Hi everyone,
I'm restoring a 1740A back to health again and its up and running but some form of calibration is now required.
- I have a Heathkit IG 4505 calibrator and the volts / div is pretty accurate with the exception of the 100v setting, scope reads 90v?
- The width of the trace is more than the screen, by about twice the screen width and I don't seem to be able to find in the service manual how to adjust this aspect?
- Sometimes there is another wave superimposed on the screen but of a far lower
- Also there is visible on some timebase speeds more than others, visible flyback lines and in instances it looks like another trace in the background?
If I can find out to link photos etc from my Flickr account I could show you these in photo and maybe video formats to give you more of true picture of whats happening then rather hoping that I can describe?it well enough so you can understand what I mean.?
Anyone able to offer any assistance with this at all? I have the service manual but it does not make it very clear on how to do these things unless of I'm going blind.
Graham
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Re: HP 8341A sucessfully FIXED!
Hi Tony
wow, cool, thanks. These files should work for the 8341A as well I think. I will give it a try ;-)
Since I cannot run HP Basic stuff, I will translate the programs to Python which runs nicely with GPIB cards and USB adaptors. I already did that with the calibration program for the HP 4195A.
Thanks
Tobias
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From: hp_agilent_equipment@... [hp_agilent_equipment@...]
Sent: Sunday, October 22, 2017 17:07
To: hp_agilent_equipment@...
Subject: Re: [hp_agilent_equipment] HP 8341A sucessfully FIXED!
?
I have the one for the 8340B if that helps.
Original files here:
?
Unlocked files here:
I think I may also have put this in the files section of the forum.
TonyG
?
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Re: HP 8341A sucessfully FIXED!
I have the one for the 8340B if that helps.
Original files here:
?
Unlocked files here:
I think I may also have put this in the files section of the forum.
TonyG ?
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Re: HP 8341A sucessfully FIXED!
Hi,
I saw that there was an automated test program which calibrates the attenuator and the ALC using HPIB commands.
However, I didn't find that program on the net.
Does anyone have a copy of it?
Tobias
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Re: 5342A: blown sampler?
My counter counts reliably up to 20 GHz. I could not yet test higher frequencies.
I wonder whether somebody has a ROM dump of it?
It would be nice if I could add the DAC option, but this requires a newer ROM which my unit does not have.
Tobias
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-------- Original message --------
From: "Steve A starmux64@... [hp_agilent_equipment]"
Date: 10/21/17 10:48 (GMT+01:00)
To: "Steve - Home Steve-Krull@... [hp_agilent_equipment]"
Subject: Re: [hp_agilent_equipment] Re: 5342A: blown sampler?
?
I have a 5342A with option 005 which extends operation from 18GHz to 24GHz. It has the original N-type connector though. So I expect there must be other hardware changes, or as Steve K suggests selected parts.? The option cost $500 extra.
Steve
On ?Friday?, ?October? ?20?, ?2017? ?02?:?00?:?22? ?PM? ?BST, Steve - Home Steve-Krull@... [hp_agilent_equipment] wrote:
?
I’ve done the connector change and, using a good quality SMA, I have two 5342As that count reliably to 26GHz and one that just won’t count reliably above about 21GHz. I don’t have a 5343A to compare to but I wonder if maybe they were just hand-selected 5342As?
73,
?
Hi Harke,
oh, interesting. So the upgrade to 26 GHz, which would actually be a 5343A, changes only the connector? :-)
This is funny, because I use a HP 8563E spectrum analyzer at work, which operates fine at 26.5 GHz using a N connector!
Best
Tobias
?
Hello Tobias,
Congrats on the repair! Happy for you the sampler was fine! I can only comment on the frequency range. I have a number of HP equipment (including the HP5342A) that are spec'd to 20-22 GHz and with an (expensive) option that range can be extended to 26
GHz. The only hw change is the input connector that goes from N to APC3.5. No other change! Try the counter at 24 GHz and you will see it will work!
Good luck!
Harke
?
Hi all,
problem solved: as I said, the counter was counting fine on the low frequency input, but on the high frequency input, it displayed only zeros. The reason was that
a) the -5.2V operating voltage was out of the spec
b) the solder joint between the semirigid coax to the front panel's N connector cracked, thus the semirigid was no longer connected to the connector. I re-soldered and now it counts fine (only tested with 2 GHz so far).
I wonder whether it is possible to replace the ROM. It would be nice to add option 004, the DAC. I have couple of DAC80 here, however, opt. 004 needs a different ROM, unfortunately.
I also read that there was an option 005, which extends the frequency range to 24 GHz. Does someone know what option 005 actually was? was it a different sampler, or something that can easily be changed?
Tobias
?
Hi,
Your measurements with the diode mode suggest the sampler is OK, digital meters don't use the same amount of current to test resistance as older analogue meters and that's the reason you didn't get their readings.
I agree with Steve, you may need to replace a number of the 1826-0371, either on the A8 main VCO, A4 offset VCO or both.
I'd also check the A5 output to see if you're getting drive to the sampler driver and then check the sampler driver A26 itself.
I'd check in that order, check the VCOs are outputting signal, check the A5 to ensure it's outputting a signal to?A26 and it should alternate between the two VCOs, then check A26.
To check the sampler driver A26?you really need a?spectrum analyser. As most spectrum analysers have a capacitor (DC block) in the front end you need to terminate the A26 module with 50 Ohm and then measure what you see ac ross that with the spec an, if
you see lots of harmonics then all is good. You will not see anything?(apart from the 325MHz drive) without a dc return for the step recovery diode.
If the A26 is not working that could either be the SRD or it could be U1 on the A26 module - I have seen faulty U1 ICs in the past, most likely due to heat - they run very hot.
For the 1826-0371, you can buy fakes/replicas/copies off ebay or do what I do, I make a small smd pcb with 2 x 2sc3356 transistors, 2 x 100 ohm resistors and a 120 ohm resistor in the emitter lead?(all smd components)?with pins to fit in the DIP footprint.
You'll see the schematic for the 1826-0371 on a number of the 5342A schematics. I've not had any issue with my made up boards yet.
If you find it is U1 on the A5 module I can also give you an alternative circuit for that but it is not quite optimised yet ?and?requires short leads to minimise parasi tics.
Good luck
Greg
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Hi? Keith;......
Thanks for the reply...
My scope the HP 1701, has three (3) knobs on the shafts
that control 'Main TIME/DEV, Delay TIME/Dev, and Sweep
Select'.? I beleive they were used on several 170x series
up the 1707 model..? I've checked invetory of the usual
old part suppliers to no avail... Hoping someone in the
group my have something they will part with ,even a
parts unit.? (reasonable $$$)
Thanks Again..? ...BOB...? ? ? KD0IJI@...
--------------------------------------------
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On Sat, 10/21/17, 'Keith Cockburn' keith77777@... [hp_agilent_equipment] <hp_agilent_equipment@...> wrote:
Subject: RE: [hp_agilent_equipment] KNOBS? HP1701? SCOPE
To: hp_agilent_equipment@...
Date: Saturday, October 21, 2017, 5:59 AM
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Re: 8566B PL1 Unlock, PL2 Unlock and Ref Unlock
The failed cap has an ESR of 56.32k and slowly dropping.? The capacitance is 48.78nF and rising.? This was measured with an Agilent 1733C.? I have an HP bench unit down in the lab so I'll walk down later but generally it agrees with this little handheld I wonder why I still have it.
The Mallorys were worth trying for the price.? I did find brand new Mallorys later today for $12.? But with ebay, you never really know what you get when they have more than one.
The weird thing is the way this thing failed. I never thought about switching an LM317K regulator on and off like that by pulsing the ref pin.? ?So the -10v supply is used to set the reference for the 12V supply and because this cap was bad, the -10V was pulsing up and down at 12Hz switching the 12v off and on.??
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Re: HP 1740A HV Oscillator has stopped running
Dave,
Bullseye, I took the 3 pin socket of the transistor and gave it a squirt of contact cleaner in the socket tubes and then plugged it back on and repeated the unplugging and replugging a few times and bingo, the traces are back on the screen, bobbie dazzler.
Many many thanks
Graham
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Re: 8566B PL1 Unlock, PL2 Unlock and Ref Unlock
The one that you found is marked with a HP part number and was made
in 1986.
If you have an ESR meter, I would be interested in knowing the
capacitance, ESR and leakage of the failed part.
You might want to check the ones that you ordered to ensure that
they are in fact good, as advertised.
Glenn
On 10/21/2017 8:39 PM,
jehancoc@... [hp_agilent_equipment] wrote:
Yes, looks like it.? They only come in a few sizes and bolt
patterns.
I found the actual part in the UK on ebay.? It is a
Mepco/Centralab 0180-0452 as in:
?
I sent him a note but purchased the ones in your prior
reply.? Nothing to loose at that price.
Thanks.
--
-----------------------------------------------------------------------
Glenn Little ETCS(SS) USN Ret, ARRL Technical Specialist, SBE ARRL TAPR
Amateur Callsign: WB4UIV wb4uiv@... AMSAT LM 2178
QTH: Goose Creek, SC USA (EM92xx) USSVI, FRA, NRA LM QCWA LM 28417
"It is not the class of license that the Amateur holds but the class
of the Amateur that holds the license"
---------------------------------------------------------------------------
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Re: OT Omni Spectra Semi-Rigid Tools
Thanks Steve.
I also have found the Tyco instruction sheets that show the use of the tooling. They also reference the M/A-Com and Omni-Spectra part numbers for the various tools.
However, the T-250A/450A is a mystery still......
Also, they must have made kits for N and TNC, but I find no reference to them...
So, I was wondering if Omni-Spectra ever put out tool info in their literature/catalogs...
Dan
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Re: 8566B PL1 Unlock, PL2 Unlock and Ref Unlock
Yes, looks like it.? They only come in a few sizes and bolt patterns.
I found the actual part in the UK on ebay.? It is a Mepco/Centralab 0180-0452 as in:
?
I sent him a note but purchased the ones in your prior reply.? Nothing to loose at that price.
Thanks.
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Re: 8566B PL1 Unlock, PL2 Unlock and Ref Unlock
Does this look like the part?
The price seems reasonable.
Glenn
On 10/21/2017 7:41 PM,
jehancoc@... [hp_agilent_equipment] wrote:
OK, so the award goes to Glen to who called it correctly.?
Though the problem manifested itself as low 12V, the issue
was in the -10V supply.? This caused a 120Hz pulse in the -5.6V
(approx.)?voltage to the reference circuit?for the 12V
regulator.? I didn't have the correct cap but I swapped in a
4,000uf (13,000uf required) and up it came albeit with noise
sidebands from the lack of filtering.
So where can I find a MEPCO/CENTRALAB 13,000UF 25Vdc 30 surge
cap?
Thanks for all the help.?
Jerry
--
-----------------------------------------------------------------------
Glenn Little ETCS(SS) USN Ret, ARRL Technical Specialist, SBE ARRL TAPR
Amateur Callsign: WB4UIV wb4uiv@... AMSAT LM 2178
QTH: Goose Creek, SC USA (EM92xx) USSVI, FRA, NRA LM QCWA LM 28417
"It is not the class of license that the Amateur holds but the class
of the Amateur that holds the license"
---------------------------------------------------------------------------
|
Re: HP 1740A HV Oscillator has stopped running
No, the bias on Q2 is correct if 120v is good.? The 16.8v base
voltage reverse biases the b-e junction of Q2 turning it OFF.? The
7.27v b-e bias on Q1 HV OSC is problematic.? This shoud be no more
than 1vdc or so with the oscillator running.? Power transistor
sockets can get flaky with age, and sometimes simply removing and
re-installing the transistor will cure the problem.
Dave
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Yes, you are correct, it is the HV Osc Q1, I was mixed with
another section that was giving problems but resolved.
I'll pull it out and test it, I have already done that HV
Disable Q1 and Q2. Someone else suggested on another group that
Q2 was dicky, despite it checking ok on my tester, it was
replaced as I have loads of equivalents but that wasn't the
problem.?
So I'll try this test and let you now if is OK or not.
Graham
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Re: HP 1740A HV Oscillator has stopped running
Dave,
HV OSC Q1 checks out just fine on my transistor tester and the connections to it from the board.
Graham
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Re: HP 1740A HV Oscillator has stopped running
Dennis,
Do you mean like a capacitor shorting to ground? C3, C6, C7, C8 or C14 for instance?
Graham
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Re: 8566B PL1 Unlock, PL2 Unlock and Ref Unlock
OK, so the award goes to Glen to who called it correctly.?
Though the problem manifested itself as low 12V, the issue was in the -10V supply.? This caused a 120Hz pulse in the -5.6V (approx.)?voltage to the reference circuit?for the 12V regulator.? I didn't have the correct cap but I swapped in a 4,000uf (13,000uf required) and up it came albeit with noise sidebands from the lack of filtering.
So where can I find a MEPCO/CENTRALAB 13,000UF 25Vdc 30 surge cap?
Thanks for all the help.?
Jerry
|
Re: 8566B PL1 Unlock, PL2 Unlock and Ref Unlock
Glen, it could be a bad cap on the -10V as the voltage is lower than it should be and of all the caps, that is where I see 4.6V of AC.? I'm going to take it out and bridge in a cap that I have in that range.? It strange that it is showing up in the 12V supply but I guess since the reference voltage is hosed it could be the issue.
It's almost always a cap.
Thanks
Jerry
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Re: HP 1740A HV Oscillator has stopped running
Graham,
By chance did you check the secondary is not being loaded down by a bad component? That would likely stall the oscillator.
Dennis
--------------------------------------------
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On Sat, 10/21/17, graham.l.n.butcher@... [hp_agilent_equipment] <hp_agilent_equipment@...> wrote:
Subject: [hp_agilent_equipment] Re: HP 1740A HV Oscillator has stopped running
To: hp_agilent_equipment@...
Date: Saturday, October 21, 2017, 6:59 PM
Yes, you are correct, it is the HV Osc Q1, I was mixed with
another section that was giving problems but
resolved.
I'll pull it
out and test it, I have already done that HV Disable Q1 and
Q2. Someone else suggested on another group that Q2 was
dicky, despite it checking ok on my tester, it was replaced
as I have loads of equivalents but that wasn't the
problem.?
So I'll
try this test and let you now if is OK or not.
Graham
|
Re: HP 1740A HV Oscillator has stopped running
Yes, you are correct, it is the HV Osc Q1, I was mixed with another section that was giving problems but resolved.
I'll pull it out and test it, I have already done that HV Disable Q1 and Q2. Someone else suggested on another group that Q2 was dicky, despite it checking ok on my tester, it was replaced as I have loads of equivalents but that wasn't the problem.?
So I'll try this test and let you now if is OK or not.
Graham
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Re: 1853-0063 transistor needed
Sorry abpit the NTE214; I must have mixed up the number.? But the info is online.
Bob
On Saturday, October 21, 2017 1:47 PM, "george g_einst@... [hp_agilent_equipment]" wrote:
Electrically equivalent mechanically no, the 1853-0063 is a TO3 device not a TO66 George G6HIG ________________________________________
From: hp_agilent_equipment@... < hp_agilent_equipment@...> on behalf of Dennis Czelusniak czelusniakd@... [hp_agilent_equipment] < hp_agilent_equipment@...> Sent: 21 October 2017 20:22:48 To: hp_agilent_equipment@...Subject: Re: [hp_agilent_equipment] 1853-0063 transistor needed A-1853-0063-1 NTE Equvilent NTE218 TRANSISTOR PNP SILICON 90V IC=4A TO-66 CASE All I did was GOOGLE and that's what it shows as equivalent. Dennis -------------------------------------------- On Sat, 10/21/17, mmaseda@... [hp_agilent_equipment] < hp_agilent_equipment@...> wrote: Subject: [hp_agilent_equipment] 1853-0063 transistor needed To: hp_agilent_equipment@...Date: Saturday, October 21, 2017, 1:25 PM Anyone know of a source or cross reference for a 1853-0063 transistor used in the 410C?? I’ve already have a query into Walter at Sphere. Thanks in advance,Manuel ------------------------------------ ------------------------------------ ------------------------------------ Yahoo Groups Links <*> To visit your group on the web, go to: ? ? <*> Your email settings: ? ? Individual Email | Traditional <*> To change settings online go to: ? ? ? ? (Yahoo! ID required) <*> To change settings via email: ? ? hp_agilent_equipment-digest@... ? ? hp_agilent_equipment-fullfeatured@...<*> To unsubscribe from this group, send an email to: ? ? hp_agilent_equipment-unsubscribe@...<*> Your use of Yahoo Groups is subject to: ? ?
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