Hp 10544A repair
Hi all,
Have anyone some experience about 10544A repair? I've recently fixed a
10811A, and it is relatively easy to disassemble, but 10544 has not screws
and the manual does not deal about servicing. Can i try to open the box by
removing the white plastic tips without demage something? And then how to
correctly extract the inner stuff? The malfunction is that the oven monitor
signal is bad and the 10MHz signal has low amplitude and very bad shape
(distorted), but the output frequency is ok and oven heather and
control seems to be ok too (current drain from power supply is ok). So
there are probably some defective components in the output buffer zone of
the circuit. Another question is that the schematic (thanks to KO4BB!)
seems to have a mistake about drawing of the oven monitor signal (the pin
11 wire is taken between the thermal fuse and the power darlington: how
does can it work in that way?).
Thanks and regards
Luca
iw2lje
Hi all,
Sorry for bad english
The transistor Q4 has the emitter and the collector reversed; R12 is connected to the collector and the waveform is square wave with duty cycle that depends on the oven temperature; supply voltage = cold, minimun duty cycle = warm.
It is relatively easy to extract the boards and access the oven controller and amplifier AGC.
Pay attention to the black wires (NTC) and red (oven heather).
Remember that the output impedance is about 1000 ohm as for data sheet and check the power supply.
Semiconductor type
Q4 = MJE700
Q2 = MPS A12
Q3 = 2N2646
U1 = LM201NPN = 2N3906
if you want more detailed information in Italian you can contact me directly.
Best regards
John (Gianni)
Il 26 aprile 2015, Luca Dal Passo iw2lje@gmail.com ha scritto:
Hi all,
Have anyone some experience about 10544A repair? I've recently fixed a
10811A, and it is relatively easy to disassemble, but 10544 has not screws
and the manual does not deal about servicing. Can i try to open the box by
removing the white plastic tips without demage something? And then how to
correctly extract the inner stuff? The malfunction is that the oven monitor
signal is bad and the 10MHz signal has low amplitude and very bad shape
(distorted), but the output frequency is ok and oven heather and
control seems to be ok too (current drain from power supply is ok). So
there are probably some defective components in the output buffer zone of
the circuit. Another question is that the schematic (thanks to KO4BB!)
seems to have a mistake about drawing of the oven monitor signal (the pin
11 wire is taken between the thermal fuse and the power darlington: how
does can it work in that way?).
Thanks and regards
Luca
iw2lje
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
That reminds me -- years ago I cleaned up, corrected, and annotated a
copy of the HP 10544 schematic. I dug it up and just posted it to
Didier's site (http://www.ko4bb.com/manuals/). When it comes off
quarantine, you can find it by searching for "HP 10544A schematic
corrected and annotated".
Best regards,
Charles
Ok, very good, many thanks Gianni, Corby, Charly, for your suggestions and
hints!
I will be here again if there will be interesting topics related with this
item.
Cheers
Luca
iw2lje
Milano - Italy
Il lunedì 27 aprile 2015, Charles Steinmetz csteinmetz@yandex.com ha
scritto:
That reminds me -- years ago I cleaned up, corrected, and annotated a copy
of the HP 10544 schematic. I dug it up and just posted it to Didier's site
(http://www.ko4bb.com/manuals/). When it comes off quarantine, you can
find it by searching for "HP 10544A schematic corrected and annotated".
Best regards,
Charles
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
The quarantine is officially over (for this week :)
Thanks for the uploads
Didier KO4BB
PS: I am now trying to move the manuals and equipment specific docs out of the GPS Timing folder into the manufacturer's folders. I realize it may be less convenient for those who are only interested in timing information, but it makes the overall organization of the site easier for me and (I hope) for a majority of users.
Until that is complete, you can find HP timing info in two folders, the GPS Timing folder and in the HP Agilent folder for instance. The search works through the entire site, so finding stuff should not be harder.
As I am sure most of you have noticed, I have implemented a Content Management System. The main reason was to make the site easier to manage. A side benefit is to keep my Google rankings up since the CMS is mobile friendly and now Google ranks down the sites that are not. I am sorry for those who lament the loss of Comic Sans... The old site is still there, the old links still work but the old pages won't be maintained. After a while, they will go away.
On April 27, 2015 4:14:07 AM CDT, Charles Steinmetz csteinmetz@yandex.com wrote:
That reminds me -- years ago I cleaned up, corrected, and annotated a
copy of the HP 10544 schematic. I dug it up and just posted it to
Didier's site (http://www.ko4bb.com/manuals/). When it comes off
quarantine, you can find it by searching for "HP 10544A schematic
corrected and annotated".
Best regards,
Charles
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
--
Sent from my Motorola Droid Razr HD 4G LTE wireless tracker while I do other things.
Thank you very much Didier for your wonderful site and thank you again
Charles for your precious schematic. Finally i'm able to understand
something more!
Ciao!
Luca
iw2lje
Milano
Italy
Il domenica 3 maggio 2015, Didier Juges shalimr9@gmail.com ha scritto:
The quarantine is officially over (for this week :)
Thanks for the uploads
Didier KO4BB
PS: I am now trying to move the manuals and equipment specific docs out of
the GPS Timing folder into the manufacturer's folders. I realize it may be
less convenient for those who are only interested in timing information,
but it makes the overall organization of the site easier for me and (I
hope) for a majority of users.
Until that is complete, you can find HP timing info in two folders, the
GPS Timing folder and in the HP Agilent folder for instance. The search
works through the entire site, so finding stuff should not be harder.
As I am sure most of you have noticed, I have implemented a Content
Management System. The main reason was to make the site easier to manage. A
side benefit is to keep my Google rankings up since the CMS is mobile
friendly and now Google ranks down the sites that are not. I am sorry for
those who lament the loss of Comic Sans... The old site is still there, the
old links still work but the old pages won't be maintained. After a while,
they will go away.
On April 27, 2015 4:14:07 AM CDT, Charles Steinmetz <csteinmetz@yandex.com
javascript:;> wrote:
That reminds me -- years ago I cleaned up, corrected, and annotated a
copy of the HP 10544 schematic. I dug it up and just posted it to
Didier's site (http://www.ko4bb.com/manuals/). When it comes off
quarantine, you can find it by searching for "HP 10544A schematic
corrected and annotated".
Best regards,
Charles
time-nuts mailing list -- time-nuts@febo.com javascript:;
To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
--
Sent from my Motorola Droid Razr HD 4G LTE wireless tracker while I do
other things.
time-nuts mailing list -- time-nuts@febo.com javascript:;
To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
That reminds me -- years ago I cleaned up, corrected, and annotated a
copy of the HP 10544 schematic. I dug it up and just posted it to
Didier's site (http://www.ko4bb.com/manuals/). When it comes off
quarantine, you can find it by searching for:
"HP 10544A schematic corrected and annotated" (do not type the
quotation marks).
Didier wrote:
The quarantine is officially over (for this week :)
Luca wrote:
Thank you very much Didier for your wonderful site
Yes, thank you for the terrific resource, Didier!
thank you again Charles for your precious schematic.
My pleasure. I hope people find it useful.
Charles