¿ªÔÆÌåÓý

  1. HP-Agilent-Keysight-Equipment
  2. Messages
Expanded Topics Messages
Date
Re: checking line module setting for 110V / 220V

 

there is small hole on card
use a hook and pull, swinging the card from side to side
There is no locking except fuse lever
Re: checking line module setting for 110V / 220V

 

¿ªÔÆÌåÓý

As I recall, there should be a little hole in the small PC Board. Hook it with a Small Screwdriver or anything else you can hook it with, and pull.

Regards Bill Lauchlan

?

From: [email protected] [mailto:[email protected]] On Behalf Of tom_iphi via groups.io
Sent: Friday, May 27, 2022 2:20 PM
To: [email protected]
Subject: [HP-Agilent-Keysight-equipment] checking line module setting for 110V / 220V

?

Hi folks,

mayby I'm stupid, but I need guidance.
I want to make sure my HP85101 is set for 220V before connecting it to mains and powering it up.
The line module seems pretty much standard across the HP equipment of that age.
A lever next to the mains socket removes the fuse. Below the lever there is a little pcb plug that allows to change the voltage setting.
Is there a trick to remove that card? It seems to be stuck. Is there a locking mechanism or do I just not pull hard enough?
I don't want to break anything.

Thanks, Tom

checking line module setting for 110V / 220V

 

Hi folks,

mayby I'm stupid, but I need guidance.
I want to make sure my HP85101 is set for 220V before connecting it to mains and powering it up.
The line module seems pretty much standard across the HP equipment of that age.
A lever next to the mains socket removes the fuse. Below the lever there is a little pcb plug that allows to change the voltage setting.
Is there a trick to remove that card? It seems to be stuck. Is there a locking mechanism or do I just not pull hard enough?
I don't want to break anything.

Thanks, Tom
Re: 8662A - a warning about dangerous service directions

 

Hi George,


On Fri, May 27, 2022 at 05:04 AM, george edmonds wrote:

Hi Dmitry

?

Whilst I share your concerns may I say that the HP fault finding guidance is based around having a set of their 8622A or 8623A PCB card extenders available.Under most circumstances using the card extenders will leave the power supply loads in place and limit the extent to which the voltages can rise.

This is not an issue with the loads being disconnected. When the overvoltage condition exists, HP advice is to bypass the safety shutdown and measure the voltages. With the normal loads in place, peak excursions were sufficient to damage multiple components in the -40 V regulator. Trusting the service manual in this case was clearly wrong.

?

?

The biggest problem that I see with most SMPSU repairs is a lack of understanding as to how they work and the limitations placed on their control circuitry.? I would suggest reading the excellent posting by Dave G8KBV in the previous 8622A repair thread, the key point is only one voltage control loop.

I know fairly well how 8662A switching supply works, not my first time fixing one. First time I ran into the high voltage shutdown, though. If the service manual was silent on the issue, I'd figure out a way to capture the transients, just like I suggested in the original post. But I tend to trust the service manual troubleshooting guidance. It did feel wrong to bypass the shut-off, but if HP says "do it", you do it. At least the first time :)
Re: Info Need on a RF FET for a Agilent E4438C signal generator

 

I used this one for a similar job, worked fine, didn't need to modify the matching networks,

You won't get 20dB gain out of it but perhaps you can get along with less... Don't ask me where you can get this critter from, nowadays...
Re: 8662A - a warning about dangerous service directions

 

Hi Dmitry

?

Whilst I share your concerns may I say that the HP fault finding guidance is based around having a set of their 8622A or 8623A PCB card extenders available.? Under most circumstances using the card extenders will leave the power supply loads in place and limit the extent to which the voltages can rise.

?

The biggest problem that I see with most SMPSU repairs is a lack of understanding as to how they work and the limitations placed on their control circuitry.? I would suggest reading the excellent posting by Dave G8KBV in the previous 8622A repair thread, the key point is only one voltage control loop.

?

G Edmonds.
Re: first post - new home lab - tips on using HP/Agilent gear

 

I replace the 75 ohm resistors that are in series with the output connectors with 50 ohm. The Inputs on the amps that I convert are high impedance, with loop through so I can easily configure a unit for a single input and up to 64 outputs. Or I can feed other frequencies through each of the eight plug in 350 MHz video amplifiers.
I also have some remote controlled video routers to select which output goes where. These were pulled from a commercial TV station when it was moved to a new site and converted to HD.


On Tue, May 24, 2022 at 1:34 PM Samudra <samudra.haque@...> wrote:
On Tue, May 24, 2022 at 11:58 AM, Mark Bielman wrote:
Samudra,

I did this with a KTS-250 (the smaller version, setup as 1 input x 8 outputs) and I changed everything to 50 Ohms... works great. Not sure you need to though.
Have the schematic somewhere in my stash. Not much to it. I think the resistors are in a SIP so I used the DIY method instead of buying some.

I would NOT recommend connecting all the inputs together as that would load the GPSDO too much. If you need more than 8 references, better to:
Feed GPSDO output to KTS input. Use 1 of the 8 KTS outputs and connect to another KTS input. Etc, etc. Then each KTS group will have 7 reference outputs except the last one will have 8.

Follow that?

Have fun!

Mark
Interesting.- thank you Mark. I don't mind DIY, if I had a schematic. I would appreciate a suggestion if we can convert it 50 ohm distribution. That's a resistor network at the end of the signal path or so, per the youtube video tear down I think. But if 75/50 ohm in such a small signal chain is not really critical for distributing 10 MHz, to a short few runs of BNC cable - then all the better. Yes, I did get the tip to use two stages for distribution of the 10 MHz ref clock.?

The GPSDO device is s a Chinese clone of PLL-GPSDO BG7TBL. Just arrived and waiting for it to warm up with the antenna outside my window. The output is noted as "SINE WAVE,6dBm+-2dB", so that's fairly hefty and wondering if this is useful or do we need to attenuate it for a cleaner signal? I'll hook up an oscilloscope shortly to see the 10 MHz carrier.?

Do HP equipment mind a sine-wave and not a square wave? Haven't read the big manuals yet in detail :-)?
Re: 8662A - a warning about dangerous service directions

 

Dmitry,

It always puzzled me that the manual advised you to bypass the over-voltage protection shutdown in the situation of a potentially damaging over-voltage condition. Seems to me that is only asking for trouble. I went down the route of disconnecting P2 and then capturing the unregulated turn-on transients as you?suggested. That helped me to identify a problem with the -40V line (or rather a problem with the way I was loading it during testing.?

regards

Tony


On Fri, 27 May 2022 at 08:48, Dmitry Teytelman <dimtey@...> wrote:
Hello,

During a recent repair my 8662A went into shutdown due to the high
input voltage at the linear regulator (A7A1) input. Service sheet 56
directs one to ground the collector of A7A1Q16 and then measure
voltages on test points TP4, TP5, TP6. Well, if a true overvoltage
condition exists on the -40 V regulator input, that ends up blowing a
bunch of parts, since the absolute maximum voltage rating on A7A1U1 is
50 V. I lost R37, U1, Q1, and Q5 on A7A1.

I think two different approaches would work better:

1. Capture the turn-on transients on the unregulated supplies (-45 V,
23 V, -13 V) and the regulated -5.2 V supply with a scope.

2. Disconnect P2 from the power supply motherboard, remove A7A1
completely, then load the four above mentioned supplies with power
resistors (1 A for -5.2/-13/+23 V, 0.5 A for -40 V). Signals ON and
HI-V on the power supply motherboard must be grounded. Now supply
voltages can be safely examined without worrying about damaging A7A1
or the rest of the synthesizer.

Regards,
--
Dmitry Teytelman <dimtey@...>
8662A - a warning about dangerous service directions

 

Hello,

During a recent repair my 8662A went into shutdown due to the high
input voltage at the linear regulator (A7A1) input. Service sheet 56
directs one to ground the collector of A7A1Q16 and then measure
voltages on test points TP4, TP5, TP6. Well, if a true overvoltage
condition exists on the -40 V regulator input, that ends up blowing a
bunch of parts, since the absolute maximum voltage rating on A7A1U1 is
50 V. I lost R37, U1, Q1, and Q5 on A7A1.

I think two different approaches would work better:

1. Capture the turn-on transients on the unregulated supplies (-45 V,
23 V, -13 V) and the regulated -5.2 V supply with a scope.

2. Disconnect P2 from the power supply motherboard, remove A7A1
completely, then load the four above mentioned supplies with power
resistors (1 A for -5.2/-13/+23 V, 0.5 A for -40 V). Signals ON and
HI-V on the power supply motherboard must be grounded. Now supply
voltages can be safely examined without worrying about damaging A7A1
or the rest of the synthesizer.

Regards,
--
Dmitry Teytelman <dimtey@...>
Re: WTB: 5265A Digital Voltmeter for HP 5245L Electronic Counter.

 

Hi Stephen, do you still have the 5265A for sale? im in Australia, thanks Ben
Re: HP/Agilent/Keysight 8478B thermistor mount

 

¿ªÔÆÌåÓý

Yes 8478B is a transfer power standard for 7mm connectors . It¡¯s very stable , the matching is not the best but with a good VNA are used as transfer standard on most national lab. The efficiency are measured on microcalorimeter with extreme accuracy close to as remember .1%

Ing. Patricio A. Greco
Taller Aeron¨¢utico de Reparaci¨®n 1B-349
Organizaci¨®n de Mantenimiento Aeron¨¢utico de la Defensa OMAD-001
Gral. Mart¨ªn Rodr¨ªguez 2159
San Miguel (1663)
Buenos Aires
T:?+5411-4455-2557
F:?+5411-4032-0072

On 26 May 2022, at 18:54, Lothar baier <Lothar@...> wrote:

?I haven¡¯t seen any 8478B used as transfer standard ?, we used them with some special option to calibrate the 50MHz reference on 43x series meters , for sensor calibration we used a weinschel system2 , Yes NIST - if you can afford it - ?will calibrate any sensors that are using a self nulling bridge circuit which certainly includes the 8478B as well as the weinschel sensors

-----Original Message-----
From: [email protected] <[email protected]> On Behalf Of Dave McGuire via groups.io
Sent: Thursday, May 26, 2022 3:31 PM
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] HP/Agilent/Keysight 8478B thermistor mount

On 5/26/22 16:10, Lothar baier wrote:
i wouldnt call it a transfer standard , weinschel/tegam makes sensors
that use the same principle that are heated (1109/1111)? that are used
with system 2 units to calibrate sensors , they are outrageously
expensive

??They certainly can be, and certainly are, used as transfer standards.
?Further, NIST will calibrate them. (they won't calibrate any other type of RF power sensor, unless something has changed very recently)

???????????-Dave

--
Dave McGuire, AK4HZ
New Kensington, PA
Re: HP/Agilent/Keysight 8478B thermistor mount

Lothar baier
 

If it was used in a standards lab it more than likely has option H01 which guarantees a VSWR < 1.05 at 50MHz , usually either the 8478B-H01 or 478A-H75 or H76 are used for the power level accuracy test for the 50MHz calibrator on HP Power meters

-----Original Message-----
From: [email protected] <[email protected]> On Behalf Of Bruce via groups.io
Sent: Thursday, May 26, 2022 5:32 PM
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] HP/Agilent/Keysight 8478B thermistor mount

This one came from an auction at McDonnell Douglas plant in St. Louis
- It was in their standards lab - a long time ago.

AFIK the "B" version is the only one available from HP

Cheers!



Quoting Lothar baier <Lothar@...>:

I haven¡¯t seen any 8478B used as transfer standard , we used them
with some special option to calibrate the 50MHz reference on 43x
series meters , for sensor calibration we used a weinschel system2 ,
Yes NIST - if you can afford it - will calibrate any sensors that are
using a self nulling bridge circuit which certainly includes the 8478B
as well as the weinschel sensors

-----Original Message-----
From: [email protected]
<[email protected]> On Behalf Of Dave McGuire
via groups.io
Sent: Thursday, May 26, 2022 3:31 PM
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] HP/Agilent/Keysight 8478B
thermistor mount

On 5/26/22 16:10, Lothar baier wrote:
i wouldnt call it a transfer standard , weinschel/tegam makes sensors
that use the same principle that are heated (1109/1111)? that are
used with system 2 units to calibrate sensors , they are outrageously
expensive
They certainly can be, and certainly are, used as transfer standards.
Further, NIST will calibrate them. (they won't calibrate any other
type of RF power sensor, unless something has changed very recently)

-Dave

--
Dave McGuire, AK4HZ
New Kensington, PA
Re: HP/Agilent/Keysight 8478B thermistor mount

 

This one came from an auction at McDonnell Douglas plant in St. Louis - It was in their standards lab - a long time ago.

AFIK the "B" version is the only one available from HP

Cheers!



Quoting Lothar baier <Lothar@...>:

I haven¡¯t seen any 8478B used as transfer standard , we used them with some special option to calibrate the 50MHz reference on 43x series meters , for sensor calibration we used a weinschel system2 , Yes NIST - if you can afford it - will calibrate any sensors that are using a self nulling bridge circuit which certainly includes the 8478B as well as the weinschel sensors

-----Original Message-----
From: [email protected] <[email protected]> On Behalf Of Dave McGuire via groups.io
Sent: Thursday, May 26, 2022 3:31 PM
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] HP/Agilent/Keysight 8478B thermistor mount

On 5/26/22 16:10, Lothar baier wrote:
i wouldnt call it a transfer standard , weinschel/tegam makes sensors
that use the same principle that are heated (1109/1111)? that are used
with system 2 units to calibrate sensors , they are outrageously
expensive
They certainly can be, and certainly are, used as transfer standards.
Further, NIST will calibrate them. (they won't calibrate any other type of RF power sensor, unless something has changed very recently)

-Dave

--
Dave McGuire, AK4HZ
New Kensington, PA
Re: HP/Agilent/Keysight 8478B thermistor mount

Lothar baier
 

I haven¡¯t seen any 8478B used as transfer standard , we used them with some special option to calibrate the 50MHz reference on 43x series meters , for sensor calibration we used a weinschel system2 , Yes NIST - if you can afford it - will calibrate any sensors that are using a self nulling bridge circuit which certainly includes the 8478B as well as the weinschel sensors

-----Original Message-----
From: [email protected] <[email protected]> On Behalf Of Dave McGuire via groups.io
Sent: Thursday, May 26, 2022 3:31 PM
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] HP/Agilent/Keysight 8478B thermistor mount

On 5/26/22 16:10, Lothar baier wrote:
i wouldnt call it a transfer standard , weinschel/tegam makes sensors
that use the same principle that are heated (1109/1111)? that are used
with system 2 units to calibrate sensors , they are outrageously
expensive
They certainly can be, and certainly are, used as transfer standards.
Further, NIST will calibrate them. (they won't calibrate any other type of RF power sensor, unless something has changed very recently)

-Dave

--
Dave McGuire, AK4HZ
New Kensington, PA
Re: Limits of the Port Extension on the Cal screen for calibrating at end of cable

 

Could you have used a single point frequency measurement n the VNA? I know the 8510 will do that.

But I am sure the experience was educational - thanks for the education - it would have taken me a bit of time to catch on to that.

Cheers!

Bruce

Quoting "Harke Smits via groups.io" <yrrah@...>:

Hello,


There is one more issue to consider. Long lines give delays. Once I wanted to measure the loss of a coaxial cable on a vna. Was an interesting experience: no response. Until I realized the receiver had already traveled higher up in frequency at the time the response was back. You need to consider a delay in between frequency steps, long enough so as to give the receiver time to read the response. This is a documented feature (of course).

Good luck,

Harke, PA0HRK


On 26/05/2022 20:09, Tom Lee wrote:
Hi Karin,

"Upper limit" is not as hard a cliff as your question presupposes. Whether or not a given length of cable is too much depends on your acceptance criteria. What are you trying to measure, and to what accuracy do you need to measure it?

When you add cable, you get loss, so that loss subtracts directly from your dynamic range. For example, if you are making meaurements at a gigahertz or so, with RG-213 you can expect to lose about 10dB in each direction, roughly speaking. If you aren't trying to measure small deviations from an exquisitely well-matched load, you'll be fine. If you're trying to resolve small changes in the vicinity of a -60dB S11 null, then you may find the measurement challenging.

The other factor to consider with a long length of cable is that it isn't rigid, so stability of your measurement can be affected. And if you are doing a lengthy set of measurements, temperature effects can come into play as well. Whether these are "don't cares" or showstoppers depends on what you can tolerate. If you can tolerate large error bars, your measurement problems become much less severe. If you're trying to make publication-quality measurements, you may find that difficult.

Good luck!

--Cheers,
Tom
--
Prof. Thomas H. Lee
Allen Ctr., Rm. 205
350 Jane Stanford Way
Stanford University
Stanford, CA 94305-4070

On 5/26/2022 09:45, Karin Johnson wrote:
Hello Group:
I have an 8753C and am wondering what the upper limit on cable length would be if I place the cal standards at the end of a cable to do remote measurement of S11.?? In other words I am using SOL, with the cal standards placed at the end of a 100 foot length of RG-213.? Theoretically placing the measurement plane at the end of the cable.? I have already done this and the results seem to be accurate relative to an actual measurement at the that physical place.
I hope I have explained this issue sufficiently.
Regards,
Karin Johnson

BTW: I have had an account on the Keysight forums in the past and have recently tried to login to that site, but It won't let me.? Possibly password have changed, and I cannot create a new account.? I have posted with Keysight support and hope they return the email.
Re: HP/Agilent/Keysight 8478B thermistor mount

 

I actually have one of these and treat it VERY carefully whenever I use it - which is infrequently

Cheers!

Bruce

Quoting Lothar baier <Lothar@...>:

first of you have to consider that the 8478B just as the older 478 series requires a lot of manual assembly steps as it was designed in a time when there was no such thing as surface mount parts or automated assembly . one also has to consider that the QTY of those sold by keysight now is by far less than it was 10 or 20 years back ,? as bruce already pointed out those sensors nowadays are not mainstream anymore but rather used in calibration labs
Re: HP/Agilent/Keysight 8478B thermistor mount

 

I certainly would call $14K outrageously expensive.

Cheers!

Bruce
Quoting Lothar baier <Lothar@...>:

i wouldnt call it a transfer standard , weinschel/tegam makes sensors that use the same principle that are heated (1109/1111)? that are used with system 2 units to calibrate sensors , they are outrageously expensive
Re: HP 8662A Power up - overvoltage shutdown

 

Hi,

Following the comments by G Edmonds in this thread he recommended loading the PSU ?-40V rail more heavily to resolve the PSU shutdown error occurring immediately after start-up.

Pleased to say that seems to have done the trick - I loaded it with a 110mA current draw (that¡¯s the only power resistor I had that was suitable) and it starts up ok at 230V where it would not beforehand - and the (pre-regulator) input rail has climbed from >-50V to just over -41V.

So I¡¯m hoping that this PSU is actually working properly now, and it was my flawed testing approach that was the problem.

Thanks all for helpful advice and pointers. This groups is great.

Tony




On Thu, 26 May 2022 at 20:28, Bruce <bruce@...> wrote:
Dan -
Excellent ob - maybe you should publish the Gerber Files for the new?
motherboard ?

Cheers!

Bruce

Quoting "Daniel Nelson via " <djn=[email protected]>:

> Tony:
>
> I also replaced the power supply with a group of Meanwell Supplies.
> Wrote it up. In the files section under:
>
> HP 8662A_8663A Pwr Supply Changeout.pdf (?
> /g/HP-Agilent-Keysight-equipment/files/8000%20to%209999/8662A/8662A%208663A%20Power%20Supply%20Replacement/HP%208662A_8663A%20Pwr%20Supply%20Changeout.pdf?
> )
>
> What I found is that the design of the main switcher is problematic?
> as almost 500 watts of power has to be transmitted through two 22uF?
> capacitors and they do get cooked after awhile which leads to?
> killing the power transistors. I got tired of chasing that.....
>
> Dan in Chandler, AZ
>
>
>








--

Re: HP/Agilent/Keysight 8478B thermistor mount

 

On 5/26/22 16:10, Lothar baier wrote:
i wouldnt call it a transfer standard , weinschel/tegam makes sensors that use the same principle that are heated (1109/1111)? that are used with system 2 units to calibrate sensors , they are outrageously expensive
They certainly can be, and certainly are, used as transfer standards. Further, NIST will calibrate them. (they won't calibrate any other type of RF power sensor, unless something has changed very recently)

-Dave

--
Dave McGuire, AK4HZ
New Kensington, PA
Re: HP/Agilent/Keysight 8478B thermistor mount

Lothar baier
 

i wouldnt call it a transfer standard , weinschel/tegam makes sensors that use the same principle that are heated (1109/1111)? that are used with system 2 units to calibrate sensors , they are outrageously expensive?
25061 - 25080 of 151482