Re: Boonton 92BD Troubleshooting
I would do that for myself, but I've had people ak about cables for existing probes. Switcraft stopped making them so They've gone from $2 to $25 on the surplus maket, and som appear to be used. I'm considering? using the plated brass dustcaps? to make my own. Custom probes can be built without a connector at that end. I bought a couple meters just to get varios probes with the cables. I won't modify the 4200 or 9200 series, but the older units wilson't bother me.? So called 'Aviation connectors'? (Think CB microphones) also have a two pin version. but I question the quality. I used them in radio repair years ago, and they weren't very good The contacts didn'tt wet while soldering, and the insulators broke easily.
Michael,
Don't overlook the idea of wholesale replacing the connector with something else in case you can't find the OEM.? The original seems to be about the size of the usual "Aviation" connectors one finds on things like amateur radio microphone connectors.
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Re: Boonton 92BD Troubleshooting
Michael,
Don't overlook the idea of wholesale replacing the connector with something else in case you can't find the OEM.? The original seems to be about the size of the usual "Aviation" connectors one finds on things like amateur radio microphone connectors.
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Re: Thoughts on upgraded(?) replacement parts for vintage equipment
Microdyne serviced the Scientific Atlanta clone of one of our designs We still built a few new units a tear but most of the analog IC were obsolete so I selected modern replacements fr each. The tech had to log the reason for the substitution,? but itt was either accept the update, or wait to locate olsd stock from questionable sources. .S A bought one receiver from us, and copied the entire circuitry, except for the front panel. They replaced the LED displays with an early LCD panel that didn't age well. We sued them, and they lost the case.
On Mon, Oct 7, 2024 at 10:43?AM Jared Cabot via <jaredcabot= [email protected]> wrote: I have no problems upgrading things. If it means the instrument can go harder, better, faster, stronger, then all good.
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For example, I am currently repairing a 53132A Universal counter. Turns out an LM308AM opamp and TL431C (2.2% tolerance) vref on Channel 1 were bad, so they are getting LT1008 (A drop-in upgrade also specified in the later parts list) and TL431BCDR2G (0.4% tolerance, +/-50ppm) parts on both channels.
I figured while I was in there, why not use some nicer parts for the repair?
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If I see a potential for an easy upgrade, why not take it and get better performance? The more likely you are to use it, the less likely it will go to waste.
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Jared
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Re: Thoughts on upgraded(?) replacement parts for vintage equipment
I have no problems upgrading things. If it means the instrument can go harder, better, faster, stronger, then all good.
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For example, I am currently repairing a 53132A Universal counter. Turns out an LM308AM opamp and TL431C (2.2% tolerance) vref on Channel 1 were bad, so they are getting LT1008 (A drop-in upgrade also specified in the later parts list) and TL431BCDR2G (0.4% tolerance, +/-50ppm) parts on both channels.
I figured while I was in there, why not use some nicer parts for the repair?
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If I see a potential for an easy upgrade, why not take it and get better performance? The more likely you are to use it, the less likely it will go to waste.
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Jared
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HP/Agilent 4284A electrolitic capacitor defect & A2/A3 board schematic
Hi,
I have a problem with my LCR meter HP4284A:
Due to some faulty electrolytic capacitors, some burns occurred on the A2 and A3 boards.
Unfortunately, the HP service manual is not complete with diagrams in all its parts (I guess due to confidentiality constraints), so now I cannot complete the repairs if I do not find the value of the R432 resistor on the A2 "modulator" board. I would like to thank anyone who can help me with the diagram of the A2 and A3 boards or simply with the value of the R432 component on the A2 board? Thanks   --
Alessandro
IW3HIR
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Re: Agilent 34461A schenmatic
See if these images are of any help.
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I tried to get the markings as clear as possible, as clear as my phone could manage anyway......
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Regards,
Jared
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On Mon, Oct 7, 2024 at 10:27 PM, Keith Harvey wrote:
Thank you Jared.
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I don't know how helpful photos will be unless they clearly show the manufacturer part number, but it's certainly worth a try.
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Re: Agilent 34461A schenmatic
Gotcha. That makes perfect sense!?
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Looks like someone will help with photos, but when I'm dealing with unknown parts it is helpful sometimes to trace out the circuit a bit. If youre interested in knowing what that IC is for example. This is especially helpful for when a search comes up with multiple part #s. At least you can identify this is an op-amp, regulator, etc.?
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Re: Boonton 92BD Troubleshooting Cataract
Well, it seems I'm a youngster at 59.? Worn glasses since 1979, for nearsightedness up until the last 15-20 years when farsightedness has set in as well.? I'll keep the special replacement lenses in mind for when my God-given ones get too dim and yellowed.? I'm a firm believer in technological helps for when we need them.? I'm looking forward to becoming a cyborg in my old age!? ? Jim Ford, Laguna Hills, California, USA?
On Mon, Oct 7, 2024 at 6:07 AM, Harold Foster <halfoster@...> wrote: I'm in northern AL and would be more than willing to help if possible - and I'm sure that there are many others in the group that would as well.? As Steve suggested, if you could give at least a general geographic area then hopefully someone will step up and offer assistance.
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Hal
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Re: Thoughts on upgraded(?) replacement parts for vintage equipment
I fully agree.? Though it is slightly OT, comes to my mind the nice display replacement card for the Tek DC508 frequency counter.? Else these nice units would not be usable any more as these old LED display are all slowly dying.
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73 from Claude VA2 HDD
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Re: Agilent 34461A schenmatic
Thank you Jared.
I don't know how helpful photos will be unless they clearly show the manufacturer part number, but it's certainly worth a try.
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I'll take photos from my 34461A when I get home from work if you like?
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Jared
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Re: Agilent 34461A schenmatic
Ok, I am used to FB for ferrite beads; E is a new one on me.? ?I'm a professional EE working on airborne military radar subsystems for Raytheon at the moment. The 34416A DMMs are leased and belong to the program (government).? No way am I going to risk voiding warranty or calibration.? ? Jim
On Sun, Oct 6, 2024 at 9:49 PM, Jared Cabot via groups.io <jaredcabot@...> wrote: I'll take photos from my 34461A when I get home from work if you like?
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Jared
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Re: Boonton 92BD Troubleshooting Cataract
I'm in northern AL and would be more than willing to help if possible - and I'm sure that there are many others in the group that would as well.? As Steve suggested, if you could give at least a general geographic area then hopefully someone will step up and offer assistance.
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Hal
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Re: Boonton 92BD Troubleshooting Cataract
On 2024-10-07 7:58 AM, Michael A. Terrell wrote: The VA is to do mine. I want iit, but I've been unable to find anyone willing to spend an entire day with me. The VA wo't do the surgery without an escort, because of the need for sedation. Where are you located, and where's the facility? Steve Hendrix (ex USAF myself...)
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That's good!? If the error is on the transducer board, that board has no ASICs.? Just some transistor arrays that could be hard to find these days.? But there are ways around that.??
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Re: Thoughts on upgraded(?) replacement parts for vintage equipment
DaveD & Michael - you both pretty much mirror my feelings on it.? The 5087A is the reason that it has been on my mind lately since it is a current work in progress.? I currently have 7 of them that I have accumulated over the years and, of course,? only enough cards to fully populate 4, which will be sold. My plan is to use my own designs in two of them as I am looking for functionality first and the cool HP case is just a bonus; I'm currently using a Brandywine FDA-1050 as my main distribution amplifier and it will be replaced by the HP units and sold.? I've done several iterations of the output amplifier and divide-by-2/5 cards just trying different approaches for fun and seeing how much I can better the original performance. High hopes for the batch coming in - I went fully modern with the designs and not only is the BOM cheaper, hopefully the HD numbers are quite a bit lower.? Only one design each for the divider and the output amplifier - just install different values L&C for the filter section as well as a jumper for the divider.? I did not do any of the multiplication cards as they are just not something that would ever be used (and I already have a couple of each just in case.)? I did do a pretty much exact copy of the input amplifier just for giggles - I already have a *ton* of the originals.? I did the PS board as well, also just for fun - same design, just moved the bulk filter cap to the board itself and used a DIP-14 package for the reg.? The end result of this, for me, is two fully populated units with only one original card (the input card) in each.? Nicely functional but hardly "original."??
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Hal
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Re: Boonton 92BD Troubleshooting Cataract
The VA is to do mine. I want iit, but I've been unable to find anyone willing to spend an entire day with me. The VA wo't do the surgery without an escort, because of the need for sedation. I've worn glases for over 60 years and even then I couldn't deal with tiny things. I currently use a 24" monitor, wih 28 point font and sit about four inches from it. I have a decent Loupe to bring things into better focus, but I can't do any troubleshooting like this. Sadly, I was the one who took care o a lot of other Veterans to make sure they received treatment, ut I'm the only one left.
I had an off last year, but I couldn't make the trip at that time. I'm in my 70s as well, and have several other issues.I appologize for the off topic continuation of this thread.
This is off topic, but I figured most of us are probably in the same age group and will have to face cataract surgery. I am 79 and had one eye done on April 1st and the other on the 15th. You can get the special lenses, but insurance will not cover them. I opted for the special lenses at $3K per eye. Getting those means you essentially will never need glasses for anything. Since I did not need glasses previously, I decided I did not want to start now. I am amazed. It is like I now have completely new eyes. The colors are all vivid and small print is no problem. So, if any of you are on the fence about it, go for it. 73 ¨C Mike ? Mike B. Feher, N4FS 89 Arnold Blvd. Howell NJ 07731 908-902-3831 ? ? I have? one 42B and three 92B? that I plan on doing this to, after my Cataract surgery.? I will leave a note inside each describing the modification, and the reason for it. I've moved on tho the 4200 & 9200 meters I used a 9200 at Microdyne to read the -3dB points on Sallen=Key video filters, along with a HP3325A These replaced a tunable Wavetch function generator? and an analog meter. I could? get it to the exact? point. Foe lower frequencies I used a Floke 8920A Digital True RMS voltmeter.? I miss being able to work. This was top of the line Telemetry equipment for the Aerospace industry. I would love to find a source for the two pin sensor cables. I have a 250 foot spool of SVHS video cable that will be perfect, since it has two coaxial cables in it. ?
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Re: Boonton 92BD Troubleshooting Cataract
This is off topic, but I figured most of us are probably in the same age group and will have to face cataract surgery. I am 79 and had one eye done on April 1st and the other on the 15th. You can get the special lenses, but insurance will not cover them. I opted for the special lenses at $3K per eye. Getting those means you essentially will never need glasses for anything. Since I did not need glasses previously, I decided I did not want to start now. I am amazed. It is like I now have completely new eyes. The colors are all vivid and small print is no problem. So, if any of you are on the fence about it, go for it. 73 ¨C Mike ? Mike B. Feher, N4FS 89 Arnold Blvd. Howell NJ 07731 908-902-3831 ?
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From: [email protected] < [email protected]> On Behalf Of Michael A. Terrell Sent: Monday, October 7, 2024 3:55 AM To: [email protected]Subject: Re: [HP-Agilent-Keysight-equipment] Boonton 92BD Troubleshooting ? I have? one 42B and three 92B? that I plan on doing this to, after my Cataract surgery.? I will leave a note inside each describing the modification, and the reason for it. I've moved on tho the 4200 & 9200 meters I used a 9200 at Microdyne to read the -3dB points on Sallen=Key video filters, along with a HP3325A These replaced a tunable Wavetch function generator? and an analog meter. I could? get it to the exact? point. Foe lower frequencies I used a Floke 8920A Digital True RMS voltmeter.? I miss being able to work. This was top of the line Telemetry equipment for the Aerospace industry. I would love to find a source for the two pin sensor cables. I have a 250 foot spool of SVHS video cable that will be perfect, since it has two coaxial cables in it. ?
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Re: Thoughts on upgraded(?) replacement parts for vintage equipment
I've had to scrap equipment with a physically? damaged board that? I couldn't locate a replacement for. The ability to drop in a new board for a reasonable price would keep a lot more old equipment in service.
On Mon, Oct 7, 2024 at 5:37?AM Harold Foster via <halfoster= [email protected]> wrote: The current thread on the Boonton 92BD had a reference to someone having developed a modern replacement for the chopper amplifier portion of the instrument.? Others, including myself, have made replacements for all of the cards in a HP 3400A and I am currently awaiting a complete set or redesigned cards for the HP5087A - including the power supply, just because, and there are many more instances where replacements have been made simply because of unobtanium parts.? My question is: how do modifications such as this affect your feelings about the instrument?? At what point is it "just not the same" in a philosophical sense I suppose? For me if it's something that I have designed and made myself then that goes a long way to offsetting the lack of originality, especially if it enables the use of equipment that would otherwise have to be parted out.? Anyway, just some idle thoughts while waiting on the caffeine to kick in...
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Hal
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Re: Thoughts on upgraded(?) replacement parts for vintage equipment
Many vintage units had limitations based on the available technology at the time that they were designed. For the most part, GenRad, HP and Tektronix (to name just three) built the most advanced instruments they were able to at the time.?
One of the great things about those vintage instruments is that they are repairable (a la Jim Williams). In my opinion, creating replacement PWBs and other improvements make the instruments more useful. The notion of extending their useful life time is an excellent idea and worth the effort. Just my 25 cents (inflation). DaveD KC0WJN
Thanks for all the fish.
============================== All spelling mistakes are the responsibilty of the reader (Rick Renz, STK, ca. 1994) ==============================
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On Oct 7, 2024, at 05:37, Harold Foster via groups.io <halfoster@...> wrote:
? The current thread on the Boonton 92BD had a reference to someone having developed a modern replacement for the chopper amplifier portion of the instrument.? Others, including myself, have made replacements for all of the cards in a HP 3400A and I am currently awaiting a complete set or redesigned cards for the HP5087A - including the power supply, just because, and there are many more instances where replacements have been made simply because of unobtanium parts.? My question is: how do modifications such as this affect your feelings about the instrument?? At what point is it "just not the same" in a philosophical sense I suppose? For me if it's something that I have designed and made myself then that goes a long way to offsetting the lack of originality, especially if it enables the use of equipment that would otherwise have to be parted out.? Anyway, just some idle thoughts while waiting on the caffeine to kick in...
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Hal
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Managed to have a brief look at these over the weekend. Looks like I do indeed have two faulty output boards (both channel 1) and one good one (channel 2) I was sure I had tested the output board from unit 1 in a good unit and it worked, but maybe I made some error.?
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Looking at the self test flow diagram in the manual this this makes sense, X04 error can only occur if the input to the transducer board is correct, but the output is wrong.? The manual suggests checking the transducer board pins, be nice if it was that simple. Will have further look when I get chance.?
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Michael A. Terrell
Jared Cabot
Frank Mashockie
Harold Foster