Chris I had the same problem ,12.6V on the flood gun pin - no obvious flood gun operation. It turned out to be the ground lead from the "cold" side of the flood gun ( pin 11, black wire )was not continuous to ground. The black lead inner conductor was broken at the push-on connector to the HV board. These connectors are known for poor crimping which fails after several pushon /pulloff events. Cheers Richard Pett (owner of 2 systems) --- In hp_agilent_equipment@..., "Chris van Lint" <chrisvanlint@...> wrote:
I have a problem with my 141T/8555A spectrum analyzer. The gear
works perfect in the conventional mode, but it will not store. When I push the "store" button, the screen simply goes blank. Pushing either the STD or FAST button makes it operate as a conventional CRT.
Don Collie has very generously swapped my pulse circuit board in his analyzer and has confirmed that the pulse board is OK. Indeed I have checked all voltages and waveforms / amplitudes on the pulse board and confirmed that they operate as expected. I have also checked all supply voltages and adjusted them to be spot on. The voltages at the various pins of the CRT have been checked, including the -12.6V heater voltage for the flood gun and are all within limits. I have not checked the heater voltage for the main gun, as the unit operates fine as a conventional analyzer. Similarly I have not checked the
6.6KV supply, as the unit is fine in conventional mode. I did check the voltage at the anode of CR23, which is -1350V as specified. The voltage at the anode of CR24 varies between -2518V to 1591V in what I would describe as being almost a saw tooth like fashion. Perhaps the experts can find a clue in this observation.
In sheer desperation I replaced the CRT with a brand new one I have, (which of course includes a brand new infamous 3 conductor ribbon cable), but it has not solved the problem. In other words everything is fine as a
conventional analyzer, but when the "store" button is pushed, nothing changes. Again voltages have been re-checked and re-adjusted and are as expected according to the circuit diagram.
I cannot perform the pulse circuit adjustments described in section 5-0 of the manual, simply because I cannot get past sub paragraph f, which requires the fast collimator adjustment A5R14B to be adjusted so that the entire flood gun illumination is visible. I cannot get any illumination
whatsoever.
I would be grateful for any suggestions as to what my next move(s) should be.
Cheers,
Chris
|
I have a problem with my 141T/8555A spectrum analyzer. The gear works perfect in the conventional mode, but it will not store. When I push the "store" button, the screen simply goes blank. Pushing either the STD or FAST button makes it operate as a conventional CRT.
Don Collie has very generously swapped my pulse circuit board in his analyzer and has confirmed that the pulse board is OK. Indeed I have checked all voltages and waveforms / amplitudes on the pulse board and confirmed that they operate as expected. I have also checked all supply voltages and adjusted them to be spot on. The voltages at the various pins of the CRT have been checked, including the -12.6V heater voltage for the flood gun and are all within limits. I have not checked the heater voltage for the main gun, as the unit operates fine as a conventional analyzer. Similarly I have not checked the
6.6KV supply, as the unit is fine in conventional mode. I did check the voltage at the anode of CR23, which is -1350V as specified. The voltage at the anode of CR24 varies between -2518V to 1591V in what I would describe as being almost a saw tooth like fashion. Perhaps the experts can find a clue in this observation.
In sheer desperation I replaced the CRT with a brand new one I have, (which of course includes a brand new infamous 3 conductor ribbon cable), but it has not solved the problem. In other words everything is fine as a conventional analyzer, but when the "store" button is pushed, nothing changes. Again voltages have been re-checked and re-adjusted and are as expected according to the circuit diagram.
I cannot perform the pulse circuit adjustments described in section 5-0 of the manual, simply because I cannot get past sub paragraph f, which requires the fast collimator adjustment A5R14B to be adjusted so that the entire flood gun illumination is visible. I cannot get any illumination whatsoever.
I would be grateful for any suggestions as to what my next move(s) should be.
Cheers,
Chris
|
Re: HP 1650A boot diskette
--- In hp_agilent_equipment@..., "tunerwiz" <tunerwiz@...> wrote:
--- In hp_agilent_equipment@..., "va7dij" <va7dij@>
wrote:
Can anyone help me get a copy of one of these?
Agilent site, here
<; Apro&pageMode=DS&cc=US&lc=eng>
[Non-text portions of this message have been removed]
I have these files but the disk is in a non-standard format and, anyway, I no longer have a floppy drive. I believe that, if you already have the 1650A, you can copy the boot diskette onto another diskette and that is what I'd like to find.
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3586A SLM Error 3.1 AGAIN !
3586A, Options 003, 004 fitted with REV B ROMs
After a major habitat move I unpacked and fired up my 3586A after a
12 month hibernation to do some tests (not having a Spec Analyzer) on
some circuitry and was confronted with the 3.1 Error again.
This was an original problem when I bought it, cleared up with the
help of Group Members at the time (and particularly Didier Juges,
thanks again, Didier!)
At that time my A-11 boards vco had drifted high, cleared by lifting
the ground off the XTAL case, but here it was back on Error 3.1 again
after laying idle for a year.
The control volts was way too high , >9v which indicated either a
vcxo fault again or other component failure. The 3 frequencies on
this board were spot on, but opening the loop and swinging an
external +/-control voltage to one end of R27 showed the vcxo not
generating the correct frequency span inside its stated control range
despite 'tuning' L22
Removing C22 (2.4pF) in parallel with the Varicap by lifting one leg
(of the cap, not my own!) 'fixed' the problem.
Likely the Varicap CR20 has changed its characteristics over time.
The main functional combination of variable L22 (series) and L21
(fixed, parallel) with the XTAL appears to be there to give a linear
shift in XTAL frequency either side of its central fo, in combination
with the varicap, and is still quite linear with no sudden jumps,
so I think the XTAL is ok as far as that goes
C22 might have been put across the varicap for temp compensation as
well, but long term monitoring of TP2 tween the cool of an early
morning to a hot late afternoon showed no major changes due to this
(a slow drift up from a mean of +2.4v by 200mV max)
My TP2 test point mean voltage is +2.4 volts now. I would be happier
to see it around 0 volts but I guess it will have to do as a 24 hr
soak test shows the unit working within specs with all operator "TF"
tests, etc, applied (except TF 61, omitted from the 'B' ROM version).
So What do other members get for the mean voltage at TP2 in their
working 3586's ? Has anyone made a note of it at any time? Should it
be around 0 v ? (The manual is silent on this, leaving you largely on
yr own where A11 board ERROR 3.1 problems occur)
If most members are not, I guess this shows a trend for the varicap
to drift with time, understandable given the age span of the 3586
Incidentally I checked the A-11 boards U80 integrator and its
components while I was at it
It had an input offset of 0.4 mV between pins 2 and 3 of U80.
After checking the integration cap C81 and other components I also
changed U80 for a NOS metal can LM308H (ime out ofstock of the can
type A version) which appears to have the same pinout and
compensation arrangements as the HP part number for U80 (whatever
that is)
This reduced the differential input offset to just over 100uV so I
have left it in, though I dont think this was a major problem in my
unit.
I have found my 3586A to be a VERY useful piece of test gear for
doing all sorts of things and one of my favorite acquisitions.
Finally the A version ROM set provides a SWEPT output for filter, etc
testing! (a 1000 points of resolution between selected front panel
frequencies, with a sync output available to trigger an external CRO).
Makes me wish there had been enough ROM space left after the 'B'
model improvements to keep this useful feature in!
Rgds all
John (hpxref)
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Free GPIB software for Prologix GPIB USB Interface
Hi folks,
I am a newbie to this group. While I own a number of older HP devices
this is not the reason why I enter this newsgroup. Instead, the people
at Prologix told me that my EZGPIB utility that I have programmed for
their USB GPIB Interface might be of interest to some of you.
So, if you own a Prologix USB GPIB interface or plan to buy one: I have
done a utility that gives you high level access to the Prologix USB GPIB
interface in a PASCAL like programming environment without the necessity
to deal with low level serial programming. It is freeware. If your are
interested I suggest you download the (still not complete) manual from
and the complete utility with examples from
Have fun with it and send me your feedback for improvements!
Ulrich Bangert
df6jb@...
Ortholzer Weg 1
D-27243 Gross Ippener
Germany
|
Re: HP8568B on screen text intensity - FIXED !!!
Don't feel bad, you learned something (we all did), the instrument is working and your wallet is not depleted, that's all that matters :-)
A lot of these magnificent instruments do have CRT wear-out issues, and this has been addressed here many times, so you are actually one of the lucky ones.
I'll take lucky over smart any day :-)
Didier KO4BB
david_woodhead wrote:
toggle quoted message
Show quoted text
Well I feel pretty stupid as all it was was an adjustment! - the intensity limit pot (R516) was incorrectly set. It's not imeadiately obvious from the schematic but this POT has the effect of offsetting the Z intensity and pushing the lower intensity (voltage) levels into cutoff but with little effect on the higher intensity levels - this was exactly what I was seeing.
Thanks for the comments posted.
David.
|
Re: HP8568B on screen text intensity - FIXED !!!
Well I feel pretty stupid as all it was was an adjustment! - the intensity limit pot (R516) was incorrectly set. It's not imeadiately obvious from the schematic but this POT has the effect of offsetting the Z intensity and pushing the lower intensity (voltage) levels into cutoff but with little effect on the higher intensity levels - this was exactly what I was seeing. Thanks for the comments posted. David. --- In hp_agilent_equipment@..., "david_woodhead" <david_woodhead@...> wrote:
I have 2 of these analyzers and both demonstrate exactly the same
problem - the trace intensity becomes inreasingly less visible as
the trace line lengths get shorter. On screen text, consisting of short
lines, is barely visible (unless I really turn up the intensity
control).
Has anyone else seen this? I have posted a pic here of the signal on TP301 (Z axis output) with 0 volts being the bottom graticule. The
intensity control is adjusted for a low intensity (but clearly visible) trace.
I'd appreciate hearing from anyone that might have seen this or can
compare my scope trace with thiers?
David.
KM5TZ
|
Re: HP8568B on screen text intensity
Chuck Harris wrote: Hi David,
You have a low emission CRT. Most HP CRT's are on RF instruments
where the operator feels inclined to leave the instrument on 24/7 to
keep it warmed up and stable for use at a moment's notice. This wears
out the cathode in the CRT's gun assembly, and makes it become increasingly
dim, and blurry.
There are only two fixes for this problem: 1) replace the CRT, something
that is becoming more and more difficult, and 2) restore/rejuvenate the
CRT, a process that sometimes extends the useful life of the CRT for a
good while.
There is a third fix: a company (I forgot whom, but they should not be too hard to google, or John Miles can post it here) makes a color LCD replacement for the entire display. Pretty neat, and great use of color. It's not cheap, but worth it, considering what these instruments are worth in good condition. This replacement makes it better than new! Didier KO4BB
|
Re: HP8568B on screen text intensity
Hi David,
You have a low emission CRT. Most HP CRT's are on RF instruments
where the operator feels inclined to leave the instrument on 24/7 to
keep it warmed up and stable for use at a moment's notice. This wears
out the cathode in the CRT's gun assembly, and makes it become increasingly
dim, and blurry.
There are only two fixes for this problem: 1) replace the CRT, something
that is becoming more and more difficult, and 2) restore/rejuvenate the
CRT, a process that sometimes extends the useful life of the CRT for a
good while.
I have restored several HP CRTS (I have never needed to do a tektronix CRT)
using my Sencore CR70 CRT restorer. The Sencore CR70, and CR7000 are about
the best that are routinely available. They were made for the television/
computer monitor repair market, but are equally applicable to scope, and
test equipment CRT's.
After you have restored/rejuvenated a CRT, you should avoid leaving the
instrument on 24/7. If you only turn it on when you need it, it will last
you for many many years. If you use it 24/7, it might last you only another
couple of thousand hours. Each additional time you restore/rejuvenate the
CRT, you get less of an improvement, and less additional life, until it
just quits.
-Chuck Harris
david_woodhead wrote:
toggle quoted message
Show quoted text
I have 2 of these analyzers and both demonstrate exactly the same problem - the trace intensity becomes inreasingly less visible as the trace line lengths get shorter. On screen text, consisting of short lines, is barely visible (unless I really turn up the intensity control).
Has anyone else seen this? I have posted a pic here of the signal on TP301 (Z axis output) with 0 volts being the bottom graticule. The intensity control is adjusted for a low intensity (but clearly visible) trace.
I'd appreciate hearing from anyone that might have seen this or can compare my scope trace with thiers?
David.
KM5TZ
|
HP8568B on screen text intensity
I have 2 of these analyzers and both demonstrate exactly the same
problem - the trace intensity becomes inreasingly less visible as the
trace line lengths get shorter. On screen text, consisting of short
lines, is barely visible (unless I really turn up the intensity
control).
Has anyone else seen this? I have posted a pic here of the signal on
TP301 (Z axis output) with 0 volts being the bottom graticule. The
intensity control is adjusted for a low intensity (but clearly visible)
trace.
I'd appreciate hearing from anyone that might have seen this or can
compare my scope trace with thiers?
David.
KM5TZ
|
Looking for CPU board 54111D (later 2Gs/s version)
Looking to buy a CPU board (later version that supports 2Gs/s option in
software). Anyone that can offer a working board at a reasonable price?
I want to upgrade my unit with the 54114 test set and my unit's CPU
board too old.
Dean
|
Re: [TekScopes] Want to use a high-res voltmeter in the Portland Oregon area
Thanks Lars, but that instrument is only specified to
1% accuracy. I need one that's about 10000 times better.
And so do you!
Please, send further replies off-list to avoid crossposting. If I hear
anything of interest to the lists, I'll forward it.
Dave
toggle quoted message
Show quoted text
-----Original Message-----
From: Lars Ahlstr?m [mailto:lea56@...]
Sent: Friday, January 12, 2007 3:16 PM
To: David Wise; hp_agilent_equipment@...; TekScopes@...
Subject: SV: [TekScopes] Want to use a high-res voltmeter in the Portland Oregon area
Hi Dave,
I could recommend this one. Ebay: 140070877954
I think its just a question of square dollars. ;)
I have the former model, and this one has even BNC out. Its just great, I checked my 8520's with it... allmost just zeroes after the dot... =)
They have a UK website as well: (where you can se their former one)
/Lars
-----Ursprungligt meddelande-----
Fr?n: TekScopes@... [mailto:TekScopes@...] F?r David Wise
Skickat: den 12 januari 2007 23:09
Till: hp_agilent_equipment@...; TekScopes@...
?mne: [TekScopes] Want to use a high-res voltmeter in the Portland Oregon area
I have a couple of 5-1/2 digit differential
voltmeters (Fluke 877A and 895A) in whose
calibration I have lost confidence.
Since (a) I don't have cubic dollars to spare
and (b) it's Just A Hobby, a cal lab is out of
the question. Do you know of anyone local to me
(Portland Oregon) who has a 6-1/2 digit or better
voltmeter that's in good cal? I will also gladly
accept suggestions for other places to ask.
No profits are riding on this. I'm doing it
just for the heck of it, to satisfy myself
that they're in spec.
Thanks,
Dave Wise
|
Want to use a high-res voltmeter in the Portland Oregon area
I have a couple of 5-1/2 digit differential
voltmeters (Fluke 877A and 895A) in whose
calibration I have lost confidence.
Since (a) I don't have cubic dollars to spare
and (b) it's Just A Hobby, a cal lab is out of
the question. Do you know of anyone local to me
(Portland Oregon) who has a 6-1/2 digit or better
voltmeter that's in good cal? I will also gladly
accept suggestions for other places to ask.
No profits are riding on this. I'm doing it
just for the heck of it, to satisfy myself
that they're in spec.
Thanks,
Dave Wise
|
Due to a programming error [Me], I have lost all emails between 2-30 PM yesterday, and
11-00AM today. Please resend. Sorry about that!
Cheers,.................................Don Collie jnr.
|
If your friend isn't planning on keeping his 8753A turned on 24/7,
he can probably restore the CRT's brightness by using a common
CRT restorer/rejuvenator. I have done this with other HP CRT's,
and had good success. Another poster has done some life experiments,
and found that the restored/rejuvenated HP CRT's have quite a few
hours left in them after the procedure is done.
-Chuck Harris
rovmkr wrote:
toggle quoted message
Show quoted text
Hi Dean, I'm not sure what you are looking for on the 8753A but on behalf of a friend without internet (dont ask)... His HP 8753B has a very faint display, does he need a new CRT? Any one with similar experience? Any one know where to get one?
He needs to scan continuous to 6 GHz and is thinking of an 8753D with opt 006. Will this do it or is it in two bands? Anyone know where to get one?
Another thought is the 8752C but is the instruction set for these different instruments the same as that of the 8753B? He doesnt want to re-write the software. We need to get hold of a catalog in the mid '90s. Peter.
--- In hp_agilent_equipment@..., "tunerwiz" <tunerwiz@...> wrote:
Now that all these CLIP's start to appear, was there ever anything on the 8753A?
Dean
Yahoo! Groups Links
|
Hi Dean, I'm not sure what you are looking for on the 8753A but on behalf of a friend without internet (dont ask)... His HP 8753B has a very faint display, does he need a new CRT? Any one with similar experience? Any one know where to get one? He needs to scan continuous to 6 GHz and is thinking of an 8753D with opt 006. Will this do it or is it in two bands? Anyone know where to get one? Another thought is the 8752C but is the instruction set for these different instruments the same as that of the 8753B? He doesnt want to re-write the software. We need to get hold of a catalog in the mid '90s. Peter. --- In hp_agilent_equipment@..., "tunerwiz" <tunerwiz@...> wrote:
Now that all these CLIP's start to appear, was there ever anything on
the 8753A?
Dean
|
HP1000 gold plated prototyping board with bus decoders
Hi Chaps,
Have an HP1000 prototyping board, its gold plated and fits in the CPU chassis,
has 11 bus decoder logic chips and room for 40+ ICs, in excellent condition :0
Anyone still using these around the traps /
Regards from
Mike Massen
Network Power Systems
Lab +61 (0) 8 9444 8961
Mb +61 (0) 438 048961
Perth, Western Australia
* USA GMC, Opel and Australian VL/VK/VN,VP Commodore Fuse Rail that wont warp or melt !
* RB30 Skyline/Nissan/VL Upgraded ignition driver now in long term economy trials
* Twin tyres for most sedans, trikes and motorcycle sidecars
* Industrial grade PolyVinyliDeneChloride (PVDC Copolymer) in bulk, the best
oxygen and water protective barrier you can find for circuit boards.
* Special Equipment for sale: 60KVA 3-phase UPS with large battery cabinet - $12,000
Web site under construction, Ebay and Oztion Auctions
|
Re: 1820-0098 decade divider IC for 5321A
--- In hp_agilent_equipment@..., "arthurok" <arthurok@...> wrote:
does the unit use a 5 volt power supply?
one trick would be to build up a circuit to divide a
crystal osc down to 5 hz i think a 7492 is a divide by 12 counter.
7490 is divide by 10 in ttl More informations on the schematics: The logic power supply is +5V (more exactly 5,1V according to the manual), the logic is TTL (not ECL) but the function of the I/O pins is not totally trivial. The decade divider chip 1820-0098 picks up its 100Hz input with a capacitor coupling just behind the 155V high voltage rectifier. The chip has an input pin and divide by 10 output cascaded to another divide by 10 chip, a reset input, plus a couple of less obvious pins: I named them control input and controlled output. The controlled outputs from the two cascaded dividers are connected together directly and to the Clock input of the counter Main Gate JK flip-flop. The control pins are connected to the gate time selector switch that can ground one or the other divider's control pin. The logic appears to be: grounded control pin => controlled output is active divide by 10 output, else controlled output is high Z. So I guess I could effectively replace this chip with a modern decade divider such as a 7490, a logic OR and an open collector transistor. My main option is still to try to find a spare chip ... -Marc-
|
Re: Powering a HP 1141A probe
Mark,
Thanks! I am watching the item now!
Bob
Mark Kahrs <mark.kahrs@...> wrote:
Why bother? Just buy a 1142A supply; one is on epay right now for $9.99.
toggle quoted message
Show quoted text
On 1/10/07, Robert Hagenbach <rc_hagenbach@...> wrote:
Hi,
I bought a HP 1141A RF Differential probe on eBay. It
did not come with a power supply. The power connector
looks like a 8 pin DIN connector. This would seem to
me to indicate that the power supply is more
complicated than +/- 12 volts. Can anyone help me with
a pin out of the power connector? Should I considered
buying a power supply or is it possible to build one?
Bob Hagenbach
Largo, Fl
|
--- In hp_agilent_equipment@..., "tunerwiz" <tunerwiz@...
wrote:
> Now that all these CLIP's start to appear, was there ever anything on
> the 8753A? I just want to add that I need a schematic for the frac-N digital
board. I have a problem on this board that seems to be heat related.
Thanks, Dean I'm also chasing a sporadic problem with my 8753B - it appears to also be in the Frac-N synthesiser board. Maybe a 'sticky' gate. I've been asking around about a CLIP for about a year. Someone did contact me with an offer of a pack for $100, which I'd be quite prepared to pay - particularly at the current UK?-US$ exchange rate(!!) - but I lost his email address in a bout of finger trouble. I've also emailed Mike Kawasaki at Agilent, who has been extraordinarily helpful, but has not been able to assist with the CLIP. My suspicion is that the early 8753 analysers still form a revenue stream for Agilent repair facilities, and that they are (understandably) reluctant to allow the information into the public domain. Cheers Chris GW4DGU
|
