Re: 3457A and other meter low resistance tips?
Too funny. Well I've already got 5 meters of decent quality and I'm looking for more. It's also sad when I'm building up power supplies to get 1000v DC and 1000V AC at various frequencies to calibrate items like the DMM on my 2465BDM. I don't need 1000, buy hey I figured I may as well have overhead. Think those little gator clip wires from ebay are safe at 1000v, lol. I've already managed to kill 1000 piv rated diodes. I also partake in the crazy practice of joining my fixed 1000v supply with my 30 volt isolated lab supply to tweak to precise high voltages. Pretty stupid practice..but someones got to do it. The only saving grace is the current is at least limited to about 100ma..not that it would save me.
I have the dilemma that if I get a calibrated voltage reference and it disagrees with the 3457A then I'll naturally have to do one of two things. Send it off to Agilent to get the meter calibrated, or self calibrate so the 3457A agrees with my reference. The ladder has the advantage of not having a reference around that disagrees with the meter. If I send it off to Agilent I'll always question who was right, did the tech do a sloppy job..etc..etc. Ohh and the ranges also have to exactly agree with each other or it's back for calibration. Surprisingly they do now.
Insanity is doing the same thing over and over and expecting different results. Wonder how that plays in with calibration.
Jeff
toggle quoted message
Show quoted text
On 1/6/2013 5:02 PM, Don Black wrote:
he only sure way is to stick your finger in the light socket and guess.
Don Black.
On 07-Jan-13 10:08 AM, Dave Daniel wrote:
Unless all three voltmeters disagree. Then he needs n more until at
least two agree. Then again, what if more than one pair agree, but with
different values? Then I guess he needs a fifth meter which agrees with
one of the pairs which agree.
As you said, it's addicting and it makes my brain hurt.
Dave
On 1/6/2013 3:38 PM, J. L. Trantham wrote:
A man with one voltmeter knows what the voltage is. A man with two is
never
quite sure. Therefore he needs a third. :^)
Careful. This stuff is addicting.
Joe
-----Original Message-----
From: hp_agilent_equipment@...
<mailto:hp_agilent_equipment%40yahoogroups.com>
[mailto:hp_agilent_equipment@...
<mailto:hp_agilent_equipment%40yahoogroups.com>
] On Behalf Of Jeff
Machesky
Sent: Sunday, January 06, 2013 2:58 PM
To: hp_agilent_equipment@...
<mailto:hp_agilent_equipment%40yahoogroups.com>
Subject: Re: [hp_agilent_equipment] 3457A and other meter low
resistance
tips?
Thanks again for the info.
Hmm, to join such a group and come in as a total newb might be a
bit of
a humbling experience. Then again I have to admit I'm enjoying
attempting to get the precision. Even just working with the Hamon
dividers and monitoring temperatures and matching resistors to
precision
is kind of entertaining. It's however not very productive. I'm very
clear with my wife that my "hobby" is all about learning for me, it's
not about trying to improve the garage door opener. Once in a
while I'll
make something cool that gets used, but it's not my goal. I may join
them just to get an education on what I'm clueless about from their
point of view.
Thanks,
Jeff
On 1/6/2013 1:32 PM, Steve Byan wrote:
On Jan 6, 2013, at 3:07 PM, J. L. Trantham jltran@...
<mailto:jltran%40att.net>
wrote: It's called 'volt-nuts'. More fully, the volt-nuts mailing list -- volt-nuts@...
<mailto:volt-nuts%40febo.com>
To subscribe, go to
Best regards,
-Steve
-----Original Message-----
From: hp_agilent_equipment@...
<mailto:hp_agilent_equipment%40yahoogroups.com>
[mailto:hp_agilent_equipment@...
<mailto:hp_agilent_equipment%40yahoogroups.com>
] On Behalf Of Jeff
Machesky
Sent: Sunday, January 06, 2013 1:08 PM
To: hp_agilent_equipment@...
<mailto:hp_agilent_equipment%40yahoogroups.com>
Subject: Re: [hp_agilent_equipment] Re: 3457A and other meter low resistance
tips?
Do they have a club for people with a certain number
of digits on their multimeters. I feel they should as it's a
whole new
world. --
Steve Byan stevebyan@... <mailto:stevebyan%40me.com> >
Littleton, MA 01460
------------------------------------
Yahoo! Groups Links
|
Re: 3457A and other meter low resistance tips?
he only sure way is to stick your finger in the light socket and guess.
Don Black.
toggle quoted message
Show quoted text
On 07-Jan-13 10:08 AM, Dave Daniel wrote:
Unless all three voltmeters disagree. Then he needs n more until at
least two agree. Then again, what if more than one pair agree, but with
different values? Then I guess he needs a fifth meter which agrees with
one of the pairs which agree.
As you said, it's addicting and it makes my brain hurt.
Dave
On 1/6/2013 3:38 PM, J. L. Trantham wrote:
A man with one voltmeter knows what the voltage is. A man with two is
never
quite sure. Therefore he needs a third. :^)
Careful. This stuff is addicting.
Joe
-----Original Message-----
From: hp_agilent_equipment@...
<mailto:hp_agilent_equipment%40yahoogroups.com>
[mailto:hp_agilent_equipment@...
<mailto:hp_agilent_equipment%40yahoogroups.com>
] On Behalf Of Jeff
Machesky
Sent: Sunday, January 06, 2013 2:58 PM
To: hp_agilent_equipment@... <mailto:hp_agilent_equipment%40yahoogroups.com>
Subject: Re: [hp_agilent_equipment] 3457A and other meter low resistance
tips?
Thanks again for the info.
Hmm, to join such a group and come in as a total newb might be a bit of
a humbling experience. Then again I have to admit I'm enjoying
attempting to get the precision. Even just working with the Hamon
dividers and monitoring temperatures and matching resistors to precision
is kind of entertaining. It's however not very productive. I'm very
clear with my wife that my "hobby" is all about learning for me, it's
not about trying to improve the garage door opener. Once in a while I'll
make something cool that gets used, but it's not my goal. I may join
them just to get an education on what I'm clueless about from their
point of view.
Thanks,
Jeff
On 1/6/2013 1:32 PM, Steve Byan wrote:
On Jan 6, 2013, at 3:07 PM, J. L. Trantham jltran@...
<mailto:jltran%40att.net>
wrote: It's called 'volt-nuts'. More fully, the volt-nuts mailing list -- volt-nuts@...
<mailto:volt-nuts%40febo.com>
To subscribe, go to
Best regards,
-Steve
-----Original Message-----
From: hp_agilent_equipment@...
<mailto:hp_agilent_equipment%40yahoogroups.com>
[mailto:hp_agilent_equipment@...
<mailto:hp_agilent_equipment%40yahoogroups.com>
] On Behalf Of Jeff
Machesky
Sent: Sunday, January 06, 2013 1:08 PM
To: hp_agilent_equipment@...
<mailto:hp_agilent_equipment%40yahoogroups.com>
Subject: Re: [hp_agilent_equipment] Re: 3457A and other meter low resistance
tips?
Do they have a club for people with a certain number
of digits on their multimeters. I feel they should as it's a
whole new
world. --
Steve Byan stevebyan@... <mailto:stevebyan%40me.com> >
Littleton, MA 01460
------------------------------------
Yahoo! Groups Links
|
Re: 3457A and other meter low resistance tips?
But that's when you need standards, not voltmeters. :^)
Joe
toggle quoted message
Show quoted text
-----Original Message----- From: hp_agilent_equipment@... [mailto:hp_agilent_equipment@...] On Behalf Of Dave Daniel Sent: Sunday, January 06, 2013 5:08 PM To: hp_agilent_equipment@... Subject: Re: [hp_agilent_equipment] 3457A and other meter low resistance tips? Unless all three voltmeters disagree. Then he needs n more until at least two agree. Then again, what if more than one pair agree, but with different values? Then I guess he needs a fifth meter which agrees with one of the pairs which agree. As you said, it's addicting and it makes my brain hurt. Dave On 1/6/2013 3:38 PM, J. L. Trantham wrote:
A man with one voltmeter knows what the voltage is. A man with two is
never
quite sure. Therefore he needs a third. :^)
Careful. This stuff is addicting.
Joe
-----Original Message-----
From: hp_agilent_equipment@...
<mailto:hp_agilent_equipment%40yahoogroups.com>
[mailto:hp_agilent_equipment@...
<mailto:hp_agilent_equipment%40yahoogroups.com> ] On Behalf Of Jeff
Machesky
Sent: Sunday, January 06, 2013 2:58 PM
To: hp_agilent_equipment@... <mailto:hp_agilent_equipment%40yahoogroups.com>
Subject: Re: [hp_agilent_equipment] 3457A and other meter low resistance
tips?
Thanks again for the info.
Hmm, to join such a group and come in as a total newb might be a bit of
a humbling experience. Then again I have to admit I'm enjoying
attempting to get the precision. Even just working with the Hamon
dividers and monitoring temperatures and matching resistors to precision
is kind of entertaining. It's however not very productive. I'm very
clear with my wife that my "hobby" is all about learning for me, it's
not about trying to improve the garage door opener. Once in a while I'll
make something cool that gets used, but it's not my goal. I may join
them just to get an education on what I'm clueless about from their
point of view.
Thanks,
Jeff
On 1/6/2013 1:32 PM, Steve Byan wrote:
On Jan 6, 2013, at 3:07 PM, J. L. Trantham jltran@...
<mailto:jltran%40att.net>
wrote: It's called 'volt-nuts'. More fully, the volt-nuts mailing list -- volt-nuts@...
<mailto:volt-nuts%40febo.com>
To subscribe, go to
Best regards,
-Steve
-----Original Message-----
From: hp_agilent_equipment@...
<mailto:hp_agilent_equipment%40yahoogroups.com>
[mailto:hp_agilent_equipment@...
<mailto:hp_agilent_equipment%40yahoogroups.com>
] On Behalf Of Jeff
Machesky
Sent: Sunday, January 06, 2013 1:08 PM
To: hp_agilent_equipment@...
<mailto:hp_agilent_equipment%40yahoogroups.com>
Subject: Re: [hp_agilent_equipment] Re: 3457A and other meter low resistance
tips?
Do they have a club for people with a certain number
of digits on their multimeters. I feel they should as it's a whole new
world. --
Steve Byan stevebyan@... <mailto:stevebyan%40me.com> >
Littleton, MA 01460
------------------------------------
Yahoo! Groups Links
|
Re: 3457A and other meter low resistance tips?
Unless all three voltmeters disagree. Then he needs n more until at
least two agree. Then again, what if more than one pair agree, but with
different values? Then I guess he needs a fifth meter which agrees with
one of the pairs which agree.
As you said, it's addicting and it makes my brain hurt.
Dave
toggle quoted message
Show quoted text
On 1/6/2013 3:38 PM, J. L. Trantham wrote:
A man with one voltmeter knows what the voltage is. A man with two is
never
quite sure. Therefore he needs a third. :^)
Careful. This stuff is addicting.
Joe
-----Original Message-----
From: hp_agilent_equipment@...
<mailto:hp_agilent_equipment%40yahoogroups.com>
[mailto:hp_agilent_equipment@...
<mailto:hp_agilent_equipment%40yahoogroups.com>] On Behalf Of Jeff
Machesky
Sent: Sunday, January 06, 2013 2:58 PM
To: hp_agilent_equipment@...
<mailto:hp_agilent_equipment%40yahoogroups.com>
Subject: Re: [hp_agilent_equipment] 3457A and other meter low resistance
tips?
Thanks again for the info.
Hmm, to join such a group and come in as a total newb might be a bit of
a humbling experience. Then again I have to admit I'm enjoying
attempting to get the precision. Even just working with the Hamon
dividers and monitoring temperatures and matching resistors to precision
is kind of entertaining. It's however not very productive. I'm very
clear with my wife that my "hobby" is all about learning for me, it's
not about trying to improve the garage door opener. Once in a while I'll
make something cool that gets used, but it's not my goal. I may join
them just to get an education on what I'm clueless about from their
point of view.
Thanks,
Jeff
On 1/6/2013 1:32 PM, Steve Byan wrote:
On Jan 6, 2013, at 3:07 PM, J. L. Trantham jltran@...
<mailto:jltran%40att.net>
wrote: It's called 'volt-nuts'. More fully, the volt-nuts mailing list -- volt-nuts@...
<mailto:volt-nuts%40febo.com>
To subscribe, go to
Best regards,
-Steve
-----Original Message-----
From: hp_agilent_equipment@...
<mailto:hp_agilent_equipment%40yahoogroups.com>
[mailto:hp_agilent_equipment@...
<mailto:hp_agilent_equipment%40yahoogroups.com>
] On Behalf Of Jeff
Machesky
Sent: Sunday, January 06, 2013 1:08 PM
To: hp_agilent_equipment@... <mailto:hp_agilent_equipment%40yahoogroups.com>
Subject: Re: [hp_agilent_equipment] Re: 3457A and other meter low resistance
tips?
Do they have a club for people with a certain number
of digits on their multimeters. I feel they should as it's a whole new
world. --
Steve Byan stevebyan@... <mailto:stevebyan%40me.com> >
Littleton, MA 01460
------------------------------------
Yahoo! Groups Links
|
Re: 3457A and other meter low resistance tips?
A man with one voltmeter knows what the voltage is. A man with two is never
quite sure. Therefore he needs a third. :^)
Careful. This stuff is addicting.
Joe
toggle quoted message
Show quoted text
-----Original Message----- From: hp_agilent_equipment@... [mailto:hp_agilent_equipment@...] On Behalf Of Jeff Machesky Sent: Sunday, January 06, 2013 2:58 PM To: hp_agilent_equipment@... Subject: Re: [hp_agilent_equipment] 3457A and other meter low resistance tips? Thanks again for the info. Hmm, to join such a group and come in as a total newb might be a bit of a humbling experience. Then again I have to admit I'm enjoying attempting to get the precision. Even just working with the Hamon dividers and monitoring temperatures and matching resistors to precision is kind of entertaining. It's however not very productive. I'm very clear with my wife that my "hobby" is all about learning for me, it's not about trying to improve the garage door opener. Once in a while I'll make something cool that gets used, but it's not my goal. I may join them just to get an education on what I'm clueless about from their point of view. Thanks, Jeff On 1/6/2013 1:32 PM, Steve Byan wrote:
On Jan 6, 2013, at 3:07 PM, J. L. Trantham jltran@...
<mailto:jltran%40att.net>> wrote:
It's called 'volt-nuts'. More fully, the volt-nuts mailing list -- volt-nuts@...
<mailto:volt-nuts%40febo.com>
To subscribe, go to
Best regards,
-Steve
-----Original Message-----
From: hp_agilent_equipment@... <mailto:hp_agilent_equipment%40yahoogroups.com>
[mailto:hp_agilent_equipment@... <mailto:hp_agilent_equipment%40yahoogroups.com>] On Behalf Of Jeff
Machesky
Sent: Sunday, January 06, 2013 1:08 PM
To: hp_agilent_equipment@... <mailto:hp_agilent_equipment%40yahoogroups.com>
Subject: Re: [hp_agilent_equipment] Re: 3457A and other meter low resistance
tips?
Do they have a club for people with a certain number
of digits on their multimeters. I feel they should as it's a whole new
world. --
Steve Byan stevebyan@... <mailto:stevebyan%40me.com>>
Littleton, MA 01460
------------------------------------ Yahoo! Groups Links
|
Re: 3457A and other meter low resistance tips?
Thanks again for the info.
Hmm, to join such a group and come in as a total newb might be a bit of a humbling experience. Then again I have to admit I'm enjoying attempting to get the precision. Even just working with the Hamon dividers and monitoring temperatures and matching resistors to precision is kind of entertaining. It's however not very productive. I'm very clear with my wife that my "hobby" is all about learning for me, it's not about trying to improve the garage door opener. Once in a while I'll make something cool that gets used, but it's not my goal. I may join them just to get an education on what I'm clueless about from their point of view.
Thanks,
Jeff
toggle quoted message
Show quoted text
On 1/6/2013 1:32 PM, Steve Byan wrote:
On Jan 6, 2013, at 3:07 PM, J. L. Trantham jltran@... <mailto:jltran%40att.net>> wrote:
It's called 'volt-nuts'. More fully, the volt-nuts mailing list -- volt-nuts@... <mailto:volt-nuts%40febo.com>
To subscribe, go to
Best regards,
-Steve
-----Original Message-----
From: hp_agilent_equipment@... <mailto:hp_agilent_equipment%40yahoogroups.com>
[mailto:hp_agilent_equipment@... <mailto:hp_agilent_equipment%40yahoogroups.com>] On Behalf Of Jeff Machesky
Sent: Sunday, January 06, 2013 1:08 PM
To: hp_agilent_equipment@... <mailto:hp_agilent_equipment%40yahoogroups.com>
Subject: Re: [hp_agilent_equipment] Re: 3457A and other meter low resistance
tips?
Do they have a club for people with a certain number
of digits on their multimeters. I feel they should as it's a whole new
world. --
Steve Byan stevebyan@... <mailto:stevebyan%40me.com>>
Littleton, MA 01460
|
Re: 3457A and other meter low resistance tips?
On Jan 6, 2013, at 3:07 PM, J. L. Trantham <jltran@...> wrote: It's called 'volt-nuts'. More fully, the volt-nuts mailing list -- volt-nuts@... To subscribe, go to Best regards, -Steve -----Original Message-----
From: hp_agilent_equipment@...
[mailto:hp_agilent_equipment@...] On Behalf Of Jeff Machesky
Sent: Sunday, January 06, 2013 1:08 PM
To: hp_agilent_equipment@...
Subject: Re: [hp_agilent_equipment] Re: 3457A and other meter low resistance
tips?
Do they have a club for people with a certain number
of digits on their multimeters. I feel they should as it's a whole new
world. -- Steve Byan <stevebyan@...> Littleton, MA 01460
|
Re: 3457A and other meter low resistance tips?
It's called 'volt-nuts'.
Joe
toggle quoted message
Show quoted text
-----Original Message-----
From: hp_agilent_equipment@...
[mailto:hp_agilent_equipment@...] On Behalf Of Jeff Machesky
Sent: Sunday, January 06, 2013 1:08 PM
To: hp_agilent_equipment@...
Subject: Re: [hp_agilent_equipment] Re: 3457A and other meter low resistance
tips?
Do they have a club for people with a certain number
of digits on their multimeters. I feel they should as it's a whole new
world.
|
Re: HP 11660A Shunt for HP 8556A
This does make a slight difference in the readings in case any one else is interested in the results.
Thanks again to all that help resolve this issue.
Steve, KJ5RV
toggle quoted message
Show quoted text
--- In hp_agilent_equipment@..., Steve Vineyard wrote:
That is interesting and it would now make sense why they did not use the
50 ohm pass thru, but created a unit specific shunt.
I will have to change mine to that value and see if it makes any
difference to my test results.
Thank you Martin for your effort and thank you Steve (AZUR Electronics)
for your courtesy of unveiling the secret.
Steve, KJ5RV
martin_u_fischer wrote:
Hello Steve,
today I got a PM from Steve [AZUR Electronics];
he shows a "HP 11660A Tracking Generator Shunt (home made version)" on
his website
and by courtesy he unveiled the secret around the component values of
the 11660A.
He figures out that the 11660A contains a single shunt resistor of
54.5 Ohms.
Albeit this will constitute a gross mismatch for the 600 ohms output
resistance of the TG,
it will transform the effective source resistance into exactly 50 ohms.
³Õ´Ç¾±±ô¨¤!
Regards
Martin
|
Re: 3457A and other meter low resistance tips?
Thanks for the link. I signed up and got the full PDF version, lots of great info within. Do they have a club for people with a certain number of digits on their multimeters. I feel they should as it's a whole new world. I made the mistake of connecting a 5k thermistor to the meter and placing it in temperature mode. 70.42135F sounds great until you realize anything past that tenth place moves around a whole lot. If you so much as breath in the direction of the thermistor it goes sailing off. Crazy stuff.
Based on other tests I've done such as resistance measurements with volts and amps and a calculator it appears the meter is as close as I could ever want it to be. My 0.001 ohm resistor should have been 0.00101 ohms based on other higher current tests and the 3457A reads ~0.00102 after subtracting the Kelvin tip offsets. I work a lot with power supply designs, so I often need to measure current sense shunts. I'll stick with my tried and true 1 amp method to get the precise readings I'm looking for. I can get down in the nano ohms with that technique and this new meter. The self heating is actually desirable in this case for real world applications. Then again it's all overkill and easier to compensate for in software.
I'm going to build up a precision current source for use with the Kelvin probes and the meter for those crazy low resistances. I've found that successive approximation can get you very accurate in a home based lab. Enough samples and you can narrow down the accuracy over time.
Thanks,
Jeff
toggle quoted message
Show quoted text
On 1/6/2013 8:22 AM, marvgozum wrote:
Congratulations! Peruse the tips here, the document is free:
There are various phenomena that show their heads on either extreme of resistance you're measuring.
|
Re: Frequency / Function Generator for the Hamshack
HP 8165a. Not sure it'd work with the SA, though. I drive mine with GPIB. Usually can be had cheaply. Norm On Sun, Jan 6, 2013 at 12:36 PM, W8KZW <w8kzw@...> wrote: **
I'm keeping watch for an HP-8662A or HP-3335A as an all-around frequency
source for my bench.
Most of what I do ranges from DC to 148 MHz, and about the most complex
task
I think I'd do is sweep an IF filter or align a rig. I'd like to use it as
an outboard tracking generator for my HP-8591E also.
I like being able to spin a knob and change frequency ... to rock back and
forth to find an IF center frequency, for example.
Give the application, am I better off with one of the above units vs. the
other? Something else? Price IS a considertion.
Thanks, and forgive me if this has been "asked and answered".
Jeff
W8KZW
[Non-text portions of this message have been removed]
|
Frequency / Function Generator for the Hamshack
I'm keeping watch for an HP-8662A or HP-3335A as an all-around frequency
source for my bench.
Most of what I do ranges from DC to 148 MHz, and about the most complex task
I think I'd do is sweep an IF filter or align a rig. I'd like to use it as
an outboard tracking generator for my HP-8591E also.
I like being able to spin a knob and change frequency ... to rock back and
forth to find an IF center frequency, for example.
Give the application, am I better off with one of the above units vs. the
other? Something else? Price IS a considertion.
Thanks, and forgive me if this has been "asked and answered".
Jeff
W8KZW
|
Hi Joe, ... I have been reluctant to open this particular instrument due to
concerns about my 'skills' at this level. However, I'm gaining
confidence and getting closer to the required 'courage' to open it
up. Don't worry about that!. If I have been able to (almost, except CRT) fix mine, everyone could do it :-)! It is a matter of apllying logic and use the available tools. I don't have a TAM and you can do also without it. In fact, I think you learn more if you don't have it :-). And, for me at least, it is a matter of learning new things. Then, if the result (i.e. the fixed equipment) is useful for my work, still better! I plan to develop a WEB page on my site for the 8562A repair. I have been re-checking my notes and pictures and I think it may help some others with similar troubles. I will keep you posted when I upload it. Regards, JOSE -- 73 EB5AGV - JOSE V. GAVILA - IM99sm La Canyada - Valencia(SPAIN) AGVradio Personal WEB
|
Re: HP 11660A Shunt for HP 8556A
That is interesting and it would now make sense why they did not use the 50 ohm pass thru, but created a unit specific shunt.
I will have to change mine to that value and see if it makes any difference to my test results.
Thank you Martin for your effort and thank you Steve (AZUR Electronics) for your courtesy of unveiling the secret.
Steve, KJ5RV
martin_u_fischer wrote:
toggle quoted message
Show quoted text
Hello Steve,
today I got a PM from Steve [AZUR Electronics];
he shows a "HP 11660A Tracking Generator Shunt (home made version)" on his website
and by courtesy he unveiled the secret around the component values of the 11660A.
He figures out that the 11660A contains a single shunt resistor of 54.5 Ohms.
Albeit this will constitute a gross mismatch for the 600 ohms output resistance of the TG,
it will transform the effective source resistance into exactly 50 ohms.
Voil???!
Regards
Martin
|
Re: 3457A and other meter low resistance tips?
Congratulations! Peruse the tips here, the document is free:
There are various phenomena that show their heads on either extreme of resistance you're measuring.
|
|
|
Re: Choosing a quiet replacement fan
I'm not sure what point silentpcfan were trying to make: the advice is so vague that you can't make any practical use of it. For any "box" of electronics which incorpoates a fan, there is the simple electrical power-in = heat power out balance, and if you make the pessimistic assumption that no heat escapes from the case (by convection), you can calculate the air-flow required for a given air temperature rise (T airin v Tairout) knowing the thermal capacity of air [=circa 33 joules/cu ft/deg C]. They may be tangentially hinting at the characteristics of finned heatsinks when force-air cooled. As the air velocity rises, there is a gradual increase in the temperature drop along the fin (i.e from root to tip at rt angles to the air-flow). I recall this parameter being quantified as "fin efficiency": if the tip is cooled to aroud that of the airstream, it becomes relatively ineffective and the fin should either be thicker or shorter (or both). John --- In hp_agilent_equipment@..., Dave C wrote:
I read occasionally that owners of T&M equipment tire of the noise a
cooling fan makes and asks for help to determine if/how a quieter replacement can be found. There are many factors at play in such a decision, none as simple as "it's quieter".
This web site addresses choosing a fan for PC enclosures, and many of
the criteria are the same (heat being the most important one for us):
A quote:
"Over the years, we have observed one clear phenomenon about fans and
cooling: The relationship between airflow and temperature invariably becomes exponential at some point. Increase airflow from nothing to something, and the drop in temperature can be dramatic. Keep increasing airflow, and the cooling improvement becomes less and less significant, until at some point, the temperature hardly drops at all. The trick, for the PC builder who seeks both good cooling and low noise, is to find the point where any decrease in airflow (or fan speed) effects a significant increase in temperature, while only a very large airflow increase effects a significant temperature drop. In other words, once you have enough airflow, additional airflow has very little cooling effect, so all you're doing is increasing noise. "Enough airflow" is not a constant, of course, it varies for each system of components."
FYI,
Dave
|
Harke,
Do you have Firmware Note, Agilent Technologies 8560 Series, 85620A, and
85629B, Part Number 08560-90163?
It outlines all the 'requirements' for using the TAM with the various
firmware choices for the SA. It is a .PDF file that I got off the Agilent
website some time in the past. I recall it was very difficult to find. I
just went to the Agilent website and could not find it. If you don't have
it, I can send it to you via PM.
I think you will need a 85629B. but I am very new to this area.
Another resource is the Agilent Forum's. I posted a question about my issue
about a year ago and got a very knowledgeable response in a couple of weeks.
Although the 8562A is no longer supported, there are some folks there that
appear to be able to help a lot. I have been reluctant to open this
particular instrument due to concerns about my 'skills' at this level.
However, I'm gaining confidence and getting closer to the required 'courage'
to open it up.
Good luck.
Joe
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-----Original Message----- From: hp_agilent_equipment@... [mailto:hp_agilent_equipment@...] On Behalf Of Harke Smits Sent: Sunday, January 06, 2013 5:50 AM To: hp_agilent_equipment@... Subject: Re: [hp_agilent_equipment] HP-8562A repair Dear all, I also have a HP8562A (sn: 3040A5503, quite low milage btw) to work on. The sa fires up and runs the startup procedure without any errors. However the amplitude calibration at the higher end seems to be low by 10-15 dB. I do not suspect the mixer, right now. The cal signal at 300 MHz is fine. I got myself a TAM (HP 85629A, rev: 870218A). Page 3-6 of the sa Installation manual gives a table of compatibilty between the two. Unfortunately my numbers are not stated. Can someone with a newer manual give me the correct table, please? In addition: when I start running the Automatic Fault Isolation routine it aborts at test 3: IF log check fauilure. "Cal Oscillator tune line error" and some more info. But before digging further I'd like to know compatibility between TAM and SA. It could be the reason. Can the TAM be upgraded if necessary? Thanks a lot so far, I expect more to come. Kind regards, Harke --- On Thu, 1/3/13, Jose V. Gavila eb5agv@... <mailto:eb5agv%40amsat.org> > wrote: From: Jose V. Gavila eb5agv@... <mailto:eb5agv%40amsat.org> > Subject: [hp_agilent_equipment] HP-8562A repair To: hp_agilent_equipment@... <mailto:hp_agilent_equipment%40yahoogroups.com> Date: Thursday, January 3, 2013, 4:04 PM Hi Joe, I have started this new thread, but with the previous comments attached: Perhaps we should start a 'new' thread but mine, on power on, gives ERR 317 and 334. When I hit REALIGN LO & IF, I get ERR 301 and 317. Haven't started down that path but sounds like you had a similar issue, perhaps. Maybe... now I feel the urge to fix my unit :-)!!! Well, let me look at the notes I took and also to the pictures (big hint: take lots of pictures of all you do, they are very valuable later!) and I will get back with the faults I found on my unit. Best regards and thanks for igniting the fire again :-) JOSE -----Original Message----- Hi Joe, I have an 8562A project as well that I haven't had time for yet. Hopefully in 2013. Interesting ! Mine was bought at eBay UK cheap, as it was non working. When I got it and fixed the power supply, I was able to barely see (without light in the room!) that it had more than 43.000 hours on it. It generated several errors: ERR 304 ROL UNLK, ERR 324 FREQ ACC and ERR 301 YTO UNLK. I was able to fix all of them (I will detail that on another post) and it seems to work, but then there is the extremely dimm display. And that is the condition it is now. Regards, JOSE -- 73 EB5AGV - JOSE V. GAVILA - IM99sm La Canyada - Valencia(SPAIN) AGVradio Personal WEB
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Re: HP 11660A Shunt for HP 8556A
Hello Steve,
today I got a PM from Steve [AZUR Electronics];
he shows a "HP 11660A Tracking Generator Shunt (home made version)" on his website
and by courtesy he unveiled the secret around the component values of the 11660A.
He figures out that the 11660A contains a single shunt resistor of 54.5 Ohms.
Albeit this will constitute a gross mismatch for the 600 ohms output resistance of the TG,
it will transform the effective source resistance into exactly 50 ohms.
³Õ´Ç¾±±ô¨¤!
Regards
Martin
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On 1/6/2013 6:49 AM, Harke Smits wrote:
Dear all,
I also have a HP8562A (sn: 3040A5503, quite low milage btw) to work
on. The sa fires up and runs the startup procedure without any errors.
However the amplitude calibration at the higher end seems to be low by
10-15 dB. I do not suspect the mixer, right now. The cal signal at 300
MHz is fine. I got myself a TAM (HP 85629A, rev: 870218A). Page 3-6 of
the sa Installation manual gives a table of compatibilty between the
two. Unfortunately my numbers are not stated. Can someone with a newer
manual give me the correct table, please? In addition: when I start
running the Automatic Fault Isolation routine it aborts at test 3: IF
log check fauilure. "Cal Oscillator tune line error" and some more
info. But before digging further I'd like to know compatibility
between TAM and SA. It could be the reason. Can the TAM be upgraded if
necessary?
They have it for the B not the A but very expensive. I have rev C but will not take it apart and unsolder the ROM. Parts List for Product85629B Refine by Part Category - <> Return to Find-A-Part <> Cables(2) <>Components/Memory(33) <>Connectors/Adapters(2) <>Hardware(10) <>Kits(1)Manuals/Software(2) <>Miscellaneous(7) <>Modules(1) <>PC Boards(5) <> View <> Download to Excel <> Print <> DetachDetach <> Total Records 1 Image Part Number Part Description Status Reference Price no image available 85629-60009 <> Firmware Upgrade Orderable US$1241.00Quantity on Hand <>Add to cart <>
Thanks a lot so far, I expect more to come.
Kind regards,
Harke
--- On Thu, 1/3/13, Jose V. Gavila eb5agv@...
<mailto:eb5agv%40amsat.org>> wrote:
From: Jose V. Gavila eb5agv@... <mailto:eb5agv%40amsat.org>>
Subject: [hp_agilent_equipment] HP-8562A repair
To: hp_agilent_equipment@...
<mailto:hp_agilent_equipment%40yahoogroups.com>
Date: Thursday, January 3, 2013, 4:04 PM
Hi Joe,
I have started this new thread, but with the previous comments attached:
Perhaps we should start a 'new' thread but mine, on power on, gives ERR 317 and 334. When I hit REALIGN LO & IF, I get ERR 301 and 317. Haven't started down that path but sounds like you had a similar issue, perhaps. Maybe... now I feel the urge to fix my unit :-)!!!
Well, let me look at the notes I took and also to the pictures (big
hint: take lots of pictures of all you do, they are very valuable
later!) and I will get back with the faults I found on my unit.
Best regards and thanks for igniting the fire again :-)
JOSE
-----Original Message-----
Hi Joe,
I have an 8562A project as well that I haven't had time for yet. Hopefully in 2013. Interesting !
Mine was bought at eBay UK cheap, as it was non working. When I got it
and fixed the power supply, I was able to barely see (without light in
the room!) that it had more than 43.000 hours on it. It generated
several errors: ERR 304 ROL UNLK, ERR 324 FREQ ACC and ERR 301 YTO UNLK.
I was able to fix all of them (I will detail that on another post) and
it seems to work, but then there is the extremely dimm display. And that
is the condition it is now.
Regards,
JOSE
--
73 EB5AGV - JOSE V. GAVILA - IM99sm La Canyada - Valencia(SPAIN)
AGVradio
Personal WEB
[Non-text portions of this message have been removed]
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John Sykes