8MBY

Am 18.04.2011 12:58, schrieb Markus Wolfgart:

Dear OM's

I'm looking for some help concerning a defective driver pcb for a
yig oscillator inside the mentioned device above.

see link: (http://www.mikrocontroller.net/topic/215840#2149959)

I'm looking for the proper value of the destroyed resistor ( 50 ohm) in
the lower corner as well as for the value of the capacitor.

Have any of you a link to the service schematic of the mentioned driver,
or could send me a copy of it.

Any help would be appreciated.

vy73

Markus
alias
DL8MBY

Addendum: the label on the op amp, PMI9017, is undoubtedly the date
code: 17th week of 1990. The 1826-1149 is an HP part number: all
common HP parts have a "4x4" HP number; ones special to a single
instrument or a few instruments may have a "5x5" number. Note that
the printed circuit board has a 4x4 number: 5062-0752. That suggests
to me that the YTO is used in several other instruments, though it
could also be the case that when it was made, the team _thought_ it
would be used in other places. I'd expect some of the boards in your
instrument will have 5x5 numbers beginning with 08562, showing that
they are used in the 8562. Many (most) parts with 4x4 part numbers
have one or more equivalent industry-standard part numbers; for
example a 316 ohm resistor could be purchased from any of several
different suppliers, all qualified to meet the requirements of the
particular 4x4 part number. But in some rare cases, a 4x4 number
refers to a part selected for especially good performance in some
area, and you couldn't be guaranteed to maintain performance of the
instrument with a similar non-selected "generic" part.

Cheers,
Tom