|
The connecters are available, Binder make 3 types and they did cost ?10 , ? 13 ?and ?16? each ? Regarding Diode sensors do not forget the 430 meter was made for Diode sensors? also I believe the early 431 A had a switch position for Diode ? Personally looking for a modern meter ( not expensive ) for wave guide diode detectors but calibrated in dB Paul ?
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From: [email protected] [mailto:[email protected]] On Behalf Of Alexandre Souza
Sent: 19 May 2022 20:49
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] A homemade diode power sensor for HP meters ? Talking about power sensor, I got lucky enough to get a (working) 436b and a WORKING \o/ sensor. But unfortunately, got it without the cable. Is there a cheaper source for the cable than ebay? ---8<---Corte aqui---8<--- ---8<---Corte aqui---8<--- ? ? Em qui., 19 de mai. de 2022 às 13:41, visitslovenija <musto102@...> escreveu: An interesting and long running thread.
Like many, I have a bit of a soft spot for the old HP435 meters and would like to have one working on the bench.
Since broken detectors do show up now and again at a decent price, has anyone successfully reworked one with busted thermocouples and modified for a diode front end? I know it’s small and very fiddly, but is that not easier than trying to build one from scratch?
|
OK Bruce? please explain !
You say ? (The 8484 is a dione power sensor.? Many other HP diode sensors end with t "D" instead of an "A" in the model number.)
I do not understand ??? also is dione in the above line a typo
So Is the 8484A power sensor is a diode? front end ??
Paul
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-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of Bruce
Sent: 19 May 2022 20:45
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] A homemade diode power sensor for HP meters
The 8484 is a dione power sensor.? Many other HP diode sensors end with t "D" instead of an "A" in the model number.
E.g. 8485D as opposed to 8485A
Cheers!
Bruce
Quoting Paul Bicknell <admin@...>:
> From memory the 8484 power sensor is a diode? front end
>
>
>
> But a working 8481? or 8484 go for about ?120 to ?160 in the UK
> equivalent to a day’s wages
>
> And it would take best part of a day to modify busted thermocouples
> for a diode by the time you did any calibration
>
> Regards Paul
>
>
>
> From: [email protected]
> [mailto:[email protected]] On Behalf Of
> visitslovenija
> Sent: 19 May 2022 11:20
> To: [email protected]
> Subject: Re: [HP-Agilent-Keysight-equipment] A homemade diode power
> sensor for HP meters
>
>
>
> An interesting and long running thread.
>
> Like many, I have a bit of a soft spot for the old HP435 meters and
> would like to have one working on the bench.
>
> Since broken detectors do show up now and again at a decent price, has
> anyone successfully reworked one with busted thermocouples and
> modified for a diode front end? I know it’s small and very fiddly, but
> is that not easier than trying to build one from scratch?
>
>
>
>
>
>
|
Hi Paul sounds like you have re engendered the 435? and you say you have achieved a 65 dB dynamic range? that is excellent and good for most Amateurs to ?6 Ghz ?but a lot want 10 Ghz? ?suggest you write it up for one of the magazines that Pay just as mater of interest? other than lots of Time ( I assume Weeks ) how much did it cost excluding the donor 435 ? Personally I repair the 432 and 435 meter usually it is the meter face and help UK Amateurs out with parts Paul ?
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From: [email protected] [mailto:[email protected]] On Behalf Of paulswed
Sent: 19 May 2022 18:52
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] A homemade diode power sensor for HP meters ? The diode approach would be the way to go. Like many of you I also like the large scale HP power meters. You can pick the bodies up for nothing. Though suddenly there seems to be a magical market for a body without sensors. An approach I recently took that has worked was to leverage the analog devices power sensors into a 435 body. This approach really couldn't use anything?inside of the 435. The Analog device sensor in a small box with very flexible?cable goes to an arduino that maps the linear to the log scale of the 435. Since the sensor works from?+15 to -50db I reused the switch to select new scaling in 10 db steps. Also to create a broad range 0 to -50 db scale. I like the meter a lot and it now sets on top?the real HP-435. The real one for very accurate readings to 18 GHz the new one good to 6 GHz. It really works well as I rarely need .25 db accuracy on anything. The Linear to log was quite a challenge as I learned. Though the meter is very nice this was a complex project so not sure its useful to many. If the diode approach can work as Dave says then that would be the best approach with the least building challenge. If you don't need 18GHz bandwidth maybe you can get away with larger components.
|
Talking about power sensor, I got lucky enough to get a (working) 436b and a WORKING \o/ sensor. But unfortunately, got it without the cable. Is there a cheaper source for the cable than ebay?
73 de PU2SEX Alexandre
---8<---Corte aqui---8<---
---8<---Corte aqui---8<--- Em qui., 19 de mai. de 2022 às 13:41, visitslovenija < musto102@...> escreveu:
An interesting and long running thread.
Like many, I have a bit of a soft spot for the old HP435 meters and would like to have one working on the bench.
Since broken detectors do show up now and again at a decent price, has anyone successfully reworked one with busted thermocouples and modified for a diode front end? I know it’s small and very fiddly, but is that not easier than trying to build one from scratch?
|
The 8484 is a dione power sensor. Many other HP diode sensors end with t "D" instead of an "A" in the model number. E.g. 8485D as opposed to 8485A Cheers! Bruce Quoting Paul Bicknell <admin@...>:
From memory the 8484 power sensor is a diode front end
But a working 8481 or 8484 go for about ?120 to ?160 in the UK equivalent to a day’s wages
And it would take best part of a day to modify busted thermocouples for a diode by the time you did any calibration
Regards Paul
From: [email protected] [mailto:[email protected]] On Behalf Of visitslovenija
Sent: 19 May 2022 11:20
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] A homemade diode power sensor for HP meters
An interesting and long running thread.
Like many, I have a bit of a soft spot for the old HP435 meters and would like to have one working on the bench.
Since broken detectors do show up now and again at a decent price, has anyone successfully reworked one with busted thermocouples and modified for a diode front end? I know it’s small and very fiddly, but is that not easier than trying to build one from scratch?
|
From memory the 8484 power sensor is a diode? front end ? But a working 8481? or 8484 go for about ?120 to ?160 in the UK equivalent to a day’s wages? And it would take best part of a day to modify busted thermocouples for a diode by the time you did any calibration Regards Paul ?
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From: [email protected] [mailto:[email protected]] On Behalf Of visitslovenija
Sent: 19 May 2022 11:20
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] A homemade diode power sensor for HP meters ? An interesting and long running thread.
Like many, I have a bit of a soft spot for the old HP435 meters and would like to have one working on the bench.
Since broken detectors do show up now and again at a decent price, has anyone successfully reworked one with busted thermocouples and modified for a diode front end? I know it’s small and very fiddly, but is that not easier than trying to build one from scratch?
|
The biggest issue you run into with diodes is that they have a limited dynamic range if it comes to linearity , agilent tried to compensate for this in the E9300 series sensors by using multiple sensing elements that are switched based
on the input power , generally reaching 10GHz with packaged diodes that are manageable in a regular home lab is doable but above you need to use beam leads or die level parts which are not quite as easy to handle !
?
?
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From: [email protected] < [email protected]>
On Behalf Of paulswed via groups.io
Sent: Thursday, May 19, 2022 12:52 PM
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] A homemade diode power sensor for HP meters
?
The diode approach would be the way to go. Like many of you I also like the large scale HP power meters. You can pick the bodies up for nothing. Though suddenly there seems to be a magical
market for a body without sensors.
An approach I recently took that has worked was to leverage the analog devices power sensors into a 435 body. This approach really couldn't use anything?inside of the 435.
The Analog device sensor in a small box with very flexible?cable goes to an arduino that maps the linear to the log scale of the 435.
Since the sensor works from?+15 to -50db I reused the switch to select new scaling in 10 db steps. Also to create a broad range 0 to -50 db scale.
I like the meter a lot and it now sets on top?the real HP-435.
The real one for very accurate readings to 18 GHz the new one good to 6 GHz. It really works well as I rarely need .25 db accuracy on anything.
The Linear to log was quite a challenge as I learned.
Though the meter is very nice this was a complex project so not sure its useful to many.
If the diode approach can work as Dave says then that would be the best approach with the least building challenge.
If you don't need 18GHz bandwidth maybe you can get away with larger components.
|
The diode approach would be the way to go. Like many of you I also like the large scale HP power meters. You can pick the bodies up for nothing. Though suddenly there seems to be a magical market for a body without sensors. An approach I recently took that has worked was to leverage the analog devices power sensors into a 435 body. This approach really couldn't use anything?inside of the 435. The Analog device sensor in a small box with very flexible?cable goes to an arduino that maps the linear to the log scale of the 435. Since the sensor works from?+15 to -50db I reused the switch to select new scaling in 10 db steps. Also to create a broad range 0 to -50 db scale. I like the meter a lot and it now sets on top?the real HP-435. The real one for very accurate readings to 18 GHz the new one good to 6 GHz. It really works well as I rarely need .25 db accuracy on anything. The Linear to log was quite a challenge as I learned. Though the meter is very nice this was a complex project so not sure its useful to many. If the diode approach can work as Dave says then that would be the best approach with the least building challenge. If you don't need 18GHz bandwidth maybe you can get away with larger components. Regards Paul WB8TSL
|
Of course. I have a Weinschel NBS power sensor calibration system in my lab. B-)
-Dave
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On 5/19/22 13:35, Lothar baier wrote: It’s a different story obviously if you design a complete new sensor but then you still have the problem that you need access to a calibrated sensor to establish your calibration factors
-----Original Message-----
From: [email protected] <[email protected]> On Behalf Of Dave McGuire via groups.io
Sent: Thursday, May 19, 2022 12:28 PM
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] A homemade diode power sensor for HP meters
I'm not talking about putting a diode where the thermocouple used to be, I'm talking generally about diode-based sensors on these meters.
I'm quite aware of the internals, having studied them extensively and designed hardware for that interface.
-Dave
On 5/19/22 13:22, Lothar baier wrote:
Yes there were diode based models ( 81D , 84A) but the electronics
differed from the A/B/H series circuit boards , you can compare the
schematics to see that there are differences , its also not just about
"working" you can most certainly get something that will read power
but duplicating the original specs in terms of linearity and accuracy
is a different story
-----Original Message-----
From: [email protected]
<[email protected]> On Behalf Of Dave McGuire
via groups.io
Sent: Thursday, May 19, 2022 12:14 PM
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] A homemade diode power
sensor for HP meters
I have a diode front end for this power meter interface working on the bench. It's certainly possible. And let's not forget that there were already diode-based sensors in that product line.
-Dave
On 5/19/22 12:52, Lothar baier wrote:
Long story short you cant fix the 8481 or replace them with a diode ,
the 848x series was based on a thermocouple that was designed by HP ,
the parts are not available from HP , one guy sells waffle packs of
them on ebay for like $7000 or so but even if you buy them replacing
the part requires a lot of skills and a steady hand , as far as
diodes concerns the output voltage of diodes and the characteristics
are not compatible with the electronics in the 848x
*From:* [email protected]
<[email protected]> *On Behalf Of
*visitslovenija via groups.io
*Sent:* Thursday, May 19, 2022 5:20 AM
*To:* [email protected]
*Subject:* Re: [HP-Agilent-Keysight-equipment] A homemade diode power
sensor for HP meters
An interesting and long running thread.
Like many, I have a bit of a soft spot for the old HP435 meters and
would like to have one working on the bench.
Since broken detectors do show up now and again at a decent price,
has anyone successfully reworked one with busted thermocouples and
modified for a diode front end? I know it’s small and very fiddly,
but is that not easier than trying to build one from scratch?
--
Dave McGuire, AK4HZ
New Kensington, PA
--
Dave McGuire, AK4HZ
New Kensington, PA
--
Dave McGuire, AK4HZ
New Kensington, PA
|
It’s a different story obviously if you design a complete new sensor but then you still have the problem that you need access to a calibrated sensor to establish your calibration factors
toggle quoted message
Show quoted text
-----Original Message----- From: [email protected] < [email protected]> On Behalf Of Dave McGuire via groups.io Sent: Thursday, May 19, 2022 12:28 PM To: [email protected]Subject: Re: [HP-Agilent-Keysight-equipment] A homemade diode power sensor for HP meters I'm not talking about putting a diode where the thermocouple used to be, I'm talking generally about diode-based sensors on these meters. I'm quite aware of the internals, having studied them extensively and designed hardware for that interface. -Dave On 5/19/22 13:22, Lothar baier wrote: Yes there were diode based models ( 81D , 84A) but the electronics
differed from the A/B/H series circuit boards , you can compare the
schematics to see that there are differences , its also not just about
"working" you can most certainly get something that will read power
but duplicating the original specs in terms of linearity and accuracy
is a different story
-----Original Message-----
From: [email protected]
<[email protected]> On Behalf Of Dave McGuire
via groups.io
Sent: Thursday, May 19, 2022 12:14 PM
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] A homemade diode power
sensor for HP meters
I have a diode front end for this power meter interface working on the bench. It's certainly possible. And let's not forget that there were already diode-based sensors in that product line.
-Dave
On 5/19/22 12:52, Lothar baier wrote:
Long story short you cant fix the 8481 or replace them with a diode ,
the 848x series was based on a thermocouple that was designed by HP ,
the parts are not available from HP , one guy sells waffle packs of
them on ebay for like $7000 or so but even if you buy them replacing
the part requires a lot of skills and a steady hand , as far as
diodes concerns the output voltage of diodes and the characteristics
are not compatible with the electronics in the 848x
*From:* [email protected]
<[email protected]> *On Behalf Of
*visitslovenija via groups.io
*Sent:* Thursday, May 19, 2022 5:20 AM
*To:* [email protected]
*Subject:* Re: [HP-Agilent-Keysight-equipment] A homemade diode power
sensor for HP meters
An interesting and long running thread.
Like many, I have a bit of a soft spot for the old HP435 meters and
would like to have one working on the bench.
Since broken detectors do show up now and again at a decent price,
has anyone successfully reworked one with busted thermocouples and
modified for a diode front end? I know it’s small and very fiddly,
but is that not easier than trying to build one from scratch?
--
Dave McGuire, AK4HZ
New Kensington, PA
-- Dave McGuire, AK4HZ New Kensington, PA
|
I'm not talking about putting a diode where the thermocouple used to be, I'm talking generally about diode-based sensors on these meters. I'm quite aware of the internals, having studied them extensively and designed hardware for that interface.
-Dave
toggle quoted message
Show quoted text
On 5/19/22 13:22, Lothar baier wrote: Yes there were diode based models ( 81D , 84A) but the electronics differed from the A/B/H series circuit boards , you can compare the schematics to see that there are differences , its also not just about "working" you can most certainly get something that will read power but duplicating the original specs in terms of linearity and accuracy is a different story
-----Original Message-----
From: [email protected] <[email protected]> On Behalf Of Dave McGuire via groups.io
Sent: Thursday, May 19, 2022 12:14 PM
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] A homemade diode power sensor for HP meters
I have a diode front end for this power meter interface working on the bench. It's certainly possible. And let's not forget that there were already diode-based sensors in that product line.
-Dave
On 5/19/22 12:52, Lothar baier wrote:
Long story short you cant fix the 8481 or replace them with a diode ,
the 848x series was based on a thermocouple that was designed by HP ,
the parts are not available from HP , one guy sells waffle packs of
them on ebay for like $7000 or so but even if you buy them replacing
the part requires a lot of skills and a steady hand , as far as diodes
concerns the output voltage of diodes and the characteristics are not
compatible with the electronics in the 848x
*From:* [email protected]
<[email protected]> *On Behalf Of
*visitslovenija via groups.io
*Sent:* Thursday, May 19, 2022 5:20 AM
*To:* [email protected]
*Subject:* Re: [HP-Agilent-Keysight-equipment] A homemade diode power
sensor for HP meters
An interesting and long running thread.
Like many, I have a bit of a soft spot for the old HP435 meters and
would like to have one working on the bench.
Since broken detectors do show up now and again at a decent price, has
anyone successfully reworked one with busted thermocouples and
modified for a diode front end? I know it’s small and very fiddly, but
is that not easier than trying to build one from scratch?
--
Dave McGuire, AK4HZ
New Kensington, PA
--
Dave McGuire, AK4HZ
New Kensington, PA
|
Yes there were diode based models ( 81D , 84A) but the electronics differed from the A/B/H series circuit boards , you can compare the schematics to see that there are differences , its also not just about "working" you can most certainly get something that will read power but duplicating the original specs in terms of linearity and accuracy is a different story
toggle quoted message
Show quoted text
-----Original Message----- From: [email protected] < [email protected]> On Behalf Of Dave McGuire via groups.io Sent: Thursday, May 19, 2022 12:14 PM To: [email protected]Subject: Re: [HP-Agilent-Keysight-equipment] A homemade diode power sensor for HP meters I have a diode front end for this power meter interface working on the bench. It's certainly possible. And let's not forget that there were already diode-based sensors in that product line. -Dave On 5/19/22 12:52, Lothar baier wrote: Long story short you cant fix the 8481 or replace them with a diode ,
the 848x series was based on a thermocouple that was designed by HP ,
the parts are not available from HP , one guy sells waffle packs of
them on ebay for like $7000 or so but even if you buy them replacing
the part requires a lot of skills and a steady hand , as far as diodes
concerns the output voltage of diodes and the characteristics are not
compatible with the electronics in the 848x
*From:* [email protected]
<[email protected]> *On Behalf Of
*visitslovenija via groups.io
*Sent:* Thursday, May 19, 2022 5:20 AM
*To:* [email protected]
*Subject:* Re: [HP-Agilent-Keysight-equipment] A homemade diode power
sensor for HP meters
An interesting and long running thread.
Like many, I have a bit of a soft spot for the old HP435 meters and
would like to have one working on the bench.
Since broken detectors do show up now and again at a decent price, has
anyone successfully reworked one with busted thermocouples and
modified for a diode front end? I know it’s small and very fiddly, but
is that not easier than trying to build one from scratch?
-- Dave McGuire, AK4HZ New Kensington, PA
|
I have a diode front end for this power meter interface working on the bench. It's certainly possible. And let's not forget that there were already diode-based sensors in that product line.
-Dave
toggle quoted message
Show quoted text
On 5/19/22 12:52, Lothar baier wrote: Long story short you cant fix the 8481 or replace them with a diode , the 848x series was based on a thermocouple that was designed by HP , the parts are not available from HP , one guy sells waffle packs of them on ebay for like $7000 or so but even if you buy them replacing the part requires a lot of skills and a steady hand , as far as diodes concerns the output voltage of diodes and the characteristics are not compatible with the electronics in the 848x
*From:* [email protected] <[email protected]> *On Behalf Of *visitslovenija via groups.io
*Sent:* Thursday, May 19, 2022 5:20 AM
*To:* [email protected]
*Subject:* Re: [HP-Agilent-Keysight-equipment] A homemade diode power sensor for HP meters
An interesting and long running thread.
Like many, I have a bit of a soft spot for the old HP435 meters and would like to have one working on the bench.
Since broken detectors do show up now and again at a decent price, has anyone successfully reworked one with busted thermocouples and modified for a diode front end? I know it’s small and very fiddly, but is that not easier than trying to build one from scratch?
--
Dave McGuire, AK4HZ
New Kensington, PA
|
Long story short you cant fix the 8481 or replace them with a diode ,? the 848x series was based on a thermocouple that was designed by HP , the parts are not available from HP , one guy sells waffle packs of them on ebay for like $7000
or so but even if you buy them replacing the part requires a lot of skills and a steady hand , as far as diodes concerns the output voltage of diodes and the characteristics are not compatible with the electronics in the 848x
?
toggle quoted message
Show quoted text
From: [email protected] < [email protected]>
On Behalf Of visitslovenija via groups.io
Sent: Thursday, May 19, 2022 5:20 AM
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] A homemade diode power sensor for HP meters
?
An interesting and long running thread.
Like many, I have a bit of a soft spot for the old HP435 meters and would like to have one working on the bench.
Since broken detectors do show up now and again at a decent price, has anyone successfully reworked one with busted thermocouples and modified for a diode front end? I know it’s small and very fiddly, but is that not easier than trying to build one from scratch?
|
An interesting and long running thread.
Like many, I have a bit of a soft spot for the old HP435 meters and would like to have one working on the bench.
Since broken detectors do show up now and again at a decent price, has anyone successfully reworked one with busted thermocouples and modified for a diode front end? I know it’s small and very fiddly, but is that not easier than trying to build one from scratch?
|
Please trim everything, after the item number. The rest is your tracking information. Highlight and delete the question mark and everything that follows to give a result like this:
On Sat, Mar 12, 2022 at 6:36 PM Bob Stewart < bob@...> wrote: Lothar,
Is this what you're looking for by any chance?
On Wednesday, March 9, 2022, 1:03:13 AM CST, Lothar baier < lothar@...> wrote:
Oh I was not talking about myself, I have calibrated power sensors and meters this was just for people to consider?
?
A couple of thoughts on that…
?
It assumes you don’t have friends with a suitable sensor, or are unwilling to pay a commercial cal house to do it for you.
?
Also, if you have a decent SA and sig gen that you have reasonable faith in, those can be used, Yes, they aren’t quite as good as having another sensor, but for hobby purposes,
you could get within a half dB with care and decent gear. If you have both the SA and SG, you now have two reference instruments, and if they are in agreement then you can be fairly confident of your cal. Most SG’s provide output level indications, and SA
markers are more accurate than eyeballs.
?
It should be noted that power meters are the most accurate devices for power measurements, if traceable to NIST or equivalent. Typically less than .2 dB uncertainty. SG’s are
calibrated for output power with a power meter. The 8566 is +/- 1 dB or more over its frequency range (from memory). More modern SA’s, such as the PSA and PXA series, can almost match a power meter for uncertainty, however.
?
Building a sensor as a challenge is a good exercise even if you have a real one. You could keep the real one on the shelf as a reference and use the homebrewed unit for you daily
testing.
?
BTW, I am trying to revive an really old HP sensor from the 60’s that used 4 AGX 0.01 amp fuses as the sense and reference elements. So far they appear to be unobtanium. Even
the fuse makers don’t list them anymore and I haven’t yet found anything that looks to be equivalent. Just finding a 0.01 amp fuse in any style is a tough one.
?
?
the problem you run into when developing any substitute sensor ,? which is calibration , in order for a sensor to be of value you have to calibrate it which usually is done by comparing it to a calibrated sensor but obviously if you have
a calibrated sensor there was no need to design a sensor?
|
Hi Bob… ? Got ‘em. Thanks! ? Tom, N8ZM ?
toggle quoted message
Show quoted text
From: [email protected] <[email protected]> On Behalf Of Bob Stewart
Sent: Saturday, March 12, 2022 6:36 PM
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] A homemade diode power sensor for HP meters? Is this what you're looking for by any chance? | 
| Lot of 10 Bussmann AGX1/100 Glass Fuses 250V 1/4" x 1" Fast Acting 1/10...Find many great new & used options and get the best deals for Lot of 10 Bussmann AGX1/100 Glass Fuses 250V 1/4"... |
|
|
On Wednesday, March 9, 2022, 1:03:13 AM CST, Lothar baier <lothar@...> wrote: Oh I was not talking about myself, I have calibrated power sensors and meters this was just for people to consider?
On Mar 9, 2022, at 00:07, n8zmTWH via groups.io <n8zmTWH@...> wrote:
A couple of thoughts on that… ? It assumes you don’t have friends with a suitable sensor, or are unwilling to pay a commercial cal house to do it for you. ? Also, if you have a decent SA and sig gen that you have reasonable faith in, those can be used, Yes, they aren’t quite as good as having another sensor, but for hobby purposes, you could get within a half dB with care and decent gear. If you have both the SA and SG, you now have two reference instruments, and if they are in agreement then you can be fairly confident of your cal. Most SG’s provide output level indications, and SA markers are more accurate than eyeballs. ? It should be noted that power meters are the most accurate devices for power measurements, if traceable to NIST or equivalent. Typically less than .2 dB uncertainty. SG’s are calibrated for output power with a power meter. The 8566 is +/- 1 dB or more over its frequency range (from memory). More modern SA’s, such as the PSA and PXA series, can almost match a power meter for uncertainty, however. ? Building a sensor as a challenge is a good exercise even if you have a real one. You could keep the real one on the shelf as a reference and use the homebrewed unit for you daily testing. ? BTW, I am trying to revive an really old HP sensor from the 60’s that used 4 AGX 0.01 amp fuses as the sense and reference elements. So far they appear to be unobtanium. Even the fuse makers don’t list them anymore and I haven’t yet found anything that looks to be equivalent. Just finding a 0.01 amp fuse in any style is a tough one. ? ? the problem you run into when developing any substitute sensor ,? which is calibration , in order for a sensor to be of value you have to calibrate it which usually is done by comparing it to a calibrated sensor but obviously if you have a calibrated sensor there was no need to design a sensor?
|
Lothar,
Is this what you're looking for by any chance?
On Wednesday, March 9, 2022, 1:03:13 AM CST, Lothar baier <lothar@...> wrote:
Oh I was not talking about myself, I have calibrated power sensors and meters this was just for people to consider?
On Mar 9, 2022, at 00:07, n8zmTWH via groups.io <n8zmTWH@...> wrote:
?
A couple of thoughts on that…
?
It assumes you don’t have friends with a suitable sensor, or are unwilling to pay a commercial cal house to do it for you.
?
Also, if you have a decent SA and sig gen that you have reasonable faith in, those can be used, Yes, they aren’t quite as good as having another sensor, but for hobby purposes,
you could get within a half dB with care and decent gear. If you have both the SA and SG, you now have two reference instruments, and if they are in agreement then you can be fairly confident of your cal. Most SG’s provide output level indications, and SA
markers are more accurate than eyeballs.
?
It should be noted that power meters are the most accurate devices for power measurements, if traceable to NIST or equivalent. Typically less than .2 dB uncertainty. SG’s are
calibrated for output power with a power meter. The 8566 is +/- 1 dB or more over its frequency range (from memory). More modern SA’s, such as the PSA and PXA series, can almost match a power meter for uncertainty, however.
?
Building a sensor as a challenge is a good exercise even if you have a real one. You could keep the real one on the shelf as a reference and use the homebrewed unit for you daily
testing.
?
BTW, I am trying to revive an really old HP sensor from the 60’s that used 4 AGX 0.01 amp fuses as the sense and reference elements. So far they appear to be unobtanium. Even
the fuse makers don’t list them anymore and I haven’t yet found anything that looks to be equivalent. Just finding a 0.01 amp fuse in any style is a tough one.
?
?
the problem you run into when developing any substitute sensor ,? which is calibration , in order for a sensor to be of value you have to calibrate it which usually is done by comparing it to a calibrated sensor but obviously if you have
a calibrated sensor there was no need to design a sensor?
|
Understood ,
Generally if I were to pursue a sensor design I would design a USB sensor rather than pursuing a replacement for a existing sensor , there are small mixed signal Processors with USB such as CYPRESS PSOC that can be used , for the sensing
element I would use analog devices detector mmic which are cheap and readily available or for higher frequency a self balancing bridge design using thermistors or a thermal sensor design
?
Back when I was a teen getting started with microwave ham radio I build my first powermeter using a thermal bridge ,? the design used a 50ohm chip termination with a thermistor attached using thermal conductive glue , the thermistor was
put in a bridge circuit and used a DMM module for readout , the beauty of this design was that you could do a rough calibration using a DMM and DC power supply
?
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Show quoted text
From: [email protected] < [email protected]>
On Behalf Of n8zmTWH via groups.io
Sent: Wednesday, March 9, 2022 7:58 AM
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] A homemade diode power sensor for HP meters
?
I didn’t think you were. My ‘you’ was just a general case.
?
?
Oh I was not talking about myself, I have calibrated power sensors and meters this was just for people to consider?
On Mar 9, 2022, at 00:07, n8zmTWH via groups.io <n8zmTWH@...> wrote:
?
A couple of thoughts on that…
?
It assumes you don’t have friends with a suitable sensor, or are unwilling to pay a commercial cal house to do it for you.
?
Also, if you have a decent SA and sig gen that you have reasonable faith in, those can be used, Yes, they aren’t quite as good as having another sensor, but for hobby purposes,
you could get within a half dB with care and decent gear. If you have both the SA and SG, you now have two reference instruments, and if they are in agreement then you can be fairly confident of your cal. Most SG’s provide output level indications, and SA
markers are more accurate than eyeballs.
?
It should be noted that power meters are the most accurate devices for power measurements, if traceable to NIST or equivalent. Typically less than .2 dB uncertainty. SG’s are
calibrated for output power with a power meter. The 8566 is +/- 1 dB or more over its frequency range (from memory). More modern SA’s, such as the PSA and PXA series, can almost match a power meter for uncertainty, however.
?
Building a sensor as a challenge is a good exercise even if you have a real one. You could keep the real one on the shelf as a reference and use the homebrewed unit for you daily
testing.
?
BTW, I am trying to revive an really old HP sensor from the 60’s that used 4 AGX 0.01 amp fuses as the sense and reference elements. So far they appear to be unobtanium. Even
the fuse makers don’t list them anymore and I haven’t yet found anything that looks to be equivalent. Just finding a 0.01 amp fuse in any style is a tough one.
?
?
the problem you run into when developing any substitute sensor ,? which is calibration , in order for a sensor to be of value you have to calibrate it which usually is done by comparing it to a calibrated sensor but obviously if you have
a calibrated sensor there was no need to design a sensor?
|
I didn’t think you were. My ‘you’ was just a general case. ?
toggle quoted message
Show quoted text
From: [email protected] <[email protected]> On Behalf Of Lothar baier
Sent: Wednesday, March 09, 2022 2:03 AM
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] A homemade diode power sensor for HP meters? Oh I was not talking about myself, I have calibrated power sensors and meters this was just for people to consider?
On Mar 9, 2022, at 00:07, n8zmTWH via groups.io <n8zmTWH@...> wrote:
? A couple of thoughts on that… ? It assumes you don’t have friends with a suitable sensor, or are unwilling to pay a commercial cal house to do it for you. ? Also, if you have a decent SA and sig gen that you have reasonable faith in, those can be used, Yes, they aren’t quite as good as having another sensor, but for hobby purposes, you could get within a half dB with care and decent gear. If you have both the SA and SG, you now have two reference instruments, and if they are in agreement then you can be fairly confident of your cal. Most SG’s provide output level indications, and SA markers are more accurate than eyeballs. ? It should be noted that power meters are the most accurate devices for power measurements, if traceable to NIST or equivalent. Typically less than .2 dB uncertainty. SG’s are calibrated for output power with a power meter. The 8566 is +/- 1 dB or more over its frequency range (from memory). More modern SA’s, such as the PSA and PXA series, can almost match a power meter for uncertainty, however. ? Building a sensor as a challenge is a good exercise even if you have a real one. You could keep the real one on the shelf as a reference and use the homebrewed unit for you daily testing. ? BTW, I am trying to revive an really old HP sensor from the 60’s that used 4 AGX 0.01 amp fuses as the sense and reference elements. So far they appear to be unobtanium. Even the fuse makers don’t list them anymore and I haven’t yet found anything that looks to be equivalent. Just finding a 0.01 amp fuse in any style is a tough one. ? ? the problem you run into when developing any substitute sensor ,? which is calibration , in order for a sensor to be of value you have to calibrate it which usually is done by comparing it to a calibrated sensor but obviously if you have a calibrated sensor there was no need to design a sensor?
|
Paul Bicknell
Alexandre Souza
Dave McGuire
EI2KU
Michael A. Terrell