|
Has anyone had any joy repairing on of these.
Dave
|
Sorry I rushed that last email.
For more relevance the second converter
I am talking about is a 5086-7957 and it is low on gain.
Dave
On 8/02/2022 1:10 pm, Dave Ireland
wrote:
toggle quoted message
Show quoted text
Has anyone had any joy repairing on of these.
Dave
|
Hi Dave,
I once fixed a 5086-7812? second converter with a 5021-8661 board. The only problem on this, was cracked solder joints on the feed through capacitors on the board. So I did not have to open the cavity part of the converter. HP had cut the legs after soldering, all the way down in the solder joint. This is a bad thing as it adds stress to the solder. I was sure HP would have known better. I have pictures of it, but not at hand right now.
Do you have a second spectrum analyzer? You should check the output of the test port on the converter. And also the input level of the LO and IF.
Maybe you can tell us a bit more about the fault. What is the loss through the converter? Guess this SA only go to 2.9GHz? so there is no high band? What test equipment do you have to test and fault find with.
Regards, Askild
On Tue, Feb 8, 2022 at 6:20 AM Dave Ireland < mirrors@...> wrote:
Sorry I rushed that last email.
For more relevance the second converter
I am talking about is a 5086-7957 and it is low on gain.
Dave
On 8/02/2022 1:10 pm, Dave Ireland
wrote:
Has anyone had any joy repairing on of these.
Dave
|
Askild
I have a sig gen and a specan that both
go to 3GHz.
The test point on the converter is
labelled LO test and I assume that this is the 600MHZ but I see
nothing on this even though the 600MHz input is correct. If
however it is the 3.9Ghz, then I have no way of seeing this
without mixing it to another frequency.
I can't see the output of the A8 Low
Band mixer as it is again too high for my specan but the RF input
is correct according to the manual at -21dBm and the drive
voltages are -4.96V for the -5V rail and -4.14V for the -4V rail.
The 310.75MHz output of the converter
when measured as per the manual is -59dBm where it should be
-38dBm.? When I measure the voltage between the test connector J19
pins 15 and 6, the drive to the converter pin switch, I get
+14.48V which is in the range of the manual.
The next item in the manual is
measuring the mixer bias on the test connector J19 pin 1 where I
get -39mV which is outside the required range of -150mV and
-800mV. After that it just says if outside the range, probably the
second converter is faulty.
The voltages to the second converter
are:-
J12-1 Mixer Bias:??? ??? ??? ??? ???
??? -39mV
J12-2 +5VF:?? ??? ???? ?? ?? ???? ???
??? ??? 4.87V
J12-3 Analogue Gnd: ??? ??? ??? ??? ???
Yes
J12-4 +10VR:?? ??? ??? ?? ??? ??? ???
??? ??? ? 9.9V
J12-5 Pin Switch:??? ??? ??? ??? ???
??? 14.48V
J12-7 Drain Current Sense: ??? ???
4.86V
J12-8 Drain Voltage:??? ??? ??? ?? ??
?? 4.85V
J12-9 Doubler Bias:??? ??? ??? ??? ???
14.48V
J12-10 Driver Bias:??? ?? ?? ??? ??? ??
0.465V
Without the circuit of the converter I
don't know the relevance of these but the only one that looks a
bit strange is the doubler bias.
Do you have any thoughts after your
experience?
I will pull it apart again and check
out some of yours and Gerald's suggestions on the DC feeds, the
feed throughs and where this LO test point comes from.
Thanks
Dave
On 8/02/2022 5:38 pm, Askild wrote:
toggle quoted message
Show quoted text
Hi Dave,
I once fixed a 5086-7812? second converter with a 5021-8661
board.
The only problem on this, was cracked solder joints on the
feed through capacitors on the board. So I did not have to
open the cavity part of the converter.
HP had cut the legs after soldering, all the way down in
the solder joint. This is a bad thing as it adds stress to the
solder. I was sure HP would have known better.
I have pictures of it, but not at hand right now.
Do you have a second spectrum analyzer? You should check
the output of the test port on the converter.
And also the input level of the LO and IF.
Maybe you can tell us a bit more about the fault. What is
the loss through the converter?
Guess this SA only go to 2.9GHz? so there is no high band?
What test equipment do you have to test and fault find
with.
Regards,
Askild
On Tue, Feb 8, 2022 at 6:20 AM
Dave Ireland < mirrors@...>
wrote:
Sorry I rushed that last email.
For more relevance the second converter I am talking
about is a 5086-7957 and it is low on gain.
Dave
On 8/02/2022 1:10 pm, Dave Ireland wrote:
Has anyone had any joy repairing on
of these.
Dave
|
I'm trying to get my head around the LO amp, doubler and tripler
circuit of the 8560E Second Converter.
Does anyone know to identify the transistor "Bz" and the
propriety chip 1GXX-XXX?
Dave
|
Hi Dave,
The test port on the second converter should be 3.6GHz (6*600MHz). Normally I think that the first mixer is the part that is most likely to fail, as its exposed to over power or dc voltage from the input connector. It will be difficult to fault find without test instrument that go above 3GHz.? You don't need a full lab of equipment that go above 3GHz, but having one that can detect power would help. So a power meter, or maybe just a diode detector that is usable above 3 GHz. You don't need exact measurement, you could compare a known power level from your signal generator at 3GHz, to what come out of mixer at 3.9GHz. Will not be accurate, but should not be 20dB difference. Also, an ADF4351 will go to 4.4GHz. You can get complete units with touch screen. Here would be the same, set the frequency at 3GHz, and measure level with your spectrum analyzer, making sure the level is correct for the second converter (use attenuators if necessary), then increase frequency to 1st IF (3.9xxGHz) and measure output of second converter with your SA. You could possibly also make a down converter with a mixer and a LO source.
So I think you need to invest in something that lets you either measure or source above 3GHz, if you don't know somebody that have equipment you could borrow.
I can't answer on your voltage measurements, hopefully someone else can help.
Regards, Askild
On Thu, Feb 10, 2022 at 8:00 AM Dave Ireland < mirrors@...> wrote:
Askild
I have a sig gen and a specan that both
go to 3GHz.
The test point on the converter is
labelled LO test and I assume that this is the 600MHZ but I see
nothing on this even though the 600MHz input is correct. If
however it is the 3.9Ghz, then I have no way of seeing this
without mixing it to another frequency.
I can't see the output of the A8 Low
Band mixer as it is again too high for my specan but the RF input
is correct according to the manual at -21dBm and the drive
voltages are -4.96V for the -5V rail and -4.14V for the -4V rail.
The 310.75MHz output of the converter
when measured as per the manual is -59dBm where it should be
-38dBm.? When I measure the voltage between the test connector J19
pins 15 and 6, the drive to the converter pin switch, I get
+14.48V which is in the range of the manual.
The next item in the manual is
measuring the mixer bias on the test connector J19 pin 1 where I
get -39mV which is outside the required range of -150mV and
-800mV. After that it just says if outside the range, probably the
second converter is faulty.
The voltages to the second converter
are:-
J12-1 Mixer Bias:??? ??? ??? ??? ???
??? -39mV
J12-2 +5VF:?? ??? ???? ?? ?? ???? ???
??? ??? 4.87V
J12-3 Analogue Gnd: ??? ??? ??? ??? ???
Yes
J12-4 +10VR:?? ??? ??? ?? ??? ??? ???
??? ??? ? 9.9V
J12-5 Pin Switch:??? ??? ??? ??? ???
??? 14.48V
J12-7 Drain Current Sense: ??? ???
4.86V
J12-8 Drain Voltage:??? ??? ??? ?? ??
?? 4.85V
J12-9 Doubler Bias:??? ??? ??? ??? ???
14.48V
J12-10 Driver Bias:??? ?? ?? ??? ??? ??
0.465V
Without the circuit of the converter I
don't know the relevance of these but the only one that looks a
bit strange is the doubler bias.
Do you have any thoughts after your
experience?
I will pull it apart again and check
out some of yours and Gerald's suggestions on the DC feeds, the
feed throughs and where this LO test point comes from.
Thanks
Dave
On 8/02/2022 5:38 pm, Askild wrote:
Hi Dave,
I once fixed a 5086-7812? second converter with a 5021-8661
board.
The only problem on this, was cracked solder joints on the
feed through capacitors on the board. So I did not have to
open the cavity part of the converter.
HP had cut the legs after soldering, all the way down in
the solder joint. This is a bad thing as it adds stress to the
solder. I was sure HP would have known better.
I have pictures of it, but not at hand right now.
Do you have a second spectrum analyzer? You should check
the output of the test port on the converter.
And also the input level of the LO and IF.
Maybe you can tell us a bit more about the fault. What is
the loss through the converter?
Guess this SA only go to 2.9GHz? so there is no high band?
What test equipment do you have to test and fault find
with.
Regards,
Askild
On Tue, Feb 8, 2022 at 6:20 AM
Dave Ireland < mirrors@...>
wrote:
Sorry I rushed that last email.
For more relevance the second converter I am talking
about is a 5086-7957 and it is low on gain.
Dave
On 8/02/2022 1:10 pm, Dave Ireland wrote:
Has anyone had any joy repairing on
of these.
Dave
|
Askild
After my email I pulled it apart again and had a good look. Nothing stood out other than some of the soldering looked a bit cold. The feed thrus where ok, nice and shinny.
It was interesting about the voltages. The descriptions in the manual are all wrong with only 5v, mixer bias and "pin switch" being used and repeated accross several of the pins.?
I will see if I can source a higher spec an to check the LO.
Thanks
Dave
toggle quoted message
Show quoted text
-------- Original message -------- From: Askild <megafluffy@...> Date: 11/2/22 04:22 (GMT+08:00) Subject: Re: [HP-Agilent-Keysight-equipment] 8560E Second Converter
Hi Dave,
The test port on the second converter should be 3.6GHz (6*600MHz). Normally I think that the first mixer is the part that is most likely to fail, as its exposed to over power or dc voltage from the input connector. It will be difficult to fault find without test instrument that go above 3GHz.? You don't need a full lab of equipment that go above 3GHz, but having one that can detect power would help. So a power meter, or maybe just a diode detector that is usable above 3 GHz. You don't need exact measurement, you could compare a known power level from your signal generator at 3GHz, to what come out of mixer at 3.9GHz. Will not be accurate, but should not be 20dB difference. Also, an ADF4351 will go to 4.4GHz. You can get complete units with touch screen. Here would be the same, set the frequency at 3GHz, and measure level with your spectrum analyzer, making sure the level is correct for the second converter (use attenuators if necessary), then increase frequency to 1st IF (3.9xxGHz) and measure output of second converter with your SA. You could possibly also make a down converter with a mixer and a LO source.
So I think you need to invest in something that lets you either measure or source above 3GHz, if you don't know somebody that have equipment you could borrow.
I can't answer on your voltage measurements, hopefully someone else can help.
Regards, Askild
On Thu, Feb 10, 2022 at 8:00 AM Dave Ireland < mirrors@...> wrote:
Askild
I have a sig gen and a specan that both
go to 3GHz.
The test point on the converter is
labelled LO test and I assume that this is the 600MHZ but I see
nothing on this even though the 600MHz input is correct. If
however it is the 3.9Ghz, then I have no way of seeing this
without mixing it to another frequency.
I can't see the output of the A8 Low
Band mixer as it is again too high for my specan but the RF input
is correct according to the manual at -21dBm and the drive
voltages are -4.96V for the -5V rail and -4.14V for the -4V rail.
The 310.75MHz output of the converter
when measured as per the manual is -59dBm where it should be
-38dBm.? When I measure the voltage between the test connector J19
pins 15 and 6, the drive to the converter pin switch, I get
+14.48V which is in the range of the manual.
The next item in the manual is
measuring the mixer bias on the test connector J19 pin 1 where I
get -39mV which is outside the required range of -150mV and
-800mV. After that it just says if outside the range, probably the
second converter is faulty.
The voltages to the second converter
are:-
J12-1 Mixer Bias:??? ??? ??? ??? ???
??? -39mV
J12-2 +5VF:?? ??? ???? ?? ?? ???? ???
??? ??? 4.87V
J12-3 Analogue Gnd: ??? ??? ??? ??? ???
Yes
J12-4 +10VR:?? ??? ??? ?? ??? ??? ???
??? ??? ? 9.9V
J12-5 Pin Switch:??? ??? ??? ??? ???
??? 14.48V
J12-7 Drain Current Sense: ??? ???
4.86V
J12-8 Drain Voltage:??? ??? ??? ?? ??
?? 4.85V
J12-9 Doubler Bias:??? ??? ??? ??? ???
14.48V
J12-10 Driver Bias:??? ?? ?? ??? ??? ??
0.465V
Without the circuit of the converter I
don't know the relevance of these but the only one that looks a
bit strange is the doubler bias.
Do you have any thoughts after your
experience?
I will pull it apart again and check
out some of yours and Gerald's suggestions on the DC feeds, the
feed throughs and where this LO test point comes from.
Thanks
Dave
On 8/02/2022 5:38 pm, Askild wrote:
Hi Dave,
I once fixed a 5086-7812? second converter with a 5021-8661
board.
The only problem on this, was cracked solder joints on the
feed through capacitors on the board. So I did not have to
open the cavity part of the converter.
HP had cut the legs after soldering, all the way down in
the solder joint. This is a bad thing as it adds stress to the
solder. I was sure HP would have known better.
I have pictures of it, but not at hand right now.
Do you have a second spectrum analyzer? You should check
the output of the test port on the converter.
And also the input level of the LO and IF.
Maybe you can tell us a bit more about the fault. What is
the loss through the converter?
Guess this SA only go to 2.9GHz? so there is no high band?
What test equipment do you have to test and fault find
with.
Regards,
Askild
On Tue, Feb 8, 2022 at 6:20 AM
Dave Ireland < mirrors@...>
wrote:
Sorry I rushed that last email.
For more relevance the second converter I am talking
about is a 5086-7957 and it is low on gain.
Dave
On 8/02/2022 1:10 pm, Dave Ireland wrote:
Has anyone had any joy repairing on
of these.
Dave
|
Hello in 90% cases of that failure your U501 in A15 is dead. It is a 18-19dBm MMIC . Not critical use ERA5 or MSA0586 etc.
also if your 300Mhz Cal output is bad it that failure. They look ok still if measuring current arount it but it looses amplification. It will not tripple the 100Mhz to 300 and then not double to the 600Mhz.
best regards Peter OZ1LPR
Askild
I have a sig gen and a specan that both go to 3GHz.
The test point on the converter is labelled LO test and I assume that this is the 600MHZ but I see nothing on this even though the 600MHz input is correct. If however it is the 3.9Ghz, then I have no way of seeing this without
mixing it to another frequency.
I can't see the output of the A8 Low Band mixer as it is again too high for my specan but the RF input is correct according to the manual at -21dBm and the drive voltages are -4.96V for the -5V rail and -4.14V for the -4V rail.
The 310.75MHz output of the converter when measured as per the manual is -59dBm where it should be -38dBm.? When I measure the voltage between the test connector J19 pins 15 and 6, the drive to the converter pin switch, I get
+14.48V which is in the range of the manual.
The next item in the manual is measuring the mixer bias on the test connector J19 pin 1 where I get -39mV which is outside the required range of -150mV and -800mV. After that it just says if outside the range, probably the second
converter is faulty.
The voltages to the second converter are:-
J12-1 Mixer Bias:??? ??? ??? ??? ??? ??? -39mV
J12-2 +5VF:?? ??? ???? ?? ?? ???? ??? ??? ??? 4.87V
J12-3 Analogue Gnd: ??? ??? ??? ??? ??? Yes
J12-4 +10VR:?? ??? ??? ?? ??? ??? ??? ??? ??? ? 9.9V
J12-5 Pin Switch:??? ??? ??? ??? ??? ??? 14.48V
J12-7 Drain Current Sense: ??? ??? 4.86V
J12-8 Drain Voltage:??? ??? ??? ?? ?? ?? 4.85V
J12-9 Doubler Bias:??? ??? ??? ??? ??? 14.48V
J12-10 Driver Bias:??? ?? ?? ??? ??? ?? 0.465V
Without the circuit of the converter I don't know the relevance of these but the only one that looks a bit strange is the doubler bias.
Do you have any thoughts after your experience?
I will pull it apart again and check out some of yours and Gerald's suggestions on the DC feeds, the feed throughs and where this LO test point comes from.
Thanks
Dave
On 8/02/2022 5:38 pm, Askild wrote:
toggle quoted message
Show quoted text
Hi Dave,
I once fixed a 5086-7812? second converter with a 5021-8661 board.
The only problem on this, was cracked solder joints on the feed through capacitors on the board. So I did not have to open the cavity part of the converter.
HP had cut the legs after soldering, all the way down in the solder joint. This is a bad thing as it adds stress to the solder. I was sure HP would have known better.
I have pictures of it, but not at hand right now.
Do you have a second spectrum analyzer? You should check the output of the test port on the converter.
And also the input level of the LO and IF.
Maybe you can tell us a bit more about the fault. What is the loss through the converter?
Guess this SA only go to 2.9GHz? so there is no high band?
What test equipment do you have to test and fault find with.
Regards,
Askild
On Tue, Feb 8, 2022 at 6:20 AM Dave Ireland < mirrors@...> wrote:
Sorry I rushed that last email.
For more relevance the second converter I am talking about is a 5086-7957 and it is low on gain.
Dave
On 8/02/2022 1:10 pm, Dave Ireland wrote:
Has anyone had any joy repairing on of these.
Dave
|
Hi,
Just for completeness I will share a couple of pictures of the second converter in a 8563A that I fixed. In the first picture, it was not easy to see the issue:
I then grabbed a better camera to get better close in shot: So it is obvious that they cut the legs after soldering, and they cut down into the solder joint.
If you cut like this, you need to re-solder the joint! This is one of the first things I learned at the soldering course at my first job.
Regards, Askild
On Fri, Feb 11, 2022 at 1:02 AM Dave Ireland < mirrors@...> wrote: Askild
After my email I pulled it apart again and had a good look. Nothing stood out other than some of the soldering looked a bit cold. The feed thrus where ok, nice and shinny.
It was interesting about the voltages. The descriptions in the manual are all wrong with only 5v, mixer bias and "pin switch" being used and repeated accross several of the pins.?
I will see if I can source a higher spec an to check the LO.
Thanks
Dave
-------- Original message -------- Date: 11/2/22 04:22 (GMT+08:00) Subject: Re: [HP-Agilent-Keysight-equipment] 8560E Second Converter
Hi Dave,
The test port on the second converter should be 3.6GHz (6*600MHz). Normally I think that the first mixer is the part that is most likely to fail, as its exposed to over power or dc voltage from the input connector. It will be difficult to fault find without test instrument that go above 3GHz.? You don't need a full lab of equipment that go above 3GHz, but having one that can detect power would help. So a power meter, or maybe just a diode detector that is usable above 3 GHz. You don't need exact measurement, you could compare a known power level from your signal generator at 3GHz, to what come out of mixer at 3.9GHz. Will not be accurate, but should not be 20dB difference. Also, an ADF4351 will go to 4.4GHz. You can get complete units with touch screen. Here would be the same, set the frequency at 3GHz, and measure level with your spectrum analyzer, making sure the level is correct for the second converter (use attenuators if necessary), then increase frequency to 1st IF (3.9xxGHz) and measure output of second converter with your SA. You could possibly also make a down converter with a mixer and a LO source.
So I think you need to invest in something that lets you either measure or source above 3GHz, if you don't know somebody that have equipment you could borrow.
I can't answer on your voltage measurements, hopefully someone else can help.
Regards, Askild
On Thu, Feb 10, 2022 at 8:00 AM Dave Ireland < mirrors@...> wrote:
Askild
I have a sig gen and a specan that both
go to 3GHz.
The test point on the converter is
labelled LO test and I assume that this is the 600MHZ but I see
nothing on this even though the 600MHz input is correct. If
however it is the 3.9Ghz, then I have no way of seeing this
without mixing it to another frequency.
I can't see the output of the A8 Low
Band mixer as it is again too high for my specan but the RF input
is correct according to the manual at -21dBm and the drive
voltages are -4.96V for the -5V rail and -4.14V for the -4V rail.
The 310.75MHz output of the converter
when measured as per the manual is -59dBm where it should be
-38dBm.? When I measure the voltage between the test connector J19
pins 15 and 6, the drive to the converter pin switch, I get
+14.48V which is in the range of the manual.
The next item in the manual is
measuring the mixer bias on the test connector J19 pin 1 where I
get -39mV which is outside the required range of -150mV and
-800mV. After that it just says if outside the range, probably the
second converter is faulty.
The voltages to the second converter
are:-
J12-1 Mixer Bias:??? ??? ??? ??? ???
??? -39mV
J12-2 +5VF:?? ??? ???? ?? ?? ???? ???
??? ??? 4.87V
J12-3 Analogue Gnd: ??? ??? ??? ??? ???
Yes
J12-4 +10VR:?? ??? ??? ?? ??? ??? ???
??? ??? ? 9.9V
J12-5 Pin Switch:??? ??? ??? ??? ???
??? 14.48V
J12-7 Drain Current Sense: ??? ???
4.86V
J12-8 Drain Voltage:??? ??? ??? ?? ??
?? 4.85V
J12-9 Doubler Bias:??? ??? ??? ??? ???
14.48V
J12-10 Driver Bias:??? ?? ?? ??? ??? ??
0.465V
Without the circuit of the converter I
don't know the relevance of these but the only one that looks a
bit strange is the doubler bias.
Do you have any thoughts after your
experience?
I will pull it apart again and check
out some of yours and Gerald's suggestions on the DC feeds, the
feed throughs and where this LO test point comes from.
Thanks
Dave
On 8/02/2022 5:38 pm, Askild wrote:
Hi Dave,
I once fixed a 5086-7812? second converter with a 5021-8661
board.
The only problem on this, was cracked solder joints on the
feed through capacitors on the board. So I did not have to
open the cavity part of the converter.
HP had cut the legs after soldering, all the way down in
the solder joint. This is a bad thing as it adds stress to the
solder. I was sure HP would have known better.
I have pictures of it, but not at hand right now.
Do you have a second spectrum analyzer? You should check
the output of the test port on the converter.
And also the input level of the LO and IF.
Maybe you can tell us a bit more about the fault. What is
the loss through the converter?
Guess this SA only go to 2.9GHz? so there is no high band?
What test equipment do you have to test and fault find
with.
Regards,
Askild
On Tue, Feb 8, 2022 at 6:20 AM
Dave Ireland < mirrors@...>
wrote:
Sorry I rushed that last email.
For more relevance the second converter I am talking
about is a 5086-7957 and it is low on gain.
Dave
On 8/02/2022 1:10 pm, Dave Ireland wrote:
Has anyone had any joy repairing on
of these.
Dave
|
Wow a bit ordinary for HP.
I am loaning one of those nano spec an
that proports to go to 4.4GHz and check the LO and the output of
the 1st mixer.
Then I will go back in and have a
closer look at all the solder joints.
Dave
On 11/02/2022 3:18 pm, Askild wrote:
toggle quoted message
Show quoted text
Hi,
Just for completeness I will share a couple of pictures of
the second converter in a 8563A that I fixed.
In the first picture, it was not easy to see the issue:
I then grabbed a better camera to get better close in shot:
So it is obvious that they cut the legs after soldering,
and they cut down into the solder joint.
If you cut like this, you need to re-solder the joint! This
is one of the first things I learned at the soldering course
at my first job.
Regards,
Askild
On Fri, Feb 11, 2022 at 1:02
AM Dave Ireland < mirrors@...>
wrote:
Askild
After my email I pulled it apart again and
had a good look. Nothing stood out other than some of the
soldering looked a bit cold. The feed thrus where ok, nice
and shinny.
It was interesting about the voltages. The
descriptions in the manual are all wrong with only 5v,
mixer bias and "pin switch" being used and repeated
accross several of the pins.?
I will see if I can source a higher spec an
to check the LO.
Thanks
Dave
-------- Original message --------
Date: 11/2/22 04:22 (GMT+08:00)
Subject: Re: [HP-Agilent-Keysight-equipment] 8560E
Second Converter
Hi Dave,
The test port on the second converter should be
3.6GHz (6*600MHz).
Normally I think that the first mixer is the part
that is most likely to fail, as its exposed to over
power or dc voltage from the input connector.
It will be difficult to fault find without test
instrument that go above 3GHz.?
You don't need a full lab of equipment that go above
3GHz, but having one that can detect power would help.
So a power meter, or maybe just a diode detector that
is usable above 3 GHz. You don't need exact measurement,
you could compare a known power level from your signal
generator at 3GHz, to what come out of mixer at 3.9GHz.
Will not be accurate, but should not be 20dB difference.
Also, an ADF4351 will go to 4.4GHz. You can get
complete units with touch screen. Here would be the
same, set the frequency at 3GHz, and measure level with
your spectrum analyzer, making sure the level is correct
for the second converter (use attenuators if necessary),
then increase frequency to 1st IF (3.9xxGHz) and measure
output of second converter with your SA.
You could possibly also make a down converter with a
mixer and a LO source.
So I think you need to invest in something that lets
you either measure or source above 3GHz, if you don't
know somebody that have equipment you could borrow.
I can't answer on your voltage measurements,
hopefully someone else can help.
Regards,
Askild
On Thu, Feb 10, 2022 at
8:00 AM Dave Ireland < mirrors@...>
wrote:
Askild
I have a sig gen and a specan that both go to
3GHz.
The test point on the converter is labelled LO
test and I assume that this is the 600MHZ but I see
nothing on this even though the 600MHz input is
correct. If however it is the 3.9Ghz, then I have no
way of seeing this without mixing it to another
frequency.
I can't see the output of the A8 Low Band mixer
as it is again too high for my specan but the RF
input is correct according to the manual at -21dBm
and the drive voltages are -4.96V for the -5V rail
and -4.14V for the -4V rail.
The 310.75MHz output of the converter when
measured as per the manual is -59dBm where it should
be -38dBm.? When I measure the voltage between the
test connector J19 pins 15 and 6, the drive to the
converter pin switch, I get +14.48V which is in the
range of the manual.
The next item in the manual is measuring the
mixer bias on the test connector J19 pin 1 where I
get -39mV which is outside the required range of
-150mV and -800mV. After that it just says if
outside the range, probably the second converter is
faulty.
The voltages to the second converter are:-
J12-1 Mixer Bias:??? ??? ??? ??? ??? ??? -39mV
J12-2 +5VF:?? ??? ???? ?? ?? ???? ??? ??? ???
4.87V
J12-3 Analogue Gnd: ??? ??? ??? ??? ??? Yes
J12-4 +10VR:?? ??? ??? ?? ??? ??? ??? ??? ??? ?
9.9V
J12-5 Pin Switch:??? ??? ??? ??? ??? ??? 14.48V
J12-7 Drain Current Sense: ??? ??? 4.86V
J12-8 Drain Voltage:??? ??? ??? ?? ?? ?? 4.85V
J12-9 Doubler Bias:??? ??? ??? ??? ??? 14.48V
J12-10 Driver Bias:??? ?? ?? ??? ??? ?? 0.465V
Without the circuit of the converter I don't know
the relevance of these but the only one that looks a
bit strange is the doubler bias.
Do you have any thoughts after your experience?
I will pull it apart again and check out some of
yours and Gerald's suggestions on the DC feeds, the
feed throughs and where this LO test point comes
from.
Thanks
Dave
On 8/02/2022 5:38 pm, Askild wrote:
Hi Dave,
I once fixed a 5086-7812? second converter
with a 5021-8661 board.
The only problem on this, was cracked solder
joints on the feed through capacitors on the
board. So I did not have to open the cavity part
of the converter.
HP had cut the legs after soldering, all the
way down in the solder joint. This is a bad
thing as it adds stress to the solder. I was
sure HP would have known better.
I have pictures of it, but not at hand right
now.
Do you have a second spectrum analyzer? You
should check the output of the test port on the
converter.
And also the input level of the LO and IF.
Maybe you can tell us a bit more about the
fault. What is the loss through the converter?
Guess this SA only go to 2.9GHz? so there is
no high band?
What test equipment do you have to test and
fault find with.
Regards,
Askild
On Tue, Feb 8,
2022 at 6:20 AM Dave Ireland < mirrors@...>
wrote:
Sorry I rushed that last email.
For more relevance the second converter I
am talking about is a 5086-7957 and it is
low on gain.
Dave
On 8/02/2022 1:10 pm, Dave Ireland wrote:
Has anyone had any
joy repairing on of these.
Dave
|
Peter
The first fault was U700 and the series
pass transistor on U700 supply that was gone. Replaced that and
all the alarms cleared. The 600MHz is still a bit low but
comparing the device 600MHz and a signal generator injected in at
the right level, the second converter output is still about 25dB
low.
I will try and sort that out and then
go back to U501 to see if I can raise the 600MHz.
Thanks for tip.
Dave
On 11/02/2022 2:17 pm, Peter Hansen
wrote:
toggle quoted message
Show quoted text
Hello in 90% cases of that failure your U501 in A15 is dead. It
is a 18-19dBm MMIC . Not critical use ERA5 or MSA0586 etc.
also if your 300Mhz Cal output is bad it that failure. They look
ok still if measuring current arount it but it looses
amplification. It will not tripple the 100Mhz to 300 and then
not double to the 600Mhz.
best regards Peter OZ1LPR
Askild
I have a sig gen and a specan
that both go to 3GHz.
The test point on the converter
is labelled LO test and I assume that this is the 600MHZ but I
see nothing on this even though the 600MHz input is correct.
If however it is the 3.9Ghz, then I have no way of seeing this
without mixing it to another frequency.
I can't see the output of the A8
Low Band mixer as it is again too high for my specan but the
RF input is correct according to the manual at -21dBm and the
drive voltages are -4.96V for the -5V rail and -4.14V for the
-4V rail.
The 310.75MHz output of the
converter when measured as per the manual is -59dBm where it
should be -38dBm.? When I measure the voltage between the test
connector J19 pins 15 and 6, the drive to the converter pin
switch, I get +14.48V which is in the range of the manual.
The next item in the manual is
measuring the mixer bias on the test connector J19 pin 1 where
I get -39mV which is outside the required range of -150mV and
-800mV. After that it just says if outside the range, probably
the second converter is faulty.
The voltages to the second
converter are:-
J12-1 Mixer Bias:??? ??? ??? ???
??? ??? -39mV
J12-2 +5VF:?? ??? ???? ?? ?? ????
??? ??? ??? 4.87V
J12-3 Analogue Gnd: ??? ??? ???
??? ??? Yes
J12-4 +10VR:?? ??? ??? ?? ??? ???
??? ??? ??? ? 9.9V
J12-5 Pin Switch:??? ??? ??? ???
??? ??? 14.48V
J12-7 Drain Current Sense: ???
??? 4.86V
J12-8 Drain Voltage:??? ??? ???
?? ?? ?? 4.85V
J12-9 Doubler Bias:??? ??? ???
??? ??? 14.48V
J1210 Driver Bias:??? ?? ?? ???
??? ?? 0.465V
Without the circuit of the
converter I don't know the relevance of these but the only one
that looks a bit strange is the doubler bias.
Do you have any thoughts after
your experience?
I will pull it apart again and
check out some of yours and Gerald's suggestions on the DC
feeds, the feed throughs and where this LO test point comes
from.
Thanks
Dave
On 8/02/2022 5:38 pm, Askild
wrote:
Hi Dave,
I once fixed a 5086-7812? second converter with a
5021-8661 board.
The only problem on this, was cracked solder joints on
the feed through capacitors on the board. So I did not
have to open the cavity part of the converter.
HP had cut the legs after soldering, all the way down
in the solder joint. This is a bad thing as it adds stress
to the solder. I was sure HP would have known better.
I have pictures of it, but not at hand right now.
Do you have a second spectrum analyzer? You should
check the output of the test port on the converter.
And also the input level of the LO and IF.
Maybe you can tell us a bit more about the fault. What
is the loss through the converter?
Guess this SA only go to 2.9GHz? so there is no high
band?
What test equipment do you have to test and fault find
with.
Regards,
Askild
On Tue, Feb 8, 2022 at
6:20 AM Dave Ireland < mirrors@...>
wrote:
Sorry I rushed that last email.
For more relevance the second converter I am
talking about is a 5086-7957 and it is low on gain.
Dave
On 8/02/2022 1:10 pm, Dave Ireland wrote:
Has anyone had any joy repairing
on of these.
Dave
|
Hi Dave limits needs to be accurate as the level is used in doublers too low does not work.
best regards Peter
Peter
The first fault was U700 and the series pass transistor on U700 supply that was gone. Replaced that and all the alarms cleared. The 600MHz is still a bit low but comparing the device 600MHz and a signal generator injected in at
the right level, the second converter output is still about 25dB low.
I will try and sort that out and then go back to U501 to see if I can raise the 600MHz.
Thanks for tip.
Dave
On 11/02/2022 2:17 pm, Peter Hansen wrote:
toggle quoted message
Show quoted text
Hello in 90% cases of that failure your U501 in A15 is dead. It is a 18-19dBm MMIC . Not critical use ERA5 or MSA0586 etc.
also if your 300Mhz Cal output is bad it that failure. They look ok still if measuring current arount it but it looses amplification. It will not tripple the 100Mhz to 300 and then not double to the 600Mhz.
best regards Peter OZ1LPR
Askild
I have a sig gen and a specan that both go to 3GHz.
The test point on the converter is labelled LO test and I assume that this is the 600MHZ but I see nothing on this even though the 600MHz input is correct. If however it is the 3.9Ghz, then I have no way of seeing this without
mixing it to another frequency.
I can't see the output of the A8 Low Band mixer as it is again too high for my specan but the RF input is correct according to the manual at -21dBm and the drive voltages are -4.96V for the -5V rail and -4.14V for the -4V rail.
The 310.75MHz output of the converter when measured as per the manual is -59dBm where it should be -38dBm.? When I measure the voltage between the test connector J19 pins 15 and 6, the drive to the converter pin switch, I get
+14.48V which is in the range of the manual.
The next item in the manual is measuring the mixer bias on the test connector J19 pin 1 where I get -39mV which is outside the required range of -150mV and -800mV. After that it just says if outside the range, probably the second
converter is faulty.
The voltages to the second converter are:-
J12-1 Mixer Bias:??? ??? ??? ??? ??? ??? -39mV
J12-2 +5VF:?? ??? ???? ?? ?? ???? ??? ??? ??? 4.87V
J12-3 Analogue Gnd: ??? ??? ??? ??? ??? Yes
J12-4 +10VR:?? ??? ??? ?? ??? ??? ??? ??? ??? ? 9.9V
J12-5 Pin Switch:??? ??? ??? ??? ??? ??? 14.48V
J12-7 Drain Current Sense: ??? ??? 4.86V
J12-8 Drain Voltage:??? ??? ??? ?? ?? ?? 4.85V
J12-9 Doubler Bias:??? ??? ??? ??? ??? 14.48V
J1210 Driver Bias:??? ?? ?? ??? ??? ?? 0.465V
Without the circuit of the converter I don't know the relevance of these but the only one that looks a bit strange is the doubler bias.
Do you have any thoughts after your experience?
I will pull it apart again and check out some of yours and Gerald's suggestions on the DC feeds, the feed throughs and where this LO test point comes from.
Thanks
Dave
On 8/02/2022 5:38 pm, Askild wrote:
Hi Dave,
I once fixed a 5086-7812? second converter with a 5021-8661 board.
The only problem on this, was cracked solder joints on the feed through capacitors on the board. So I did not have to open the cavity part of the converter.
HP had cut the legs after soldering, all the way down in the solder joint. This is a bad thing as it adds stress to the solder. I was sure HP would have known better.
I have pictures of it, but not at hand right now.
Do you have a second spectrum analyzer? You should check the output of the test port on the converter.
And also the input level of the LO and IF.
Maybe you can tell us a bit more about the fault. What is the loss through the converter?
Guess this SA only go to 2.9GHz? so there is no high band?
What test equipment do you have to test and fault find with.
Regards,
Askild
On Tue, Feb 8, 2022 at 6:20 AM Dave Ireland < mirrors@...> wrote:
Sorry I rushed that last email.
For more relevance the second converter I am talking about is a 5086-7957 and it is low on gain.
Dave
On 8/02/2022 1:10 pm, Dave Ireland wrote:
Has anyone had any joy repairing on of these.
Dave
|
