Re: General microwave switch type 1699 details needed
I thnk Ed meant, schematics and info for the HP product it was used in.? (The HP8720B)
That should tell you what is needed to use it correctly.
Nothing like a little reverse engineering from a good quality schematic.
73.
Dave 'KBV.
--
Created on and sent from a Unix like PC running and using free and open source software:
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Thank you for this information. I see these are available in the Mouser catalogue.
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The Cinch number you provided does match those on the motherboard. The ones on eBay do look like the originals. What would be the difference between the '301' of these and the '341' of the originals?
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The closest match I have found is an EDAC 307-015-521-102, given the spacing and pitch. However, it is only one set of contacts. I checked their catalogue and they do not make one with a set of two contacts.
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Sorry, this is the correct link to use at first:
Hal
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Re: 11048C feed through termination data?
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Re: General microwave switch type 1699 details needed
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Re: HP 8405A Vector Voltmeter Probes
I've just completed the curve tracer comparison of the HP8405A diode against the 1N6263 diode. The diodes are quite similar, but the HP8405A diode shows much lower dynamic resistance when biased fairly hard. It gets as low as about 11 ohms at about 10mA forward bias. This is probably good when used in a sampling gate? I'm just guessing though... I use a couple of 6.5 digit Keithley DMMs and a precision programmable PSU and a precision current sensor to measure the diode down to about 0.01uA forward bias. I usually use lots of averaging to get smooth data but I've not bothered in this case. So there is some wiggle in the curves down below about 1uA. The VNA tests are going to be much more interesting as I test each diode as a two port device (across 300kHz to about 2GHz) and then vary the bias conditions for both the on and the off states. I can then post process the data to get information about resistance and capacitance for each bias condition. This will create lots of data for these diodes. I think it's probably best I post up most of my results and data on Eevblog as there are going to be lots of plots and simulations. I think there will be too much traffic for some users on the HP groups. There's not much danger of me overloading Eevblog :) 
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Re: General microwave switch type 1699 details needed
Hello to the group. I downloaded the service manual on the unit. Quite a nice unit. However its also at the point that HP stopped including schematics. So the manual is of no use. Not even sure it had a block diagram. Good luck Paul. WB8TSL
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Re: HP 8405A Vector Voltmeter Probes
I've been told I can have the 8405A meter, so I can now start examining the B probe more closely. It may be that something else is damaged in it and this is causing the poor frequency response and increased input capacitance. All the diodes check out OK on a meter but maybe one of the surviving diodes is subtly damaged in some way.
I've also simulated the entire sampler circuit in the time domain on a computer and this was quite educational for me. I'm now less concerned about spreads in the JFET characteristics.
However, I will try and reverse engineer the original type of JFET used in the good probe. I can do this with a VNA and also a curve tracer. The suggested alternative JFET is the MMBFJ176 and this is a process 88 part. Looking at the datasheet, this does look to be the right type of JFET to use so I'm hoping this will turn out OK. The JFET analysis might not happen for a while though.?
I'm a bit poorly at the moment so I can't do much, but I'll try and look at the original diodes today.?
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Re: Agt N5230A-220 Need help
If you have not already done so, I would recommend replacing the coin cell battery on the CPU board and then shorting the reset pins on this board.? Not sure if this will solve your problem, but it did help me with a booting problem on this instrument and it's something that's easy to try.? Also double check the health of your hard drive and that it is properly connected.? You may want to also consider cloning the hard drive to a modern SSD drive to speed up the boot process.
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The original appears to be made by Cinch:
NSN 5935-00-236-7955: 1251-1886? Keysight Technologies, Inc.
252-15-30-341? Cinch Connectors, Inc.
SCM15D/7-4HP? Interconnection Products Inc
1251-1886? Hewlett-packard Company
252-15-30-340? Cinch Connectors, Inc. is a listing for 2, for $15.95, free shipping.
On Mon, May 6, 2024 at 4:02?PM Christopher Tucker via <cartheur= [email protected]> wrote: Hello All,
I have an hp1611A Logic State Analyzer that has two broken 15-pin, 2-row card-edge connector sockets, part number 1251-1886.
Would anyone have some of these sockets so I could fix this motherboard?
Thanks in advance.
Christopher
 
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341-030-521-202
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Try Edac?
341-030-521-202 that is 0.1 inch as well?
The edac
305-030-500-204???has 0.156 Inch? pin spacing?? TE?1-5530841-8 has 0.1 inch spacing?
On Tue, May 7, 2024 at 6:52?AM Maciej Kawalkowski, Liberty Electronics Design and Service LLC via <kawalkowski.m= [email protected]> wrote: There is a store near me that might have these: Midwest Surplus Electronics . They have all kinds of?old school parts . Provide dimensions and I can? check next time I am there.?
Maciej
Hi,
Might, or not, be the original parts but you certainly want to look at EDAC connectors:
This is a 30p PCB mounted connector, I suggest to measure yours with a caliper and compare. They have several different sizes.
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The edac
305-030-500-204???has 0.156 Inch? pin spacing?? TE?1-5530841-8 has 0.1 inch spacing?
On Tue, May 7, 2024 at 6:52?AM Maciej Kawalkowski, Liberty Electronics Design and Service LLC via <kawalkowski.m= [email protected]> wrote:
There is a store near me that might have these: Midwest Surplus Electronics . They have all kinds of?old school parts . Provide dimensions and I can? check next time I am there.?
Maciej
Hi,
Might, or not, be the original parts but you certainly want to look at EDAC connectors:
This is a 30p PCB mounted connector, I suggest to measure yours with a caliper and compare. They have several different sizes.
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There is a store near me that might have these: Midwest Surplus Electronics . They have all kinds of?old school parts . Provide dimensions and I can? check next time I am there.?
Maciej
Hi,
Might, or not, be the original parts but you certainly want to look at EDAC connectors:
This is a 30p PCB mounted connector, I suggest to measure yours with a caliper and compare. They have several different sizes.
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Re: Another 3GHz 53132-68003 Chanel 3 option design for the 53131A and 53132A
Hi Yves,
Thanks for your reply. My units 53181A and 53132A are both HP models not
the newer Agilent ones. Both were basic versions without OCXO and
without 2nd channel for 53181A and 3rd channel for 53132A.
I built my own OCXO boards and I wanted for some time to add the extra
channel.
I have some PLCC sockets so I will attempt to remove the EEPROM.
You were lucky with your units because some people reported they didn't
have in the EEPROM header written 'HP53131 is a winner!' so those will
not work to add the 3rd channel unless firmware is upgraded.
For calibration you will need the following:
1) 10MHz source
2) precise 5V reference source
3) pulse generator
4) time interval calibrator (J06-59992A)
Someone on EEVblog made a board to replace the parts from points 2-3-4.
He says he sells the kit for $30.
Thanks,
Razvan
toggle quoted message
Show quoted text
On 07/05/2024 02:42, Yves Tardif via groups.io wrote: Hi Razvan,
When you have a 5313xA firmware 3403, I think by default the EEPROM includes the configuration for the 3GHz option.
So, only the hardware option would be missing.
When I bought my hp53132A several years ago, I installed the 3GHz option only later.
After installing the PCB, the 53132A worked normally without having to modify the EEPROM or adjust the scale.
Since then, I have acquired another meter, Agilent 53132A (newer, firmware 3944); I transferred the 3GHz option to this one without problems and the frequency displayed was normal, without having to put a compensation scale or modify the EEPROM.
Hence my conclusion that the 3GHz option is activated in the EEPROM by default, but it obviously requires the hardware part to be added.
The 124 option (12.4GHz), the divider is 512 instead of 128 for 3GHz, then you must put a scale of 4, to multiply the result by 4 to display the correct frequency.
By modifying the EEPROM as suggested in the document, I should be able to make the 12.4GHz option work without changing the scale.
It's quite easy to simply activate the scale at 4.
But in my opinion, it may be a lot of work and a risk to remove the EEPROM, put a socket (restricted place on the PCB), and make modifications in the EEPROM.
Furthermore, on the PCB of my hp53132A, I cannot find the R334 resistor cited in the document.
In short, I will look at the implications of making this change, and I will take the opportunity to do a firmware update, if I decide to move forward with this little project.
I need to check the calibration procedure first.
Yves
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Re: General microwave switch type 1699 details needed
Hello Ed I know it is a switch and does not have? schematics for it. I hope someone has some info would not like to burn the nice switches by adding wrong voltages.
Maybe someone owning a8720A or B is willing to open it and measure the voltages for me
best regards Peter
Also, if you have the manual/schematics for the application, you can figure out the arrangements and currents necessary.
Ed
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Re: General microwave switch type 1699 details needed
Also, if you have the manual/schematics for the application, you can figure out the arrangements and currents necessary.
Ed
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Re: General microwave switch type 1699 details needed
I don't know what the "LGC" means - I can picture "GC" for gain control of some sort, then "L" must be something specific to the unit or application. Instead of voltage drive, look at current through the PIN diodes. If you don't have any info about the internal structure, assume you'll have some diodes pointing in various directions, between RF ports, and to ground. On and off function is much simpler than variable attenuation control.
The easiest way to figure out the PIN arrangements is to use a curve tracer, but ohmage/dode test readings can do it too, with enough interpretation. With a CT, you'll see right away if there's significant series R that could set a voltage drive range, but I'd guess it's all diodes via RF chokes for isolation, and the currents are set up by external Rs. This is the most flexible arrangement.
Figure on needing a few tens of mA forward for ON diodes, and a few V reverse bias for OFF. Good luck.
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Christopher Tucker
Harold Foster
Jared Cabot
Michael A. Terrell