Re: Slightly OT: How can I dissolve Potting Compound?
The balast resistor value must cancel the negative resistance of the tube discharge plus 10 to 20 percent to make the system stable, the combined tube negative and resistor positive resistanc must be positive or the tube will oscillate.?
Leon Robinson ?K5JLR
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-------- Original message -------- From: Leon Robinson <leon-robinson@...> Date: 01/04/2021 11:38 AM (GMT-06:00) To: [email protected] Subject: Re: [TekScopes] Slightly OT: How can I dissolve Potting Compound? The balast resistor should be located as close to the tube anode as possible (minimum stray capacitance to the tube anode). Leon Robinson ?K5JLR -------- Original message -------- From: - <rrrr6789@...> Date: 01/04/2021? 11:18 AM? (GMT-06:00) To: [email protected] Subject: Re: [TekScopes] Slightly OT: How can I dissolve Potting Compound? ? I talked to a friend of mine that used to do Failure Analysis for Litton Laser. He has some PSUs made by Laser Drive, Inc. and he's going to look and see if he can find something with a similar part number.? He said that most of those lasers need 800 to 2000 volts at about 2mA to run and a 5,000 to 10,000 volt pulse on top of that to start them. If you can measure the tube and get an idea of the coherence length and internal tube diameter then he might be able to give you a better idea.?? He has also de-potted a lot of electrical devices and his advice is to start with the mildest solvent that will work. He said that anything that will soften the potting compound will likely break down the plastics on the internal devices (including removing the insulating varnish on the coils) and will ruin them.? He said to start with Acetone and use Methylene Chloride (ZIP Strip) as a last resort. ???? Other things, if the tube is flickering then the current is too low not too high. I'm sure that you're already aware that the tubes have a negative resistance just like a neon lamp. If the current is too high then the lamp can over heat and be damaged but you can montor the temperature in an effort to prevent that. And since the tube has a negative resistance then you MUST have a ballast resister in series with it. He said that in most lasers the ballast resister is built into the connector.? Also polarity is important but if you're using the usual Aldin connector then it should be properly polarized. On Sat, Jan 2, 2021 at 9:18 PM Dennis Tillman W7pF <dennis@...> wrote: I need to dissolve the black HV potting compound of a 12VDC powered
Helium-Neon laser inverter power supply I have that stopped working. I
would
appreciate any suggestions on what works to do this. I¡¯m guessing it may be
epoxy. I stuck the tip of a hot soldering iron in it for a few seconds
without much effect.
When it was working it turned out to be perfect for powering gas filled
Spectrum Tubes. These spectrum tubes (smaller versions of neon signs)
filled
with a variety of gasses are an excellent source of spectral lines for the
7J20 / J20 Rapid Scan (Optical) Spectrometer to measure.
Spectrum tubes require an initial high voltage (1,000V to 1,500V for
example) to break down the gas and start it conducting. Once the gas in the
spectrum tube conducts the voltage across the gas drops (250V to 450V for
example) and unless you limit the current (to a few mA) it will destroy the
tube. Can anyone can point me to a source of information on how to
determine
the proper voltage and current I need to power these spectrum tubes? Is
there a web site or group devoted to Spectrum Tubes?
Something happened to the inverter and it stopped working. The input is now
open. The inverter is a black potted brick 3¡± x 1?¡± x 1¡±. The ballast
resistor has continuity so that is not the problem. The original label on
the inverter is partially destroyed so I can¡¯t tell what its initial high
voltage output was or what it current limits at. All I do know is that it
was made by
Laser Drive Inc.
5465 Wm. Flynn Hwy. Gibsonia, PA 15044
Model: 1150-6330, S/N: 610574
The input was +12VDC at 0.35A.
I wrote to the company that took over the company that took over Laser
Drive
Inc. asking if they could tell me the output voltage and limiting current
but I didn¡¯t receive a reply.
At this point I am hoping if I can remove the potting compound I can figure
out what went wrong with it.
I have a different, bigger Laser Drive Inc. potted inverter which is
powered
by 115VAC. It puts out 2350VDC at 6.5mA. This causes the Spectrum Tubes to
flicker. They do not run continuously. I am guessing that this because
6.5mA
is more current than the tube can conduct. The amount of current the tube
draws increases in proportion to the inside diameter of the tube but I
»å´Ç²Ô¡¯³Ù
know much about this matching the power supply to the tube. All I do know
is
the one that went bad seems to be an ideal match for the spectrum tubes I
have.
Battery operated (DC input) inverters are much more desirable than AC input
inverters for this application because the AC rectification and poor
filtering shows up on the output DC as significant ripple causing the
amplitude of each spectral line to be blurred.
Dennis Tillman W7pF
|
Re: Slightly OT: How can I dissolve Potting Compound?
Emerson-Cumming used to sell a very good epoxy dissolving liquid. Wear super strong gloves and an N95 mask on your face, or the liquid will dissolve the skin on your fingers and wreak havoc on your sinus passages. Gary On Mon, Jan 4, 2021 at 9:38 AM Leon Robinson <leon-robinson@...> wrote: The balast resistor should be located as close to the tube anode as
possible (minimum stray capacitance to the tube anode).
Leon Robinson K5JLR
-------- Original message --------
From: - <rrrr6789@...>
Date: 01/04/2021 11:18 AM (GMT-06:00)
To: [email protected]
Subject: Re: [TekScopes] Slightly OT: How can I dissolve Potting Compound?
I talked to a friend of mine that used to do Failure Analysis for Litton
Laser. He has some PSUs made by Laser Drive, Inc. and he's going to look
and see if he can find something with a similar part number. He said that
most of those lasers need 800 to 2000 volts at about 2mA to run and a 5,000
to 10,000 volt pulse on top of that to start them. If you can measure the
tube and get an idea of the coherence length and internal tube diameter
then he might be able to give you a better idea. He has also de-potted a
lot of electrical devices and his advice is to start with the mildest
solvent that will work. He said that anything that will soften the potting
compound will likely break down the plastics on the internal devices
(including removing the insulating varnish on the coils) and will ruin
them. He said to start with Acetone and use Methylene Chloride (ZIP Strip)
as a last resort.
Other things, if the tube is flickering then the current is too low
not too high. I'm sure that you're already aware that the tubes have a
negative resistance just like a neon lamp. If the current is too high then
the lamp can over heat and be damaged but you can montor the temperature in
an effort to prevent that. And since the tube has a negative resistance
then you MUST have a ballast resister in series with it. He said that in
most lasers the ballast resister is built into the connector. Also
polarity is important but if you're using the usual Aldin connector then it
should be properly polarized.
On Sat, Jan 2, 2021 at 9:18 PM Dennis Tillman W7pF <dennis@...>
wrote:
I need to dissolve the black HV potting compound of a 12VDC powered
Helium-Neon laser inverter power supply I have that stopped working. I
would
appreciate any suggestions on what works to do this. I¡¯m guessing it may be
epoxy. I stuck the tip of a hot soldering iron in it for a few seconds
without much effect.
When it was working it turned out to be perfect for powering gas filled
Spectrum Tubes. These spectrum tubes (smaller versions of neon signs)
filled
with a variety of gasses are an excellent source of spectral lines for the
7J20 / J20 Rapid Scan (Optical) Spectrometer to measure.
Spectrum tubes require an initial high voltage (1,000V to 1,500V for
example) to break down the gas and start it conducting. Once the gas in the
spectrum tube conducts the voltage across the gas drops (250V to 450V for
example) and unless you limit the current (to a few mA) it will destroy the
tube. Can anyone can point me to a source of information on how to
determine
the proper voltage and current I need to power these spectrum tubes? Is
there a web site or group devoted to Spectrum Tubes?
Something happened to the inverter and it stopped working. The input is now
open. The inverter is a black potted brick 3¡± x 1?¡± x 1¡±. The ballast
resistor has continuity so that is not the problem. The original label on
the inverter is partially destroyed so I can¡¯t tell what its initial high
voltage output was or what it current limits at. All I do know is that it
was made by
Laser Drive Inc.
5465 Wm. Flynn Hwy. Gibsonia, PA 15044
Model: 1150-6330, S/N: 610574
The input was +12VDC at 0.35A.
I wrote to the company that took over the company that took over Laser
Drive
Inc. asking if they could tell me the output voltage and limiting current
but I didn¡¯t receive a reply.
At this point I am hoping if I can remove the potting compound I can figure
out what went wrong with it.
I have a different, bigger Laser Drive Inc. potted inverter which is
powered
by 115VAC. It puts out 2350VDC at 6.5mA. This causes the Spectrum Tubes to
flicker. They do not run continuously. I am guessing that this because
6.5mA
is more current than the tube can conduct. The amount of current the tube
draws increases in proportion to the inside diameter of the tube but I
»å´Ç²Ô¡¯³Ù
know much about this matching the power supply to the tube. All I do know
is
the one that went bad seems to be an ideal match for the spectrum tubes I
have.
Battery operated (DC input) inverters are much more desirable than AC input
inverters for this application because the AC rectification and poor
filtering shows up on the output DC as significant ripple causing the
amplitude of each spectral line to be blurred.
Dennis Tillman W7pF
-- Gary Robert Bosworth grbosworth@... Tel: 310-317-2247
|
Re: I built a TM500 mainframe tester, and updated the design. Someone might find this useful?
A frame and front panel from a 5000 series scope plugin is the same as the TM500[0] plugins. Sometimes they can be found for under $20 on ebay.
Vince.
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Show quoted text
On 01/04/2021 02:17 AM, Brian Cockburn wrote: Ladies and Gents,
Don't forget that you'll need a chassis to put this in. And there are now 50 people all trying to buy such a thing right now. Get your skates on!
Brian.
--
K8ZW
|
Re: Slightly OT: How can I dissolve Potting Compound?
The balast resistor should be located as close to the tube anode as possible (minimum stray capacitance to the tube anode).
Leon Robinson ?K5JLR
toggle quoted message
Show quoted text
-------- Original message -------- From: - <rrrr6789@...> Date: 01/04/2021 11:18 AM (GMT-06:00) To: [email protected] Subject: Re: [TekScopes] Slightly OT: How can I dissolve Potting Compound? ? I talked to a friend of mine that used to do Failure Analysis for Litton Laser. He has some PSUs made by Laser Drive, Inc. and he's going to look and see if he can find something with a similar part number.? He said that most of those lasers need 800 to 2000 volts at about 2mA to run and a 5,000 to 10,000 volt pulse on top of that to start them. If you can measure the tube and get an idea of the coherence length and internal tube diameter then he might be able to give you a better idea.?? He has also de-potted a lot of electrical devices and his advice is to start with the mildest solvent that will work. He said that anything that will soften the potting compound will likely break down the plastics on the internal devices (including removing the insulating varnish on the coils) and will ruin them.? He said to start with Acetone and use Methylene Chloride (ZIP Strip) as a last resort. ???? Other things, if the tube is flickering then the current is too low not too high. I'm sure that you're already aware that the tubes have a negative resistance just like a neon lamp. If the current is too high then the lamp can over heat and be damaged but you can montor the temperature in an effort to prevent that. And since the tube has a negative resistance then you MUST have a ballast resister in series with it. He said that in most lasers the ballast resister is built into the connector.? Also polarity is important but if you're using the usual Aldin connector then it should be properly polarized. On Sat, Jan 2, 2021 at 9:18 PM Dennis Tillman W7pF <dennis@...> wrote: I need to dissolve the black HV potting compound of a 12VDC powered
Helium-Neon laser inverter power supply I have that stopped working. I
would
appreciate any suggestions on what works to do this. I¡¯m guessing it may be
epoxy. I stuck the tip of a hot soldering iron in it for a few seconds
without much effect.
When it was working it turned out to be perfect for powering gas filled
Spectrum Tubes. These spectrum tubes (smaller versions of neon signs)
filled
with a variety of gasses are an excellent source of spectral lines for the
7J20 / J20 Rapid Scan (Optical) Spectrometer to measure.
Spectrum tubes require an initial high voltage (1,000V to 1,500V for
example) to break down the gas and start it conducting. Once the gas in the
spectrum tube conducts the voltage across the gas drops (250V to 450V for
example) and unless you limit the current (to a few mA) it will destroy the
tube. Can anyone can point me to a source of information on how to
determine
the proper voltage and current I need to power these spectrum tubes? Is
there a web site or group devoted to Spectrum Tubes?
Something happened to the inverter and it stopped working. The input is now
open. The inverter is a black potted brick 3¡± x 1?¡± x 1¡±. The ballast
resistor has continuity so that is not the problem. The original label on
the inverter is partially destroyed so I can¡¯t tell what its initial high
voltage output was or what it current limits at. All I do know is that it
was made by
Laser Drive Inc.
5465 Wm. Flynn Hwy. Gibsonia, PA 15044
Model: 1150-6330, S/N: 610574
The input was +12VDC at 0.35A.
I wrote to the company that took over the company that took over Laser
Drive
Inc. asking if they could tell me the output voltage and limiting current
but I didn¡¯t receive a reply.
At this point I am hoping if I can remove the potting compound I can figure
out what went wrong with it.
I have a different, bigger Laser Drive Inc. potted inverter which is
powered
by 115VAC. It puts out 2350VDC at 6.5mA. This causes the Spectrum Tubes to
flicker. They do not run continuously. I am guessing that this because
6.5mA
is more current than the tube can conduct. The amount of current the tube
draws increases in proportion to the inside diameter of the tube but I
»å´Ç²Ô¡¯³Ù
know much about this matching the power supply to the tube. All I do know
is
the one that went bad seems to be an ideal match for the spectrum tubes I
have.
Battery operated (DC input) inverters are much more desirable than AC input
inverters for this application because the AC rectification and poor
filtering shows up on the output DC as significant ripple causing the
amplitude of each spectral line to be blurred.
Dennis Tillman W7pF
|
7L5 shaft encoder disassembly
Bonjour a tous,
Working on my 7L5, has just one bad shaft encoder knob, the FREQ span/div
Usual flaky positions 1/2/5 kHz are acting like 100/200/500 kHz. Just using contact cleaner does not fix the issue.
The great TEKWIKI page has instructions for disassembly of the panel and for repari of the dot freq and ref level.
However the FREQ/div and RES knobs have the encoders inside the knob housing.
After extracting the assembly from the FP, a few questions:
a/ How to get the steel version of the snap in retaining ring, this one has a bad plastic retaining ring.
b/ How to open up the smaller inner FREQ span/div knob?
No setscrew or any means visible to open it.
Will later post photos
Mille mercis
Jon
|
Rodger: Mille mercis:
1/ Swapping into another 7904 MF, the issues are in the 7603.
Opened up, Voila, dirty board edge connectors on the backplane, folded biz card soaked in contact renew, cleaned all 3 compartments.
2/ Found corroded axial tant on the backplane, wonder how many others lurk inside 7603?
Best Regards,
Jon
|
Re: Slightly OT: How can I dissolve Potting Compound?
I talked to a friend of mine that used to do Failure Analysis for Litton Laser. He has some PSUs made by Laser Drive, Inc. and he's going to look and see if he can find something with a similar part number. He said that most of those lasers need 800 to 2000 volts at about 2mA to run and a 5,000 to 10,000 volt pulse on top of that to start them. If you can measure the tube and get an idea of the coherence length and internal tube diameter then he might be able to give you a better idea. He has also de-potted a lot of electrical devices and his advice is to start with the mildest solvent that will work. He said that anything that will soften the potting compound will likely break down the plastics on the internal devices (including removing the insulating varnish on the coils) and will ruin them. He said to start with Acetone and use Methylene Chloride (ZIP Strip) as a last resort. Other things, if the tube is flickering then the current is too low not too high. I'm sure that you're already aware that the tubes have a negative resistance just like a neon lamp. If the current is too high then the lamp can over heat and be damaged but you can montor the temperature in an effort to prevent that. And since the tube has a negative resistance then you MUST have a ballast resister in series with it. He said that in most lasers the ballast resister is built into the connector. Also polarity is important but if you're using the usual Aldin connector then it should be properly polarized. On Sat, Jan 2, 2021 at 9:18 PM Dennis Tillman W7pF <dennis@...> wrote: I need to dissolve the black HV potting compound of a 12VDC powered
Helium-Neon laser inverter power supply I have that stopped working. I
would
appreciate any suggestions on what works to do this. I¡¯m guessing it may be
epoxy. I stuck the tip of a hot soldering iron in it for a few seconds
without much effect.
When it was working it turned out to be perfect for powering gas filled
Spectrum Tubes. These spectrum tubes (smaller versions of neon signs)
filled
with a variety of gasses are an excellent source of spectral lines for the
7J20 / J20 Rapid Scan (Optical) Spectrometer to measure.
Spectrum tubes require an initial high voltage (1,000V to 1,500V for
example) to break down the gas and start it conducting. Once the gas in the
spectrum tube conducts the voltage across the gas drops (250V to 450V for
example) and unless you limit the current (to a few mA) it will destroy the
tube. Can anyone can point me to a source of information on how to
determine
the proper voltage and current I need to power these spectrum tubes? Is
there a web site or group devoted to Spectrum Tubes?
Something happened to the inverter and it stopped working. The input is now
open. The inverter is a black potted brick 3¡± x 1?¡± x 1¡±. The ballast
resistor has continuity so that is not the problem. The original label on
the inverter is partially destroyed so I can¡¯t tell what its initial high
voltage output was or what it current limits at. All I do know is that it
was made by
Laser Drive Inc.
5465 Wm. Flynn Hwy. Gibsonia, PA 15044
Model: 1150-6330, S/N: 610574
The input was +12VDC at 0.35A.
I wrote to the company that took over the company that took over Laser
Drive
Inc. asking if they could tell me the output voltage and limiting current
but I didn¡¯t receive a reply.
At this point I am hoping if I can remove the potting compound I can figure
out what went wrong with it.
I have a different, bigger Laser Drive Inc. potted inverter which is
powered
by 115VAC. It puts out 2350VDC at 6.5mA. This causes the Spectrum Tubes to
flicker. They do not run continuously. I am guessing that this because
6.5mA
is more current than the tube can conduct. The amount of current the tube
draws increases in proportion to the inside diameter of the tube but I
»å´Ç²Ô¡¯³Ù
know much about this matching the power supply to the tube. All I do know
is
the one that went bad seems to be an ideal match for the spectrum tubes I
have.
Battery operated (DC input) inverters are much more desirable than AC input
inverters for this application because the AC rectification and poor
filtering shows up on the output DC as significant ripple causing the
amplitude of each spectral line to be blurred.
Dennis Tillman W7pF
|
Jean-Paul,
You may also need to clean the switch segments in the plugins that are responsible for changing the readout characters - you will find some of the cam switch segments just switch different combinations of resistors into circuit to define the current into the digitisers on the readout board. If the scrambled readout is always in the same character position, eg the third character, then it is probably due to bad switch contacts, if it is the same font character eg if 15Mhz and 51MHz both scramble the '5' but not the '1' then it is likely to be a fault in the character generating ROMs. Somewhere in the manuals you will find a table showing which characters are generated by each of the several ROMs.
It does seem odd that both plugins have the same fault so maybe it is the second explanation that is more likely. Do you have any other plugins that are OK?
Regards,
Roger
|
Re: Odd 2247A problem, looking for insight
I have just had an idea for aligning holes in cases where access to some internal item might be required (and I wish I'd thought about it some time ago). It occurred to me that lots of simple little devices (such as laser pointers, laser measurers, laser torches, IR thermometers and the like) have a laser beam incorporated. If the item that needs the access-hole and the laser-pointer device are aligned without the casing being present, making as sure as possible that the laser-beam is aligned horizontally and vertically with the item to access, then when the casing is in place the laser-spot will mark on the casing where the hole needs to be made. This necessitates that neither the laser-pointer nor the device that needs external access are allowed to move between initial alignment and replacement of the casing, but that should not be beyond the wit of man. I may not have made myself clear and I haven't personally tried this idea out. I think it might just work. It would certainly be better than the bodges that I have done in the past. Who wants to be the guinea-pig?
Colin.
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-----Original Message----- From: [email protected] [mailto: [email protected]] On Behalf Of tekscopegroup@... Sent: 04 January 2021 14:21 To: [email protected]Subject: Re: [TekScopes] Odd 2247A problem, looking for insight On Sun, Jan 3, 2021 at 04:38 PM, Harvey White wrote: on a related topic, this 2247A unit has the same terrible frequency
cal issue (on screen counter) I have seen in other units. the
adjustment is incredibly sensitive, and no matter how you set it, once
closed up and run for a while, it drifts low by about 50 Hz. I am
going to put a hole in the case to set it, it's just too frustrating
the way it is.
all the best,
walter
Hi Walter, if you make that adjustment hole and it aligns successfully, could you please post the information so as to be able to duplicate it? I still need to make that same adjustment on my 2247A and was also considering making a small access hole to the trimmer, but I am terrible at matching things up and it will probably end up being way off. Thanks -Alex
|
Re: Odd 2247A problem, looking for insight
Walter,
I'm not familiar with this instrument; so, I may be way off base --but -
Rather than drilling a hole in the case, why not the following?
1) Adjust as normal
2) Close the case
3) Measure, as accurately as possible, the amount of drift.
4) Open and readjust - this time high by the measured drift.
It might drift down to the correct value when closed again.
Stephen
|
Re: Odd 2247A problem, looking for insight
On Sun, Jan 3, 2021 at 04:38 PM, Harvey White wrote: on a related topic, this 2247A unit has the same terrible frequency
cal issue (on screen counter) I have seen in other units. the
adjustment is incredibly sensitive, and no matter how you set it, once
closed up and run for a while, it drifts low by about 50 Hz. I am
going to put a hole in the case to set it, it's just too frustrating
the way it is.
all the best,
walter
Hi Walter, if you make that adjustment hole and it aligns successfully, could you please post the information so as to be able to duplicate it? I still need to make that same adjustment on my 2247A and was also considering making a small access hole to the trimmer, but I am terrible at matching things up and it will probably end up being way off. Thanks -Alex
|
Re: Tek 4041 GPIB Controller
Monty: How can I purchase the EZ-Test tapes and others you mention?
Gary
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Show quoted text
On Sun, Jan 3, 2021 at 8:00 PM Monty McGraw <mmcgraw74@...> wrote: I rediscovered a dozen 4041 tapes that I had stored in the back of a logic
analyzer drawer just before Christmas.
I worked all week to recover the files from those tapes and posted the
recovered files on my github repository for 4041 at:
I recovered ALL the files on EZ-TEST Volume I and Volume II !
And I recovered a great 4041 tape backup program from a copy of MP2501
tape.
I also modified this backup program to also allow the tape to be uploaded
to the PC in HEX format and named it BAKAL3
I have also added Tektronix catalog page info for EZ-TEST and MP2501 in
those folders on my repository.
You folks should be able to download the files to your 4041 tapes!
--
Gary Robert Bosworth
grbosworth@...
Tel: 310-317-2247
|
I should add Roger that I am not convinced that U2102 is the problem...but it might be. After reading the theory of operation, which I only partially understand, it could be many different things. If I had a tektronix guru in front of me the question(s) I'd ask are - why are both traces overlaid over each other and no way of separating them using the position controls and what would lead to each input being influenced by the other. Wherever that was caused in the circuit would answer everything I reckon.
|
Bonjour a tous, Voeux Nouvelle Ann¨¦e!
The 7603 is used with 7L5 or 7L12 SA plugins.
All OK except both SA have a flaky RO, with several areas showing scrambled alphanumerics.
If I push on the FP of the SA, the RO is fine. I cleaned the edge connectors of both, and put contact cleaner in the 7603 backplane sockets, No effect.
Has anyone else seen this symptom, perhaps on other 7000 MF?
Mille Mercis,
Jon
|
Hi Bert. Cables not the issue in this case as the problem follows the input on the storage board not the cables connected to them. I'm continuing to investigate but this scope is not the easiest to work on. Cheers.
|
Thanks for that Roger. My 2230 used the later U2101 234-0408-20 chip which absolutely does not seem to exist anywhere but I believe I could get the earlier more common one you mention to work. My service manual actually shows the circuit with the earlier chip Your suggestion is probably the route I'd go in the absence of any other direction from someone. Many thanks.
|
Re: Spectrum analyzer Tektronix 7L13 on mainframe Tektronix 7603
Hi Attilio,
It's in a TO-5 transistor package, so a bit non-standard. It's not soldered in place -- it plugs into a 3-pin socket (the nice ones Tek used in later products -- the ones with the silicone gaskets around the pins), but there is enough room in the cavity to fit in a more-standard packaged device (e.g., HC-18; just bend it over).
By the way, in case you haven't already read it, I recommend taking a look at
The same instructions apply in the direction you're interested in, except the crystal swap goes the other way, of course. The nice observation there is that you don't need a separate instrument to retune the filter -- you use the spectrum analyzer that you already have. Just follow the manual's instructions for tuning the filter as if it were an ordinary maintenance/repair task.
You will not have to alter the inter-cavity couplings at all because the retuning is a small percentage. You'd probably make things worse by playing with the couplings, so just leave those alone.
-- Cheers,
Tom
--
Prof. Thomas H. Lee
Allen Ctr., Rm. 205
350 Jane Stanford Way
Stanford University
Stanford, CA 94305-4070
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On 1/4/2021 01:56, Attilio wrote: Hi Tom,
so it is a standard AT cut crystal, a third overtone crystal, with an accuracy of 5 ppm.
But what kind of container is the crystal in ?
Thanks
-- Cheers
Attilio
|
Re: Slightly OT: How can I dissolve Potting Compound?
Reading through Wikipedia, MEK is also a *welding* agent for plastic parts, used in scale modelling.
I remember having put together many scale buildings for my fathers model railroad. The "glue" I was using (from the "Kibri" company that made the kits) must have been MEK... at least in the 70ies there was no other mention for safety as good ventilation. I often got that stuff on my fingers, didn't seem to harm.
:-/
cheers
Martin
|
Re: Spectrum analyzer Tektronix 7L13 on mainframe Tektronix 7603
Hi Tom,
so it is a standard AT cut crystal, a third overtone crystal, with an accuracy of 5 ppm.
But what kind of container is the crystal in ?
Thanks
-- Cheers
Attilio
|
Re: I built a TM500 mainframe tester, and updated the design. Someone might find this useful?
Maybe I should draw up some 3D files for 3D printable chassis parts. :D
toggle quoted message
Show quoted text
On Mon, Jan 4, 2021 at 04:17 PM, Brian Cockburn wrote:
Ladies and Gents,
Don't forget that you'll need a chassis to put this in. And there are now
50 people all trying to buy such a thing right now. Get your skates on!
Brian.
|
Gary Robert Bosworth
Jean-Paul
Kevin
Martin
Attilio
Jared Cabot