Re: HP8568A strange problems
As I recall, 1854-0071 was a very widely used transistor in HP Instruments. I know we used lots of them in the Division where I worked in the early 70's. The JEDEC reference 2N3391 rings a Bell. I also recall vaguely that it made a corporate rogues gallery for failure rate. I think that as a result of failure rate it was likely engineered out from that time on.
Regards Bill Lauchlan
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-----Original Message----- From: [email protected] [mailto: [email protected]] On Behalf Of Brad Thompson Sent: Sunday, November 25, 2018 2:53 PM To: [email protected]Subject: Re: [HP-Agilent-Keysight-equipment] HP8568A strange problems On 11/25/2018 1:23 PM, Ed Breya via Groups.Io wrote: <snip>
Q21 and the surroundings look OK solder-wise, and are fairly clean - I
was imagining a simple bad joint, but figured on replacing it anyway,
just in case. So, I've been looking for the type to match. All I could
find in the HP cross reference is that this part 1854-0071 is an Rohm
brand CP4071.
Hello-- Rohm offers a line of "digital transistors" which comprise an ANA or PNP transistors and base resistors in various configurations. Go here... ...For more information, and possiblly some suggestions for determining what's inside the failing part. To make the chase a little merrier, HP may have ordered a custom part number for the device. I suspected it may be special for high gain, since it seems so softly driven - a 100 k R from TTL to the base, while needing
to pull about 3 mA Ic if it's supposed to saturate. However, there are a
bunch of others in the area, so it likely isn't all that special. The
actual parts are in TO-92, and marked with a symbol "2" with a circle
around it, and "CT1200 138." The "circle 2" is Sprague's trademark, so some exploration of older Sprague literature might turn up some leads.
Now, here's what makes it even more interesting. While searching for
"CP4071," I got some hits of discussions about woes caused by this part
in some other HP equipment, specifically, random and thermally-related
failures, which perfectly relate to this problem of mine. Here's one
from a few years ago that has some detailed info:
Look at messages #30-32, in particular.
So, it looks like this part has some history of trouble anyway, and that
HP may have used it a lot, so it could be the cause of other problems.
Good ideas come and go, but crappy parts are forever. 73-- Brad AA1IP
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Re: failed trimmer capacitors, was Re: [HP-Agilent-Keysight-equipment] 8566B - notches in response
Thank you, Dave! I had a 7L12 Tek spectrum analyzer module on the ¡°to do¡± pile. I decided to check for the integrity of all of the trimmer caps, just to cross that newly-added item off the list, and what you know: two were mechanically damaged just as you described! There are other problems with that unit, but this brings it closer to resolution.
Cheers, Kuba
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25 nov. 2018 kl. 11:33 skrev Dave McGuire <mcguire@...>:
On 11/25/18 5:01 AM, pianovt via Groups.Io wrote:
It would be good to see pictures of the notches. However, even without
seeing the pictures, I would say that this looks like a problem with the
SYM adjustment on the 3 MHz filter board. If the problem appeared
suddenly, it may be a failed adjustable capacitor. If it showed up
slowly, the filter probably needs adjustment. You will need to build the
3 MHz crystal bypass networks in order troubleshoot and adjust.
Still, it would be good to post some pictures before you take my word
for it. Speaking of failed adjustable capacitors...My new-to-me 8568B had been
sitting unused for a long time; I picked it up as part of an EMI
receiver setup (preselector, QPA, TEM cell, etc) and had just started
putting the final pieces together a couple of weeks ago. I knew it was
way out of calibration but I didn't have time to worry about it until I
got the other components for the system, which finally came together
recently.
Finally, being able to perform FCC pre-qualification testing on my
prototypes in my own lab, rather than paying other labs to do it, is
within reach.
So, after building my bypass networks, I started calibrating the IF
section, and it was behaving very poorly. I observed very unpredictable
behavior in response to the rotation of those trimmer capacitors. It
just didn't make any sense; filters just don't act that way. Perplexed,
I pulled out some of the boards for inspection. I came across no less
than four trimmer capacitors on those two filter boards whose rotors had
either cracked or shattered. In one case, pie-slice-shaped pieces of
ceramic littered the bottom of the subchassis well.
The only thing I could think of that could've caused this is some
ham-handed oaf jamming a screwdriver into the holes too hard, or
torquing the adjustment screws off to the side, placing pressure on the
hole in the rotor with leverage from the top subchassis plate.
After replacing all failed trimmer capacitors and starting over, it
calibrated fine.
Watch out for this problem.
-Dave
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Re: HP8568A strange problems
On 11/25/2018 1:23 PM, Ed Breya via Groups.Io wrote: <snip> Q21 and the surroundings look OK solder-wise, and are fairly clean - I was imagining a simple bad joint, but figured on replacing it anyway, just in case. So, I've been looking for the type to match. All I could find in the HP cross reference is that this part 1854-0071 is an Rohm brand CP4071. Hello-- Rohm offers a line of "digital transistors" which comprise an ANA or PNP transistors and base resistors in various configurations. Go here... ...For more information, and possiblly some suggestions for determining what's inside the failing part. To make the chase a little merrier, HP may have ordered a custom part number for the device. I suspected it may be special for high gain, since it seems so softly driven - a 100 k R from TTL to the base, while needing to pull about 3 mA Ic if it's supposed to saturate. However, there are a bunch of others in the area, so it likely isn't all that special. The actual parts are in TO-92, and marked with a symbol "2" with a circle around it, and "CT1200 138." The "circle 2" is Sprague's trademark, so some exploration of older Sprague literature might turn up some leads. Now, here's what makes it even more interesting. While searching for "CP4071," I got some hits of discussions about woes caused by this part in some other HP equipment, specifically, random and thermally-related failures, which perfectly relate to this problem of mine. Here's one from a few years ago that has some detailed info:
Look at messages #30-32, in particular.
So, it looks like this part has some history of trouble anyway, and that HP may have used it a lot, so it could be the cause of other problems. Good ideas come and go, but crappy parts are forever. 73-- Brad AA1IP
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Re: What were your easiest and your most difficult equipment repairs?
11 nov. 2018 kl. 19:39 skrev rmc321 via Groups.Io < rmc321@...>: Like many here, I like to buy useful, non-working test equipment on the cheap and I generally look forward to the challenge of repairing it.? So, I got to thinking about which of those repairs were the easiest and which were the most difficult.
I got a 1kV voltage standard on eBay a while ago, and it just didn¡¯t work properly: the series regulator transistor chain would always overheat and individual transistors drifted like crazy, their beta seemingly dropping over an order of magnitude as it got warmer. It turned out that transistors were bad. Every one of them. I don¡¯t understand their failure mode, but when warm they looked almost like first-try homemade semiconductors on the curve tracer ¨C not unlike Jeri Ellsworth¡¯s experiments??Then it also turned out that the PCB got leaky, presumably from overheating: I laid out a copy of the power PCB, and assembled a new-old replacement.
An easy recent repair was a Maytag fridge. It was ¡°ailing¡± for a month or two: there was some internal water leakage, and I was close to a point where I had to ¡°get round toit¡±. Then the water dispenser stopped working. That was the true non-maskable interrupt in a household where everyone drinks water. It turns out that the 12V supply was low at around 7V, below what was needed to pull in the various relays and solenoids: those of the water valves, and those of the internal heaters and coolant valves that managed the automatic defrosting and dehumidification. The switched mode power supply was thankfully a simple design, and it turned out that the voltage reference zener was acting like a 200 Ohm resistor. I substituted a 9V battery to confirm the diagnosis, and then found a 12V Zener with a slightly higher power rating in my parts bin.
Cheers, Kuba
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Re: HP8568A strange problems
I think I finally figured it out, and found info that may explain miscellaneous problems in the 8568, 8566, and other HP equipment.
The sweep stopping problem disappeared for a while - running rock solid for several days continuously, and seemingly independent of ambient temperature, unlike before. I figured I wouldn't be able to troubleshoot it anymore, so still in limbo, waiting to go bad again if I put it back in service. Then our dry spell ended, and we had lots of rain and increase in humidity. The next day, it crapped out again, really badly - it couldn't run for more than a few seconds before stalling out. I decided to dive in deep, and figure out what's going on once and for all.
After several hours of poking around in the digital control system and trying to figure out how everything is supposed to work, I couldn't find anything wrong in the brain parts. The processor did its thing, and the sweeps looked right, but it would just stop. I was running out of suspects in the logic, so revisited the A22 Frequency Control board sweep circuit. There was one last signal involved, related to resetting the sweep, from logic on A22. This is the last thing, apparently, that the processor could affect, sweep-wise.
Q21, driven by U31, can change the comparator threshold in the sweep circuit, but I couldn't tell why or when. I found it is located up near the top of the board, adjacent the SWP test point. I figured I could quickly check its base drive by poking the scope probe on the lead, through the test point hole, without having to remove the plastic cover over A22. I carefully jammed the hook-tip in there and grabbed onto it, and got the base signal on the scope.
The 8568 immediately started working properly! Something about hanging the probe there did it - I figured the stress on Q21s leads and package, or a bad solder joint, slightly (microscopically) moved something back into contact, or more remotely, maybe the probe capacitance did something. I let it run for a while, and was watching the base signal on the scope, and it suddenly disappeared. Oh oh, but no - the probe had popped loose, and the 8568 was still going strong. I left it running overnight, and it was still good this morning, so I pulled A22 to check it out.
Q21 and the surroundings look OK solder-wise, and are fairly clean - I was imagining a simple bad joint, but figured on replacing it anyway, just in case. So, I've been looking for the type to match. All I could find in the HP cross reference is that this part 1854-0071 is an Rohm brand CP4071. I suspected it may be special for high gain, since it seems so softly driven - a 100 k R from TTL to the base, while needing to pull about 3 mA Ic if it's supposed to saturate. However, there are a bunch of others in the area, so it likely isn't all that special. The actual parts are in TO-92, and marked with a symbol "2" with a circle around it, and "CT1200 138."
Now, here's what makes it even more interesting. While searching for "CP4071," I got some hits of discussions about woes caused by this part in some other HP equipment, specifically, random and thermally-related failures, which perfectly relate to this problem of mine. Here's one from a few years ago that has some detailed info:
Look at messages #30-32, in particular.
So, it looks like this part has some history of trouble anyway, and that HP may have used it a lot, so it could be the cause of other problems. It's going on my list of suspects for mysterious problems. I think that when I find and install a proper substitute, this 8568 problem will be gone - until something else comes up.
Now I'd like to find the data on this part and find a substitute. I could probably find the exact same kind from some junked HP boards, but after what I've been through, I think I'd rather have something else in there for long-term reliability. Does anyone have more info on this part type, or similar experience?
BTW I think the sweep stopping was due to the processor getting confused about the state of the sweep. It appears able to control the sweep start/stop, and the reset, but I couldn't find any feedback signal telling the processor whether it's completed or running - I could have missed something, with all the pages and pages of schematics and signals going every which way. It seems that normally each full sweep runs once, according to the settings the processor sends, but it does not report reaching the end of sweep, so the processor must know approximately how much time to allow, then does its updating activity, then the reset, then HSWP lets it start up again. I think if Q21 gets flakey, everything gets out of sync.
Ed
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Re: HP8663A Power supply, was: Firmware difference
Hi all,
Its a little while since I received all four PSU modules. It seems to perform well. It draws about 200watts (or closer to 190watts when the ref osc is warm). The numbers from my uncalibrated HP 6812B is: Voltage: 230V Current: 1.18A Power: 193W ?????????? 272VA Powerfactor: 0.7
But I have read somewhere that this is a 500watt consuming generator. That's a bit more than mine is using.. Please a note, I don't have the phase modulation option, so that may be some watts extra. Is there anyone here with a 8663A that has measured the power consumption?
While I was installing an testing the different modules, the instrument got a problem starting up, it started fine if it had been off for a long time, and as long as it started up fine, there was no problems, could have it on for hours. Could also reset the uC on a dedicated TP, and all would be fine. But if I turned it off, and on again, it would just freeze. Traced it down to the clock generator circuit for the uC, if it had been on recently it would give out a crazy clock signal with way to high frequency for the uC. The problem was the capacitor in parallel with the crystal. This capacitor was probably not in the original design, as it is not in the drawings, but it is mention in the service manual that a 22pF chip capacitor should be mounted in parallel with the crystal between the two legs on the osc IC connected to the crystal. This capacitor was mounted, but when I removed it and measured it, it was only 10pF. I don't know if something has happen to it or if the one mounting it didn't? have a 22pF, and just mounted a 10pF instead, as the instrument was working fine.. I guess maybe this capacitor is due to aging if the crystal, and then a 10pF would probably work fine for a long time.
I didn't have a chip capacitor at home, so I used a 22pF trough hole capacitor where i cut the legs 1mm long and mounted it directly on the crystal, on the backside of the pcb, and now it starts up fine every time :)
If anyone is interested, I can post some pictures of the PSU modification.
I still have to do a full check an calibration of the generator.
For the right price, I'm interested in top, bottom and left cover. And also the phase modulation option. (I'll put this in the buy/sell group when I'm sure there isn't anything else)
BR, Askild
Hi Scott
Thanks for your input, But the 8663A originally has a SMPS, same PSU thats in the 8662A. Three of the voltages, -40V, -10V and +20V go trough a linear regulator board, that I do have, and will use.
At least Mean Well is a known producer from Taiwan that's been in this businesses? for several years, so guess it will be better than the noname Chinese PSU modules.
Time will show.
Askild
On Mon, Oct 29, 2018 at 3:30 PM Scott McGrath < scott@...> wrote: I think you are going to want better supplies than the inexpensive mean-wells SMPS,? ?HP used linear power supplies for a reason and that was there are no HF components on the DC supply rails to cause noise problems in the circuits.?
One place they deviated from that? was the 70000 series where the main chassis was a massive SMPS
Content by Scott
Typos by Siri
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Re: HP 8643A, Lithium battery instead of NiCad(!!!)
Thisis what I use to replace the NiCd in these units:
You definitely do not want to be charging the Li battery.
Regards
On 11/25/2018 11:53 AM, Siggi wrote:
Hey y'all,
my HP8643A signal generator suffered another failure
recently so I had to go back into it (another tantalum, no
big drama). After I'd been into it, it would re-calibrate
after each time I unplugged it, so I figured the backup
battery has to be bad.?
Per the CLIP's parts list and schematic, this is a 3.6V
NiCad battery pack, a Sanyo N-50SB3-PB, which is
apparently obsolete. Since I couldn't find an exact part
replacement, I opened'er up to have a look at the
footprint, see what I had to work with.
Imagine my surprise when I found a ?with a 99
date code soldered onto the board. This is apparently a
lithium thionyl chloride?primary cell.
The number on the PCB matches the CLIP (08645-60101),
and at first blush it looks like all the components having
to do with battery charging are fitted.
Replacing a chargeable battery with primary, I figure
you'd want to put a diode inline with it, but I'm not
finding any evidence of such.
I¡¯m wondering whether someone just soldered in a likely
looking battery-on-hand, or whether this is a proper mod
or a revision of the controller PCB. I can¡¯t find any
relevant notices on the Keysight web - WDYT?
Siggi
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HP 8643A, Lithium battery instead of NiCad(!!!)
Hey y'all,
my HP8643A signal generator suffered another failure recently so I had to go back into it (another tantalum, no big drama). After I'd been into it, it would re-calibrate after each time I unplugged it, so I figured the backup battery has to be bad.? Per the CLIP's parts list and schematic, this is a 3.6V NiCad battery pack, a Sanyo N-50SB3-PB, which is apparently obsolete. Since I couldn't find an exact part replacement, I opened'er up to have a look at the footprint, see what I had to work with. Imagine my surprise when I found a ?with a 99 date code soldered onto the board. This is apparently a lithium thionyl chloride?primary cell. The number on the PCB matches the CLIP (08645-60101), and at first blush it looks like all the components having to do with battery charging are fitted. Replacing a chargeable battery with primary, I figure you'd want to put a diode inline with it, but I'm not finding any evidence of such.
I¡¯m wondering whether someone just soldered in a likely looking battery-on-hand, or whether this is a proper mod or a revision of the controller PCB. I can¡¯t find any relevant notices on the Keysight web - WDYT?
Siggi
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failed trimmer capacitors, was Re: [HP-Agilent-Keysight-equipment] 8566B - notches in response
On 11/25/18 5:01 AM, pianovt via Groups.Io wrote: It would be good to see pictures of the notches. However, even without
seeing the pictures, I would say that this looks like a problem with the
SYM adjustment on the 3 MHz filter board. If the problem appeared
suddenly, it may be a failed adjustable capacitor. If it showed up
slowly, the filter probably needs adjustment. You will need to build the
3 MHz crystal bypass networks in order troubleshoot and adjust.
Still, it would be good to post some pictures before you take my word
for it. Speaking of failed adjustable capacitors...My new-to-me 8568B had been sitting unused for a long time; I picked it up as part of an EMI receiver setup (preselector, QPA, TEM cell, etc) and had just started putting the final pieces together a couple of weeks ago. I knew it was way out of calibration but I didn't have time to worry about it until I got the other components for the system, which finally came together recently. Finally, being able to perform FCC pre-qualification testing on my prototypes in my own lab, rather than paying other labs to do it, is within reach. So, after building my bypass networks, I started calibrating the IF section, and it was behaving very poorly. I observed very unpredictable behavior in response to the rotation of those trimmer capacitors. It just didn't make any sense; filters just don't act that way. Perplexed, I pulled out some of the boards for inspection. I came across no less than four trimmer capacitors on those two filter boards whose rotors had either cracked or shattered. In one case, pie-slice-shaped pieces of ceramic littered the bottom of the subchassis well. The only thing I could think of that could've caused this is some ham-handed oaf jamming a screwdriver into the holes too hard, or torquing the adjustment screws off to the side, placing pressure on the hole in the rotor with leverage from the top subchassis plate. After replacing all failed trimmer capacitors and starting over, it calibrated fine. Watch out for this problem. -Dave -- Dave McGuire, AK4HZ New Kensington, PA
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Re: 8566B - notches in response
It would be good to see pictures of the notches. However, even without seeing the pictures, I would say that this looks like a problem with the SYM adjustment on the 3 MHz filter board. If the problem appeared suddenly, it may be a failed adjustable capacitor. If it showed up slowly, the filter probably needs adjustment. You will need to build the 3 MHz crystal bypass networks in order troubleshoot and adjust.
Still, it would be good to post some pictures before you take my word for it.
Vladan
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8566B - notches in response
My 8566B continues to work well after more than 30 years. On the 300 Hz Res BW setting there is a 15 dB notch apparent at center frequency?+1.2KHz, while on the 1KHz Res BW setting there is a 15dB notch at CF+1.5 KHz.. I`m thinking that there is a problem in the crystal filters. Has anyone struck this problem before? TIA for your consideration
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Re: 50 ohm thermocouples was RE: [HP-Agilent-Keysight-equipment] 478A power sensor recal for HP meters (was diode mounts)
Reginald,
Which Millivac Meter do you have, I have a MV-28 and Manual. I will be glad to copy the schematic if it will help.
? Leon Robinson ?? K5JLR
Political Correctness is a Political Disease.
From: jfphp via Groups.Io <jfphp@...>
To: [email protected]
Sent: Saturday, November 24, 2018 11:43 AM
Subject: Re: 50 ohm thermocouples was RE: [HP-Agilent-Keysight-equipment] 478A power sensor recal for HP meters (was diode mounts)
Have a look at the head of the old Rohde & Schwartz NRS power meter
--------------------------------------------
On Sat, 11/24/18, Reginald Beardsley via Groups.Io <pulaskite= [email protected]> wrote:
Subject: Re: 50 ohm thermocouples was RE: [HP-Agilent-Keysight-equipment] 478A power sensor recal for HP meters (was diode mounts)
Date: Saturday, November 24, 2018, 6:31 PM
I started working on using
2N3904s for temperature sensors.? A Brazilian wanted to
build a sensor and as I had lots of experience with the 1D
heat equation suggested a design that biased a resistor to
constant temperature.? But by the time I got the parts, he
had wandered off to other things.
Basic idea was to hold one transistor at
constant temp with a Peltier junction and then use two other
transistors to hold the heat flux constant by varying the DC
bias through the load resistor.? .? All insulated with
fine aerogel powder.? The power being the change? of DC
bias through the load resistance required to keep the flux
constant.
I very much wish
the manual for my Millivac were not so pricey or that I
could at least get a schematic for the diode sensor they
use.
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Re: Warning to buy equipment on Ebay on auctions using GSP (global shipping programme)
I don't know how the GSP can be profitable. I sold some new diabetes monitoring kits on Ebay and a Japanese buyer bought them via GSP. They went through all the screening processes here in the? US, but when they hit customs in Japan they were a banned medical device. I got my money from the buyer, the buyer got refunded and I never got any negative feedback. The system does protect buyer and seller. I have shipped overseas for years without the GSP and never had a problem. It is a shame that rare and expensive test equipment might be destroyed. More likely it gets shipped back to US and sold surplus again.
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Re: Synthesizer module in ESG series E4435B
Leo
No I dont have a paper or digital copy at this time.
What is driving the component changes?
Please let us know when a schematic is available
Dave
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On 11/24/2018 12:57 PM, Leo Bodnar wrote: Dave,
I am still working on the final design - it is going through revision B6 already and I keep changing the components - but I have provided enough information and, hopefully, motivation for anybody to replicate what I have done.
The next day after posting Mouser stock of HMC862A was fully depleted - I did not even have a chance to get more for my own use!? Perhaps somebody was paying attention.
By the way, somebody asked for ESG series CLIP source - they are available from this guy
I have bought from him as yes, they are proper usable CLIP scans.
I would prefer proper paper copy, however.? Do you happen to have them, Dave?
Thanks
Leo
--
Dave
Manuals@...
www.ArtekManuals.com
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Re: Synthesizer module in ESG series E4435B
Dave,
I am still working on the final design - it is going through revision B6 already and I keep changing the components - but I have provided enough information and, hopefully, motivation for anybody to replicate what I have done.
The next day after posting Mouser stock of HMC862A was fully depleted - I did not even have a chance to get more for my own use!? Perhaps somebody was paying attention.
By the way, somebody asked for ESG series CLIP source - they are available from this guy https://www.ebay.co.uk/itm/362488998252
I have bought from him as yes, they are proper usable CLIP scans.
I would prefer proper paper copy, however.? Do you happen to have them, Dave?
Thanks
Leo
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Re: 50 ohm thermocouples was RE: [HP-Agilent-Keysight-equipment] 478A power sensor recal for HP meters (was diode mounts)
Have a look at the head of the old Rohde & Schwartz NRS power meter
--------------------------------------------
toggle quoted message
Show quoted text
On Sat, 11/24/18, Reginald Beardsley via Groups.Io <pulaskite@...> wrote: Subject: Re: 50 ohm thermocouples was RE: [HP-Agilent-Keysight-equipment] 478A power sensor recal for HP meters (was diode mounts) To: [email protected] Date: Saturday, November 24, 2018, 6:31 PM I started working on using 2N3904s for temperature sensors.? A Brazilian wanted to build a sensor and as I had lots of experience with the 1D heat equation suggested a design that biased a resistor to constant temperature.? But by the time I got the parts, he had wandered off to other things. Basic idea was to hold one transistor at constant temp with a Peltier junction and then use two other transistors to hold the heat flux constant by varying the DC bias through the load resistor.? .? All insulated with fine aerogel powder.? The power being the change? of DC bias through the load resistance required to keep the flux constant. I very much wish the manual for my Millivac were not so pricey or that I could at least get a schematic for the diode sensor they use.
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Re: 50 ohm thermocouples was RE: [HP-Agilent-Keysight-equipment] 478A power sensor recal for HP meters (was diode mounts)
I started working on using 2N3904s for temperature sensors. A Brazilian wanted to build a sensor and as I had lots of experience with the 1D heat equation suggested a design that biased a resistor to constant temperature. But by the time I got the parts, he had wandered off to other things.
Basic idea was to hold one transistor at constant temp with a Peltier junction and then use two other transistors to hold the heat flux constant by varying the DC bias through the load resistor. . All insulated with fine aerogel powder. The power being the change of DC bias through the load resistance required to keep the flux constant.
I very much wish the manual for my Millivac were not so pricey or that I could at least get a schematic for the diode sensor they use.
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Re: Synthesizer module in ESG series E4435B
Folks,
this is a gift which keeps on giving.
Please allow me to schedule them for the week from the 13th of December.
I will be away from my lab then, and need content!
Leo: if it is OK for you, I will give you TWO posts.
Tam
With best regards
Tam Hanna
---
Enjoy electronics? Join 13700 other followers by visiting the Crazy Electronics Lab at
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Show quoted text
On 24. 11. 2018 14:46, Chuck Harris wrote: There are a whole bunch of pictures linked at the bottom of
this, and the original posts.
-Chuck Harris
Tam Hanna wrote:
Hello,
BIG thanks.
Now all I need is a good picture of the IC, and I will run it for free!!!
Tam
With best regards
Tam Hanna ...
Here are a few pictures of the current version:
If you are interested in getting one of these please contact me off
the list. The ballpark figure for assembled PCB is ?100.
If this looks like a daunting process, for a small fee I can install
it into a synthesizer module and test it afterwards if you ship it over.
This is experimental work so please consider it as it is. From my
phase noise and performance measurements this looks identical or
better than 1GC1-4210.
Cheers
Leo
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Dave McGuire
Alexandre Souza
RFI-EMI-GUY