¿ªÔÆÌåÓý

  1. HP-Agilent-Keysight-Equipment
  2. Messages
Expanded Topics Messages
Date
Re: How to Test an NE75 Neon Lamp

 

I got around to testing that lamp.? With R135 and R136 still in place, I connected to the end marked +100V and the other side of the lamp to ground.? The lamp fires very close to 90V so it's still good.? Looks like I get to start troubleshooting why it doesn't work (presuming it still doesn't) when I get the plugin reassembled.

Thanks,
Barry - N4BUQ

From: "Barry" <n4buq@...>
To: "HP-Agilent-Keysight-equipment" <[email protected]>
Sent: Tuesday, March 26, 2024 8:15:24 AM
Subject: 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: 5086-7337 *Yig Oscillator issue*

 

Refreshing:

still looking for a medium size knob for my 83592A rf plugin rpg :)

anyone who wants sell it, please PM

Thanks!
Re: 11048C feed through termination data?

 

I've found Weak-ipedia to be a politicized cesspool of ignorance,? like much of Reddit.? People just delete things they don't like regardless of accuracy.?


On Tue, Mar 26, 2024, 7:51?PM Jim Ford <james.ford@...> wrote:
I had a similar experience with Wikipedia about 10 years ago.? I wrote some stuff on the phase lock loop page about how one can think of the inputs to the phase detector as 2 cars going around a racetrack, track position being analogous to the phase difference, and speed being analogous to frequency.? I thought it was an easy-to-understand way to explain it.? But somebody thought otherwise and deleted my entry.? I have not submitted anything since then.? I should have asked why.? ? ? ? ? Jim Ford?



Sent from my T-Mobile 4G LTE Device


-------- Original message --------
From: "Roy J. Tellason, Sr." <roy@...>
Date: 3/26/24 1:47 PM (GMT-08:00)
Subject: Re: [HP-Agilent-Keysight-equipment] 11048C feed through termination data?

On Monday 25 March 2024 12:25:40 pm Dave McGuire wrote:
> On 3/25/24 12:24, Robert G8RPI via wrote:
> > Yes
>
>??? Bravo, I'm glad to hear it.? Lots of people whine about errors in
> Wikipedia articles, but almost no one puts their money where there mouth
> is and corrects them.
>
>????????????? -Dave
>

I made a few small additions to two or three pages there,? and they got immediately removed.? So I went badk in there and un-did that,? and suggested that if somebody had a problem with what I'd done that we should talk about it.

Just checked,? they're not in there now.

--
Member of the toughest, meanest, deadliest, most unrelenting -- and
ablest -- form of life in this section of space, ?a critter that can
be killed but can't be tamed. ?--Robert A. Heinlein, "The Puppet Masters"
-
Information is more dangerous than cannon to a society ruled by lies. --James
M Dakin
Re: 11048C feed through termination data?

 

¿ªÔÆÌåÓý

I had a similar experience with Wikipedia about 10 years ago.? I wrote some stuff on the phase lock loop page about how one can think of the inputs to the phase detector as 2 cars going around a racetrack, track position being analogous to the phase difference, and speed being analogous to frequency.? I thought it was an easy-to-understand way to explain it.? But somebody thought otherwise and deleted my entry.? I have not submitted anything since then.? I should have asked why.? ? ? ? ? Jim Ford?



Sent from my T-Mobile 4G LTE Device


-------- Original message --------
From: "Roy J. Tellason, Sr." <roy@...>
Date: 3/26/24 1:47 PM (GMT-08:00)
Subject: Re: [HP-Agilent-Keysight-equipment] 11048C feed through termination data?

On Monday 25 March 2024 12:25:40 pm Dave McGuire wrote:
> On 3/25/24 12:24, Robert G8RPI via groups.io wrote:
> > Yes
>
>??? Bravo, I'm glad to hear it.? Lots of people whine about errors in
> Wikipedia articles, but almost no one puts their money where there mouth
> is and corrects them.
>
>????????????? -Dave
>

I made a few small additions to two or three pages there,? and they got immediately removed.? So I went badk in there and un-did that,? and suggested that if somebody had a problem with what I'd done that we should talk about it.

Just checked,? they're not in there now.

--
Member of the toughest, meanest, deadliest, most unrelenting -- and
ablest -- form of life in this section of space, ?a critter that can
be killed but can't be tamed. ?--Robert A. Heinlein, "The Puppet Masters"
-
Information is more dangerous than cannon to a society ruled by lies. --James
M Dakin
Re: A document about the 8165A

 

Another one of your superb books, and especially as I just purchased a 8165A last week.

So much to read and enjoy
Philip
Re: Service Notes on HPWiki

 

Thanks very much.? Like John, I was astounded with all the things that were totally new to me.

Regards,

Bruce, KG6OJI
Re: 11048C feed through termination data?

 

On Monday 25 March 2024 12:25:40 pm Dave McGuire wrote:
On 3/25/24 12:24, Robert G8RPI via groups.io wrote:
Yes
Bravo, I'm glad to hear it. Lots of people whine about errors in
Wikipedia articles, but almost no one puts their money where there mouth
is and corrects them.

-Dave
I made a few small additions to two or three pages there, and they got immediately removed. So I went badk in there and un-did that, and suggested that if somebody had a problem with what I'd done that we should talk about it.

Just checked, they're not in there now.

--
Member of the toughest, meanest, deadliest, most unrelenting -- and
ablest -- form of life in this section of space, ?a critter that can
be killed but can't be tamed. ?--Robert A. Heinlein, "The Puppet Masters"
-
Information is more dangerous than cannon to a society ruled by lies. --James
M Dakin
Re: How to Test an NE75 Neon Lamp

 

You would need to modify the circuit to use an LED, as it would be lit all the time with the resistors used, if you break the series resistor chain, the transistor might need changing too if it's not rated to switch 112V.

Closest currently available neon (without large minimum order quantity) would be the A9A. If you want one with reduced dark effect, A1D-T might do.?

David
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
8981 - 9000 of 151592