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Date
Re: How to Test an NE75 Neon Lamp

 

It's a typical leaded bulb characteristic of many neons of the era.? If it's bad and I can't find a suitable neon, I might go with an LED.? It would be easy enough to install.? The existing bulb is held in a soft plastic semicircle that helps lock the assembly to the front panel.? An LED would easily do the same thing.? A yellow LED would resemble the neon closely enough for me.

Thanks,
Barry - N4BUQ

BTW if it turns out the lamp is bad, it should be easy enough to find an equivalent, depending on how it's hooked up. If just wire leads, no problem. If it's on a base like a bayonet style, that should be common enough too, but if not, you can bust out the glass bulb and solder a regular leaded one into the base.

Another option is to put in a high efficiency LED, as long as the circuit has suitable current limiting and polarity. Simple mods can make it right if needed. It's quite amazing to see how much light you can get from high efficiency LEDs with currents below 1 mA, like you'd have in neon circuits. My favorites are the high power "white" LEDs commonly used en masse for lighting. They're made for up to hundreds of mA sometimes, but at tiny currents can run rings around a neon lamp when properly used in its place. The color won't necessarily match, but if it's in a fixture jewel or behind a filter, there are more options.

I have done this for neon replacement in optical choppers, and many times for various bulb and regular LED upgrading of indicator light fixtures.

Ed

HP 8341B Unlock error at some frequencies

 

Hi,

My HP 8341B is showing unlock message in certain frequency bands such as:
1.1GHz - 2.4 GHz
4.73 GHz - 7.0 GHz
9.57 GHz - 13.5 GHz
14.5 GHz - 20 GHz.

The 6.99999 GHz is unlocked but 7.0000 GHz is locked so at a minimum it has to do with what band is selected.

I have gone through some of the service level steps to check certain voltages like Pretune, VDAC etc.
I admit I do not have a complete understanding of the machine yet (fairly new to all this), but I was hoping someone could nudge me in the right direction.
I bought the unit in a non-functioning state, No display showing, SHIFT-M4 functional tests with multiple fails, AC voltage transformer wires mistakes and more. I have sorted through those, i.e. SHIFT-M4 shows PASS on all tests, I have a functioning display etc.
I don't know the state of the YO, but from my limited spectrum analysis up to 5 GHz, I can see there is a peak at approximately the frequency of interest. My frequency counter also shows spot-on frequencies when locked, and several tens of MHz off, when unlocked.
The YO is the only lock is that does not seem to fully lock, i.e. REF, M/N, HET, etc seem to lock.

Also, does anybody know what YOs are compatible with the 8341B? Is is only the 5086-7430 listed in the manual or are there possibly other 2.3-7.0 GHz that can be used?

All comments, questions and pointers are welcome.

saevar
Re: Service Notes on HPWiki

 

On Tue, Mar 26, 2024 at 10:10 AM, ebrucehunter wrote:
Wolfgang,

Can you provide a link to these files.? Perhaps they have not been posted by the moderator yet.

Bruce, KG6OJI
Here you go:?

Thx, Wolfgang
Re: How to Test an NE75 Neon Lamp

 

BTW if it turns out the lamp is bad, it should be easy enough to find an equivalent, depending on how it's hooked up. If just wire leads, no problem. If it's on a base like a bayonet style, that should be common enough too, but if not, you can bust out the glass bulb and solder a regular leaded one into the base.

Another option is to put in a high efficiency LED, as long as the circuit has suitable current limiting and polarity. Simple mods can make it right if needed. It's quite amazing to see how much light you can get from high efficiency LEDs with currents below 1 mA, like you'd have in neon circuits. My favorites are the high power "white" LEDs commonly used en masse for lighting. They're made for up to hundreds of mA sometimes, but at tiny currents can run rings around a neon lamp when properly used in its place. The color won't necessarily match, but if it's in a fixture jewel or behind a filter, there are more options.

I have done this for neon replacement in optical choppers, and many times for various bulb and regular LED upgrading of indicator light fixtures.

Ed
Re: Service Notes on HPWiki

 

¿ªÔÆÌåÓý

Very nice, lots of stuff there I hadn¡¯t seen before.? Thanks to both of you!

?

-- john, KE5FX

?

From: [email protected] <[email protected]> On Behalf Of Wolfgang Schraml
Sent: Tuesday, March 26, 2024 5:21 AM
To: [email protected]
Subject: [HP-Agilent-Keysight-equipment] Service Notes on HPWiki

?

I uploaded the following service notes to HPWiki. Thank you, Don Bitters, for opening your vaults!

¡­
Re: HP-1404A - Question About Power Supply/Distribution

 

I took a look at that during my lunch time.? I didn't realize that was a Zener but it makes sense.? If I'm not mistaken, the A13 board and the A14 board are back-to-back and, apparently, there are some transistors(?) that make contact between them.? I still haven't found a schematic for either board but I'll just have to do without it.

Thanks!
Barry - N4BUQ

From wire 902 (white-black-red), which goes to the stud mount Zener diode VR1 (1N2979) on the chassis, at the back of the plug-in. The pdf is missing circuit details for the chassis mounted parts, one of the larger resistors nearby will almost certainly be dropping the +100V rail for the Zener based +15V supply.



David

Re: HP-1404A - Question About Power Supply/Distribution

 

From wire 902 (white-black-red), which goes to the stud mount Zener diode VR1 (1N2979) on the chassis, at the back of the plug-in. The pdf is missing circuit details for the chassis mounted parts, one of the larger resistors nearby will almost certainly be dropping the +100V rail for the Zener based +15V supply.



David
Re: Service Notes on HPWiki

 

Wolfgang,

Can you provide a link to these files.? Perhaps they have not been posted by the moderator yet.

Bruce, KG6OJI
Re: HP-1404A - Question About Power Supply/Distribution

 

The +15V supply is split into three rails that have small-value series resistors and 0.01uF caps on the other side of those resistors. That's done on the A10 board. The A9 board has a similar arrangement but without the caps. I just can't find where that +15V supply comes from. I assume on the A13 board but I can't find a schematic for that board.

Thanks,
Barry - N4BUQ

If HP is doing what Tek does, the (A) and (B) are isolated (by choke)
and filtered (caps) power rails derived from the 15 volt supply.? Tek's
preferred method is to take a 1/2 watt resistor and wind a few turns of
wire around it, making a choke.? Should the wire ever burn out, the
resistor (typically 10 to 100 ohms, IIRC) will still give some voltage.
Likely not designed to do that as a failure mode, but possible.

Look to see where the 15 volt rail comes into the board.

Harvey


On 3/26/2024 11:48 AM, n4buq wrote:
I've been doing some troubleshooting with a few aspects of my 1404A and am
confused about something regarding the power rails. Various schematics
reference +15V (some have a +15V(A) and +15V(B) designations); however, I'm not
finding where those are sourced.

The mainframe supplies various voltages to the two plugin jacks but those don't
include 15V. I think there may be a regulator of sorts on the an A13 board
but, so far, I have not found that schematic. Furthermore, Paragraph 8-21
Section d states there is supposed to be various voltages present on the A13
board as well as a "VR1" that provides +15Vdc but I have not found that
regulator. Figure 8-28 shows an image of the A13 board (which, like the rest
of the scanned images, is very poor) but I can't find a schematic.

Is the A13 schematic missing from the online PDFs? Is there another board that
contains VR1 and, for that matter, a better scan of the manual somewhere?

Thanks,
Barry - N4BUQ
Re: HP8640B

 

Hello,
When you find the problem with your unit, please let the rest of us know what fixed it.
That way the group will have some more info on possible fixes in the future.
Happy troubleshooting.
Re: HP-1404A - Question About Power Supply/Distribution

 

If HP is doing what Tek does, the (A) and (B) are isolated (by choke) and filtered (caps) power rails derived from the 15 volt supply.? Tek's preferred method is to take a 1/2 watt resistor and wind a few turns of wire around it, making a choke.? Should the wire ever burn out, the resistor (typically 10 to 100 ohms, IIRC) will still give some voltage.? Likely not designed to do that as a failure mode, but possible.

Look to see where the 15 volt rail comes into the board.

Harvey

On 3/26/2024 11:48 AM, n4buq wrote:
I've been doing some troubleshooting with a few aspects of my 1404A and am confused about something regarding the power rails. Various schematics reference +15V (some have a +15V(A) and +15V(B) designations); however, I'm not finding where those are sourced.

The mainframe supplies various voltages to the two plugin jacks but those don't include 15V. I think there may be a regulator of sorts on the an A13 board but, so far, I have not found that schematic. Furthermore, Paragraph 8-21 Section d states there is supposed to be various voltages present on the A13 board as well as a "VR1" that provides +15Vdc but I have not found that regulator. Figure 8-28 shows an image of the A13 board (which, like the rest of the scanned images, is very poor) but I can't find a schematic.

Is the A13 schematic missing from the online PDFs? Is there another board that contains VR1 and, for that matter, a better scan of the manual somewhere?

Thanks,
Barry - N4BUQ
Re: 35670a UFC RAM Upgrade

 

On Tue, Apr 17, 2018 at 09:08 PM, David G. wrote:
https://groups.yahoo.com/neo/groups/hp_agilent_equipment/photos/albums/1376880405
Hi David,

Did you find out the proper DIMM to add in the 35670A for UFC option upgrade?

Best,
Christian
HP-1404A - Question About Power Supply/Distribution

 

I've been doing some troubleshooting with a few aspects of my 1404A and am confused about something regarding the power rails. Various schematics reference +15V (some have a +15V(A) and +15V(B) designations); however, I'm not finding where those are sourced.

The mainframe supplies various voltages to the two plugin jacks but those don't include 15V. I think there may be a regulator of sorts on the an A13 board but, so far, I have not found that schematic. Furthermore, Paragraph 8-21 Section d states there is supposed to be various voltages present on the A13 board as well as a "VR1" that provides +15Vdc but I have not found that regulator. Figure 8-28 shows an image of the A13 board (which, like the rest of the scanned images, is very poor) but I can't find a schematic.

Is the A13 schematic missing from the online PDFs? Is there another board that contains VR1 and, for that matter, a better scan of the manual somewhere?

Thanks,
Barry - N4BUQ
Re: 11048C feed through termination data?

 

Volume 9 of the RAD lad sereis refers to NAVSEA 900102 "a complete indexof r-f transmission lines anfl fittings vas published by the same committeeon June 15, 1945. " see section 5.1 page 244. A lot of the diagrams and table also come from 900102. No mention of Neill or Concelman that I can find.

Robert.
Re: 11048C feed through termination data?

 

Well said. I started by saying that BNC's were good to 4 GHz, not <1. J. Kruth

In a message dated 3/26/2024 10:40:22 AM Eastern Standard Time, jaredcabot@... writes:
?
And yet, absolutely NOTHING about this enitire conversation since the first few pasts has ANYTHING to do with the original quastion posed by me, the OP.

No-one has even noticed that my posts have dissapeared as I have withdrawn from this completely irellevant topic that has already been discussed to death multiple times....


Good work guys, on completely derailing a simple question into absolute tangential irrelevancy.

I'm out of this one... Have fun with your continued rehashed discussion.



Jared

Re: 11048C feed through termination data?

 

And yet, absolutely NOTHING about this enitire conversation since the first few pasts has ANYTHING to do with the original quastion posed by me, the OP.

No-one has even noticed that my posts have dissapeared as I have withdrawn from this completely irellevant topic that has already been discussed to death multiple times....


Good work guys, on completely derailing a simple question into absolute tangential irrelevancy.

I'm out of this one... Have fun with your continued rehashed discussion.



Jared
Re: How to Test an NE75 Neon Lamp

 

Arie,

Okay - that makes a bit more sense to me.? Thanks so much for that!

Barry - N4BUQ

From: "Arie de Muijnck via groups.io" <mygroups@...>
To: "HP-Agilent-Keysight-equipment" <[email protected]>
Sent: Tuesday, March 26, 2024 8:30:09 AM
Subject: Re: [HP-Agilent-Keysight-equipment] How to Test an NE75 Neon Lamp
On 2024-03-26 05:33, n4buq wrote:
The ready lamp for SINGLE triggering mode in my HP 1421A isn't/wasn't working. ?I'm not sure what the problem is but I have removed the front panel to clean it and before I reinstall it, I'd like to determine whether the lamp is good as it's fairly messy to remove the front panel to get to it.

From what I can tell, there's about 50V across that but not sure if that's when the lamp is supposed to be on or off so I'm not sure if that's enough to turn the lamp on.? I'm not finding much in the way of specs for an NE75 either.

Anyone know how I can test it?


Thanks,
Barry - N4BUQ


50V on the lamp, if dark, is the idle state and will not turn the lamp on.
If the +100V is present and you temporarily jumper point (4)? to GND the lamp should turn on.

Arie
Re: How to Test an NE75 Neon Lamp

 

¿ªÔÆÌåÓý

On 2024-03-26 05:33, n4buq wrote:
The ready lamp for SINGLE triggering mode in my HP 1421A isn't/wasn't working. ?I'm not sure what the problem is but I have removed the front panel to clean it and before I reinstall it, I'd like to determine whether the lamp is good as it's fairly messy to remove the front panel to get to it.

From what I can tell, there's about 50V across that but not sure if that's when the lamp is supposed to be on or off so I'm not sure if that's enough to turn the lamp on.? I'm not finding much in the way of specs for an NE75 either.

Anyone know how I can test it?


Thanks,
Barry - N4BUQ


50V on the lamp, if dark, is the idle state and will not turn the lamp on.
If the +100V is present and you temporarily jumper point (4)? to GND the lamp should turn on.

Arie
Re: How to Test an NE75 Neon Lamp

 

Ozan, David,

Thanks so much for the replies.? The two resistors (R135 and R136) are both mounted with the lamp so I can power it with R135 in series.? Since that lamp should be lit in both NORMAL and SINGLE and both modes appeared to be working, then I'm even more suspect of the lamp.? Testing it out of the circuit will confirm that one way or the other.

Thanks guys,
Barry - N4BUQ

From: "Barry" <n4buq@...>
To: "HP-Agilent-Keysight-equipment" <[email protected]>
Sent: Monday, March 25, 2024 11:33:32 PM
Subject: How to Test an NE75 Neon Lamp
The ready lamp for SINGLE triggering mode in my HP 1421A isn't/wasn't working. ?I'm not sure what the problem is but I have removed the front panel to clean it and before I reinstall it, I'd like to determine whether the lamp is good as it's fairly messy to remove the front panel to get to it.

From what I can tell, there's about 50V across that but not sure if that's when the lamp is supposed to be on or off so I'm not sure if that's enough to turn the lamp on.? I'm not finding much in the way of specs for an NE75 either.

Anyone know how I can test it?


Thanks,
Barry - N4BUQ
Re: Service Notes on HPWiki

 

¿ªÔÆÌåÓý

Wow thank you!

Att.,
Bernardo Santos

Em 26 de mar. de 2024, ¨¤(s) 09:20, Wolfgang Schraml <wschraml@...> escreveu:

?I uploaded the following service notes to HPWiki. Thank you, Don Bitters, for opening your vaults!

11729C-04 Isolator (AT2) Replacement 08/27/93
33220A-03 Flatness Calibration Error 08/24/09
3582A-16 Modification to A13 Rev. D board for use in older 3582As 12/12/91
3582A-17 Modification to A13 Rev. D board for use in older 3582As 04/09/92
3582A-18 Modification to prevent A1K6 input relay from welding shut 02/20/93
8340A-22 Rear Panel to Front Panel Retrofit Instructions 01/06/93
8340A-M61A Y2K update information. RMB support software update information. 1998-12
8340A-M62A Y2K update information. Microsoft Windows, Win 3.1, Win95 and Win98 software update information. 1998-12
8340A-M63A The Pascal operating environment has a defect related to the year 2000. 1998-12
8340B-05 Rear Panel to Front Panel Retrofit Instructions 01/06/93
8340B-M61A Y2K update information. RMB support software update information. 1998-12
8340B-M62A Y2K update information. Microsoft Windows, Win 3.1, Win95 and Win98 software update information. 1998-12
8340B-M63A The Pascal operating environment has a defect related to the year 2000. 1998-12
8563E-01A Modification for Intermittent sampler unlock errors 02/05/93
8563E-02C Defective 5-volt regulators on A6 power supply and A14 frequency control assemblies 01/10/94
8563E-04L Firmware Upgrade Kit and Information 1999-11
8563E-06 I.F. errors falsely displayed at cold temperatures before OCXO is warmed up 09/08/93
8563E-07A Modification to improve focus reliability 1996-08
8563E-08 5-Volt Regulator Reliability Improvement on A6 11/24/93
8563E-09 High displayed average noise level in wide bandwidths 1994-05
8563E-10C Possible Frequency Response Drift 2000-06
8563E-10D Possible Frequency Response Drift 11/11/03
8563E-12 VCO adjustment for later ¡°1X6¡± A15 RF assemblies 1996-01
8563E-13 Intermittent flashing display intensity 1996-01
8563E-14 A17 CRT Driver Reliability Improvement 1996-10
8563E-15 Intermittent Error 335 Sampler Unlock 1997-03
8563E-16 Intermittent Error 337 (Frac-N Unlock) Under Certain Conditions 1997-07
8563E-17 Reducing 300 kHz Sidebands 1997-12
8563E-19C Year 2K Update Information 01/20/99
8563E-22 A15 Assembly Shield Can Load Down Supply 1999-05
8563E-23 A1A2 RPG Assembly and A1 Keyboard Part Number Change 1999-01
8563E-24A Possible Failure of A6A1 High Voltage Module 1999-03
8563E-25 New A15 RF Board Replacement Part Numbers 12/20/04
8563E-M62A Y2K update information. Microsoft Windows, Win 3.1, Win95 and Win98 software update information. 1998-12
8563E-M63A The Pascal operating environment has a defect related to the year 2000. 1998-12
8563E-M71 Tightening torque on p/n 08673-60040 APC 3.5mm(m)to(f) connector. 1999-02
8563EC-02 Possible Frequency Response Drift 2000-06
8563EC-02B Possible Frequency Response Drift 11/11/03
8563EC-06 Perform butch on A3 interface board to remove gated video problems 03/13/02
8563EC-07 New A15 RF Board Replacement Part Numbers 12/20/04
8563ER-19C Year 2K Update Information 01/20/99
8563ER-M61A Y2K update information. RMB support software update information. 1998-12
8563ER-M62A Y2K update information. Microsoft Windows, Win 3.1, Win95 and Win98 software update information. 1998-12
8563ER-M63A The Pascal operating environment has a defect related to the year 2000. 1998-12
8565EC-02B Possible Frequency Response Drift 11/11/03
8565EC-06 Perform butch on A3 interface board to remove gated video problems 03/13/02
8565EC-07 New A15 RF Board Replacement Part Numbers 12/20/04
8566B-05 Repair and replacement of A5A2 Rotary Pulse Generator 12/09/92
8566B-10B Option 462 6 dB resolution bandwidths 12/21/93
8566B-19A RF Attenuator with Calibration ROM Replacement 03/02/93
8566B-37 New A4A1 Video Processor 12/04/91
8566B-39 Intermittent PC Edge Connectors on A4A4 Bandwidth Filter Assembly 02/20/93
8566B-40 Spurious Responses in Low Band 1997-07
8566B-41 Recommended replacement for A10A6U2 OP AMP 1994-10
8566B-42 RF Section Fan Motor Replacement 1996-01
8662A-12E Modification Kit to correct Error 03/04 conditions. 04/07/92
8662A-17A Synthesised Signal Generator VCO (08662-60485) failures 1998-08
8662A-18 Procedure to resolve A7A4 (08662-60376) C2 and C3 leakage 1999-03
8662A-19 Procedure to resolve 2-4 MHz spurs out from 640-1280 MHz carrier 1999-07
8662A-20 Procedure to resolve 230V misprinted fuse rating on fuse plate. 2000-03
8662A-21 Procedure to resolve A7A3C10 polarity misprinted. 2000-09
8663A-06E Modification Kit to correct Error 03/04 conditions. 04/03/92
8663A-11A Synthesised Signal Generator VCO (08662-60485) failures 1998-08
8663A-13 Procedure to resolve 2-4 MHz spurs out from 640-1280 MHz carrier 1999-07
8663A-14 Procedure to resolve 230V misprinted fuse rating on fuse plate. 2000-03
8663A-15 Procedure to resolve A7A3C10 polarity misprinted. 2000-09
E8362B-04 The new 1.1 GHz CPU board provided in PNA CPU Kit E8364-60026 functions properly only with Hard Disk Drive (HDD) part number E8364-60190 and Firmware Revision A.06.01 or higher installed in the PNA. 03/01/06
E8362BH85-04 The new 1.1 GHz CPU board provided in PNA CPU Kit E8364-60026 functions properly only with Hard Disk Drive (HDD) part number E8364-60190 and Firmware Revision A.06.01 or higher installed in the PNA. 01/16/08

Wolfgang Schraml
KI7PFX
8501 - 8520 of 151127