Would hope the BNC spacing is the same. Probably is. These are good from DC to 13Mhz and up to 42VDC per the manufacturer.
Regards
Tony
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Re: Agilent/Keysigh ESG series CLIP
Corrections: The 2019 date was when I OCR'd and bookmarked the files. The purchase date was in 2018 and the files were scanned in 2011.
-Xu
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Re: Agilent/Keysigh ESG series CLIP
Thanks, Paul, for the background information. I joined the Yahoo group in 2009, so I wouldn't know about what happend 15 years ago in the group.
The topic has been brought up a couple of times in here and also in the Tek group. That's how I came to know that a license exist for distributing manuals of obsolete HP test equipment. At one time I even wanted to apply for one, so that I can make avaiable some of the CLIPs that I scanned and couldn't find elsewhere online. But I didn't follow through. I still think it would be wise to 'stay on the safe side'.
The very CLIP that Milan talked about here (E4400-90336), I bought a pdf copy online in 2019 for not much money, and used it to fix my E4436B. The scan quality isn't as good as the earliver version E4400-90015 I scanned myself, but was good enough and didn't take any guesswork to read. The pdf files were dated 2018 so there may be other copies sold before mine.
-Xu
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Re: Re-capping an HP-130 Scopes
In general, the same reason to do it in audio would apply to a scope also.
You might as well (there's no 'cost' to doing it, right?).
Pete
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Sometimes the plates are bent during initial calibration to
linearize the? scale or hit calibration points within the range.?
Some people "straighten them out" because "someone" had to bend
things out of position.?
Unless you specifically know that someone has re-bent the plates
on the capacitors, I'd suggest leaving them alone.? The plates may
be bent to make it accurate.
All the above is invalid if someone has made adjustments with a
small hammer.
Harvey
On 10/26/2021 10:00 PM, Jeremy Nichols
wrote:
toggle quoted message
Show quoted text
There’s really no reason to check the capacitance
of the frequency tuning capacitors. If some of the plates are
significantly bent (but are not touching), the oscillator will
still work but will be inaccurate. With power off, you should be
able to check across the capacitor with an ohmmeter and get
infinite resistance (an open circuit).?
OK, thanks
They look clear of debris. Is there a way to check their
capacitance or resistance easily ? I have an LCR meter.
Regards
--
Jeremy Nichols
6.
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There’s really no reason to check the capacitance of the frequency tuning capacitors. If some of the plates are significantly bent (but are not touching), the oscillator will still work but will be inaccurate. With power off, you should be able to check across the capacitor with an ohmmeter and get infinite resistance (an open circuit).?
OK, thanks
They look clear of debris. Is there a way to check their capacitance or resistance easily ? I have an LCR meter.
Regards
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OK, thanks
They look clear of debris. Is there a way to check their capacitance or resistance easily ? I have an LCR meter.
Regards
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Re: Does anyone have an Agilent 16452A Liquid Test Fixture?
On Tue, Oct 26, 2021 at 12:33 AM, Dr. David Kirkby, Kirkby Microwave Ltd wrote:
If you accept that relative permittivity is a better term
Oh, I agree that relative permittivity is probably a better term, and it is even possible that I will get used to it in the 20 or 25 years I may have left in this life.? I did, after all, get used to saying "Hertz" instead of cycles per second (or cps), "megahertz" instead of megacycles, and gigahertz instead of kmc.? But it's tough to stop using a term you have used for decades, especially when everybody around you still uses the old term. I try to think in metric sometimes, and it's getting a little more comfortable - very slowly.? Perhaps some time we will happen to be in the same country at the same time, and we can discuss it over a pint or two, which I understand is still the only legal measure used for beer in the UK.? In the meantime, remember:
“Science advances one funeral at a time.” - Max Planck
The switch to "relative permittivity" in the United States will probably go much as Mr. Planck suggests.
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Be sure to carefully check the frequency tuning variable capacitors for any contaminants causing plate to plate short circuits, which will stop any oscillation in any band.?
On Tue, Oct 26, 2021 at 6:03 PM Morris Odell < vilgotch1@...> wrote: That's good news about R40 and also indicates no shorts in the transformers! That still leaves you with no current draw. The DC voltage to the 6CW5s is applied through R27 & 28 which each drop 30 volts across 500 ohms from 60 mA each, all of which is the 6CW5 plate & screen currents and is most of the current supplied by the 5AR4. The 6AU6s don't draw very much and get their feed from before R27 and 28. The cathode currents of the 6CW5s? flow back through sections C, D, E and F of the range switch and primaries of T1 and T2 and ultimately through R330 and 31 to the negative side of the power supply. There should be close to? -200 volts across R40 if all the current draws are OK. Check that the 12K resistances from the cathodes (pin 3) of the 6CW5s to chassis are correct to confirm that the DC current paths are intact. If so it's hard to think of anything other than dud tubes causing the problem.
Morris
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That's good news about R40 and also indicates no shorts in the transformers! That still leaves you with no current draw. The DC voltage to the 6CW5s is applied through R27 & 28 which each drop 30 volts across 500 ohms from 60 mA each, all of which is the 6CW5 plate & screen currents and is most of the current supplied by the 5AR4. The 6AU6s don't draw very much and get their feed from before R27 and 28. The cathode currents of the 6CW5s? flow back through sections C, D, E and F of the range switch and primaries of T1 and T2 and ultimately through R330 and 31 to the negative side of the power supply. There should be close to? -200 volts across R40 if all the current draws are OK. Check that the 12K resistances from the cathodes (pin 3) of the 6CW5s to chassis are correct to confirm that the DC current paths are intact. If so it's hard to think of anything other than dud tubes causing the problem.
Morris
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The cathodes (pin 3) of the 6CW5's measure 12K to chassis.
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FWIW, 122 Megohms makes it a 410-B.? Probably makes no difference if a lower resistance is used.
toggle quoted message
Show quoted text
On 10/26/2021 2:52 AM, Morris Odell wrote: Yes, the voltages on the schematic are DC using a voltmeter with a high input resistance quoted on the schematic as 122 megohms. The voltage using a modern DMM with an input resistance of 10 megohms or so should be pretty similar.? Is the 200CD producing any output and does this vary with the coarse frequency range switch? Assuming the mains voltage is correct, the higher voltage at the junction of R27/28 and reduced voltage drop across L6 suggests no current draw by the oscillator circuitry. You could check that by measuring the voltages across R27 and R28 which should be about 30 volts each. If it is much lower than that or even zero you should check all the tubes by substitution if possible. Also check R40.
The output voltage into 600 ohms at the maximum output setting should be 11.5 volts AC.
Good luck!
Morris
--
Richard Knoppow
dickburk@...
WB6KBL
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Thanks Morris. Sorry in my haste late last night I ended up measuring R30 at 3.1k, I will check R40 but it appears ok to look at.
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Thanks Jim
yes I have the 229 prefix manual. Apologies I measured R30 late last night as 3.1k, I will check R40 now and the ripple when I get the 2 pots back in.
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Another useful page in the manual is the one quoting resistance (cold) and voltage (hot) values at the tube sockets. The cathodes (pin 3) of the 6CW5's are merant to be 12K to chassis which would not be possible if R40 is 3.1K .
Nigel is right that the 120 Hz is power supply ripple. It certainly looks like the oscillator circuitry is not drawing current and therefore not working at all. R40 needs to be 10K and even in situ should not measure as low as 3.1 K. It's a 10 Watt wirewound so you need to make sure it's correct - it has a lot to do with proper biasing of the tubes. You might also check that T1 and T2 primaries or the centre tap of the HV winding of T3 don't have shorts to chassis. Once R40 is correct and there is not enough voltage across R27/28 I would suspect tube failure.
6CW5's are not exactly cheap unfortunately. If you were near me I could lend you one or two to check but as I'm down under that's not possible.....
Morris
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I am in need of a test fixture for my 1MHz HP 4271B LCR meter, a Hamfest find which I just fixed.
Does anyone know if the Tonghui test fixtures work at this freq?
TH26001A or TH26029 (with tweezer test probe)
Example:
https://www.ebay.com/itm/333389541337?hash=item4d9f90afd9:g:YTYAAOSwtJha6~Oq
Wally KC9INK
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HP 4274a measure with BIAS card
Dear All,?
Finally I collected all things for my 4274a with high voltage measurement.
The high voltage card working fine, but I can use it only on lower ranges in capacity mode.?
Video show what happen. Under 1uF looks like everything is okay but below 1uF I got Error 4. On the back the switch on the second position. =<2F
Video is here:
Whats wrong with the measure?
Thank you
Krisztian?
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Re-capping an HP-130 Scopes
Just a general general questions on replacing the paper caps.
Does it matter if the replacement caps are placed with their foil side orientated in the same direction as the old caps?
?
I know in audio circuits it cam make a difference but does that hold true on scopes as well?
?
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Re: HP 3245A Universal Source
Hi Roy, Well you might be lucky and I assume you've looked to see whether the PCB is still available from Keysight? Probably not, as the 3245A is so old, but maybe. Otherwise, you might need to fix yourself. Replace the caps (I'm only seeing 4 electrolytics on that board), fix any obvious damage and replace these chips only if necessary?  I'm thinking only 1826-2377/8 might need a bit of thought - the others should be OK? It's also worth checking out xDevs: There's a specific section there that talks about the A3 (high-voltage) board and the PB58 high-voltage power amp on it. Alan
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saipan59 (Pete)
Jeremy Nichols
Jim Allyn - N7JA