Reg, I replied to your off-list mail earlier today, but based on a previous conversation, I suspect you're filtering my messages.
-Dave
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Dave McGuire, AK4HZ
New Kensington, PA
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Re: HP XY Display PSU Query
On 11/23/23 16:44, Tony wrote: I have an HP XY display without the matching external power supply and so Im planning to hook up my own. The input power connector is labelled as shown in the picture attached.
My interpretation is that the pins with an ¡°R¡± suffix means ¡°return¡±. So ¡°+250R¡± is the return for the ¡°+250 IN¡±. Likewise for the 21V .
Is that the right way to read this? That's how I would interpret it. Can you find a schematic? Odd, though, that there's a +15V and -15V, but no ground. Are +21R and +250R connected to each other on the board, meaning could that constitute a circuit-wide ground? -Dave -- Dave McGuire, AK4HZ New Kensington, PA
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Hi,
I have an HP XY display without the matching external power supply and so Im planning to hook up my own. The input power connector is labelled as shown in the picture attached.?
My interpretation is that the pins with an ¡°R¡± suffix means ¡°return¡±. So ¡°+250R¡± is the return for the ¡°+250 IN¡±. Likewise for the 21V .
Is that the right way to read this?
thanks
tony
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Re: HP 4145A - Power Transistor Measurement Setup
There's a HP apps note attached on using some other types of power supplies that may be of interest. Although it mentions the 4155/4156, it looks like it will work with a 4145 too.
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Re: Gauging interest in custom made Canare coax cables?
Here's some rough prices to give a ballpark idea.
Cable - 320yen per meter
BNC Connector - 650yen each
N Connector - 1200yen each
SMA Connector - 1000yen each
TNC Connector - 410yen each
Boots (BNC, TNC, N only) - 30yen each
(Actual prices may vary slightly once the supplier finishes updating their stuff)
The physical quality is very good. Canare specialise in broadcast video cabling and connectors, so their products are very high quality.
I wouldn't say proper metrology grade on par with cables costing hundreds of dollars or more, but they are definitely far above the ebay stuff. Great for general lab use and light metrology when ebay crap doesn't cut it.
I have the proper Canare crimpers and cable stripping tools, so they will be made exactly to specification.
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Re: Gauging interest in custom made Canare coax cables?
Roughly what price range do you think it could be ? closer to 'metrology at a good price' or competitive with e.g. ? ?
Thanks,
Chris
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Re: Adding front panel output to 8340B
How are you going to switch the software to match each line?
On Thu, Nov 23, 2023 at 8:32?AM Reginald Beardsley via <pulaskite= [email protected]> wrote: Bruce,
Thanks.? That's exactly what I want.? I have suitable suitable relays.
Have Fun!
Reg
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Gauging interest in custom made Canare coax cables?
As I live in Japan, I have easy access to Canare brand coax cables and coax connectors.
Canare make very high quality connectors, and I have been using the RG-58 connectors for a while but I am looking to upgrade to using better cable.
I was thinking I could maybe offer custom length cables with a selection of crimp type connectors (No soldered joins!) for a reasonable price depending on interest.
Shipping isn't too expensive to most countries for a couple cables, so it might be a good way to get some nice test cables good to a few GHz, and take advantage of the weak yen! :D
The cable used will be dual braided shield coax (3D-2W type 50ohm cable) which is roughly a dual shield version of RG-58 cable, with a selection of BNC, TNC, N, and SMA male connectors. The BNC, TNC and N connectors are also able to have a rainbow of strain relief boots added too.
There are also female BNC covers and BNC female-female joiners available too.
Here's the details and photos of all the connectors and cable:
Let me know if this is something you would be interested in so I can see if this is something worth pursuing and I'll work out pricing.
Also, if some of you are able to do some in-depth tests of the cables, I can work out a deal too.
Jared
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Re: Adding front panel output to 8340B
Bruce,
Thanks. That's exactly what I want. I have suitable suitable relays.
Have Fun!
Reg
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Re: HP 4145A - Power Transistor Measurement Setup
Thank you, this is what I call just in time delivery. Two days ago I managed to repair a HP 4155A, lucky me it was only the power supply, and now I'm looking into acquiring triaxial cables and build some sort of fixture to connect the devices under test. Your example setup will certainly make it easier for me to start experimenting.
I understand the 6024A is an external power supply that can be controlled with an analog voltage, VS from SMU1. Somehow it provides a 12x higher voltage at its output (your multiplication to calculate VCE). How is this 12x factor defined?
A4 must represent an output of the 6024A that is in relation with the current on its output. You measure this A4 voltage with SMU-3 and multiply it by 2 to have the collector current IC. How did you identify this 2x factor?
I guess these '12x' and '2x' have something to do with how the power supply works, but as this is a completely analog device I don't know for sure.
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Indeed, Tant' caps (especially the modern SMD types) don't handle surges well, so were are many used?? On power rails as decouplers.
Might be worth checking how fast that power rail is established when you power up the instrument, and if there would be any penalty if you slowed down it's rise-time at "Power ON"...? (Such as misbehavior upsetting some other aspect of the instrument as it comes alive.)
Regards to All.
??? Dave B.
--
Created on and sent from a Unix like PC running and using free and open source software:
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Agilent E8257C Schematics
Hi all,?
I've come across an E8257 in need of love - it's failing self-test on a tuning voltage problem, and the service manual calls for a replacement of the entire reference board, which I'm sure one could imagine aren't that easy to come by. The board in the unit has been modded in its precious life and what appears to be a small inductor has plenty of heat damage from some misdirected hot air it'd seem. Could anyone help me (off thread) with some docs for this, I'd be eternally grateful and would much rather keep this beautiful piece of 40GHz goodness out of the tip.
Alex
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It seems to be OK. At least I won't have to worry about those caps again, merely everything else.
Ed
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I just finished replacing all of them with 150D series - hermetic solid Ta. I'm going to fire it up shortly, and expect it to be just fine, unless I screwed up. The non-hermetic plastic molded ones are more failure-prone due to moisture ingress. Hermetic sealing of components usually gives superior results, but is much more expensive. I happen to have a big old cat food jug full of these (maybe a couple thousand pieces) 150D types of many different sizes, so I always put these in where practical. It's a mix of pulls, NOS, and unknown sources over the years, so I always test any that are to be redeployed.
Same with the wet Ta ones, but way way way far fewer pieces in stock to choose from.
Ed
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Hi Ed, Are these solid tantalum caps? I very much enjoyed your discussion of why hermetically-sealed wet tantalum capacitors feature superior longevity compared to the elastomer-sealed variety ( /g/HP-Agilent-Keysight-equipment/message/101112). If these are solid tantalums, what's the advantage of hermetic sealing in this case? Thanks, Matt On Wed, Nov 22, 2023 at 1:48?PM Ed Breya via groups.io <edbreya@...> wrote:
Not a big deal or surprise - just thought I'd mention finding bad Ta caps twice in a row same unit. These are the yellowish color molded chamfered bullet style. I found one a couple weeks ago easily (burned), and replaced with a hermetic one and was back in business. A few days later another one crapped out. These are all on the big output board on the bottom of the unit. There are about 8-10 remaining, so I'm thinking maybe I'll just do them all - or at least the 15 V supplies ones - and be done with it. This is the only board with this type of Ta caps. The others use the good hermetic style. The output board looks like a different vintage and board type, maybe a better grade low-hook material for the HF analog sections. It is quite spacious and easy to find and replace the bad caps - this second one looked OK and was not noticeably hot, but a quick DVM run through following the voltage drops led right to it.
I encountered a lot of these crappy caps in some of the IF/display units for the 3566 and 3568, and had to replace some there too, a while back. I recommend watching out for these possible suspects.
Ed
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A good friend shared with me that he read an article that contained a study regarding tantalum caps, where they found out that any reverse voltage over a certain fraction of their rating (I don't recall the number) creates microfissures in the tantalum core and that's what they, over time, fail. The kind of thing that may occur in transitory processes - turn on/off, etc. So he recommended I use tantalums further where needed, I just replace them with ones that have far higher voltage rating (such as twice that of the originals).? Radu.?
Not a big deal or surprise - just thought I'd mention finding bad Ta caps twice in a row same unit. These are the yellowish color molded chamfered bullet style. I found one a couple weeks ago easily (burned), and replaced with a hermetic one and was back in business. A few days later another one crapped out. These are all on the big output board on the bottom of the unit. There are about 8-10 remaining, so I'm thinking maybe I'll just do them all - or at least the 15 V supplies ones - and be done with it. This is the only board with this type of Ta caps. The others use the good hermetic style. The output board looks like a different vintage and board type, maybe a better grade low-hook material for the HF analog sections. It is quite spacious and easy to find and replace the bad caps - this second one looked OK and was not noticeably hot, but a quick DVM run through following the voltage drops led right to it.
I encountered a lot of these crappy caps in some of the IF/display units for the 3566 and 3568, and had to replace some there too, a while back. I recommend watching out for these possible suspects.
Ed
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Oops - I meant to say the 8566 and 8568.
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Not a big deal or surprise - just thought I'd mention finding bad Ta caps twice in a row same unit. These are the yellowish color molded chamfered bullet style. I found one a couple weeks ago easily (burned), and replaced with a hermetic one and was back in business. A few days later another one crapped out. These are all on the big output board on the bottom of the unit. There are about 8-10 remaining, so I'm thinking maybe I'll just do them all - or at least the 15 V supplies ones - and be done with it. This is the only board with this type of Ta caps. The others use the good hermetic style. The output board looks like a different vintage and board type, maybe a better grade low-hook material for the HF analog sections. It is quite spacious and easy to find and replace the bad caps - this second one looked OK and was not noticeably hot, but a quick DVM run through following the voltage drops led right to it.
I encountered a lot of these crappy caps in some of the IF/display units for the 3566 and 3568, and had to replace some there too, a while back. I recommend watching out for these possible suspects.
Ed
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Re: Adding EFC to an 8662A
On November 22, 2023 3:18:40 PM "Alan Bain" <alan.bain@...> wrote: Thanks very much for this! That is exactly the information I needed and I am glad to know someone has been this way before me and it worked. I also want to use this with a 11848 interface. It's working at the moment but using the FM input which let me test my software (I'm not using a 3561 so the official HP software isn't much help here), but for measuring low PN sources the manual is suggesting moving to EFC and I couldn't find the jack and then realised it was an option! Are you writing new PN software for the 11848A? - Dave -- Dave McGuire, AK4HZ New Kensington, PA
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Re: Adding EFC to an 8662A
Thanks very much for this! That is exactly the information I needed and I am glad to know someone has been this way before me and it worked. I also want to use this with a 11848 interface.? It's working at the moment but using the FM input which let me test my software (I'm not using a 3561 so the official HP software isn't much help here), but for measuring low PN sources the manual is suggesting moving to EFC and I couldn't find the jack and then realised it was an option!
Alan?
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Dave McGuire
Jared Cabot
fenugrec