I have three 3488 switches and a selection of plug ins.
I recently bought a well loaded 3488 at a pretty good price from Ebay in the UK.
I would love to be able to buy some of the connector blocks for the plug ins but I very rarely see them offered on their own.
MK
|
Re: Scoping the Power Rails [8566B]
I'm not too sure what Harke means. I don't see what shorting the tip to the ground is going to achieve.
I'm probing A17 and A18 boards and there is simply nowhere other than nearby aluminium chassis to clip the ground lead to. I appreciate what you say about keep the loop as short as possible, but the only alternative would be to pull the boards and solder fly-leads directly to the closest ground pours on the PCBs themselves. It's a pity HP didn't provide convenient, accessible ground pins for this purpose!
|
Interesting article/posting.
Do you have the 3488 switch with the vhf switch modules? Nigel by banging a nail into a piece of wood...
toggle quoted message
Show quoted text
On 27 Feb 2022, at 16:40, Michael Kellett < mk@...> wrote: Here's a link to a blog of mine elsewhere which I hope some on this group may find interesting.
It covers some (initial) work on the 8903A and my take on yet another USB - HPIB interface.
MK
|
Here's a link to a blog of mine elsewhere which I hope some on this group may find interesting.
It covers some (initial) work on the 8903A and my take on yet another USB - HPIB interface.
MK
|
Re: HP-8753E Reading HPGL Files
Most graphic programs use (or used) to open hpgl files... Enviado do meu Tele-Movel Em dom, 27 de fev de 2022 13:19, Rich Miller via <av8torrich= [email protected]> escreveu:
Hi Steve:
I have Jon's Software. I use it for some older Tektronix and Advantest instruments I own. I always thought it was designed to be used with a GPIB interface. Let me load this up, and see if I can read the file from the 3.5" Floppy.?
Rich?
On Sunday, February 27, 2022, 11:02:44 AM EST, Steve Hendrix < stevehx@...> wrote:
Try KE5FX. A Google search yields the
first hit at his GPIB toolkit, which includes a reader that will
take an HPGL file and display it under Windows.
Steve Hendrix
On 2022-02-27 10:30 AM, Rich Miller via
wrote:
I was reading about the .FP
file my generator produces when I want to copy a Plot. My
understanding is they are HPGL file format. A review of how to
open this format into a graphic, or plot the instruction ask me
to download?hp2xxdos.exe and hpglconv.bat,
Which do not seem to exist?on the application note I was
reading.
Does anyone
know a good way to read these files in to any of the
typical Microsoft?products?
|
Re: HP 82901M Dual Floppy Disk Drive - servicing advice
I don't believe you'll need new drive belts, afair, these belts are made from a kind of cloth + some rubber, they never lace or deteriorate. I service drives here and in some hundreds of tm100 and apple II drives I don't remember replacing a belt...
73 de pu2sex alexandre Enviado do meu Tele-Movel
Thanks Paul - very helpful.
Do you know of a source of replacement drive belts for these units?
Thanks
Tony
On Sat, 26 Feb 2022 at 19:11, Paul Berger < phb.hfx@...> wrote:
On 2022-02-26 15:00, Tony wrote:
> Hi all,
>
> I¡¯ve had an HP 82901M dual floppy disk drive in storage for a couple
> of years but never used. I got it as a bundle with my HP85. It has
> been kept dry although it gets cool in the garage at times. I¡¯m
> finally getting around to using it - but it wanted to get some advice
> before turning it on - in case there are any gotchas.
>
> Is there anything, such as checking the heads, that is best done
> before turning it on? I don¡¯t want to trash it if there any avoidable
> errors in getting a long dormant unit working again.
>
> thanks
>
> Tony
The drive in the 82901 is a Tandon TM100.? They do not suffer from
sticky? mechanism Like the Sony 3.5 drive in 9121 or 9122. Potential
issues are loose and/or degraded drive belt, motor speed drift, head
contamination, and contamination on the rails the head carriage moves
on.? The service guide for the TM100 may be found at
<>
Paul.
|
Re: HP-8753E Reading HPGL Files
Hi Steve:
I have Jon's Software. I use it for some older Tektronix and Advantest instruments I own. I always thought it was designed to be used with a GPIB interface. Let me load this up, and see if I can read the file from the 3.5" Floppy.?
Rich?
On Sunday, February 27, 2022, 11:02:44 AM EST, Steve Hendrix <stevehx@...> wrote:
Try KE5FX. A Google search yields the
first hit at his GPIB toolkit, which includes a reader that will
take an HPGL file and display it under Windows.
Steve Hendrix
On 2022-02-27 10:30 AM, Rich Miller via
groups.io wrote:
I was reading about the .FP
file my generator produces when I want to copy a Plot. My
understanding is they are HPGL file format. A review of how to
open this format into a graphic, or plot the instruction ask me
to download?hp2xxdos.exe and hpglconv.bat,
Which do not seem to exist?on the application note I was
reading.
Does anyone
know a good way to read these files in to any of the
typical Microsoft?products?
|
Re: HP-8753E Reading HPGL Files
Try KE5FX. A Google search yields the
first hit at his GPIB toolkit, which includes a reader that will
take an HPGL file and display it under Windows.
Steve Hendrix
On 2022-02-27 10:30 AM, Rich Miller via
groups.io wrote:
toggle quoted message
Show quoted text
I was reading about the .FP
file my generator produces when I want to copy a Plot. My
understanding is they are HPGL file format. A review of how to
open this format into a graphic, or plot the instruction ask me
to download?hp2xxdos.exe and hpglconv.bat,
Which do not seem to exist?on the application note I was
reading.
Does anyone
know a good way to read these files in to any of the
typical Microsoft?products?
|
Re: How can I measure the bandwidth of an audio transformer with the HP8903B ?
Thanks Jon,
I'll do further tests.
-- Cheers
??? Attilio
|
Re: Installing a HP 10544A into a HP 5335A
On 2/27/22 06:12, Dr. Frank wrote: Well, It's probably more than only 'good practice' to remove the old 10MHz XTAL.
I'd like to refer to this video from Veritasium, The Surprising Secret of Synchronisation: <>
It's a known phenomenon for electrical oscillators also, that another oscillator with a nearby frequency might shift the OCXO frequency , by 'backwards' interference.
If I remember correctly, this was discussed in the time-nuts group also. I've not watched the video, but from what you describe, this is probably "injection locking". -Dave -- Dave McGuire, AK4HZ New Kensington, PA
|
Re: Scoping the Power Rails [8566B]
On 2/27/22 07:58, Jinxie wrote: Some of you will be aware I was trying to find the source of the YTO unlock error I was getting displayed on the screen of my 8566B. I'd been advised elsewhere to scope the power rails for any signs of instability and at that time, aside from some small variations in the expected voltage levels, all seemed fine. However, I wasn't happy I'd got the right scope for the job and the optimum settings for this kind of check, so I've had another try and discovered something seriously amiss. There is some small level of noise on the DC rails, but no more than I would expect from looking at *any* power rail. The issue that jumped out this time (having got the right tool for the job; setting right etc.) is the presence of persistent, random, voltage spikes. The excursions from the DC value go at least 60mV plus and minus from the DC value. They're really skinny if that's any clue; so narrow they're sometimes hard to see. But they ARE there nevertheless. I have two questions here:
1. Could these spikes cause the YTO unlock condition?
2. What could cause these spikes, given that they're present on ALL the DC rails: -40V, -12V, -5.2V, +5.2, +12V, +22V and so on?
I'm pretty sure this isn't operator-induced error, but I guess I can't altogether rule out the vague possibility it may be an internal fault in the oscilloscope itself. But let's assume for now the spikes do not originate within the 'scope itself. As Harke said a few minutes ago, look at probe grounding. This is often dismissed as one of those "That can't happen!" things, but it's a very common and widely-misunderstood problem. Always connect your probe's ground as close to the monitored circuit node as possible, and keep the probe's ground wire as short as possible. -Dave -- Dave McGuire, AK4HZ New Kensington, PA
|
Re: Scoping the Power Rails [8566B]
Jinxie,
Have you measured with the earth clip directly connected to the
probe's tip? Close to the area you are looking at. You will be
surprised what you see. As you say you measure the same at any
power rail its probably some stray field omni present. The earth
clip to the tip makes a good pick up loop....
My best, 73 de
Harke
On 27/02/2022 13:58, Jinxie wrote:
toggle quoted message
Show quoted text
Hi all,
Some of you will be aware I was trying to find the source of the
YTO unlock error I was getting displayed on the screen of my
8566B. I'd been advised elsewhere to scope the power rails for any
signs of instability and at that time, aside from some small
variations in the expected voltage levels, all seemed fine.
However, I wasn't happy I'd got the right scope for the job and
the optimum settings for this kind of check, so I've had another
try and discovered something seriously amiss. There is some small
level of noise on the DC rails, but no more than I would expect
from looking at *any* power rail. The issue that jumped out this
time (having got the right tool for the job; setting right etc.)
is the presence of persistent, random, voltage spikes. The
excursions from the DC value go at least 60mV plus and minus from
the DC value. They're really skinny if that's any clue; so narrow
they're sometimes hard to see. But they ARE there nevertheless. I
have two questions here:
1. Could these spikes cause the YTO unlock condition?
2. What could cause these spikes, given that they're present on
ALL the DC rails: -40V, -12V, -5.2V, +5.2, +12V, +22V and so on?
I'm pretty sure this isn't operator-induced error, but I guess I
can't altogether rule out the vague possibility it may be an
internal fault in the oscilloscope itself. But let's assume for
now the spikes do not originate within the 'scope itself.
Thanks.
|
HP-8753E Reading HPGL Files
All:
I was reading about the .FP file my generator produces when I want to copy a Plot. My understanding is they are HPGL file format. A review of how to open this format into a graphic, or plot the instruction ask me to download?hp2xxdos.exe and hpglconv.bat, Which do not seem to exist?on the application note I was reading.
Does anyone know a good way to read these files in to any of the typical Microsoft?products?
Rich
|
Re: How can I measure the bandwidth of an audio transformer with the HP8903B ?
Atillo the leakage inductance of the transformers under test,are,an issue at high end of band.
If you short the transformers secondary you can measure series leakage inductance with a meter or RLC bridge
Most audio power amplifier testing is with non-inductive dummy load,
Bon chance
Jon
|
Re: HP 82901M Dual Floppy Disk Drive - servicing advice
On 2022-02-27 05:56, Tony wrote: Thanks Paul - very helpful.
Do you know of a source of replacement drive belts for these units?
Thanks
Tony
Sorry I don't know where you can get a replacement, but if they are made anything like the belts on a couple Shugart SA800 drive I just repaired they should be ok.? You may see a little flutter in the belt but that is probably ok the important thing is that the spindle? turns turns at the correct speed and is constant. One comment I will make about 5.25 diskettes is sometimes they seem to get squashed and the media does not turn freely inside the jacket, if you encounter this, running the edges across a sharp corner of a desk will spread the sides and free up the media. Since any 5.25 media you find these days is probably pretty old and you may also encounter what is called "sticky shed" caused by the binder that holds the magnetic particles to the base degrading.? If you encounter this some of the goo will and up on the heads and if not cleaned up right away, the goo may transfer to the next diskette you put in.? Personally I have only encounters this with very cheap media, recently I have been archiving old diskettes some of which are 40 years old and have not encounter any issue yet. Paul.
|
Scoping the Power Rails [8566B]
Hi all,
Some of you will be aware I was trying to find the source of the YTO unlock error I was getting displayed on the screen of my 8566B. I'd been advised elsewhere to scope the power rails for any signs of instability and at that time, aside from some small variations in the expected voltage levels, all seemed fine. However, I wasn't happy I'd got the right scope for the job and the optimum settings for this kind of check, so I've had another try and discovered something seriously amiss. There is some small level of noise on the DC rails, but no more than I would expect from looking at *any* power rail. The issue that jumped out this time (having got the right tool for the job; setting right etc.) is the presence of persistent, random, voltage spikes. The excursions from the DC value go at least 60mV plus and minus from the DC value. They're really skinny if that's any clue; so narrow they're sometimes hard to see. But they ARE there nevertheless. I have two questions here:
1. Could these spikes cause the YTO unlock condition?
2. What could cause these spikes, given that they're present on ALL the DC rails: -40V, -12V, -5.2V, +5.2, +12V, +22V and so on?
I'm pretty sure this isn't operator-induced error, but I guess I can't altogether rule out the vague possibility it may be an internal fault in the oscilloscope itself. But let's assume for now the spikes do not originate within the 'scope itself.
Thanks.
|
Re: Installing a HP 10544A into a HP 5335A
Well, It's probably more than only 'good practice' to remove the old 10MHz XTAL.
I'd like to refer to this video from Veritasium, The Surprising Secret of Synchronisation:?
It's a known phenomenon for electrical oscillators also, that another oscillator with a nearby frequency might shift the OCXO frequency , by 'backwards' interference.
If I remember correctly, this was discussed in the time-nuts group also.
Frank??
|
Re: How can I measure the bandwidth of an audio transformer with the HP8903B ?
OK, Jon.
The values are in micro Henry, so low I don't think they affect the measurements at audio frequencies.
-- Cheers
??? Attilio
|
Re: HP 82901M Dual Floppy Disk Drive - servicing advice
Thanks Paul - very helpful.
Do you know of a source of replacement drive belts for these units?
Thanks
Tony
On Sat, 26 Feb 2022 at 19:11, Paul Berger < phb.hfx@...> wrote:
On 2022-02-26 15:00, Tony wrote:
> Hi all,
>
> I¡¯ve had an HP 82901M dual floppy disk drive in storage for a couple
> of years but never used. I got it as a bundle with my HP85. It has
> been kept dry although it gets cool in the garage at times. I¡¯m
> finally getting around to using it - but it wanted to get some advice
> before turning it on - in case there are any gotchas.
>
> Is there anything, such as checking the heads, that is best done
> before turning it on? I don¡¯t want to trash it if there any avoidable
> errors in getting a long dormant unit working again.
>
> thanks
>
> Tony
The drive in the 82901 is a Tandon TM100.? They do not suffer from
sticky? mechanism Like the Sony 3.5 drive in 9121 or 9122. Potential
issues are loose and/or degraded drive belt, motor speed drift, head
contamination, and contamination on the rails the head carriage moves
on.? The service guide for the TM100 may be found at
<>
Paul.
|
Re: How can I measure the bandwidth of an audio transformer with the HP8903B ?
Ohmite REHO 150 10 LIN 10.039 14.2 uH
Ohmite REHO 150 10 NONLIN 10.225 26.6 uH
SPEAKER 5" 100 8 6.04 330 uH
GLOBAR Carbo CX 100 30 25.5 2.0 uH
Bon journee
Jon
|
Jinxie
Alexandre Souza
Attilio
Dave McGuire
Froggie the Gremlin