Re: HP-8753E Power Cycles at Start Up
I figured something like that but does this
drive this? It would make sense if it did. The 928 is the only clue that it does. E1 and E2 are shown on the schematic as connecting to line,?see below this schematic. I can see where the 5v is compared to the 1.2v ref in U2.? Thanks Ozan, I think I have it.?
On Sun, Aug 28, 2022 at 10:22 PM Ozan < ozan_g@...> wrote: On Sun, Aug 28, 2022 at 06:12 PM, peter bunge wrote:
Can someone tell me how the control loop in the pre-regulator controls the 5vD supply? What I see is T1 connected to line at E1 and E2 and switching FETs that don't seem to control anything and only drive RT1 and RT2.Is there a winding in the loop that acts like a MagAmp? The common connection of the?FETs connects through capacitor?C8 to A15A1 transformer,?what and where is that? .
What am I missing? The manual is very vague simply stating "The?+5D supply is regulated by the control loop in A15"
Am I missing a schematic? I have one for 08753-60215 and one for 08753-60115. there is a T1 on each board which makes it more confusing.
-----
Hi Peter,
I briefly looked at the schematic of 8753A.
Hopefully 8753E is similar. Mains input is rectified on C3 and C4, RT1 and RT2 are inrush current limiting NTCs. Q1 and Q2 turn on alternatively, creating an AC waveform that flows through C6 (probably C8 in your schematic) and primary of "Power Transformer". Return path of the primary is through "T3 Over Current Detection" transformer and back to mains input through S2 switch (which selects 110/220 tap points). 8753A schematic and board layout show the power transformer on A15 board.?
Ozan
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John, thanks for your answer!
It is true what they say, but I forgot to write in the previous message that I tried the two YIG oscillators on both SAs connected to a power meter and they show no signs of life.
The thing that drives me crazy is knowing what I did wrong. Murphy has struck again!
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Re: Repair of HP Keysight E4406A VSA
Hi Kurt,
Interesting repair. Thanks for the explanation and the document.
Best regards,
Razvan
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Show quoted text
On 29/08/2022 11:27, Kurt Poulsen wrote: Hi All
Recently I repaired for a friend his E4406A where a switch was defective
and where the original switch 1GG7-4218 was no longer available.
An alternative switch Hewlett Packard MGS-71018 could be acquired from
RF-Microwave (link in the document attached).
However, the original switch had control voltage as + - 5V but the
substitute 0 and -5V and the two control pin swapped, so a modification
needed.
I did a detailed document how this modification is made.
Kind regards
Kurt
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Repair of HP Keysight E4406A VSA
Hi All Recently I repaired for a friend his E4406A where a switch was defective and where the original switch 1GG7-4218 was no longer available.
An alternative switch Hewlett Packard MGS-71018 could be acquired from RF-Microwave (link in the document attached).
However, the original switch had control voltage as + - 5V but the substitute 0 and -5V and the two control pin swapped, so a modification needed.
I did a detailed document how this modification is made. Kind regards Kurt ?
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Re: Hp 8590a spectrum analyzer
I have one of those and it fails some of the selftests as well. Vlad here in the forums helped me troubleshoot, but I never found the culprit so I just left it. They are very tricky to trim as the gain is so high. 
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Re: HP-8753E Power Cycles at Start Up
Late to the party but just in case it helps someone:
My 8753C which uses the same PSU had a cycling fault. It was caused by shorted diodes on the A15 Pre-reg board. CR6 and CR7.
Cheers, Roger
On Mon, 29 Aug 2022 at 14:22, Ozan < ozan_g@...> wrote: On Sun, Aug 28, 2022 at 06:12 PM, peter bunge wrote:
Can someone tell me how the control loop in the pre-regulator controls the 5vD supply? What I see is T1 connected to line at E1 and E2 and switching FETs that don't seem to control anything and only drive RT1 and RT2.Is there a winding in the loop that acts like a MagAmp? The common connection of the?FETs connects through capacitor?C8 to A15A1 transformer,?what and where is that? .
What am I missing? The manual is very vague simply stating "The?+5D supply is regulated by the control loop in A15"
Am I missing a schematic? I have one for 08753-60215 and one for 08753-60115. there is a T1 on each board which makes it more confusing.
-----
Hi Peter,
I briefly looked at the schematic of 8753A.
Hopefully 8753E is similar. Mains input is rectified on C3 and C4, RT1 and RT2 are inrush current limiting NTCs. Q1 and Q2 turn on alternatively, creating an AC waveform that flows through C6 (probably C8 in your schematic) and primary of "Power Transformer". Return path of the primary is through "T3 Over Current Detection" transformer and back to mains input through S2 switch (which selects 110/220 tap points). 8753A schematic and board layout show the power transformer on A15 board.?
Ozan
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Re: HP-8753E Power Cycles at Start Up
On Sun, Aug 28, 2022 at 06:12 PM, peter bunge wrote:
Can someone tell me how the control loop in the pre-regulator controls the 5vD supply? What I see is T1 connected to line at E1 and E2 and switching FETs that don't seem to control anything and only drive RT1 and RT2.Is there a winding in the loop that acts like a MagAmp? The common connection of the?FETs connects through capacitor?C8 to A15A1 transformer,?what and where is that? .
What am I missing? The manual is very vague simply stating "The?+5D supply is regulated by the control loop in A15"
Am I missing a schematic? I have one for 08753-60215 and one for 08753-60115. there is a T1 on each board which makes it more confusing.
----- Hi Peter, I briefly looked at the schematic of 8753A. Hopefully 8753E is similar. Mains input is rectified on C3 and C4, RT1 and RT2 are inrush current limiting NTCs. Q1 and Q2 turn on alternatively, creating an AC waveform that flows through C6 (probably C8 in your schematic) and primary of "Power Transformer". Return path of the primary is through "T3 Over Current Detection" transformer and back to mains input through S2 switch (which selects 110/220 tap points). 8753A schematic and board layout show the power transformer on A15 board.? Ozan
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Re: HP-8753E Power Cycles at Start Up
Thanks Bruce. I have seen that problem on another 8753 and the fans are very specific. The symptoms here are different but I will investigate that as well.? Peter.
On Sun, Aug 28, 2022 at 8:40 PM Bruce Lane < kyrrin@...> wrote: ???? I'm coming in late to the discussion, but...
???? My first VNA had a similar problem. The issue turned out to be a
defective case fan. You see, the power supply had a circuit in it to
detect pulses from the fan's tachometer. No fan movement = no pulses =
no full power-on.
???? Just thinking out loud.... Happy tweaking.
On 28-Aug-22 16:53, peter bunge wrote:
> Not so easy to recap. Do you have a list of suitable replacements from
> DigiKey or Mouser?
> How do you get the boards out? Do I have to unsolder anything? Is the
> power switch mounted?to the PCB?
> I have the PreReg supply split open.
> I also do not think this is the problem because the manual
> troubleshooting points to the +5v supply which is where my
> troubleshooting pointed?from a different?direction. If the?caps are
> easy to get at with the boards out I can check them for value and
> resistance. I prefer to identify a?definite fault rather than randomly
> replace components.
> I put the?8753B on a?variac and dropped?the?voltage to 100VAC but
> could?not?trigger the fault. This probably eliminates the rear half of
> the PreReg with the two big capacitors,?but not the front board with
> the six big?caps.
> It worked fine for?a?few hours but the next time I turned it on
> the?fault returned. I took?the?Pr-Regulator out and split the?module
> and turned it on and it?is back to working perfectly. I wiggled
> all?connectors?and cannot?get?it to quit again. I don't think it is a
> bad connection.
> I checked the current in all wires to the display when the fault was
> happening and there was nothing obvious (disconnecting the display
> cured the fault repeatedly but it was only because it dropped the
> drain on the +5v. It is an LCD display).
> It seems more like a marginal?trip point setting which is why I have
> the supply open.
>
>
> On Sun, Aug 28, 2022 at 4:42 PM tony sayer <tony@...> wrote:
>
>? ? ?In message <[email protected]>, Burt K6OQK
>? ? ?<biwa@...> writes
>? ? ?>? ? Rich,
>? ? ?>
>? ? ?>? ? I have cured a lot of weird problems by fixing the obvious
>? ? ?things
>? ? ?>? ? first.? I suspect that if you were to re-cap the power supply
>? ? ?>? ? module you would be pleased.? That's been my experience in
>? ? ?90% of
>? ? ?>? ? the symptoms you describe.
>
>? ? ?FWIW - Mine too!...
>
>? ? ?>
>? ? ?>? ? Burt, K6OQK
>? ? ?>
>
>? ? ?--
>? ? ?Tony Sayer
>
>? ? ?Bancom Communications? ?U.K.
>
>
>
>
>
>
>
>
>
>
--
Bruce Lane, ARS KC7GR
kyrrin@...
"Quando Omni Flunkus Moritati" (Red Green)
|
Re: HP-8753E Power Cycles at Start Up
Can someone tell me how the control loop in the pre-regulator controls the 5vD supply? What I see is T1 connected to line at E1 and E2 and switching FETs that don't seem to control anything and only drive RT1 and RT2.Is there a winding in the loop that acts like a MagAmp? The common connection of the?FETs connects through capacitor?C8 to A15A1 transformer,?what and where is that? . What am I missing? The manual is very vague simply stating "The?+5D supply is regulated by the control loop in A15" Am I missing a schematic? I have one for 08753-60215 and one for 08753-60115. there is a T1 on each board which makes it more confusing.
Not so easy to recap. Do you have a list of suitable replacements from DigiKey or Mouser? How do you get the boards out? Do I have to unsolder anything? Is the power switch mounted?to the PCB? I have the PreReg supply split open. I also do not think this is the problem because the manual troubleshooting points to the +5v supply which is where my troubleshooting pointed?from a different?direction. If the?caps are easy to get at with the boards out I can check them for value and resistance. I prefer to identify a?definite fault rather than randomly replace components.? I put the?8753B on a?variac and dropped?the?voltage to 100VAC but could?not?trigger the fault. This probably eliminates the rear half of the PreReg with the two big capacitors,?but not the front board with the six big?caps.? It worked fine for?a?few hours but the next time I turned it on the?fault returned. I took?the?Pr-Regulator out and split the?module and turned it on and it?is back to working perfectly. I wiggled all?connectors?and cannot?get?it to quit again. I don't think it is a bad connection. I checked the current in all wires to the display when the fault was happening and there was nothing obvious (disconnecting the display cured the fault repeatedly but it was only because it dropped the drain on the +5v. It is an LCD display). It seems more like a marginal?trip point setting which is why I have the supply open.?
On Sun, Aug 28, 2022 at 4:42 PM tony sayer < tony@...> wrote: In message <[email protected]>, Burt K6OQK
<biwa@...> writes
>? ? Rich,
>
>? ? I have cured a lot of weird problems by fixing the obvious things
>? ? first.? I suspect that if you were to re-cap the power supply
>? ? module you would be pleased.? That's been my experience in 90% of
>? ? the symptoms you describe.
FWIW - Mine too!...
>
>? ? Burt, K6OQK
>? ?
--
Tony Sayer
Bancom Communications? ?U.K.
|
Re: HP-8753E Power Cycles at Start Up
I'm coming in late to the discussion, but...
??? My first VNA had a similar problem. The issue turned out to be a defective case fan. You see, the power supply had a circuit in it to detect pulses from the fan's tachometer. No fan movement = no pulses = no full power-on.
??? Just thinking out loud.... Happy tweaking.
toggle quoted message
Show quoted text
On 28-Aug-22 16:53, peter bunge wrote: Not so easy to recap. Do you have a list of suitable replacements from DigiKey or Mouser?
How do you get the boards out? Do I have to unsolder anything? Is the power switch mounted?to the PCB?
I have the PreReg supply split open.
I also do not think this is the problem because the manual troubleshooting points to the +5v supply which is where my troubleshooting pointed?from a different?direction. If the?caps are easy to get at with the boards out I can check them for value and resistance. I prefer to identify a?definite fault rather than randomly replace components.
I put the?8753B on a?variac and dropped?the?voltage to 100VAC but could?not?trigger the fault. This probably eliminates the rear half of the PreReg with the two big capacitors,?but not the front board with the six big?caps.
It worked fine for?a?few hours but the next time I turned it on the?fault returned. I took?the?Pr-Regulator out and split the?module and turned it on and it?is back to working perfectly. I wiggled all?connectors?and cannot?get?it to quit again. I don't think it is a bad connection.
I checked the current in all wires to the display when the fault was happening and there was nothing obvious (disconnecting the display cured the fault repeatedly but it was only because it dropped the drain on the +5v. It is an LCD display).
It seems more like a marginal?trip point setting which is why I have the supply open.
On Sun, Aug 28, 2022 at 4:42 PM tony sayer <tony@...> wrote:
In message <[email protected]>, Burt K6OQK
<biwa@...> writes
>? ? Rich,
>
>? ? I have cured a lot of weird problems by fixing the obvious
things
>? ? first.? I suspect that if you were to re-cap the power supply
>? ? module you would be pleased.? That's been my experience in
90% of
>? ? the symptoms you describe.
FWIW - Mine too!...
>
>? ? Burt, K6OQK
>
--
Tony Sayer
Bancom Communications? ?U.K.
--
Bruce Lane, ARS KC7GR
kyrrin@...
"Quando Omni Flunkus Moritati" (Red Green)
|
Re: HP-8753E Power Cycles at Start Up
Not so easy to recap. Do you have a list of suitable replacements from DigiKey or Mouser? How do you get the boards out? Do I have to unsolder anything? Is the power switch mounted?to the PCB? I have the PreReg supply split open. I also do not think this is the problem because the manual troubleshooting points to the +5v supply which is where my troubleshooting pointed?from a different?direction. If the?caps are easy to get at with the boards out I can check them for value and resistance. I prefer to identify a?definite fault rather than randomly replace components.? I put the?8753B on a?variac and dropped?the?voltage to 100VAC but could?not?trigger the fault. This probably eliminates the rear half of the PreReg with the two big capacitors,?but not the front board with the six big?caps.? It worked fine for?a?few hours but the next time I turned it on the?fault returned. I took?the?Pr-Regulator out and split the?module and turned it on and it?is back to working perfectly. I wiggled all?connectors?and cannot?get?it to quit again. I don't think it is a bad connection. I checked the current in all wires to the display when the fault was happening and there was nothing obvious (disconnecting the display cured the fault repeatedly but it was only because it dropped the drain on the +5v. It is an LCD display). It seems more like a marginal?trip point setting which is why I have the supply open.?
On Sun, Aug 28, 2022 at 4:42 PM tony sayer < tony@...> wrote: In message <[email protected]>, Burt K6OQK
<biwa@...> writes
>? ? Rich,
>
>? ? I have cured a lot of weird problems by fixing the obvious things
>? ? first.? I suspect that if you were to re-cap the power supply
>? ? module you would be pleased.? That's been my experience in 90% of
>? ? the symptoms you describe.
FWIW - Mine too!...
>
>? ? Burt, K6OQK
>? ?
--
Tony Sayer
Bancom Communications? ?U.K.
|
Picol,
It has been a while since I tried (with partial success) to repair on of these YTOs.? If I recall correctly, the output of the NPN oscillator is buffered by a FET amplifier with the drain fed from the +5v supply.? If that FET is a GaAs type, it probably requires a negative bias to turn off.? It might appear as a (near) short to ground with no negative bias available.
--John Gord
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Show quoted text
On Sun, Aug 28, 2022 at 11:18 AM, @Picol wrote:
Hello everyone,
about a year ago, turning on my HP8563E spectrum analyzer, several errors appeared, including the ravenous error 334.
From research on the net, and a direct inspection, I found that the YTO model 5086-7906 was broken.
Pin 1, corresponding to 4 of connector J3, of the 5 VDC power supply, appears to be shorted to ground.
About a month ago, I bought an HP8560E Spectrum Analyzer at a good price with the intention of using its YTO for my HP8563E.
In fact, the analyzer cost me as much as a used YTO!
Before mounting it, I checked that the voltages of +5V, +15V and -15V were present.
Then I mounted the YIG oscillator, checking several times that the connectors were mounted correctly. Which I always do when I reassemble an electronic instrument.
When I turned the spectrum analyzer back on, I found that the new YTO was also broken !! A check of the same confirmed this.
What could I have done wrong? Has anything like this ever happened to anyone? Is there anyone in the group who has experience with these damn YTOs?
Given that I'm not really fasting with electronic instruments, such a thing had never happened to me.
I contacted a local company that repairs the YTO at a price of around 800 euros but I'm afraid that if I don't find out the reason for the break, this too could break ...
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Re: HP-8753E Power Cycles at Start Up
In message < [email protected]>, Burt K6OQK <biwa@...> writes Rich,
I have cured a lot of weird problems by fixing the obvious things
first.? I suspect that if you were to re-cap the power supply
module you would be pleased.? That's been my experience in 90% of
the symptoms you describe. FWIW - Mine too!...
Burt, K6OQK
-- Tony Sayer Bancom Communications U.K.
|
Hello everyone,
about a year ago, turning on my HP8563E spectrum analyzer, several errors appeared, including the ravenous error 334.
From research on the net, and a direct inspection, I found that the YTO model 5086-7906 was broken.
Pin 1, corresponding to 4 of connector J3, of the 5 VDC power supply, appears to be shorted to ground.
About a month ago, I bought an HP8560E Spectrum Analyzer at a good price with the intention of using its YTO for my HP8563E.
In fact, the analyzer cost me as much as a used YTO!
Before mounting it, I checked that the voltages of +5V, +15V and -15V were present.
Then I mounted the YIG oscillator, checking several times that the connectors were mounted correctly. Which I always do when I reassemble an electronic instrument.
When I turned the spectrum analyzer back on, I found that the new YTO was also broken !! A check of the same confirmed this.
What could I have done wrong? Has anything like this ever happened to anyone? Is there anyone in the group who has experience with these damn YTOs?
Given that I'm not really fasting with electronic instruments, such a thing had never happened to me.
I contacted a local company that repairs the YTO at a price of around 800 euros but I'm afraid that if I don't find out the reason for the break, this too could break ...
|
Re: Hp 8590a spectrum analyzer
Very interesting videos. I scoped the dc power rails and a couple have heavy noise . I don't think it would hurt to recap the swps. I may start there and see if it clears anything up , besides if it doesn't need it now it will soon. I'm wondering if the shotky diodes should be swapped out also on the 1st converter given its age. . I can still get them on ebay.?
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Re: PNA Cal Kit Editor software
Is this what you're after:
Cal Kit EditorThis Cal Kit editor can be installed on a PC and used to enter or import cal kits without the need for a PNA. Once entered or modified, the kits can then be transferred to the PNA. In addition to being able to import 8510/8753/872x Cal kits with little or no modification needed, this new version also supports the new '.xkt' XML cal kit file format which FieldFox analyzers have begun using and PNA will soon. It uses an interface similar to that used in the PNA, so the learning curve is minimal. Please note that '.ckt' files saved by this new version of this editor will only function for PNAs with Firmware A.07.50 and above. It includes data-based standards capabilities. Refer also to the PNA Help file for instructions.
?this 19 MB msi file. Rev: 1.0.5045.0 (Oct 2013)
?this 2 MB version for 4.83 to 4.87.01 firmware?only!?Rev: A.04.83 (Mar 14 2005)
From?
TonyG
Yes, thank you. I will have to get into the habit of looking there, as it archives most sites. I only know of one website
that was at one time blocking the IP address of the Wayback Machine - for example
which was annoying when I wanted to find out the specification of something I had bought. Maybe
the Wayback Machine is using different IP addresses, or maybe Justin has decided to not block it any longer.
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Re: HP 8901B/8902A History
the 8902A is essentially an enhanced 8901B ....the enhancement being the low level power measurements when used with the 11722A? ( and others )?
They run the same firmware and most of the parts are the same ...about 90%
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Re: PNA Cal Kit Editor software
Is this what you're after:
Cal Kit EditorThis Cal Kit editor can be installed on a PC and used to enter or import cal kits without the need for a PNA. Once entered or modified, the kits can then be transferred to the PNA. In addition to being able to import 8510/8753/872x Cal kits with little or no modification needed, this new version also supports the new '.xkt' XML cal kit file format which FieldFox analyzers have begun using and PNA will soon. It uses an interface similar to that used in the PNA, so the learning curve is minimal. Please note that '.ckt' files saved by this new version of this editor will only function for PNAs with Firmware A.07.50 and above. It includes data-based standards capabilities. Refer also to the PNA Help file for instructions.
?this 19 MB msi file. Rev: 1.0.5045.0 (Oct 2013)
?this 2 MB version for 4.83 to 4.87.01 firmware?only!?Rev: A.04.83 (Mar 14 2005)
From? TonyG
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Re: "ADDITIONAL STANDARDS ARE NEEDED" when using E-Cal
Forgot to mention there are 2 tables of through data, table 3 which is used during calibration (all PIN's disabled #0000), and table 4 which is used for performance verification (#0200 - 2 PIN's enabled).
This means that the verification measurement has little in common to the calibration process.?? The same 2 PIN's are used during calibration but if anything was wrong with those it will show up as a discrepancy in S11/S12 or S22/S21
--
Wayne
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Re: "ADDITIONAL STANDARDS ARE NEEDED" when using E-Cal
Bruce, Steffan,
I think you are forgetting that there is another verification you can perform - completely remove the ECal module and connect the test ports together and verify the error in the calibration is close to 0.00dB across the frequency range.? That is your error ;-)? ? You can also confirm the phase starts at on the right side of the smith chart for the open port as one would even in manual calibration.
Answering your question the signalling on the DB25 uses the same protocol, in fact the first board is the same between the low and high band modules.? The primary difference is the low band uses 7 switch signals to the lower board and the high band module uses a total of 16.
Analog voltages to the PIN switches are different with the low band using 0 and -12V whereas the high band unit uses +5 and +24V for its pin switches, so the final driver board is completely different between the 2 bands.
The digital interface controlls access to the EEPROM which contains the measurement data, and a way of enabling any of the 7 (or 16) switches in the RF path.
I did open my 85097 (which I use on my 8753ES analyzer) but haven't reverse engineered it other than a conceptual understanding of it taking the signals from the parallel port and using a control line (or maybe register) to multiplex between the A and B ports.?
Following onto answer Steffan's questions,
1.? Yes recalibration this should be possible.?? The contents of the EEPROM are simply the actual S1P measurements for each PIN switch combination, so its a matter of taking a full measurement (on a mechanical calibrated VNA) against each of the PIN switch combinations to get a set of known values.? Note there are only a few standard combinations used? which have been chosen by the design engineers who have a better understanding of the phase delays along the transmission line required for best calibration.
2.? As per #1 above, because you know the complex impedance of the ECal port the VNA will measure the impedance it sees and will de-embed to solve the 12-term matrix for calibration (or 3-6 terms depending on the calibration type selected).???? Instead of a short, open or 50R in the solution matrix we use the known values for the ECal.
It should be noted that the ECal is never a perfect thru, open or short at any time of the electronic calibration.? From memory the short is a few ohms but to "hammer it home" the following 2 PIN's are also energized to ensure there is a stronger reflections.
For successful calibration there must be a ~180deg reversal observed at each frequency (perhaps 90 deg - I know quarter wave is required for unknown through).? This can be easily achieved in the high band cal with the length of transmission line.? For the low band? module there is also a PIN switch halfway through which simulates a open to create a larger phase reversal.
If you have ever used a sliding load during calibration then you will know what I mean by 90 degree observations to get a solid calibration point.
This 180deg requirement is also what sets the lower frequency limit of 45MHz for our units.? As noted in Joels book more modern ECals use a GASFET switch which allow for a more traditional SOLT standard at lower frequencies.
The Arduino board I built is able to reprogram the EEPROM but I haven't added that into the code.? The datasheet wasn't an easy read at the time! ?? After dumping the contents I found the ECals to be better than what I can achieve mechanically, so if I re-calibrate mine it would be a step backwards. ? Given I don't posses a 4 receiver VNA and lower grade test cables my calibrations will always be inferior.
Finally I believe there must be a version of firmware for the 85060C which supports the calibration process.? This is based on the references in the dumped EEPROM data.? Maybe its hidden in the current version somewhere.? If anyone is able to get a copy it would be greatly appreciated.
--
Wayne
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Kurt Poulsen
Anders
Bruce Lane
Dr. David Kirkby, Kirkby Microwave Ltd