Re: Spring loaded Old Style Front Panel Buttons
Now that I see how they're made, I can understand why lubrication should not be necessary. I plan to disassemble mine and give it the treatment. That nasty clicking is unnerving.
Thanks,
Barry - N4BUQ
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----- Original Message ----- From: "fenland787@... [hp_agilent_equipment]" <hp_agilent_equipment@...>
To: "hp agilent equipment" <hp_agilent_equipment@...>
Sent: Wednesday, February 24, 2016 11:45:14 AM
Subject: Re: [hp_agilent_equipment] Spring loaded Old Style Front Panel Buttons
I wondered about that too but advice on this forum was "no, clean and leave
dry" and that's what I did. So far it seems fine, I guess I'll need to check
again after another 30 years of use or so.....?
|
Re: Spring loaded Old Style Front Panel Buttons
I wondered about that too but advice on this forum was "no, clean and leave dry" and that's what I did. So far it seems fine, I guess I'll need to check again after another 30 years of use or so.....?
|
Good thoughts, David and Ignacio.
It should?be fairly straight forward to cut out and rebuild the traces on the A9 board to accommodate the new Minicircuits amplifier. Especially since only the amplifier chip needs to be added. Everything else is already there (probably need to change values to control the low frequency rolloff to around 150 MHz) and amplifier biasing for optimum gain. The maximum frequency would be 1.3 GHz due to the limitations of the decade counter just after the amplifier stage, so extending the frequency range is not likely.
There is also the consideration of the peak detector components just after the amplifier, but since this is isolated from the amplifier by a blocking capacitor, bias voltage in the peak detector should not affect the amplifier. It may take some tweaking to get the peak detector to work properly?with any variations in amplitude due to different gain figures from the new amplifier chip. I thinks some critical measurements of a working A9 board are in order.
|
As Ignacio points out, these parts are designed to operate in a
transmission line environment so a daughter board will be difficult to
implement.
The pins on the package from Minicircuits are probably too thick to be
bent and inserted into the existing collet socket pins because they
were intended to be soldered into a microstrip environment. I would
either solder them to the exposed top of the collets or remove the
collets and socket that HP used and solder the MAR device into place.
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On 23 Feb 2016 19:47:04 -0800, you wrote: ...
So at this point, the best route is probably to acquire a modern MMIC and use a daughter board to connect to the original board holes. It should be fairly easy with the MIcrocircuit's amplifier. Except for the physical connections, the design, supporting parts, and supply voltage are very close to the original.
Thanks again for all of the great responses! I'll post again when I have a working solution.
Best regards,
Joe, KN5U
|
Re: HP 8901A assistance needed.
Hi Thomas,
I have a HP 8902A and the command structure is very similar to the 8901A.
If this helps, here are the responses: The response to 21.0SPCL was 1111.000 The response to 61.0 SPCL was 0.0 The Response to 61.2 SPCL was 0.0
Best of luck!
Joe, KN5U
|
Re: Spring loaded Old Style Front Panel Buttons
The video on the page really helps!
Thanks,
Barry - N4BUQ
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----- Original Message ----- From: "pianovt@... [hp_agilent_equipment]" <hp_agilent_equipment@...>
To: "hp agilent equipment" <hp_agilent_equipment@...>
Sent: Wednesday, February 24, 2016 10:40:39 AM
Subject: Re: [hp_agilent_equipment] Spring loaded Old Style Front Panel Buttons
There is this from Roberto Barrios:
Also, I have written about this a few times on this forum. Search for my
posts.
Vladan
|
Re: Spring loaded Old Style Front Panel Buttons
There is this from Roberto Barrios:
Also, I have written about this a few times on this forum. Search for my posts.
Vladan
|
Re: Spring loaded Old Style Front Panel Buttons
Hi Adrian,
Okay - I may give that a try. I wonder if there was any grease originally in the mechanisms that has dried up and possibly should be replaced after cleaning?
Thanks,
Barry - N4BUQ
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----- Original Message ----- From: "Adrian Nicol fenland787@... [hp_agilent_equipment]" <hp_agilent_equipment@...>
To: "hp agilent equipment" <hp_agilent_equipment@...>
Sent: Wednesday, February 24, 2016 9:52:43 AM
Subject: Re: [hp_agilent_equipment] Spring loaded Old Style Front Panel Buttons
Hi Barry, short answer is yes, that is the reason and the fix is dead easy
and really effective, if my experience is anything to go by.
There is a parallel thread running where I and others have posted their
solutions - I just did a 3456A and 3455A as well as an 8566A and other gear
- but this is what I did:
Remove the switch PCB from the panel, flood spray the switches with IPA
(Isoprop alcohol) and operate each a few times, within just three or four
operations they free up like magic going from clunky
'feels-like-something-is-about-to-bust' to almost silky smooth! Then blow it
off with an air-gun and give it another dose for luck.
Works for me anyway!
On Wednesday, February 24, 2016 3:09 PM, "Chuck Harris cfharris@...
[hp_agilent_equipment]" <hp_agilent_equipment@...> wrote:
? Hi Martin,
The easiest thing is to find the spring that fell out. It
is sticky with grease, so it will often stick to something.
If it is in the instrument, you must find and remove it, as
it can cause short circuits.
If you can't find the spring, you will have to get one from
other instrument's keyboard. There are plenty of scrap hp
front panels with keyboards on ebay.
You can make a new spring, but it is very critical in its size,
finish, and temper. I have heard that some have had success
making springs out of steel "feeler gages" Tin snips will
cut them, but make sure that you snips don't have a serrated
blade. I seem to recall that they are 0.0015" thick. The
size is somewhere in the archives. Shim stock will not work!
It is too soft.
On occasion, while I was waiting to find the correct spring, I have
made a coil spring and placed it so that it pressed on the keytop,
and the key mechanism. It doesn't click, but otherwise suffices.
-Chuck Harris
Martin.Hepperle@... [hp_agilent_equipment] wrote:
I got a 9915 computer which uses the same leaf-spring loaded front panel
buttons
as many older HP instruments (/e.g. the 3456A DVMs).
Three of the springs have fallen out and I need to fix that.
Are there any sources for these parts or ways to obtain similar springs or
even
complete switches?
Any well known repair procedures that I should know?
I could possibly obtain some flat sheet spring steel and grind a spring to
shape
using Dremel tools etc. but that sounds like a difficult and very time
consuming
task. Also the length of these springs must probably quite accurate.
Otherwise I would have to try something with external helical springs, glue
and
other ugly constructions...
Thanks, Martin
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Re: Part Needed Ge Diode HP 1910-0016
David:
Send me your address privately and I'll mail you one for free...
Dan in Chandler, AZ
|
Re: Old 8591E firmware to L okay?
Dear Michael, I've found this old post, the only one talking about this argument, and following your suggestions I tryed to upgrade firmware on my 8591E to the H version. I have the new CLIP version (from Artek) that doesn't mention the old A16 board, so the only reference was your jumpers map. The only difference with the one i found in my SA (four eprom) was about two jumpers W102 and W105. I desoldered both and moved on the right so they are now? W112 and W115 (installed) while W102 and W105 are now "not installed". I wrote a couple of 27C020-150 AMD and pushed on U7 and U24. Power on and.... Nothing ! Where "nothing" mean no boot, only fan noises... I haven't the jumper map sheet and relied on your description, please, do you think I followed your suggestion the right way ? Thanks a lot for your invaluable help, Pino, IK2HEW ---In hp_agilent_equipment@..., <mriisj@...> wrote : Hi Craig ? I went through 2 different component level repair manual to find the right solution it is not mentioned in the newer ones I have. ? You need a little bit of solder work to upgrade to rev H, this is just jumpers there need to be set for the larger roms, I recommend that you buy or find a component level service manual, it have to be the older one 5962-5038, look at A16-08590-60342 on the first schematic of the board in the top right corner is a drawing of the jumpers, I would think that you can get the manual from Artek Manuals. ? The jumpers is beneath U6 and U7 and should be as follows for 2M proms Installed jumpers: W103, W104, W106, W107, W112 & W115 Not installed jumpers: W102, W105, W113, W114, W116, W117 ? Then you should load U7 & U24 only with option H in 2M proms and that should work for you, proms AMD AM27C020-150 or eq. ? This means that you will have to take the processor board out of the analyzer, totally it is about 1 hour to 1? hour of work. ? I have no idea where to find the files for the different revisions other than on this forum. ? For programmer I use a TOP 3100 found on eBay, it works well on windows 7 but cheaper ones will properly work fine as well. ? Michael, OZ2ELA ? ? ?
|
Re: Spring loaded Old Style Front Panel Buttons
Hi Barry, short answer is yes, that is the reason and the fix is dead easy and really effective, if my experience is anything to go by.
There is a parallel thread running where I and others have posted their solutions - I just did a 3456A and 3455A as well as an 8566A and other gear - but this is what I did:
Remove the switch PCB from the panel, flood spray the switches with IPA (Isoprop alcohol) and
operate each a few times, within just three or four operations they
free up like magic going from clunky
'feels-like-something-is-about-to-bust' to almost silky smooth! Then
blow it off with an air-gun and give it another dose for luck.
Works for me anyway!
On Wednesday, February 24, 2016 3:09 PM, "Chuck Harris cfharris@... [hp_agilent_equipment]" wrote:
?
Hi Martin,
The easiest thing is to find the spring that fell out. It
is sticky with grease, so it will often stick to something.
If it is in the instrument, you must find and remove it, as
it can cause short circuits.
If you can't find the spring, you will have to get one from
other instrument's keyboard. There are plenty of scrap hp
front panels with keyboards on ebay.
You can make a new spring, but it is very critical in its size,
finish, and temper. I have heard that some have had success
making springs out of steel "feeler gages" Tin snips will
cut them, but make sure that you snips don't have a serrated
blade. I seem to recall that they are 0.0015" thick. The
size is somewhere in the archives. Shim stock will not work!
It is too soft.
On occasion, while I was waiting to find the correct spring, I have
made a coil spring and placed it so that it pressed on the keytop,
and the key mechanism. It doesn't click, but otherwise suffices.
-Chuck Harris
Martin.Hepperle@... [hp_agilent_equipment] wrote:
> I got a 9915 computer which uses the same leaf-spring loaded front panel buttons
> as many older HP instruments (/e.g. the 3456A DVMs).
>
>
> Three of the springs have fallen out and I need to fix that.
>
>
> Are there any sources for these parts or ways to obtain similar springs or even
> complete switches?
>
>
> Any well known repair procedures that I should know?
>
>
> I could possibly obtain some flat sheet spring steel and grind a spring to shape
> using Dremel tools etc. but that sounds like a difficult and very time consuming
> task. Also the length of these springs must probably quite accurate.
>
>
> Otherwise I would have to try something with external helical springs, glue and
> other ugly constructions...
>
>
> Thanks, Martin
>
>
>
>
|
Re: HP 8640B will not lock
I would suggest that you start with the basics. Check the power supply voltages, noise and ripple. Very likely due to the age, the filter capacitors are weak.? Any noise will disrupt the logic in the counter circuits.
|
Re: Spring loaded Old Style Front Panel Buttons
Is that spring the reason why the buttons on my 3456A have such a sharp tactile action when I press them? Is that abnormal and can that be alleviated? The seem overly noisy and hard to press.
Thanks,
Barry - N4BUQ
toggle quoted message
Show quoted text
----- Original Message ----- From: "Martin.Hepperle@... [hp_agilent_equipment]" <hp_agilent_equipment@...>
To: "hp agilent equipment" <hp_agilent_equipment@...>
Sent: Wednesday, February 24, 2016 8:49:11 AM
Subject: [hp_agilent_equipment] Spring loaded Old Style Front Panel Buttons
I got a 9915 computer which uses the same leaf-spring loaded front panel
buttons as many older HP instruments (/e.g. the 3456A DVMs).
Three of the springs have fallen out and I need to fix that.
Are there any sources for these parts or ways to obtain similar springs or
even complete switches?
Any well known repair procedures that I should know?
I could possibly obtain some flat sheet spring steel and grind a spring to
shape using Dremel tools etc. but that sounds like a difficult and very
time consuming task. Also the length of these springs must probably quite
accurate.
Otherwise I would have to try something with external helical springs, glue
and other ugly constructions...
Thanks,
Martin
|
Re: Spring loaded Old Style Front Panel Buttons
Hi Martin,
The easiest thing is to find the spring that fell out. It
is sticky with grease, so it will often stick to something.
If it is in the instrument, you must find and remove it, as
it can cause short circuits.
If you can't find the spring, you will have to get one from
other instrument's keyboard. There are plenty of scrap hp
front panels with keyboards on ebay.
You can make a new spring, but it is very critical in its size,
finish, and temper. I have heard that some have had success
making springs out of steel "feeler gages" Tin snips will
cut them, but make sure that you snips don't have a serrated
blade. I seem to recall that they are 0.0015" thick. The
size is somewhere in the archives. Shim stock will not work!
It is too soft.
On occasion, while I was waiting to find the correct spring, I have
made a coil spring and placed it so that it pressed on the keytop,
and the key mechanism. It doesn't click, but otherwise suffices.
-Chuck Harris
Martin.Hepperle@... [hp_agilent_equipment] wrote:
toggle quoted message
Show quoted text
I got a 9915 computer which uses the same leaf-spring loaded front panel buttons
as many older HP instruments (/e.g. the 3456A DVMs).
Three of the springs have fallen out and I need to fix that.
Are there any sources for these parts or ways to obtain similar springs or even
complete switches?
Any well known repair procedures that I should know?
I could possibly obtain some flat sheet spring steel and grind a spring to shape
using Dremel tools etc. but that sounds like a difficult and very time consuming
task. Also the length of these springs must probably quite accurate.
Otherwise I would have to try something with external helical springs, glue and
other ugly constructions...
Thanks, Martin
|
Spring loaded Old Style Front Panel Buttons
I?got a 9915 computer which uses the same leaf-spring loaded front panel buttons as many older HP instruments (/e.g. the 3456A DVMs).
Three of the springs have fallen out and I need to fix that.
Are there any sources for these parts or ways to obtain similar springs or even complete switches?
Any well known repair procedures that I should know?
I could possibly obtain some flat sheet spring steel and grind a spring to shape using Dremel tools etc. but that sounds like a difficult and very time consuming task. Also the length of these springs must probably quite accurate.
Otherwise I would have to try something with external helical springs, glue and other ugly constructions...
Thanks, Martin
|
HP 8901A assistance needed.
Hi.? In the process of fixing my 8901A that got beat up by the carrier, I have found what I think is a problem in the fault finding section on the GPIB board.?
Could someone with a 8901A please input the following commands on the front panel and report back what the instrument answer? 61.0 SPCL 61.2 SPCL
In order to check if your instrument has the GPIB board without gettin a hernia, input: 21.0SPCL? The instrument then returns the DIP switch settings ( 01110.xxx) if you have the GPIB option.
BR. Thomas.
|
A direct plugin solution seems to be difficult.? The grounding of
MMICs is quite critical and maybe you need to do some surgery on the
circuit to connect a daughter board that can be properly grounded
and route the signal using tiny coax cables.? Ready built complete
MMIC amplifiers can be purchased very cheap on eBay.
Regards,
Ignacio
El 24/02/2016 a las 4:47,
jcline01@... [hp_agilent_equipment] escribi¨®:
?
Thanks for the great replies! Some?have tried to identify
the original part, but none of the parts matched exactly.
The Avantek came closest, but these are apparently no
longer available?with bandwidth?above 1300 MHz.
Some have offered possible substitutes, but they either
do not have the bandwidth, or the pin outs are different
from the OEM part. This makes me?suspect that the OEM part
was truly a special part just for HP. The Keysight website
offers no substitute, but marks the part as "obsolete".
So at this point, the best route is probably to acquire a
modern MMIC and use a daughter board to connect to the
original board holes. It should be fairly easy with the
MIcrocircuit's amplifier. Except for the physical
connections, the design, supporting parts, and supply
voltage are very close to the original.
Thanks again for all of the great responses! I'll post
again when I have a working solution.
Best regards,
Joe, KN5U
Este correo electr¨®nico se ha enviado desde un equipo libre de virus y protegido por Avast.
|
|
Re: HP 8640B will not lock
Hi Steve,
you need to start at the main oscillator and make your way down the signal chain. You need an oscilloscope and a frequency counter for this job. Follow the block and schematic diagrams in the manual. Try to determine if the signal is reasonable or not. At some point there will be something very wrong...
Good luck and carry on G?ran
|
Hi, I am controlling my HP34401A multimeter via GPIB with a Prologics adapter, which works quite nicely. My only problem is that the measurement speed it rather low at about 1 measurement per second. The reason for this is apparently the fact that the GPIB command meas:volt:dc? automatically switches the instrument to highest resolution, i.e. slowest speed. But I am not a GPIB expert. Thus, the manual is not very helpful for me in this respect. It states:
MEASure
:VOLTage:DC?
{<range>|MIN|MAX|DEF},{<resolution>|MIN|MAX|DEF}
Can someone tell me please, how to set the range and resolution in the measure command? All my attempts ended with an error beep. Thanks!
|
Re: HP 8640B will not lock
Even worse, now the frequency counter shows ?all zeroes, plus "overflow". none of the counter buttons have any effect.
The RF output does exist, and the amplitude knobs both work.
AM and FM modulation appear to make changes to the RF output. The frequency range switch or freq. dial do not change the output frequency, it stays at some random. fixed value. ---In hp_agilent_equipment@..., <eagle572@...> wrote : I need help to fix the HP 8640B freq. lock. ?
The output freq. wobbles greatly and will not hold onto any frequency as set by the cavity dial.
Any help would be appreciated.
I have downloaded some manuals, but no trouble shooting information was found.
Cheers, Steve Bell KJ7OG
|
David Hess
RFI-EMI-GUY
G?ran Krusell