Re: Low EMI lighting for labs and work areas
use high quality LED strip and EU not Chinese ballast compliance to EMI a nd safety
Fluorescent are arcs,and wideband RF and microwave noise emitting
Jon
|
Low EMI lighting for labs and work areas
All:
?
I'm in the process of moving and am thinking about the design of my new lab/work area and am trying to decide on the lighting.? In particular I would like to minimize the effect of radiated noise from the lights but also other factors such as the layout, CRI and color temperature.? Does anyone have any recommendations or experience they would share?? Thoughts so far are to have 4400K in general and 4800-5000K lighting over the task areas.? Having a high CRI is a plus but not strictly necessary.? The lowest noise solution would be custom LED arrays with a linear power supply - fairly straightforward to do but expensive.? Currently I am using 54W HO T-5 fluorescent fixtures in 4400K but they are fairly noisy in emissions so I would love to find alternatives.
?
TIA,
?
Hal
|
Re: HP 8341B RF sweeper has reduced output
I've had to replace 'O' rings in quite a few of these attenuators
over the years, in most cases because they had gone brittle and
disintegrated.
However, two days ago I decided to sort out an 83545A sweeper
plug-in which was showing signs of an intermittent attenuator
misfire and found 16 rings that had decided to revert to their
original liquid hydrocarbon form and presented as 16 dollops of
gooey black sludge.
After removing the chunks of it with cocktail sticks and discovering
IPA had no effect, using my ultrasonic cleaner for 3 minutes with a
10% solution of 'Crystal Simple? Green' cleaner the rods came up a
treat!
Either way, good luck and take your time - these things are a bit
fragile and somewhat fiddly to work on but eminently fixable!
Adrian
toggle quoted message
Show quoted text
thanks to all who replied, i just watched a "rf attenuator
rebuild" video and ordered a "watch repair rubber o-ring
kit"..cause I didnt have tiny o-rings like that...seems some in
there should fit...will open the 8341B and check the attenuator
when i have these on hand and hopefully open/fix/close back up in
a single "repair session"...Ill posts results then...
|
Re: HP 8341B RF sweeper has reduced output
I looked through my stash and I still have one new push rod with o-rings , I can send you this one free of charge if you email me your adress
?
Sent from for Windows
?
toggle quoted message
Show quoted text
thanks to all who replied, i just watched a "rf attenuator rebuild" video and ordered a "watch repair rubber o-ring kit"..cause I didnt have tiny o-rings like that...seems some in there should fit...will open the 8341B and check the attenuator when i have
these on hand and hopefully open/fix/close back up in a single "repair session"...Ill posts results then...
|
Re: HP 8341B RF sweeper has reduced output
Be cautious when removing the push rods not to break off the tips , ?you need a needle to push the tips over gently when pulling them out , the contacts actually have a slot that ends in a little hole you have to push the rods over to line
them up with the hole to pull them out
?
Sent from for Windows
?
toggle quoted message
Show quoted text
From: charlesterrebonne via groups.io
Sent: Thursday, March 3, 2022 10:40 PM
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] HP 8341B RF sweeper has reduced output
?
thanks to all who replied, i just watched a "rf attenuator rebuild" video and ordered a "watch repair rubber o-ring kit"..cause I didnt have tiny o-rings like that...seems some in there should fit...will open the 8341B and check the attenuator
when i have these on hand and hopefully open/fix/close back up in a single "repair session"...Ill posts results then...
|
Re: HP 8341B RF sweeper has reduced output
thanks to all who replied, i just watched a "rf attenuator rebuild" video and ordered a "watch repair rubber o-ring kit"..cause I didnt have tiny o-rings like that...seems some in there should fit...will open the 8341B and check the attenuator when i have these on hand and hopefully open/fix/close back up in a single "repair session"...Ill posts results then...
|
Re: HP 8341B RF sweeper has reduced output
Lol !? contact cleaner will ruin your RF performance .
I also seen people lubricate the plungers surefire way to gunk up the plungers in the long run
?
?
Sent from for Windows
?
toggle quoted message
Show quoted text
From: Steve - Home via groups.io
Sent: Thursday, March 3, 2022 9:47 PM
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] HP 8341B RF sweeper has reduced output
?
Absolutely agree on using surgical swabs, I should have mentioned that. And don’t flood the attenuator with isopropyl or spray on contact cleaner. I’ve replaced more o rings that had turned to gunk than I have
brittle ones, but a fair number of brittle ones that i have replaced had left loads of little black rubber chips everywhere.
On Mar 3, 2022, at 8:05 PM, Lothar baier <Lothar@...> wrote:
?
If you have dirty pads usually your loss will roll off at lower frequencies and then normalize at higher bands , this is because the dirt in essence is a series capacitor creating a high pass characteristic ,? you can check this by putting
a 50ohm termination on one side of your attenuator and connect a multimeter on the other side between center conductor and ground and then measure the resistance for each pad setting , it should read close to 50ohm , if it is higher than this points towards
dirty pads or a blown pad !
In my years fixing those beasts back at tucker the most common issue I saw was bad o-rings .
If you pull off the cover of the attenuator cover and look at the solenoids you see the plungers that actuate the contacts , you see little white pushrods that are connected to those plungers , there should be a black o-ring visible on
top and bottom ,? usually over the years the rubber becomes bridle and then falls apart , if this happens the contacts no longer make sufficient contact and the attenuator fails .
Agilent used to sell those as spare parts but you can also find them at watchmakers supply stores as they are used as sprocket gaskets , the company I ordered them from was otto frey/borrell if I remember correctly but this was like 20
years ago
One more hint on the cleaning part ,? avoid using regular cotton swabs as they fuzz , use techspray swabs or you can also use surgical swabs you can get at medical supply stores
?
Sent from for Windows
?
In the 8340/41 the output power indicator is measuring power before the attenuator so will indicated “requested” power, not actual output power. Band 0 is 10 MHz - 2.3 GHz, the swept LO is mixed with the phase locked 3.7 GHz oscillator.?
Remove the front panel, remove the attenuator, loosen the end caps of the attenuator (8 Allen screws) remove the nuts from the SMA connectors for RF in and out, remove the name plate, remove the 20 hex head
screws holding the front plate and SMA connectors and GENTLY pry the front plate off. The attenuator pads are attached to the front plate. Clean the contacts for each pad with 99.9% isopropyl alcohol. Clean the through lines the same way. Usually clears the
problem.?
On Mar 3, 2022, at 5:56 PM, charlesterrebonne@... wrote:
?Hi all
My HP 8341B sweeper looks like output down 10dbm~13dbm from requested level output...measured on a Boonton 4200 power meter know good.?
I rarely use it above 1Ghz... IIRC <2Ghz is band 0 didnt test other bands. I suspect an output step attenuator problem? a 10db pad "stuck"?
Looking at power meter at right of front panel on 8341B I see it matches requested power output...shouldnt be showing -10~13dbm down from requested value if there is an attenuator problem since that value is measured at output?
Anybody very familiar with these HP sweepers suggestions/tricks to save me time to address this? Ive fixed lots of test equipment but never this 8341B and its a *75 pound beast* that id like to fix and put back where it lives asap...its no fun to handle, flip
over and move...
Thanks all
|
Re: HP 8341B RF sweeper has reduced output
First of the JFW attenuators are by no means similar to the HP ones , they use a different design and are intended for a different target market ,? there are only 2 companies who use the edge line design Weinschel ( now API) and Keysight
, they were initially designed as precison step attenuators with main focus on repeatability and low VSWR .
JFW on the other hand traditionally always been a low cost provider mostly selling attenuators in the traditional cellular bands , the design you mentioned is obviously geared for 5G testing and uses a different design ,? looking at the
data sheet and based on the insertion loss , accuracy and frequency range it appears to me that they are using PIN diodes or PHEMT switch cells to switch the pads in and out
?
Sent from for Windows
?
toggle quoted message
Show quoted text
From: Jim Ford via groups.io
Sent: Thursday, March 3, 2022 9:33 PM
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] HP 8341B RF sweeper has reduced output
?
At least the HPAK step attenuators are high performance.? ?I checked the 40 GHz ones out not too long ago versus similar ones from JFW, and there was no comparison!? HPAK beat JFW on every single spec!? Price for used HPAK 84904L and 84906L
on eBay is similar to new JFW 50P-2072.? Let the buyer beware!
Sent from my T-Mobile 4G LTE Device
-------- Original message --------
From: Lothar baier <Lothar@...>
Date: 3/3/22 7:22 PM (GMT-08:00)
Subject: Re: [HP-Agilent-Keysight-equipment] HP 8341B RF sweeper has reduced output
?
Here is the parts breakdown of the parts available for the step attenuators
?
Sent from
for Windows
?
Those o rings always been a pain and agilent did not learn the lesson because the newer 50GHz attenuators had the same issue !? agilent used to sell the o-rings as well as the push rods with o-rings as parts but you had to go into their
parts system online to find the part numbers as the manual did not give any of the information I guess they figured nobody would fool around with this kind of stuff
?
Sent from for Windows
?
?
I would look at the solenoids before cleaning the pad contacts.? My?
guess is that one of the plungers is stuck due to a deteriorated "o"?
ring.
Cheers!
Bruce
Quoting Steve - Home <steve-krull@...>:
> In the 8340/41 the output power indicator is measuring power before?
> the attenuator so will indicated “requested” power, not actual?
> output power. Band 0 is 10 MHz - 2.3 GHz, the swept LO is mixed with?
> the phase locked 3.7 GHz oscillator.
> Remove the front panel, remove the attenuator, loosen the end caps?
> of the attenuator (8 Allen screws) remove the nuts from the SMA?
> connectors for RF in and out, remove the name plate, remove the 20?
> hex head screws holding the front plate and SMA connectors and?
> GENTLY pry the front plate off. The attenuator pads are attached to?
> the front plate. Clean the contacts for each pad with 99.9%?
> isopropyl alcohol. Clean the through lines the same way. Usually?
> clears the problem.
>
> Steve
> WB0DBS
>
>
>
>> On Mar 3, 2022, at 5:56 PM, charlesterrebonne@... wrote:
>>
>> ?Hi all
>>
>> My HP 8341B sweeper looks like output down 10dbm~13dbm from?
>> requested level output...measured on a Boonton 4200 power meter?
>> know good.
>>
>> I rarely use it above 1Ghz... IIRC <2Ghz is band 0 didnt test other?
>> bands. I suspect an output step attenuator problem? a 10db pad?
>> "stuck"?
>>
>> Looking at power meter at right of front panel on 8341B I see it?
>> matches requested power output...shouldnt be showing -10~13dbm down?
>> from requested value if there is an attenuator problem since that?
>> value is measured at output?
>>
>> Anybody very familiar with these HP sweepers suggestions/tricks to?
>> save me time to address this? Ive fixed lots of test equipment but?
>> never this 8341B and its a *75 pound beast* that id like to fix and?
>> put back where it lives asap...its no fun to handle, flip over and?
>> move...
>>
>> Thanks all
>>
>
>
>
?
|
Re: HP 8341B RF sweeper has reduced output
Absolutely agree on using surgical swabs, I should have mentioned that. And don’t flood the attenuator with isopropyl or spray on contact cleaner. I’ve replaced more o rings that had turned to gunk than I have brittle ones, but a fair number of brittle ones that i have replaced had left loads of little black rubber chips everywhere.
toggle quoted message
Show quoted text
On Mar 3, 2022, at 8:05 PM, Lothar baier <Lothar@...> wrote:
?
If you have dirty pads usually your loss will roll off at lower frequencies and then normalize at higher bands , this is because the dirt in essence is a series capacitor creating a high pass characteristic ,? you can check this by putting
a 50ohm termination on one side of your attenuator and connect a multimeter on the other side between center conductor and ground and then measure the resistance for each pad setting , it should read close to 50ohm , if it is higher than this points towards
dirty pads or a blown pad !
In my years fixing those beasts back at tucker the most common issue I saw was bad o-rings .
If you pull off the cover of the attenuator cover and look at the solenoids you see the plungers that actuate the contacts , you see little white pushrods that are connected to those plungers , there should be a black o-ring visible on
top and bottom ,? usually over the years the rubber becomes bridle and then falls apart , if this happens the contacts no longer make sufficient contact and the attenuator fails .
Agilent used to sell those as spare parts but you can also find them at watchmakers supply stores as they are used as sprocket gaskets , the company I ordered them from was otto frey/borrell if I remember correctly but this was like 20
years ago
One more hint on the cleaning part ,? avoid using regular cotton swabs as they fuzz , use techspray swabs or you can also use surgical swabs you can get at medical supply stores
?
Sent from for Windows
?
In the 8340/41 the output power indicator is measuring power before the attenuator so will indicated “requested” power, not actual output power. Band 0 is 10 MHz - 2.3 GHz, the swept LO is mixed with the phase locked 3.7 GHz oscillator.?
Remove the front panel, remove the attenuator, loosen the end caps of the attenuator (8 Allen screws) remove the nuts from the SMA connectors for RF in and out, remove the name plate, remove the 20 hex head screws holding the front plate and SMA connectors
and GENTLY pry the front plate off. The attenuator pads are attached to the front plate. Clean the contacts for each pad with 99.9% isopropyl alcohol. Clean the through lines the same way. Usually clears the problem.?
On Mar 3, 2022, at 5:56 PM, charlesterrebonne@... wrote:
?Hi all
My HP 8341B sweeper looks like output down 10dbm~13dbm from requested level output...measured on a Boonton 4200 power meter know good.?
I rarely use it above 1Ghz... IIRC <2Ghz is band 0 didnt test other bands. I suspect an output step attenuator problem? a 10db pad "stuck"?
Looking at power meter at right of front panel on 8341B I see it matches requested power output...shouldnt be showing -10~13dbm down from requested value if there is an attenuator problem since that value is measured at output?
Anybody very familiar with these HP sweepers suggestions/tricks to save me time to address this? Ive fixed lots of test equipment but never this 8341B and its a *75 pound beast* that id like to fix and put back where it lives asap...its no fun to handle, flip
over and move...
Thanks all
|
Re: HP 8341B RF sweeper has reduced output
At least the HPAK step attenuators are high performance.? ?I checked the 40 GHz ones out not too long ago versus similar ones from JFW, and there was no comparison!? HPAK beat JFW on every single spec!? Price for used HPAK 84904L and 84906L on eBay is similar to new JFW 50P-2072.? Let the buyer beware!
Jim Ford
Sent from my T-Mobile 4G LTE Device
toggle quoted message
Show quoted text
-------- Original message -------- From: Lothar baier <Lothar@...> Date: 3/3/22 7:22 PM (GMT-08:00) Subject: Re: [HP-Agilent-Keysight-equipment] HP 8341B RF sweeper has reduced output
?
Here is the parts breakdown of the parts available for the step attenuators
?
Sent from for Windows
?
Those o rings always been a pain and agilent did not learn the lesson because the newer 50GHz attenuators had the same issue !? agilent used to sell the o-rings as well as the push rods with o-rings as parts but you had to go into their
parts system online to find the part numbers as the manual did not give any of the information I guess they figured nobody would fool around with this kind of stuff
?
Sent from for Windows
?
?
I would look at the solenoids before cleaning the pad contacts.? My?
guess is that one of the plungers is stuck due to a deteriorated "o"?
ring.
Cheers!
Bruce
Quoting Steve - Home <steve-krull@...>:
> In the 8340/41 the output power indicator is measuring power before?
> the attenuator so will indicated “requested” power, not actual?
> output power. Band 0 is 10 MHz - 2.3 GHz, the swept LO is mixed with?
> the phase locked 3.7 GHz oscillator.
> Remove the front panel, remove the attenuator, loosen the end caps?
> of the attenuator (8 Allen screws) remove the nuts from the SMA?
> connectors for RF in and out, remove the name plate, remove the 20?
> hex head screws holding the front plate and SMA connectors and?
> GENTLY pry the front plate off. The attenuator pads are attached to?
> the front plate. Clean the contacts for each pad with 99.9%?
> isopropyl alcohol. Clean the through lines the same way. Usually?
> clears the problem.
>
> Steve
> WB0DBS
>
>
>
>> On Mar 3, 2022, at 5:56 PM, charlesterrebonne@... wrote:
>>
>> ?Hi all
>>
>> My HP 8341B sweeper looks like output down 10dbm~13dbm from?
>> requested level output...measured on a Boonton 4200 power meter?
>> know good.
>>
>> I rarely use it above 1Ghz... IIRC <2Ghz is band 0 didnt test other?
>> bands. I suspect an output step attenuator problem? a 10db pad?
>> "stuck"?
>>
>> Looking at power meter at right of front panel on 8341B I see it?
>> matches requested power output...shouldnt be showing -10~13dbm down?
>> from requested value if there is an attenuator problem since that?
>> value is measured at output?
>>
>> Anybody very familiar with these HP sweepers suggestions/tricks to?
>> save me time to address this? Ive fixed lots of test equipment but?
>> never this 8341B and its a *75 pound beast* that id like to fix and?
>> put back where it lives asap...its no fun to handle, flip over and?
>> move...
>>
>> Thanks all
>>
>
>
>
?
|
Re: HP 8341B RF sweeper has reduced output
?
Here is the parts breakdown of the parts available for the step attenuators
?
Sent from for Windows
?
toggle quoted message
Show quoted text
Those o rings always been a pain and agilent did not learn the lesson because the newer 50GHz attenuators had the same issue !? agilent used to sell the o-rings as well as the push rods with o-rings as parts but you had to go into their
parts system online to find the part numbers as the manual did not give any of the information I guess they figured nobody would fool around with this kind of stuff
?
Sent from for Windows
?
?
I would look at the solenoids before cleaning the pad contacts.? My?
guess is that one of the plungers is stuck due to a deteriorated "o"?
ring.
Cheers!
Bruce
Quoting Steve - Home <steve-krull@...>:
> In the 8340/41 the output power indicator is measuring power before?
> the attenuator so will indicated “requested” power, not actual?
> output power. Band 0 is 10 MHz - 2.3 GHz, the swept LO is mixed with?
> the phase locked 3.7 GHz oscillator.
> Remove the front panel, remove the attenuator, loosen the end caps?
> of the attenuator (8 Allen screws) remove the nuts from the SMA?
> connectors for RF in and out, remove the name plate, remove the 20?
> hex head screws holding the front plate and SMA connectors and?
> GENTLY pry the front plate off. The attenuator pads are attached to?
> the front plate. Clean the contacts for each pad with 99.9%?
> isopropyl alcohol. Clean the through lines the same way. Usually?
> clears the problem.
>
> Steve
> WB0DBS
>
>
>
>> On Mar 3, 2022, at 5:56 PM, charlesterrebonne@... wrote:
>>
>> ?Hi all
>>
>> My HP 8341B sweeper looks like output down 10dbm~13dbm from?
>> requested level output...measured on a Boonton 4200 power meter?
>> know good.
>>
>> I rarely use it above 1Ghz... IIRC <2Ghz is band 0 didnt test other?
>> bands. I suspect an output step attenuator problem? a 10db pad?
>> "stuck"?
>>
>> Looking at power meter at right of front panel on 8341B I see it?
>> matches requested power output...shouldnt be showing -10~13dbm down?
>> from requested value if there is an attenuator problem since that?
>> value is measured at output?
>>
>> Anybody very familiar with these HP sweepers suggestions/tricks to?
>> save me time to address this? Ive fixed lots of test equipment but?
>> never this 8341B and its a *75 pound beast* that id like to fix and?
>> put back where it lives asap...its no fun to handle, flip over and?
>> move...
>>
>> Thanks all
>>
>
>
>
?
|
Re: HP 8341B RF sweeper has reduced output
?
turns out they still sell em for $20? ,? the picture also provides a good illustration of the pushrod with the rings
?
Sent from for Windows
?
toggle quoted message
Show quoted text
From: Bruce via groups.io
Sent: Thursday, March 3, 2022 9:04 PM
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] HP 8341B RF sweeper has reduced output
?
I would look at the solenoids before cleaning the pad contacts.? My?
guess is that one of the plungers is stuck due to a deteriorated "o"?
ring.
Cheers!
Bruce
Quoting Steve - Home <steve-krull@...>:
> In the 8340/41 the output power indicator is measuring power before?
> the attenuator so will indicated “requested” power, not actual?
> output power. Band 0 is 10 MHz - 2.3 GHz, the swept LO is mixed with?
> the phase locked 3.7 GHz oscillator.
> Remove the front panel, remove the attenuator, loosen the end caps?
> of the attenuator (8 Allen screws) remove the nuts from the SMA?
> connectors for RF in and out, remove the name plate, remove the 20?
> hex head screws holding the front plate and SMA connectors and?
> GENTLY pry the front plate off. The attenuator pads are attached to?
> the front plate. Clean the contacts for each pad with 99.9%?
> isopropyl alcohol. Clean the through lines the same way. Usually?
> clears the problem.
>
> Steve
> WB0DBS
>
>
>
>> On Mar 3, 2022, at 5:56 PM, charlesterrebonne@... wrote:
>>
>> ?Hi all
>>
>> My HP 8341B sweeper looks like output down 10dbm~13dbm from?
>> requested level output...measured on a Boonton 4200 power meter?
>> know good.
>>
>> I rarely use it above 1Ghz... IIRC <2Ghz is band 0 didnt test other?
>> bands. I suspect an output step attenuator problem? a 10db pad?
>> "stuck"?
>>
>> Looking at power meter at right of front panel on 8341B I see it?
>> matches requested power output...shouldnt be showing -10~13dbm down?
>> from requested value if there is an attenuator problem since that?
>> value is measured at output?
>>
>> Anybody very familiar with these HP sweepers suggestions/tricks to?
>> save me time to address this? Ive fixed lots of test equipment but?
>> never this 8341B and its a *75 pound beast* that id like to fix and?
>> put back where it lives asap...its no fun to handle, flip over and?
>> move...
>>
>> Thanks all
>>
>
>
>
?
|
Re: HP 8341B RF sweeper has reduced output
Those o rings always been a pain and agilent did not learn the lesson because the newer 50GHz attenuators had the same issue !? agilent used to sell the o-rings as well as the push rods with o-rings as parts but you had to go into their
parts system online to find the part numbers as the manual did not give any of the information I guess they figured nobody would fool around with this kind of stuff
?
Sent from for Windows
?
toggle quoted message
Show quoted text
From: Bruce via groups.io
Sent: Thursday, March 3, 2022 9:04 PM
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] HP 8341B RF sweeper has reduced output
?
I would look at the solenoids before cleaning the pad contacts.? My?
guess is that one of the plungers is stuck due to a deteriorated "o"?
ring.
Cheers!
Bruce
Quoting Steve - Home <steve-krull@...>:
> In the 8340/41 the output power indicator is measuring power before?
> the attenuator so will indicated “requested” power, not actual?
> output power. Band 0 is 10 MHz - 2.3 GHz, the swept LO is mixed with?
> the phase locked 3.7 GHz oscillator.
> Remove the front panel, remove the attenuator, loosen the end caps?
> of the attenuator (8 Allen screws) remove the nuts from the SMA?
> connectors for RF in and out, remove the name plate, remove the 20?
> hex head screws holding the front plate and SMA connectors and?
> GENTLY pry the front plate off. The attenuator pads are attached to?
> the front plate. Clean the contacts for each pad with 99.9%?
> isopropyl alcohol. Clean the through lines the same way. Usually?
> clears the problem.
>
> Steve
> WB0DBS
>
>
>
>> On Mar 3, 2022, at 5:56 PM, charlesterrebonne@... wrote:
>>
>> ?Hi all
>>
>> My HP 8341B sweeper looks like output down 10dbm~13dbm from?
>> requested level output...measured on a Boonton 4200 power meter?
>> know good.
>>
>> I rarely use it above 1Ghz... IIRC <2Ghz is band 0 didnt test other?
>> bands. I suspect an output step attenuator problem? a 10db pad?
>> "stuck"?
>>
>> Looking at power meter at right of front panel on 8341B I see it?
>> matches requested power output...shouldnt be showing -10~13dbm down?
>> from requested value if there is an attenuator problem since that?
>> value is measured at output?
>>
>> Anybody very familiar with these HP sweepers suggestions/tricks to?
>> save me time to address this? Ive fixed lots of test equipment but?
>> never this 8341B and its a *75 pound beast* that id like to fix and?
>> put back where it lives asap...its no fun to handle, flip over and?
>> move...
>>
>> Thanks all
>>
>
>
>
?
|
Re: HP 8341B RF sweeper has reduced output
I would look at the solenoids before cleaning the pad contacts. My guess is that one of the plungers is stuck due to a deteriorated "o" ring.
Cheers!
Bruce
Quoting Steve - Home <steve-krull@...>:
toggle quoted message
Show quoted text
In the 8340/41 the output power indicator is measuring power before the attenuator so will indicated “requested” power, not actual output power. Band 0 is 10 MHz - 2.3 GHz, the swept LO is mixed with the phase locked 3.7 GHz oscillator.
Remove the front panel, remove the attenuator, loosen the end caps of the attenuator (8 Allen screws) remove the nuts from the SMA connectors for RF in and out, remove the name plate, remove the 20 hex head screws holding the front plate and SMA connectors and GENTLY pry the front plate off. The attenuator pads are attached to the front plate. Clean the contacts for each pad with 99.9% isopropyl alcohol. Clean the through lines the same way. Usually clears the problem.
Steve
WB0DBS
On Mar 3, 2022, at 5:56 PM, charlesterrebonne@... wrote:
?Hi all
My HP 8341B sweeper looks like output down 10dbm~13dbm from requested level output...measured on a Boonton 4200 power meter know good.
I rarely use it above 1Ghz... IIRC <2Ghz is band 0 didnt test other bands. I suspect an output step attenuator problem? a 10db pad "stuck"?
Looking at power meter at right of front panel on 8341B I see it matches requested power output...shouldnt be showing -10~13dbm down from requested value if there is an attenuator problem since that value is measured at output?
Anybody very familiar with these HP sweepers suggestions/tricks to save me time to address this? Ive fixed lots of test equipment but never this 8341B and its a *75 pound beast* that id like to fix and put back where it lives asap...its no fun to handle, flip over and move...
Thanks all
|
Re: HP 8341B RF sweeper has reduced output
If you have dirty pads usually your loss will roll off at lower frequencies and then normalize at higher bands , this is because the dirt in essence is a series capacitor creating a high pass characteristic ,? you can check this by putting
a 50ohm termination on one side of your attenuator and connect a multimeter on the other side between center conductor and ground and then measure the resistance for each pad setting , it should read close to 50ohm , if it is higher than this points towards
dirty pads or a blown pad !
In my years fixing those beasts back at tucker the most common issue I saw was bad o-rings .
If you pull off the cover of the attenuator cover and look at the solenoids you see the plungers that actuate the contacts , you see little white pushrods that are connected to those plungers , there should be a black o-ring visible on
top and bottom ,? usually over the years the rubber becomes bridle and then falls apart , if this happens the contacts no longer make sufficient contact and the attenuator fails .
Agilent used to sell those as spare parts but you can also find them at watchmakers supply stores as they are used as sprocket gaskets , the company I ordered them from was otto frey/borrell if I remember correctly but this was like 20
years ago
One more hint on the cleaning part ,? avoid using regular cotton swabs as they fuzz , use techspray swabs or you can also use surgical swabs you can get at medical supply stores
?
Sent from for Windows
?
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In the 8340/41 the output power indicator is measuring power before the attenuator so will indicated “requested” power, not actual output power. Band 0 is 10 MHz - 2.3 GHz, the swept LO is mixed with the phase locked 3.7 GHz oscillator.?
Remove the front panel, remove the attenuator, loosen the end caps of the attenuator (8 Allen screws) remove the nuts from the SMA connectors for RF in and out, remove the name plate, remove the 20 hex head screws holding the front plate and SMA connectors
and GENTLY pry the front plate off. The attenuator pads are attached to the front plate. Clean the contacts for each pad with 99.9% isopropyl alcohol. Clean the through lines the same way. Usually clears the problem.?
On Mar 3, 2022, at 5:56 PM, charlesterrebonne@... wrote:
?Hi all
My HP 8341B sweeper looks like output down 10dbm~13dbm from requested level output...measured on a Boonton 4200 power meter know good.?
I rarely use it above 1Ghz... IIRC <2Ghz is band 0 didnt test other bands. I suspect an output step attenuator problem? a 10db pad "stuck"?
Looking at power meter at right of front panel on 8341B I see it matches requested power output...shouldnt be showing -10~13dbm down from requested value if there is an attenuator problem since that value is measured at output?
Anybody very familiar with these HP sweepers suggestions/tricks to save me time to address this? Ive fixed lots of test equipment but never this 8341B and its a *75 pound beast* that id like to fix and put back where it lives asap...its no fun to handle, flip
over and move...
Thanks all
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Yes, cables called "null modem" tend to have pins 2 and 3 swapped, IIRC.? Apparently you don't want one of those.? Those in this group more familiar with datacom than I am can expand on this.? HTH
Jim Ford
Sent from my T-Mobile 4G LTE Device
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-------- Original message -------- From: Lothar baier <Lothar@...> Date: 3/3/22 5:47 PM (GMT-08:00) Subject: Re: [HP-Agilent-Keysight-equipment] 8516A cable question
Make sure its wired 1 to 1
?
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Ordered a 6ft cable, will report back with my results. I have tried slow sweep, less points, zero span. No luck.
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Make sure its wired 1 to 1
?
Sent from for Windows
?
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Ordered a 6ft cable, will report back with my results. I have tried slow sweep, less points, zero span. No luck.
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Re: HP 8341B RF sweeper has reduced output
In the 8340/41 the output power indicator is measuring power before the attenuator so will indicated “requested” power, not actual output power. Band 0 is 10 MHz - 2.3 GHz, the swept LO is mixed with the phase locked 3.7 GHz oscillator.? Remove the front panel, remove the attenuator, loosen the end caps of the attenuator (8 Allen screws) remove the nuts from the SMA connectors for RF in and out, remove the name plate, remove the 20 hex head screws holding the front plate and SMA connectors and GENTLY pry the front plate off. The attenuator pads are attached to the front plate. Clean the contacts for each pad with 99.9% isopropyl alcohol. Clean the through lines the same way. Usually clears the problem.?
toggle quoted message
Show quoted text
On Mar 3, 2022, at 5:56 PM, charlesterrebonne@... wrote:
?Hi all
My HP 8341B sweeper looks like output down 10dbm~13dbm from requested level output...measured on a Boonton 4200 power meter know good.?
I rarely use it above 1Ghz... IIRC <2Ghz is band 0 didnt test other bands. I suspect an output step attenuator problem? a 10db pad "stuck"?
Looking at power meter at right of front panel on 8341B I see it matches requested power output...shouldnt be showing -10~13dbm down from requested value if there is an attenuator problem since that value is measured at output?
Anybody very familiar with these HP sweepers suggestions/tricks to save me time to address this? Ive fixed lots of test equipment but never this 8341B and its a *75 pound beast* that id like to fix and put back where it lives asap...its no fun to handle, flip over and move...
Thanks all
|
On Thursday, March 3, 2022, 04:40:49 PM PST, H Kapa via groups.io <hcapela@...> wrote:
Hi Jim Adney,
I have a 200CD Ser.605- working on my bench and a few days ago in the middle of another repair my 200CD signal failed, how is it possible!! it was completely silent, it was left to wait for further analysis,
In time there I decided to check carefully, the DC voltages were present, but fluctuating in relation to the earth, result R40 of 15K / 10W open, I replaced it with an equivalent but with must the improvised fixing and nothing like the original.
?
So, I ask if you don't have an R40 to supply? , I know that transport is always the most expensive but can you still do it to Lisbon / Portugal?
Best Regards?
H Capela?
|
Hi Jim Adney,
I have a 200CD Ser.605- working on my bench and a few days ago in the middle of another repair my 200CD signal failed, how is it possible!! it was completely silent, it was left to wait for further analysis,
In time there I decided to check carefully, the DC voltages were present, but fluctuating in relation to the earth, result R40 of 15K / 10W open, I replaced it with an equivalent but with must the improvised fixing and nothing like the original.
?
So, I ask if you don't have an R40 to supply? , I know that transport is always the most expensive but can you still do it to Lisbon / Portugal?
Best Regards?
H Capela?
|
Froggie the Gremlin
Harold Foster
H Kapa