R
rickman
Guest
On 3/12/2013 1:36 PM, DaveC wrote:
--
Rick
Great idea, thanks!
--
Rick
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R
rickman
Guest
On 3/11/2013 11:25 PM, Robert Baer wrote:
them and Google Groups doesn't seem to support them either.
Thanks for the effort.
--
Rick
I don't seem to have access to binary groups. My server doesn't hostrickman wrote:
On 3/10/2013 9:33 PM, tm wrote:
"rickman" <gnuarm@gmail.com> wrote in message
news:khj0oj$c3h$1@dont-email.me...
On 2/7/2013 9:07 PM, tm wrote:
"rickman" <gnuarm@gmail.com> wrote in message
news:kf1jev$3ml$1@dont-email.me...
On 2/7/2013 7:07 PM, George Herold wrote:
On Feb 7, 6:14 pm, rickman<gnu...@gmail.com> wrote:
On 2/1/2013 11:14 PM, josephkk wrote:
How about posting a scope trace of the wonky waveform in abse? or
some
picture hosting site?
Sorry this took me a while. Here is a drawing of what I see. Not
exactly like the oscope display, but shows the important stuff.
http://arius.com/stuff/HP3310B/HP3310B_malfunction.png
Note that when set for 50 kHz, the measured frequency varies
around 80
kHz.
--
Rick- Hide quoted text -
- Show quoted text -
Weird, I understand this is a basically analog device (Not a DDS).
Then it looks like some inverter falling out of the signal chain.
Intermitent power to some section.... maybe? Does it change if you
load down the output? Have you opened it up and wiggled things?
George H.
No, I haven't loaded the output. I have probed and prodded with my
fingers. I think there was a point where it had some impact. I just
haven't taken the time to look at the docs yet. I'm thinking the ramp
generator is messing up and triggering the switch to the up ramp too
soon.
--
What were your measured power supply voltages? Ripple?
+25 = ?
-25 = ?
+10 = ?
-10 = ?
I didn't write them all down, but they are all within 0.2 volts of
nominal and I don't see any ripple on the supplies.
On the other hand, the fact that the problem is only on the two upper
ranges indicates it is within the "High Frequency Level Detector". I
measured some voltages there and the lower half seems to be way out of
whack. There are two symmetrical circuits to generate what would seem
to be a reference voltage for the +-5 volt level detector. But I'm not
sure that is how it works really. According to the schematic notes,
changing the switch from the lower ranges to the two higher ranges
changes the "references" from +10 / -10 volts to -10.6 / +10.6 volts.
What?
Something else I don't get is one transistor in each half is reverse
biased, yes, the CB junction is reverse biased, but the BE junction is
also reverse biased by 6 volts! The emitter resistor is connected to
+10 volts, the collector is connected to -10 volts and the emitter is
supposed to be at +10.6 volts! What??? The transistor is a PNP and the
base is supposed to be at +16.8 volts. How is this supposed to work?
Have I forgotten my transistor notation? PNP is arrow pointing to base
which should be more negative than the emitter, right?
Anyway, the half that is whacked out has some random fluctuations that
I can see on the scope which don't appear on the supplies. I figure
one of the components is bad but I can't trace it to anything in
particular. The circuit all interacts somewhat and the "noise" signal
appears through nearly all of it.
Parts of the large schematic pages are missing. I assume somewhere
they tell you the conditions for taking the measurements, but I
haven't found them yet. They do have a troubleshooting section that
clearly tells you to look in this circuit.
--
Rick
All the conditions for the measurements are on PDF page 71, schematic 2,
at the lower right side of the page. Look for all the waveforms just to
the right of the notes section.
What you describe cries out leaky capacitor. Since it is only doing it
on the upper two ranges, that sure points to that circuit.
All of the transistors in that circuit are 2N3904 (N) or 3906 (P) so a
shotgun approach might be worth it in case it is a leaky transistor.
Take note of Note-5.
Thanks. My copy doesn't have complete pages of the schematics. They are
cut off at the bottom and when they span two pages there is a gap in the
middle. I think I got this from the Agilent site. Is there a better copy
available somewhere else?
BTW, to make it more viewable I rearranged the schematics a bit and
rotated the vertical pages. I see notes on page 70 of 87 and this page
also has assemblies A2 and A3 and waveforms 12 through 16. Is this the
page you mean?
It includes notes 1 through 3 which is cut off a bit. I don't have notes
4 and 5 at all. On my page 68 I see notes, but all of the data on the
right is cut off and note 5 is missing.
Wait! I found an intact set of notes on page 77. I will recheck the DC
measurements with the settings indicated. This may bring the good
section into alignment with the schematic values, but I'm sure the bad
half will still be bad. Problem is I just don't know how transistors are
expected to behave when both junctions are reverse biased like the
schematic says they should be.
I think your shotgunning idea is good, I just don't relish the idea of
taking this thing apart, but I guess it can't be too bad. When they have
front panel switches soldered to the board it makes me twinge. I'm
probably just being overly worried, I expect it is made to be repaired
as well as assembled, unlike today's stuff.
Heck, I might want to get a second one so I can use it to make a sweep
generator!
See my posting "Re: HP 3310B Malfunction Generator" in a.b.s.electronic.
them and Google Groups doesn't seem to support them either.
Thanks for the effort.
--
Rick
T
tm
Guest
"rickman" <gnuarm@gmail.com> wrote in message
news:kho3l8$sv1$1@dont-email.me...
http://www.ko4bb.com/manuals/index.php?dir=HP_Agilent
About 1/2 way down the page.
news:kho3l8$sv1$1@dont-email.me...
Look here:On 3/12/2013 2:00 PM, Michael A. Terrell wrote:
rickman wrote:
Thanks. My copy doesn't have complete pages of the schematics.
Print all the partial schematics and try piecing them together.
That won't generate the missing pieces. In my copy of the manual from
Agilent the schematics are not complete.
--
Rick
http://www.ko4bb.com/manuals/index.php?dir=HP_Agilent
About 1/2 way down the page.
R
rickman
Guest
On 3/12/2013 5:26 PM, tm wrote:
I was just going to post thanking DaveC for pointing me to the yahoo
group where I found info pointing me to this link. It is downloading as
I type. It is a slightly older copy, but it is much better quality and
larger, 72 MB vs. 5 MB!
Thanks for the advice. This site is a treasure trove. I will feel much
better about buying old equipment on eBay. In fact, I may work on my
oscope to see if I can get the second channel working again. I wish I
could find a source for the horizontal position pot. It has been
terribly dirty for years. I asked HP about it once and they wanted $50
for a replacement, but that was way back when I could barely afford the
scope, much less money for expensive repairs. I think I wouldn't pay
$50 now, but only because the scope is barely worth that I think.
I'll say one thing about this unit, it is a field service model with a
vertically oriented front panel. So it takes up much less space on the
workbench than the horizontal units. Why don't they use this profile
with *all* the scopes? The screen fits nicely above most of the
controls and inputs with a small panel of buttons beside the screen
(power, brightness, etc.). With today's scopes they are very thin, but
still are wide horizontally. Why not thin and taller? I guess they
might be more tipsy... Makes me want to build my own.
--
Rick
Hi tm,"rickman" <gnuarm@gmail.com> wrote in message
news:kho3l8$sv1$1@dont-email.me...
On 3/12/2013 2:00 PM, Michael A. Terrell wrote:
rickman wrote:
Thanks. My copy doesn't have complete pages of the schematics.
Print all the partial schematics and try piecing them together.
That won't generate the missing pieces. In my copy of the manual from
Agilent the schematics are not complete.
--
Rick
Look here:
http://www.ko4bb.com/manuals/index.php?dir=HP_Agilent
About 1/2 way down the page.
I was just going to post thanking DaveC for pointing me to the yahoo
group where I found info pointing me to this link. It is downloading as
I type. It is a slightly older copy, but it is much better quality and
larger, 72 MB vs. 5 MB!
Thanks for the advice. This site is a treasure trove. I will feel much
better about buying old equipment on eBay. In fact, I may work on my
oscope to see if I can get the second channel working again. I wish I
could find a source for the horizontal position pot. It has been
terribly dirty for years. I asked HP about it once and they wanted $50
for a replacement, but that was way back when I could barely afford the
scope, much less money for expensive repairs. I think I wouldn't pay
$50 now, but only because the scope is barely worth that I think.
I'll say one thing about this unit, it is a field service model with a
vertically oriented front panel. So it takes up much less space on the
workbench than the horizontal units. Why don't they use this profile
with *all* the scopes? The screen fits nicely above most of the
controls and inputs with a small panel of buttons beside the screen
(power, brightness, etc.). With today's scopes they are very thin, but
still are wide horizontally. Why not thin and taller? I guess they
might be more tipsy... Makes me want to build my own.
--
Rick
R
rickman
Guest
On 3/12/2013 1:36 PM, DaveC wrote:
Thanks a lot for this link. I found some discussions on this unit and
one pointed me to a more complete manual! Great suggestion!!!
Now I just need to figure the durn thing out. One of the posts I read
seems to be saying that the voltages in the manual require some mods to
the circuit and I see what they mean. Voltages on the output are -16V
when the output, as we know, should be 0 volts. I may be seeing
something similar on the high frequency circuit.
--
Rick
Dave,Join the Yahoo group for HP Test Equipment. LOTS of engrs and techs have tons
of experience with the "boat anchor" HP's. I'm sure more than one has been
down this road with your particular gen.
http://groups.yahoo.com/group/hp_agilent_equipment
Good luck.
Thanks a lot for this link. I found some discussions on this unit and
one pointed me to a more complete manual! Great suggestion!!!
Now I just need to figure the durn thing out. One of the posts I read
seems to be saying that the voltages in the manual require some mods to
the circuit and I see what they mean. Voltages on the output are -16V
when the output, as we know, should be 0 volts. I may be seeing
something similar on the high frequency circuit.
--
Rick
D
DaveC
Guest
Glad to turn on someone else to a great resource.Thanks a lot for this link. I found some discussions on this unit and
one pointed me to a more complete manual! Great suggestion!!!
Now I just need to figure the durn thing out. One of the posts I read
seems to be saying that the voltages in the manual require some mods to
the circuit and I see what they mean. Voltages on the output are -16V
when the output, as we know, should be 0 volts. I may be seeing
something similar on the high frequency circuit.
It looks like you're off and running!
Good luck.
Cheers,
Dave
R
Robert Baer
Guest
rickman wrote:
On 3/11/2013 11:25 PM, Robert Baer wrote:
rickman wrote:
On 3/10/2013 9:33 PM, tm wrote:
"rickman" <gnuarm@gmail.com> wrote in message
news:khj0oj$c3h$1@dont-email.me...
On 2/7/2013 9:07 PM, tm wrote:
"rickman" <gnuarm@gmail.com> wrote in message
news:kf1jev$3ml$1@dont-email.me...
On 2/7/2013 7:07 PM, George Herold wrote:
On Feb 7, 6:14 pm, rickman<gnu...@gmail.com> wrote:
On 2/1/2013 11:14 PM, josephkk wrote:
How about posting a scope trace of the wonky waveform in abse? or
some
picture hosting site?
Sorry this took me a while. Here is a drawing of what I see. Not
exactly like the oscope display, but shows the important stuff.
http://arius.com/stuff/HP3310B/HP3310B_malfunction.png
Note that when set for 50 kHz, the measured frequency varies
around 80
kHz.
--
Rick- Hide quoted text -
- Show quoted text -
Weird, I understand this is a basically analog device (Not a DDS).
Then it looks like some inverter falling out of the signal chain.
Intermitent power to some section.... maybe? Does it change if you
load down the output? Have you opened it up and wiggled things?
George H.
No, I haven't loaded the output. I have probed and prodded with my
fingers. I think there was a point where it had some impact. I just
haven't taken the time to look at the docs yet. I'm thinking the
ramp
generator is messing up and triggering the switch to the up ramp too
soon.
--
What were your measured power supply voltages? Ripple?
+25 = ?
-25 = ?
+10 = ?
-10 = ?
I didn't write them all down, but they are all within 0.2 volts of
nominal and I don't see any ripple on the supplies.
On the other hand, the fact that the problem is only on the two upper
ranges indicates it is within the "High Frequency Level Detector". I
measured some voltages there and the lower half seems to be way out of
whack. There are two symmetrical circuits to generate what would seem
to be a reference voltage for the +-5 volt level detector. But I'm not
sure that is how it works really. According to the schematic notes,
changing the switch from the lower ranges to the two higher ranges
changes the "references" from +10 / -10 volts to -10.6 / +10.6 volts.
What?
Something else I don't get is one transistor in each half is reverse
biased, yes, the CB junction is reverse biased, but the BE junction is
also reverse biased by 6 volts! The emitter resistor is connected to
+10 volts, the collector is connected to -10 volts and the emitter is
supposed to be at +10.6 volts! What??? The transistor is a PNP and the
base is supposed to be at +16.8 volts. How is this supposed to work?
Have I forgotten my transistor notation? PNP is arrow pointing to base
which should be more negative than the emitter, right?
Anyway, the half that is whacked out has some random fluctuations that
I can see on the scope which don't appear on the supplies. I figure
one of the components is bad but I can't trace it to anything in
particular. The circuit all interacts somewhat and the "noise" signal
appears through nearly all of it.
Parts of the large schematic pages are missing. I assume somewhere
they tell you the conditions for taking the measurements, but I
haven't found them yet. They do have a troubleshooting section that
clearly tells you to look in this circuit.
--
Rick
All the conditions for the measurements are on PDF page 71,
schematic 2,
at the lower right side of the page. Look for all the waveforms just to
the right of the notes section.
What you describe cries out leaky capacitor. Since it is only doing it
on the upper two ranges, that sure points to that circuit.
All of the transistors in that circuit are 2N3904 (N) or 3906 (P) so a
shotgun approach might be worth it in case it is a leaky transistor.
Take note of Note-5.
Thanks. My copy doesn't have complete pages of the schematics. They are
cut off at the bottom and when they span two pages there is a gap in the
middle. I think I got this from the Agilent site. Is there a better copy
available somewhere else?
BTW, to make it more viewable I rearranged the schematics a bit and
rotated the vertical pages. I see notes on page 70 of 87 and this page
also has assemblies A2 and A3 and waveforms 12 through 16. Is this the
page you mean?
It includes notes 1 through 3 which is cut off a bit. I don't have notes
4 and 5 at all. On my page 68 I see notes, but all of the data on the
right is cut off and note 5 is missing.
Wait! I found an intact set of notes on page 77. I will recheck the DC
measurements with the settings indicated. This may bring the good
section into alignment with the schematic values, but I'm sure the bad
half will still be bad. Problem is I just don't know how transistors are
expected to behave when both junctions are reverse biased like the
schematic says they should be.
I think your shotgunning idea is good, I just don't relish the idea of
taking this thing apart, but I guess it can't be too bad. When they have
front panel switches soldered to the board it makes me twinge. I'm
probably just being overly worried, I expect it is made to be repaired
as well as assembled, unlike today's stuff.
Heck, I might want to get a second one so I can use it to make a sweep
generator!
See my posting "Re: HP 3310B Malfunction Generator" in a.b.s.electronic.
I don't seem to have access to binary groups. My server doesn't host
them and Google Groups doesn't seem to support them either.
Thanks for the effort.
OK; go to: http://www.oil4lessllc.org/HP3312A/
R
rickman
Guest
On 3/13/2013 4:00 PM, Robert Baer wrote:
unit at all. It looks like a much more modern unit with wide use of op
amps rather than a bazillion transistors? I guess it might be a better
unit to buy?
--
Rick
Ok, I can get to that one. But what is it for? That is not the samerickman wrote:
On 3/11/2013 11:25 PM, Robert Baer wrote:
rickman wrote:
On 3/10/2013 9:33 PM, tm wrote:
"rickman" <gnuarm@gmail.com> wrote in message
news:khj0oj$c3h$1@dont-email.me...
On 2/7/2013 9:07 PM, tm wrote:
"rickman" <gnuarm@gmail.com> wrote in message
news:kf1jev$3ml$1@dont-email.me...
On 2/7/2013 7:07 PM, George Herold wrote:
On Feb 7, 6:14 pm, rickman<gnu...@gmail.com> wrote:
On 2/1/2013 11:14 PM, josephkk wrote:
How about posting a scope trace of the wonky waveform in
abse? or
some
picture hosting site?
Sorry this took me a while. Here is a drawing of what I see. Not
exactly like the oscope display, but shows the important stuff.
http://arius.com/stuff/HP3310B/HP3310B_malfunction.png
Note that when set for 50 kHz, the measured frequency varies
around 80
kHz.
--
Rick- Hide quoted text -
- Show quoted text -
Weird, I understand this is a basically analog device (Not a DDS).
Then it looks like some inverter falling out of the signal chain.
Intermitent power to some section.... maybe? Does it change if you
load down the output? Have you opened it up and wiggled things?
George H.
No, I haven't loaded the output. I have probed and prodded with my
fingers. I think there was a point where it had some impact. I just
haven't taken the time to look at the docs yet. I'm thinking the
ramp
generator is messing up and triggering the switch to the up ramp
too
soon.
--
What were your measured power supply voltages? Ripple?
+25 = ?
-25 = ?
+10 = ?
-10 = ?
I didn't write them all down, but they are all within 0.2 volts of
nominal and I don't see any ripple on the supplies.
On the other hand, the fact that the problem is only on the two upper
ranges indicates it is within the "High Frequency Level Detector". I
measured some voltages there and the lower half seems to be way
out of
whack. There are two symmetrical circuits to generate what would seem
to be a reference voltage for the +-5 volt level detector. But I'm
not
sure that is how it works really. According to the schematic notes,
changing the switch from the lower ranges to the two higher ranges
changes the "references" from +10 / -10 volts to -10.6 / +10.6 volts.
What?
Something else I don't get is one transistor in each half is reverse
biased, yes, the CB junction is reverse biased, but the BE
junction is
also reverse biased by 6 volts! The emitter resistor is connected to
+10 volts, the collector is connected to -10 volts and the emitter is
supposed to be at +10.6 volts! What??? The transistor is a PNP and
the
base is supposed to be at +16.8 volts. How is this supposed to work?
Have I forgotten my transistor notation? PNP is arrow pointing to
base
which should be more negative than the emitter, right?
Anyway, the half that is whacked out has some random fluctuations
that
I can see on the scope which don't appear on the supplies. I figure
one of the components is bad but I can't trace it to anything in
particular. The circuit all interacts somewhat and the "noise" signal
appears through nearly all of it.
Parts of the large schematic pages are missing. I assume somewhere
they tell you the conditions for taking the measurements, but I
haven't found them yet. They do have a troubleshooting section that
clearly tells you to look in this circuit.
--
Rick
All the conditions for the measurements are on PDF page 71,
schematic 2,
at the lower right side of the page. Look for all the waveforms
just to
the right of the notes section.
What you describe cries out leaky capacitor. Since it is only doing it
on the upper two ranges, that sure points to that circuit.
All of the transistors in that circuit are 2N3904 (N) or 3906 (P) so a
shotgun approach might be worth it in case it is a leaky transistor.
Take note of Note-5.
Thanks. My copy doesn't have complete pages of the schematics. They are
cut off at the bottom and when they span two pages there is a gap in
the
middle. I think I got this from the Agilent site. Is there a better
copy
available somewhere else?
BTW, to make it more viewable I rearranged the schematics a bit and
rotated the vertical pages. I see notes on page 70 of 87 and this page
also has assemblies A2 and A3 and waveforms 12 through 16. Is this the
page you mean?
It includes notes 1 through 3 which is cut off a bit. I don't have
notes
4 and 5 at all. On my page 68 I see notes, but all of the data on the
right is cut off and note 5 is missing.
Wait! I found an intact set of notes on page 77. I will recheck the DC
measurements with the settings indicated. This may bring the good
section into alignment with the schematic values, but I'm sure the bad
half will still be bad. Problem is I just don't know how transistors
are
expected to behave when both junctions are reverse biased like the
schematic says they should be.
I think your shotgunning idea is good, I just don't relish the idea of
taking this thing apart, but I guess it can't be too bad. When they
have
front panel switches soldered to the board it makes me twinge. I'm
probably just being overly worried, I expect it is made to be repaired
as well as assembled, unlike today's stuff.
Heck, I might want to get a second one so I can use it to make a sweep
generator!
See my posting "Re: HP 3310B Malfunction Generator" in a.b.s.electronic.
I don't seem to have access to binary groups. My server doesn't host
them and Google Groups doesn't seem to support them either.
Thanks for the effort.
OK; go to: http://www.oil4lessllc.org/HP3312A/
unit at all. It looks like a much more modern unit with wide use of op
amps rather than a bazillion transistors? I guess it might be a better
unit to buy?
--
Rick
R
Robert Baer
Guest
rickman wrote:
Been awhile since i looked at the incomplete Agilent schematic, but
the diode array and biasing should be the same.
In this schematic, except for Q306 and Q309, all transistors are
fully active (no reversed biased E-B or forward biased B-C junctions).
Maybe i should look at their crummy schematic..
...still looking at it; will respond later.
seemed to be the same.On 3/13/2013 4:00 PM, Robert Baer wrote:
rickman wrote:
On 3/11/2013 11:25 PM, Robert Baer wrote:
rickman wrote:
On 3/10/2013 9:33 PM, tm wrote:
"rickman" <gnuarm@gmail.com> wrote in message
news:khj0oj$c3h$1@dont-email.me...
On 2/7/2013 9:07 PM, tm wrote:
"rickman" <gnuarm@gmail.com> wrote in message
news:kf1jev$3ml$1@dont-email.me...
On 2/7/2013 7:07 PM, George Herold wrote:
On Feb 7, 6:14 pm, rickman<gnu...@gmail.com> wrote:
On 2/1/2013 11:14 PM, josephkk wrote:
How about posting a scope trace of the wonky waveform in
abse? or
some
picture hosting site?
Sorry this took me a while. Here is a drawing of what I see. Not
exactly like the oscope display, but shows the important stuff.
http://arius.com/stuff/HP3310B/HP3310B_malfunction.png
Note that when set for 50 kHz, the measured frequency varies
around 80
kHz.
--
Rick- Hide quoted text -
- Show quoted text -
Weird, I understand this is a basically analog device (Not a
DDS).
Then it looks like some inverter falling out of the signal chain.
Intermitent power to some section.... maybe? Does it change if
you
load down the output? Have you opened it up and wiggled things?
George H.
No, I haven't loaded the output. I have probed and prodded with my
fingers. I think there was a point where it had some impact. I
just
haven't taken the time to look at the docs yet. I'm thinking the
ramp
generator is messing up and triggering the switch to the up ramp
too
soon.
--
What were your measured power supply voltages? Ripple?
+25 = ?
-25 = ?
+10 = ?
-10 = ?
I didn't write them all down, but they are all within 0.2 volts of
nominal and I don't see any ripple on the supplies.
On the other hand, the fact that the problem is only on the two
upper
ranges indicates it is within the "High Frequency Level Detector". I
measured some voltages there and the lower half seems to be way
out of
whack. There are two symmetrical circuits to generate what would
seem
to be a reference voltage for the +-5 volt level detector. But I'm
not
sure that is how it works really. According to the schematic notes,
changing the switch from the lower ranges to the two higher ranges
changes the "references" from +10 / -10 volts to -10.6 / +10.6
volts.
What?
Something else I don't get is one transistor in each half is reverse
biased, yes, the CB junction is reverse biased, but the BE
junction is
also reverse biased by 6 volts! The emitter resistor is connected to
+10 volts, the collector is connected to -10 volts and the
emitter is
supposed to be at +10.6 volts! What??? The transistor is a PNP and
the
base is supposed to be at +16.8 volts. How is this supposed to work?
Have I forgotten my transistor notation? PNP is arrow pointing to
base
which should be more negative than the emitter, right?
Anyway, the half that is whacked out has some random fluctuations
that
I can see on the scope which don't appear on the supplies. I figure
one of the components is bad but I can't trace it to anything in
particular. The circuit all interacts somewhat and the "noise"
signal
appears through nearly all of it.
Parts of the large schematic pages are missing. I assume somewhere
they tell you the conditions for taking the measurements, but I
haven't found them yet. They do have a troubleshooting section that
clearly tells you to look in this circuit.
--
Rick
All the conditions for the measurements are on PDF page 71,
schematic 2,
at the lower right side of the page. Look for all the waveforms
just to
the right of the notes section.
What you describe cries out leaky capacitor. Since it is only
doing it
on the upper two ranges, that sure points to that circuit.
All of the transistors in that circuit are 2N3904 (N) or 3906 (P)
so a
shotgun approach might be worth it in case it is a leaky transistor.
Take note of Note-5.
Thanks. My copy doesn't have complete pages of the schematics. They
are
cut off at the bottom and when they span two pages there is a gap in
the
middle. I think I got this from the Agilent site. Is there a better
copy
available somewhere else?
BTW, to make it more viewable I rearranged the schematics a bit and
rotated the vertical pages. I see notes on page 70 of 87 and this page
also has assemblies A2 and A3 and waveforms 12 through 16. Is this the
page you mean?
It includes notes 1 through 3 which is cut off a bit. I don't have
notes
4 and 5 at all. On my page 68 I see notes, but all of the data on the
right is cut off and note 5 is missing.
Wait! I found an intact set of notes on page 77. I will recheck the DC
measurements with the settings indicated. This may bring the good
section into alignment with the schematic values, but I'm sure the bad
half will still be bad. Problem is I just don't know how transistors
are
expected to behave when both junctions are reverse biased like the
schematic says they should be.
I think your shotgunning idea is good, I just don't relish the idea of
taking this thing apart, but I guess it can't be too bad. When they
have
front panel switches soldered to the board it makes me twinge. I'm
probably just being overly worried, I expect it is made to be repaired
as well as assembled, unlike today's stuff.
Heck, I might want to get a second one so I can use it to make a sweep
generator!
See my posting "Re: HP 3310B Malfunction Generator" in
a.b.s.electronic.
I don't seem to have access to binary groups. My server doesn't host
them and Google Groups doesn't seem to support them either.
Thanks for the effort.
OK; go to: http://www.oil4lessllc.org/HP3312A/
Ok, I can get to that one. But what is it for? That is not the same unit
at all. It looks like a much more modern unit with wide use of op amps
rather than a bazillion transistors? I guess it might be a better unit
to buy?
Yes, i figured that the design was different even tho the function
Been awhile since i looked at the incomplete Agilent schematic, but
the diode array and biasing should be the same.
In this schematic, except for Q306 and Q309, all transistors are
fully active (no reversed biased E-B or forward biased B-C junctions).
Maybe i should look at their crummy schematic..
...still looking at it; will respond later.
R
Robert Baer
Guest
Robert Baer wrote:
described by CR322, CR321, R353, R351 and R350. Likewise, TP7 is
equivalent to junction on mine described by CR323, CR319, R352, R346 and
R344.
Lastly, the "center", (sinewave) of TP6 is my TP13.
Now on mine, it is mostly obvious that the incoming triangle wave via
R369 (from output of op amp U301) is/must be symmetrical about ground
and (going from left to right) each pair of diodes will "clip" that
waveform at a level set by their common resistor at the output line
TP13; each clipping point being more severe (lower common R value) and
at a higher level (further away from ground).
Finally, the peak is clipped at the top, set by R348 and R342.
On the Agilent, PDF page 18, note there is NO "high frequency" monkey
business WRT the sine forming, as i seem to have seen mentioned. Ditto
with mine. Exception may be small trim caps or such.
TP6 appears to be at ground with the waveform symmetrical, just like
mine.
So...at "low" frequencies (10-1000 cps) the triangle coming from the
triangle amp (Pg 18 again) better the hell be EXACTLY symmetrical and
well behaved.
And it should stay that way all the way to the high end on the top range.
I think that may be the key, and so there may be more than one
problem - the first being this triangle waveform ain't not nowhere near
symmetrical (to use bad Engrish).
TP5 should be as negative as TP7 is positive; i derived that from the
necessary biasing for that DFG, and the schematic voltages noted confirm
that.
Resistor and voltage values from one to the other in the DFG will be
different, but more-or-less on a ratio basis, they should track.
Once you get the triangle symmetrical, then it should be fairly easy
to find a bad resistor or diode in the DFG (am guessing this as being a
secondary problem).
Maybe one of the stared capacitors in the sine shaper amplifier is
bad, but i doubt it; if there is a problem there HF-wise, it would be
due to a transistor (Q2 or Q3).
rickman wrote:
On 3/13/2013 4:00 PM, Robert Baer wrote:
*********** BIG SNIP
See Agilent PDF page 71 TP5 is equivalent to junction on mineSee my posting "Re: HP 3310B Malfunction Generator" in
a.b.s.electronic.
I don't seem to have access to binary groups. My server doesn't host
them and Google Groups doesn't seem to support them either.
Thanks for the effort.
OK; go to: http://www.oil4lessllc.org/HP3312A/
Ok, I can get to that one. But what is it for? That is not the same unit
at all. It looks like a much more modern unit with wide use of op amps
rather than a bazillion transistors? I guess it might be a better unit
to buy?
Yes, i figured that the design was different even tho the function
seemed to be the same.
Been awhile since i looked at the incomplete Agilent schematic, but the
diode array and biasing should be the same.
In this schematic, except for Q306 and Q309, all transistors are fully
active (no reversed biased E-B or forward biased B-C junctions).
Maybe i should look at their crummy schematic..
..still looking at it; will respond later.
described by CR322, CR321, R353, R351 and R350. Likewise, TP7 is
equivalent to junction on mine described by CR323, CR319, R352, R346 and
R344.
Lastly, the "center", (sinewave) of TP6 is my TP13.
Now on mine, it is mostly obvious that the incoming triangle wave via
R369 (from output of op amp U301) is/must be symmetrical about ground
and (going from left to right) each pair of diodes will "clip" that
waveform at a level set by their common resistor at the output line
TP13; each clipping point being more severe (lower common R value) and
at a higher level (further away from ground).
Finally, the peak is clipped at the top, set by R348 and R342.
On the Agilent, PDF page 18, note there is NO "high frequency" monkey
business WRT the sine forming, as i seem to have seen mentioned. Ditto
with mine. Exception may be small trim caps or such.
TP6 appears to be at ground with the waveform symmetrical, just like
mine.
So...at "low" frequencies (10-1000 cps) the triangle coming from the
triangle amp (Pg 18 again) better the hell be EXACTLY symmetrical and
well behaved.
And it should stay that way all the way to the high end on the top range.
I think that may be the key, and so there may be more than one
problem - the first being this triangle waveform ain't not nowhere near
symmetrical (to use bad Engrish).
TP5 should be as negative as TP7 is positive; i derived that from the
necessary biasing for that DFG, and the schematic voltages noted confirm
that.
Resistor and voltage values from one to the other in the DFG will be
different, but more-or-less on a ratio basis, they should track.
Once you get the triangle symmetrical, then it should be fairly easy
to find a bad resistor or diode in the DFG (am guessing this as being a
secondary problem).
Maybe one of the stared capacitors in the sine shaper amplifier is
bad, but i doubt it; if there is a problem there HF-wise, it would be
due to a transistor (Q2 or Q3).
R
rickman
Guest
On 3/14/2013 5:55 AM, Robert Baer wrote:
high speed circuit is not about clipping the triangle into a sine wave,
it "adjusts" the circuit that detects the triangle has reached +-5 volts
and reverses the direction of the waveform. The -5 volt detect seems to
work ok on the lower ranges. On the 10k and 100k ranges the high speed
circuit kicks in to modify the operation of the +-5 volt detect circuit
so that it triggers just early enough to give a proper +-5 volt triangle
in spite of whatever delays it has. This is when it malfunctions and
looks like it is not going far enough negative, which is confirmed on
the scope. The trigger level seems to vary erratically which is also
seen on the internal test points.
The symptom is clearly a malfunction of the high speed circuit, plus, I
can see erratic drift of the DC values both on the meter and with the
scope. The drift is small, but the DC values are also wrong on the -5
volt half of this circuit. I just can't pin any of this down since I'm
not clear on how the circuit works. The parts I understand will all
affect each other if any of them malfunction.
the high speed circuit. I just can't figure out which part is bad.
Someone suggested the caps often fail, at least the electrolytics
anyway. There is one cap that looks like an electrolytic, but the
schematic says it is 0.1 uF and the parts list says it is a 1.0 uF part.
I'm starting to loose confidence in HP docs. I may have to shotgun
it... or just use it on the lower ranges only.
--
Rick
Yes, that is exactly the problem. The triangle is not symmetrical. TheRobert Baer wrote:
Yes, i figured that the design was different even tho the function
seemed to be the same.
Been awhile since i looked at the incomplete Agilent schematic, but the
diode array and biasing should be the same.
In this schematic, except for Q306 and Q309, all transistors are fully
active (no reversed biased E-B or forward biased B-C junctions).
Maybe i should look at their crummy schematic..
..still looking at it; will respond later.
See Agilent PDF page 71 TP5 is equivalent to junction on mine described
by CR322, CR321, R353, R351 and R350. Likewise, TP7 is equivalent to
junction on mine described by CR323, CR319, R352, R346 and R344.
Lastly, the "center", (sinewave) of TP6 is my TP13.
Now on mine, it is mostly obvious that the incoming triangle wave via
R369 (from output of op amp U301) is/must be symmetrical about ground
and (going from left to right) each pair of diodes will "clip" that
waveform at a level set by their common resistor at the output line
TP13; each clipping point being more severe (lower common R value) and
at a higher level (further away from ground).
Finally, the peak is clipped at the top, set by R348 and R342.
On the Agilent, PDF page 18, note there is NO "high frequency" monkey
business WRT the sine forming, as i seem to have seen mentioned. Ditto
with mine. Exception may be small trim caps or such.
TP6 appears to be at ground with the waveform symmetrical, just like mine.
So...at "low" frequencies (10-1000 cps) the triangle coming from the
triangle amp (Pg 18 again) better the hell be EXACTLY symmetrical and
well behaved.
And it should stay that way all the way to the high end on the top range.
I think that may be the key, and so there may be more than one problem -
the first being this triangle waveform ain't not nowhere near
symmetrical (to use bad Engrish).
high speed circuit is not about clipping the triangle into a sine wave,
it "adjusts" the circuit that detects the triangle has reached +-5 volts
and reverses the direction of the waveform. The -5 volt detect seems to
work ok on the lower ranges. On the 10k and 100k ranges the high speed
circuit kicks in to modify the operation of the +-5 volt detect circuit
so that it triggers just early enough to give a proper +-5 volt triangle
in spite of whatever delays it has. This is when it malfunctions and
looks like it is not going far enough negative, which is confirmed on
the scope. The trigger level seems to vary erratically which is also
seen on the internal test points.
The symptom is clearly a malfunction of the high speed circuit, plus, I
can see erratic drift of the DC values both on the meter and with the
scope. The drift is small, but the DC values are also wrong on the -5
volt half of this circuit. I just can't pin any of this down since I'm
not clear on how the circuit works. The parts I understand will all
affect each other if any of them malfunction.
I'm not worried about the DFG actually, I'm confident the problem is inTP5 should be as negative as TP7 is positive; i derived that from the
necessary biasing for that DFG, and the schematic voltages noted confirm
that.
Resistor and voltage values from one to the other in the DFG will be
different, but more-or-less on a ratio basis, they should track.
Once you get the triangle symmetrical, then it should be fairly easy to
find a bad resistor or diode in the DFG (am guessing this as being a
secondary problem).
Maybe one of the stared capacitors in the sine shaper amplifier is bad,
but i doubt it; if there is a problem there HF-wise, it would be due to
a transistor (Q2 or Q3).
the high speed circuit. I just can't figure out which part is bad.
Someone suggested the caps often fail, at least the electrolytics
anyway. There is one cap that looks like an electrolytic, but the
schematic says it is 0.1 uF and the parts list says it is a 1.0 uF part.
I'm starting to loose confidence in HP docs. I may have to shotgun
it... or just use it on the lower ranges only.
--
Rick
J
josephkk
Guest
On Thu, 14 Mar 2013 18:00:37 -0400, rickman <gnuarm@gmail.com> wrote:
http://cp.literature.agilent.com/litweb/pdf/03310-90003.pdf
So that we can all be on the same pages.
?-)
May i presume that you are using this document for the schematic?:On the Agilent, PDF page 18, note there is NO "high frequency" monkey
business WRT the sine forming, as i seem to have seen mentioned. Ditto
with mine. Exception may be small trim caps or such.
TP6 appears to be at ground with the waveform symmetrical, just like mine.
So...at "low" frequencies (10-1000 cps) the triangle coming from the
triangle amp (Pg 18 again) better the hell be EXACTLY symmetrical and
well behaved.
And it should stay that way all the way to the high end on the top range.
I think that may be the key, and so there may be more than one problem -
the first being this triangle waveform ain't not nowhere near
symmetrical (to use bad Engrish).
Yes, that is exactly the problem. The triangle is not symmetrical. The
high speed circuit is not about clipping the triangle into a sine wave,
it "adjusts" the circuit that detects the triangle has reached +-5 volts
and reverses the direction of the waveform. The -5 volt detect seems to
work ok on the lower ranges. On the 10k and 100k ranges the high speed
circuit kicks in to modify the operation of the +-5 volt detect circuit
so that it triggers just early enough to give a proper +-5 volt triangle
in spite of whatever delays it has. This is when it malfunctions and
looks like it is not going far enough negative, which is confirmed on
the scope. The trigger level seems to vary erratically which is also
seen on the internal test points.
The symptom is clearly a malfunction of the high speed circuit, plus, I
can see erratic drift of the DC values both on the meter and with the
scope. The drift is small, but the DC values are also wrong on the -5
volt half of this circuit. I just can't pin any of this down since I'm
not clear on how the circuit works. The parts I understand will all
affect each other if any of them malfunction.
TP5 should be as negative as TP7 is positive; i derived that from the
necessary biasing for that DFG, and the schematic voltages noted confirm
that.
Resistor and voltage values from one to the other in the DFG will be
different, but more-or-less on a ratio basis, they should track.
Once you get the triangle symmetrical, then it should be fairly easy to
find a bad resistor or diode in the DFG (am guessing this as being a
secondary problem).
Maybe one of the stared capacitors in the sine shaper amplifier is bad,
but i doubt it; if there is a problem there HF-wise, it would be due to
a transistor (Q2 or Q3).
I'm not worried about the DFG actually, I'm confident the problem is in
the high speed circuit. I just can't figure out which part is bad.
Someone suggested the caps often fail, at least the electrolytics
anyway. There is one cap that looks like an electrolytic, but the
schematic says it is 0.1 uF and the parts list says it is a 1.0 uF part.
I'm starting to loose confidence in HP docs. I may have to shotgun
it... or just use it on the lower ranges only.
http://cp.literature.agilent.com/litweb/pdf/03310-90003.pdf
So that we can all be on the same pages.
?-)
T
tm
Guest
"josephkk" <joseph_barrett@sbcglobal.net> wrote in message
news:gr45k8dlrdb3kabpbvrjuserb5m6tu0f2r@4ax.com...
On Thu, 14 Mar 2013 18:00:37 -0400, rickman <gnuarm@gmail.com> wrote:
http://cp.literature.agilent.com/litweb/pdf/03310-90003.pdf
So that we can all be on the same pages.
?-)
+++++++++++++++++++++++++++++++++++
http://ko4bb.com/Manuals/HP_Agilent/HP_3310AB_OS.pdf
This is a better copy.
news:gr45k8dlrdb3kabpbvrjuserb5m6tu0f2r@4ax.com...
On Thu, 14 Mar 2013 18:00:37 -0400, rickman <gnuarm@gmail.com> wrote:
May i presume that you are using this document for the schematic?:On the Agilent, PDF page 18, note there is NO "high frequency" monkey
business WRT the sine forming, as i seem to have seen mentioned. Ditto
with mine. Exception may be small trim caps or such.
TP6 appears to be at ground with the waveform symmetrical, just like
mine.
So...at "low" frequencies (10-1000 cps) the triangle coming from the
triangle amp (Pg 18 again) better the hell be EXACTLY symmetrical and
well behaved.
And it should stay that way all the way to the high end on the top range.
I think that may be the key, and so there may be more than one problem -
the first being this triangle waveform ain't not nowhere near
symmetrical (to use bad Engrish).
Yes, that is exactly the problem. The triangle is not symmetrical. The
high speed circuit is not about clipping the triangle into a sine wave,
it "adjusts" the circuit that detects the triangle has reached +-5 volts
and reverses the direction of the waveform. The -5 volt detect seems to
work ok on the lower ranges. On the 10k and 100k ranges the high speed
circuit kicks in to modify the operation of the +-5 volt detect circuit
so that it triggers just early enough to give a proper +-5 volt triangle
in spite of whatever delays it has. This is when it malfunctions and
looks like it is not going far enough negative, which is confirmed on
the scope. The trigger level seems to vary erratically which is also
seen on the internal test points.
The symptom is clearly a malfunction of the high speed circuit, plus, I
can see erratic drift of the DC values both on the meter and with the
scope. The drift is small, but the DC values are also wrong on the -5
volt half of this circuit. I just can't pin any of this down since I'm
not clear on how the circuit works. The parts I understand will all
affect each other if any of them malfunction.
TP5 should be as negative as TP7 is positive; i derived that from the
necessary biasing for that DFG, and the schematic voltages noted confirm
that.
Resistor and voltage values from one to the other in the DFG will be
different, but more-or-less on a ratio basis, they should track.
Once you get the triangle symmetrical, then it should be fairly easy to
find a bad resistor or diode in the DFG (am guessing this as being a
secondary problem).
Maybe one of the stared capacitors in the sine shaper amplifier is bad,
but i doubt it; if there is a problem there HF-wise, it would be due to
a transistor (Q2 or Q3).
I'm not worried about the DFG actually, I'm confident the problem is in
the high speed circuit. I just can't figure out which part is bad.
Someone suggested the caps often fail, at least the electrolytics
anyway. There is one cap that looks like an electrolytic, but the
schematic says it is 0.1 uF and the parts list says it is a 1.0 uF part.
I'm starting to loose confidence in HP docs. I may have to shotgun
it... or just use it on the lower ranges only.
http://cp.literature.agilent.com/litweb/pdf/03310-90003.pdf
So that we can all be on the same pages.
?-)
+++++++++++++++++++++++++++++++++++
http://ko4bb.com/Manuals/HP_Agilent/HP_3310AB_OS.pdf
This is a better copy.
R
Robert Baer
Guest
tm wrote:
79 & 80 for a complete A3 (order is srdawkcab).
HF problems aside, fix the triangle FIRST and make it as perfect as
possible.
At least, see page 76 there for a complete DFG schematic, and pages"josephkk" <joseph_barrett@sbcglobal.net> wrote in message
news:gr45k8dlrdb3kabpbvrjuserb5m6tu0f2r@4ax.com...
On Thu, 14 Mar 2013 18:00:37 -0400, rickman <gnuarm@gmail.com> wrote:
On the Agilent, PDF page 18, note there is NO "high frequency" monkey
business WRT the sine forming, as i seem to have seen mentioned. Ditto
with mine. Exception may be small trim caps or such.
TP6 appears to be at ground with the waveform symmetrical, just like
mine.
So...at "low" frequencies (10-1000 cps) the triangle coming from the
triangle amp (Pg 18 again) better the hell be EXACTLY symmetrical and
well behaved.
And it should stay that way all the way to the high end on the top
range.
I think that may be the key, and so there may be more than one problem -
the first being this triangle waveform ain't not nowhere near
symmetrical (to use bad Engrish).
Yes, that is exactly the problem. The triangle is not symmetrical. The
high speed circuit is not about clipping the triangle into a sine wave,
it "adjusts" the circuit that detects the triangle has reached +-5 volts
and reverses the direction of the waveform. The -5 volt detect seems to
work ok on the lower ranges. On the 10k and 100k ranges the high speed
circuit kicks in to modify the operation of the +-5 volt detect circuit
so that it triggers just early enough to give a proper +-5 volt triangle
in spite of whatever delays it has. This is when it malfunctions and
looks like it is not going far enough negative, which is confirmed on
the scope. The trigger level seems to vary erratically which is also
seen on the internal test points.
The symptom is clearly a malfunction of the high speed circuit, plus, I
can see erratic drift of the DC values both on the meter and with the
scope. The drift is small, but the DC values are also wrong on the -5
volt half of this circuit. I just can't pin any of this down since I'm
not clear on how the circuit works. The parts I understand will all
affect each other if any of them malfunction.
TP5 should be as negative as TP7 is positive; i derived that from the
necessary biasing for that DFG, and the schematic voltages noted confirm
that.
Resistor and voltage values from one to the other in the DFG will be
different, but more-or-less on a ratio basis, they should track.
Once you get the triangle symmetrical, then it should be fairly easy to
find a bad resistor or diode in the DFG (am guessing this as being a
secondary problem).
Maybe one of the stared capacitors in the sine shaper amplifier is bad,
but i doubt it; if there is a problem there HF-wise, it would be due to
a transistor (Q2 or Q3).
I'm not worried about the DFG actually, I'm confident the problem is in
the high speed circuit. I just can't figure out which part is bad.
Someone suggested the caps often fail, at least the electrolytics
anyway. There is one cap that looks like an electrolytic, but the
schematic says it is 0.1 uF and the parts list says it is a 1.0 uF part.
I'm starting to loose confidence in HP docs. I may have to shotgun
it... or just use it on the lower ranges only.
May i presume that you are using this document for the schematic?:
http://cp.literature.agilent.com/litweb/pdf/03310-90003.pdf
So that we can all be on the same pages.
?-)
+++++++++++++++++++++++++++++++++++
http://ko4bb.com/Manuals/HP_Agilent/HP_3310AB_OS.pdf
This is a better copy.
Yes, better, but still a lot missing.
79 & 80 for a complete A3 (order is srdawkcab).
HF problems aside, fix the triangle FIRST and make it as perfect as
possible.
R
rickman
Guest
On 3/14/2013 11:22 PM, josephkk wrote:
edited the pages a bit to make it easier to view.
HP_3310AB_OS_1971_edited.pdf
--
Rick
That schematic has missing info. I found a better copy at KO4BB.com andOn Thu, 14 Mar 2013 18:00:37 -0400, rickman<gnuarm@gmail.com> wrote:
On the Agilent, PDF page 18, note there is NO "high frequency" monkey
business WRT the sine forming, as i seem to have seen mentioned. Ditto
with mine. Exception may be small trim caps or such.
TP6 appears to be at ground with the waveform symmetrical, just like mine.
So...at "low" frequencies (10-1000 cps) the triangle coming from the
triangle amp (Pg 18 again) better the hell be EXACTLY symmetrical and
well behaved.
And it should stay that way all the way to the high end on the top range.
I think that may be the key, and so there may be more than one problem -
the first being this triangle waveform ain't not nowhere near
symmetrical (to use bad Engrish).
Yes, that is exactly the problem. The triangle is not symmetrical. The
high speed circuit is not about clipping the triangle into a sine wave,
it "adjusts" the circuit that detects the triangle has reached +-5 volts
and reverses the direction of the waveform. The -5 volt detect seems to
work ok on the lower ranges. On the 10k and 100k ranges the high speed
circuit kicks in to modify the operation of the +-5 volt detect circuit
so that it triggers just early enough to give a proper +-5 volt triangle
in spite of whatever delays it has. This is when it malfunctions and
looks like it is not going far enough negative, which is confirmed on
the scope. The trigger level seems to vary erratically which is also
seen on the internal test points.
The symptom is clearly a malfunction of the high speed circuit, plus, I
can see erratic drift of the DC values both on the meter and with the
scope. The drift is small, but the DC values are also wrong on the -5
volt half of this circuit. I just can't pin any of this down since I'm
not clear on how the circuit works. The parts I understand will all
affect each other if any of them malfunction.
TP5 should be as negative as TP7 is positive; i derived that from the
necessary biasing for that DFG, and the schematic voltages noted confirm
that.
Resistor and voltage values from one to the other in the DFG will be
different, but more-or-less on a ratio basis, they should track.
Once you get the triangle symmetrical, then it should be fairly easy to
find a bad resistor or diode in the DFG (am guessing this as being a
secondary problem).
Maybe one of the stared capacitors in the sine shaper amplifier is bad,
but i doubt it; if there is a problem there HF-wise, it would be due to
a transistor (Q2 or Q3).
I'm not worried about the DFG actually, I'm confident the problem is in
the high speed circuit. I just can't figure out which part is bad.
Someone suggested the caps often fail, at least the electrolytics
anyway. There is one cap that looks like an electrolytic, but the
schematic says it is 0.1 uF and the parts list says it is a 1.0 uF part.
I'm starting to loose confidence in HP docs. I may have to shotgun
it... or just use it on the lower ranges only.
May i presume that you are using this document for the schematic?:
http://cp.literature.agilent.com/litweb/pdf/03310-90003.pdf
So that we can all be on the same pages.
edited the pages a bit to make it easier to view.
HP_3310AB_OS_1971_edited.pdf
--
Rick
R
rickman
Guest
On 3/15/2013 1:39 AM, Robert Baer wrote:
just a constant current into a cap. When it reaches +5 volts the detect
circuit switches the current source to ramp down to -5 volts, then the
cycle repeats. The HF circuit modifies the threshold of the +-5 volt
detect circuit which is part of forming the triangle wave. The problem
is the -5 volt detect is happening too soon and the triangle is not
going far enough negative. The *only* happens when switched to the 10k
or 100k ranges. The only difference in the ranges is that the HF
circuit is kicked in (and the value of the integrating cap, but they are
different between the 10k and 100k ranges).
Just to be clear, the triangle still looks just like a triangle. The
symptoms are:
1) doesn't go negative enough,
2) faster than it should be,
3) frequency is erratic,
4) sine wave is truncated on the negative half
To me, this clearly points to the HF circuit. The wave shaper only
affects the sine wave and won't change the frequency. The sine wave is
affected because the triangle doesn't go negative enough.
--
Rick
The HF circuit is the *cause* of the triangle problems. The triangle istm wrote:
May i presume that you are using this document for the schematic?:
http://cp.literature.agilent.com/litweb/pdf/03310-90003.pdf
So that we can all be on the same pages.
?-)
+++++++++++++++++++++++++++++++++++
http://ko4bb.com/Manuals/HP_Agilent/HP_3310AB_OS.pdf
This is a better copy.
Yes, better, but still a lot missing.
At least, see page 76 there for a complete DFG schematic, and pages 79 &
80 for a complete A3 (order is srdawkcab).
HF problems aside, fix the triangle FIRST and make it as perfect as
possible.
just a constant current into a cap. When it reaches +5 volts the detect
circuit switches the current source to ramp down to -5 volts, then the
cycle repeats. The HF circuit modifies the threshold of the +-5 volt
detect circuit which is part of forming the triangle wave. The problem
is the -5 volt detect is happening too soon and the triangle is not
going far enough negative. The *only* happens when switched to the 10k
or 100k ranges. The only difference in the ranges is that the HF
circuit is kicked in (and the value of the integrating cap, but they are
different between the 10k and 100k ranges).
Just to be clear, the triangle still looks just like a triangle. The
symptoms are:
1) doesn't go negative enough,
2) faster than it should be,
3) frequency is erratic,
4) sine wave is truncated on the negative half
To me, this clearly points to the HF circuit. The wave shaper only
affects the sine wave and won't change the frequency. The sine wave is
affected because the triangle doesn't go negative enough.
--
Rick
R
rickman
Guest
On 3/15/2013 9:46 PM, Jamie wrote:
That sounds like a British expression to me... "Good site, that". Or
maybe an Aussie?
--
Rick
Yeah, I thought it was pretty impressive too. BTW, are you British?rickman wrote:
That schematic has missing info. I found a better copy at KO4BB.com
and edited the pages a bit to make it easier to view.
HP_3310AB_OS_1971_edited.pdf
Good site, thats.. Put that in my Book marks.
Jamie
That sounds like a British expression to me... "Good site, that". Or
maybe an Aussie?
--
Rick
R
rickman
Guest
On 3/15/2013 10:05 PM, Jamie wrote:
--
Rick
LOL!rickman wrote:
On 3/15/2013 9:46 PM, Jamie wrote:
rickman wrote:
That schematic has missing info. I found a better copy at KO4BB.com
and edited the pages a bit to make it easier to view.
HP_3310AB_OS_1971_edited.pdf
Good site, thats.. Put that in my Book marks.
Jamie
Yeah, I thought it was pretty impressive too. BTW, are you British?
That sounds like a British expression to me... "Good site, that". Or
maybe an Aussie?
My grand father was British born (Holmes), but I was born in Maine where
every one is related. THe tree does not branch out too far!!!!!!!!!!
Some one told me the other day they don't bother to do crime
investigations with DNA in Maine any more, the results are always
inconclusive.
--
Rick
J
Jamie
Guest
rickman wrote:
Jamie
On 3/14/2013 11:22 PM, josephkk wrote:
On Thu, 14 Mar 2013 18:00:37 -0400, rickman<gnuarm@gmail.com> wrote:
On the Agilent, PDF page 18, note there is NO "high frequency" monkey
business WRT the sine forming, as i seem to have seen mentioned. Ditto
with mine. Exception may be small trim caps or such.
TP6 appears to be at ground with the waveform symmetrical, just like
mine.
So...at "low" frequencies (10-1000 cps) the triangle coming from the
triangle amp (Pg 18 again) better the hell be EXACTLY symmetrical and
well behaved.
And it should stay that way all the way to the high end on the top
range.
I think that may be the key, and so there may be more than one
problem -
the first being this triangle waveform ain't not nowhere near
symmetrical (to use bad Engrish).
Yes, that is exactly the problem. The triangle is not symmetrical. The
high speed circuit is not about clipping the triangle into a sine wave,
it "adjusts" the circuit that detects the triangle has reached +-5 volts
and reverses the direction of the waveform. The -5 volt detect seems to
work ok on the lower ranges. On the 10k and 100k ranges the high speed
circuit kicks in to modify the operation of the +-5 volt detect circuit
so that it triggers just early enough to give a proper +-5 volt triangle
in spite of whatever delays it has. This is when it malfunctions and
looks like it is not going far enough negative, which is confirmed on
the scope. The trigger level seems to vary erratically which is also
seen on the internal test points.
The symptom is clearly a malfunction of the high speed circuit, plus, I
can see erratic drift of the DC values both on the meter and with the
scope. The drift is small, but the DC values are also wrong on the -5
volt half of this circuit. I just can't pin any of this down since I'm
not clear on how the circuit works. The parts I understand will all
affect each other if any of them malfunction.
TP5 should be as negative as TP7 is positive; i derived that from the
necessary biasing for that DFG, and the schematic voltages noted
confirm
that.
Resistor and voltage values from one to the other in the DFG will be
different, but more-or-less on a ratio basis, they should track.
Once you get the triangle symmetrical, then it should be fairly easy to
find a bad resistor or diode in the DFG (am guessing this as being a
secondary problem).
Maybe one of the stared capacitors in the sine shaper amplifier is bad,
but i doubt it; if there is a problem there HF-wise, it would be due to
a transistor (Q2 or Q3).
I'm not worried about the DFG actually, I'm confident the problem is in
the high speed circuit. I just can't figure out which part is bad.
Someone suggested the caps often fail, at least the electrolytics
anyway. There is one cap that looks like an electrolytic, but the
schematic says it is 0.1 uF and the parts list says it is a 1.0 uF part.
I'm starting to loose confidence in HP docs. I may have to shotgun
it... or just use it on the lower ranges only.
May i presume that you are using this document for the schematic?:
http://cp.literature.agilent.com/litweb/pdf/03310-90003.pdf
So that we can all be on the same pages.
That schematic has missing info. I found a better copy at KO4BB.com and
edited the pages a bit to make it easier to view.
HP_3310AB_OS_1971_edited.pdf
Good site, thats.. Put that in my Book marks.
Jamie
J
Jamie
Guest
rickman wrote:
where every one is related. THe tree does not branch out too far!!!!!!!!!!
Some one told me the other day they don't bother to do crime
investigations with DNA in Maine any more, the results are always
inconclusive.
Jamie
My grand father was British born (Holmes), but I was born in MaineOn 3/15/2013 9:46 PM, Jamie wrote:
rickman wrote:
That schematic has missing info. I found a better copy at KO4BB.com
and edited the pages a bit to make it easier to view.
HP_3310AB_OS_1971_edited.pdf
Good site, thats.. Put that in my Book marks.
Jamie
Yeah, I thought it was pretty impressive too. BTW, are you British?
That sounds like a British expression to me... "Good site, that". Or
maybe an Aussie?
where every one is related. THe tree does not branch out too far!!!!!!!!!!
Some one told me the other day they don't bother to do crime
investigations with DNA in Maine any more, the results are always
inconclusive.
Jamie