Re: No contribution from David Hess since July 18th
On Fri, Nov 2, 2018 at 08:25 PM, Michael A. Terrell wrote:
I guess that you've never seen the heat shrink connectors for .500, .750 or
larger hardline that have to be heated to allow you to slide the cable into?
They are pre-shrunk.
I'm lost! Raymond
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CFL and LED EMI at the bench
FYI I had a huge problem with this. But adding a $3 Chinese EMI filter across the power leads in the light fixture solved it quite nicely. I now keep a bunch them on hand along with various size clamp on ferrite chokes.
I also use a small loop on a scope probe to track down noise. My HP Z400s emit quite a lot of noise at the PSU fan aperture, so I cover them with a 4" square of 1/8" metal screen (aka hardware cloth). There's also some emission from the fronts, but I've not fixed that yet.
My initial probe loop was about 1/4" and wound on the shanks of drill bits to be a snug fit on the probe tip. Now that I have suppressed a lot of the noise, I plan to make some larger diameter loops.
Naturally, I've taken this to demented levels. All my instruments are now powered via a custom harness made of 1/2" EMT and cut off IEC cords with 5/16" flex steel sheathing. Except for the GPSDO feed, all the instruments are powered though a single switch with the soldering gear on another switched circuit with a hardwired light to make it obvious that the soldering gear is under power..
The motivation for this was the discovery that while the front of my GW Instek MSO was quiet, the other sides emitted a huge amount of SMPS noise which was readily picked up by the power leads for other instruments. I've yet to make measurements of the conducted EMI present on the power line, but will eventually. I also plan to add an isolation transformer and a large EMI filter between the feed and the wall mains outlet. An additional factor was having a dozen instruments stacked on a couple of shelves. I initially used a regular power strip but the fat wad of power cords at the strip became very awkward.
My entire workspace is 7 x 10 ft, 4 x 7 ft for the bench and the rest for my chair, 5 computers, KVM switch, dual monitors and a pair of printers. It's "cozy".
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Re: how high would you stack them?
For many years I had a stack of the following sitting at one end of my bench. From bottom to top:
HP 8660D signal generator
HP 8556B spec an (both sections)
Tektronix TM-5006A, fully loaded
HP 3456A precision voltmeter
Heathkit GC-1000 clock
These were in a single stack on a very heavy wooden/laminated bench top which sat on two steel 3-drawer pedestals I bought from Global Industries.
I had no support problems and no heat dissipation problems.
I have also had two 7000-series ¡®scopes stacked with no problems, but I always worried about knocking the top off because there is no way to have them interlocked.
DaveD
Sent from a small flat thingy
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On Nov 2, 2018, at 15:12, John Ferguson via Groups.Io <jferg977@...> wrote:
I apologize for my simplicity, but I have height but not a lot of bench space. It occurred to be that there might be a limit to haw many scopes/ TM's one might stack so the question is what are you guys doing.
I have a TM 504 with full load of modules on top of bench with a 2445B, next, and then a 2465. I would like to stack another 2445b on top of that. (Don't ask why I have 3 similar scopes - they sort of followed me home [legally])
It looks like putting the TM504 on top would make most sense weight wise, but would make it harder to see screen on bottom scope.
What is most number of these things you'd put atop a very substantial bench?
john
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Re: 425 Mil vertical module needed....seeking
Hi Michael....how interesting....no not the PRC, I know the sets you mean though....this was a 'pioneer' set...CW on Tx/Rx and AM on Rx only. RT654A/TRC 77. Still sought after
as a great set....crystal locked but can VFO their current drain on Rx was very small....The US equivalent of Special Air Service regiment (they don't like being called SAS by civies)
used them. I think the term was 'pioneer'...Parts of it were hinged to swing up for service...well so did the p/s of the BC 342 I guess so maybe that's not so modular! I own one so I must
have a closer look..it's been on the shelf for some years, I never even tried it for working but set about trying to collect the associated bits and pieces...not easy here as the gear
in strictly USA. I think there is one of more TRC77 groups amongst the Hams....I recall seeing a very long photographic blurb on them.
I t was a lot easier to carry lightweight spare modules than complete units...but that was really 50's technology emerging as weight diminished with solid state and extra low voltage.
What I see as the forerunner of the PRC 77, the BC1000, was not an easy repair.
Did you find much card failure?
My regards
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-----Original Message----- From: Michael A. Terrell Sent: Saturday, November 3, 2018 5:17 AM To: [email protected]Subject: Re: [TekScopes] 425 Mil vertical module needed....seeking Did you mean the PRC77? if so, both of its predecessors, the PRC10 and the PRC25 were module based radios that were designed to be repaired by swapping in spare, pre-tuned modules. I did Interchangeability testing on the PRC77, along with final test at the Cincinnati Electronics factory. Michael A. Terrell -----Original Message----- From: Jack <goldmort@...>
Sent: Nov 2, 2018 2:16 PM
To: [email protected]
Subject: Re: [TekScopes] 425 Mil vertical module needed....seeking
Hi thanks Harvey....yes that's about it.....time saving with a good spares
inventory ....replace the faulty aspect of equipment and then send through
the system
to component level repairs. Repair was not always attempted and "U/S" tags
were plentiful. Reliability and cost were a decision. I recall when aircraft
mods were
done in Vietnam conflict we just dumped $millions in unusable inventory,
even here. Our (Defence's) vibration and environmental equipment was given
to AWA,
which then charged Defence for the use of it. I found that..a kind-of
peculiar arrangement. Labour costs yes, but use of the gear wasn't confined
to us.
Component level was not always done at Echelon...a level of testing might be
done and a decision made whether to send to the manufacturer but at the card
level
when it was a card....it may more likely have been tagged 'U/S' scrupulously
recorded then binned, later ...perhaps many years later and when security
allowed it and the
conflict was over.....go through the 'disposals auctions'. The equipment
need to ensure the gear met services' specs was too complex and expensive in
some cases.
Reliability warrantied as being certain is primary especially in weaponry
and radar you mentioned demands manufacturer-level accuracy. My recollection
is that
it was not until after 'Korea' thatmodularisation became common...the TRC77
for example in a small way. Until then changing tubes was the field level
repair. -- Jack
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Re: No contribution from David Hess since July 18th
I guess that you've never seen the heat shrink connectors for .500, .750 or larger hardline that have to be heated to allow you to slide the cable into? They are pre-shrunk.
Michael A. Terrell
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-----Original Message----- From: Dennis Tillman W7PF <dennis@...>
Sent: Nov 2, 2018 3:05 PM
To: [email protected]
Subject: Re: [TekScopes] No contribution from David Hess since July 18th
Hi Raymond,
Welcome to the 21st century where our members are spread around the globe and local time is a myth and UTC is the only way to avoid confusion. But that creates its own problems as was evident in this case.
I've been caught by this before specifically when I tried to post my press release announcing "Pre-Shrunk Heat Shrink Tubing" at 12:01AM on April 1st.
Dennis Tillman W7PF
|
Send me your suggestions for a TekScopes FAQ
When new members join TekScopes this may be the very first time on a forum
or mail reflector.
The thought of asking a question, or replying to a question they can answer,
could be compared to speaking to a room of 7,000 total strangers.
I know we are very helpful to new members, but they don't necessarily know
that.
I think it would help new members if we provided a list of Frequently Asked
Questions (and answers) they could refer to. My goal is to encourage them to
become actively involved rather than passive "lurkers".
So I am asking each of you to think back to when you first joined. What
questions did you have at that time?
What questions do you still have that you would like to know the answers to?
Send your suggestions to me OFF LIST at dennis at ridesoft dot com and I
will organize them into a FAQ and publish it on TekScopes.
Dennis Tillman W7PF
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Re: 425 Mil vertical module needed....seeking
Did you mean the PRC77? if so, both of its predecessors, the PRC10 and the PRC25 were module based radios that were designed to be repaired by swapping in spare, pre-tuned modules. I did Interchangeability testing on the PRC77, along with final test at the Cincinnati Electronics factory.
Michael A. Terrell
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-----Original Message----- From: Jack <goldmort@...>
Sent: Nov 2, 2018 2:16 PM
To: [email protected]
Subject: Re: [TekScopes] 425 Mil vertical module needed....seeking
Hi thanks Harvey....yes that's about it.....time saving with a good spares
inventory ....replace the faulty aspect of equipment and then send through
the system
to component level repairs. Repair was not always attempted and "U/S" tags
were plentiful. Reliability and cost were a decision. I recall when aircraft
mods were
done in Vietnam conflict we just dumped $millions in unusable inventory,
even here. Our (Defence's) vibration and environmental equipment was given
to AWA,
which then charged Defence for the use of it. I found that..a kind-of
peculiar arrangement. Labour costs yes, but use of the gear wasn't confined
to us.
Component level was not always done at Echelon...a level of testing might be
done and a decision made whether to send to the manufacturer but at the card
level
when it was a card....it may more likely have been tagged 'U/S' scrupulously
recorded then binned, later ...perhaps many years later and when security
allowed it and the
conflict was over.....go through the 'disposals auctions'. The equipment
need to ensure the gear met services' specs was too complex and expensive in
some cases.
Reliability warrantied as being certain is primary especially in weaponry
and radar you mentioned demands manufacturer-level accuracy. My recollection
is that
it was not until after 'Korea' thatmodularisation became common...the TRC77
for example in a small way. Until then changing tubes was the field level
repair.
|
how high would you stack them?
I apologize for my simplicity, but I have height but not a lot of bench space. It occurred to be that there might be a limit to haw many scopes/ TM's one might stack so the question is what are you guys doing.
I have a TM 504 with full load of modules on top of bench with a 2445B, next, and then a 2465.? I would like to stack another 2445b on top of that.? (Don't ask why I have 3 similar scopes - they sort of followed me home [legally])
It looks like putting the TM504 on top would make most sense weight wise, but would make it harder to see screen on bottom scope.
What is most number of these things you'd put atop a very substantial bench?
john
|
Raymond Domp Frank 7:52am #152078 No, it is not normal although the area is sensitive to external signals, like hum; you're covering and >grounding a high-impedance part of the vertical input amp, directly after the attenuator block with >attenuation set at 200 mV/div.
Are you sure there's no external source producing something like 50 kHz, if I'm reading the horizontal >settings correctly?
Raymond You nailed it. There are four CCFLs nearby for theseo ld eyes. Turned them off and; /g/TekScopes/photo/77251/2?p=Name,,,20,1,0,0 As a side effect I had to learn to set the camera to flash. Chuck Harris 8:27am #152079 That's a very good point. When I was using CFL illumination
in a desk lamp, at my bench, I used to see a lot of excess noise
signals in hi gain, hi-Z circuitry. There is also so much hum floating around down here you can forget playing a record on a turntable with a magnetic cartridge. I don't know what to do when I ever have to rip an LP again. I could just about charge money, I can do beta tapes of audio hifi, reel to reel and old 78RPM records. No matter what I do I got hum ion the turntable. Not in tape deck though, go figure. Now I wonder if that 50KHz got into my amp and fried a tweeter... I guess we are all going to have to remember that about the CCFLs, I wonder if LED lights do the same thing. ¸é±ð²Ô¨¦±ð 9:50am #152082 check the side of the case there may be "holes" for some of the sensitive adjustments I see a few all stickered up. Raymond Domp Frank 10:07am #152083 On Fri, Nov 2, 2018 at 05:50 PM, ¸é±ð²Ô¨¦±ð wrote: check the side of the case there may be "holes" for some of the sensitive adjustments. there are on a 475 and the case needs to be installed for those adjustments. These holes provide access to e.g. vertical position, attenuator balance and DC gain settings. They >are there as a convenience to allow some adjustments "in the field" without opening the case. You would be surprised at how much alignment etc. I can do without much equipment. Chuck Harris 10:12am #152084 I don't remember it that way. The entire 475 can be calibrated
sitting out of its case on the bench. The entire 465 family can
be calibrated sitting out of its case on the bench. I guess I found that out when I shut those lights off. I'll not soon forget that. Raymond Domp Frank 10:38am #152088 :On Fri, Nov 2, 2018 at 06:12 PM, Chuck Harris wrote: The adjustment holes in the case are an indication that some of the more sensitive circuits are not very stable, and require occasional touch-up by the operator. I've never had a need to do any of these adjustments externally, "in the field" so to say, using 464, >465(B), 466 and 475(A) scopes for decades. The "construction" allows unguided poking at least 1.5" >into the 'scope without vision and is asking for involuntary scopeslaughter if a metal screwdriver is >used. Since these 'scopes were used in all kinds of harsh environments, I can imagine that field >adjustment was done in extreme temperature use. I'll have to sharpen my plastic diddle sticks. ¸é±ð²Ô¨¦±ð 10:57am #152094 ok, all I recall is I was told ( by the counter tech at tektronix in sunnyvale when my 475 went in for cal >service eons ago... ) the case had to be on for something due to sensitivity/shielding and that is why >the holes were in the case . so that info was false!!! It seems so. Thanks for the heads up, now I am going to check the calibration. I don't have anything up to 100MHz though, well actually I do but the fastest rise time I can get out of it is from a buffered 50 ohm output with 10nS. And I have no 50 ohm cable. We'll see how I get around that :-) Just now I found out I only have to turn off one of the lights. It's the one with the arm, and of course it has a metal shield and is not grounded. I wonder what would happen if I grounded it... I'll keep you posted. The other thing is I was surprised at how cheap these things are going on eBay. I might just sell a couple of my lower end scopes and use the money to pay the guy for the "core" of this one. I just fixed the guy almost two grand worth of stuff he's going to sell so he owes me. Unfortunately I can't do the face thing because due to the topology of my generator the sine is 90 degrees out of phase from the square. Thanks again for saving me much hassle about the front end.
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Re: No contribution from David Hess since July 18th
Hi Raymond,
Welcome to the 21st century where our members are spread around the globe and local time is a myth and UTC is the only way to avoid confusion. But that creates its own problems as was evident in this case.
I've been caught by this before specifically when I tried to post my press release announcing "Pre-Shrunk Heat Shrink Tubing" at 12:01AM on April 1st.
Dennis Tillman W7PF
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-----Original Message-----
From: Raymond Domp Frank
Sent: Friday, November 02, 2018 11:47 AM
Subject: Re: [TekScopes] No contribution from David Hess since July 18th
On Fri, Nov 2, 2018 at 07:41 PM, Dennis Tillman W7PF wrote:
Dennis,
Your first message said "his last message on this forum is from July
18th."
which is the date I searched. His last post was actually on July 17.
That is why I missed it.
Ha! My date and times are related to UTC and that said July 18th...
Raymond -- Dennis Tillman W7PF TekScopes Moderator
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Re: No contribution from David Hess since July 18th
On Fri, Nov 2, 2018 at 07:41 PM, Dennis Tillman W7PF wrote: Dennis,
Your first message said "his last message on this forum is from July 18th."
which is the date I searched. His last post was actually on July 17. That is
why I missed it.
Ha! My date and times are related to UTC and that said July 18th... Raymond
|
Re: N channel fet 151-1121-00 -- V10206
Glad to help.
I was misled by those reversed connections many times before I realized why they did it and that it was not a mistake.
Dennis Tillman W7PF
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-----Original Message-----
From: lop pol via Groups.Io
Sent: Friday, November 02, 2018 11:26 AM
Subject: Re: [TekScopes] N channel fet 151-1121-00 -- V10206
Dennis
You are exactly correct. More user failure on my part. Thank you for
pointing that out. On Fri, Nov 2, 2018 at 06:37 PM, Dennis Tillman W7PF wrote:
COMMON MISTAKE: Your photo shows you did not switch the Drain and
the Gate leads when you were using the 7CT1N. I believe when you do
switch them that you will see there is nothing wrong with the FET.
-- Dennis Tillman W7PF TekScopes Moderator
|
Re: N channel fet 151-1121-00 -- V10206
On Fri, Nov 2, 2018 at 07:20 PM, Colin Herbert wrote: Hi Colin,
Hmmm.. I think there was a small clue in the fact that the scope was a 7633. I
might also point out that the Great Detective was Sherlock Holmes - Doctor
Watson was his sidekick...
...and who complimented mr. Watson on his good work in this case? OTOH, there might a clue in the fact that *mr.* Watson was complimented, not *Dr. Watson*. Could it be that we're dealing with a false Sherlock Holmes? Raymond
|
Re: No contribution from David Hess since July 18th
Hi Raymond,
Your first message said "his last message on this forum is from July 18th." which is the date I searched. His last post was actually on July 17. That is why I missed it.
For reasons I can't explain I pressed the wrong button when I searched for his activity on TekScopes and it showed there was none (which I thought was odd).
When I finally pressed the right button just now it showed there was plenty of activity right up to July 17, but none past that.
Groups.io has many nice tools designed to make it easier for the moderator to manage the forum. Now if the moderator could only learn how to use the tools he might be able to do his job better.
Dennis Tillman W7PF
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-----Original Message-----
From: Raymond Domp Frank
Sent: Friday, November 02, 2018 11:23 AM
Subject: Re: [TekScopes] No contribution from David Hess since July 18th
On Fri, Nov 2, 2018 at 07:06 PM, Dennis Tillman W7PF wrote:
Hi Dennis,
My records show he has never posted on TekScopes since we switched to
Groups.io in Dec 2017. There were no posts from him on July 18 of this
year either.
I pm' ed my copy of his message on July 18th as I have it to you.
Raymond -----Original Message-----
From: Raymond Domp Frank
Sent: Friday, November 02, 2018 10:54 AM
Subject: [TekScopes] No contribution from David Hess since July 18th
FYI:
I'm missing contributions from our long time, very active, helpful and
knowledgeable member David Hess. As far as I can see, his last message on
this forum is from July 18th. On October 7th, I sent him a pm but got no
response. No contributions on the HP_... forum either.
Raymond -- Dennis Tillman W7PF TekScopes Moderator
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Re: N channel fet 151-1121-00 -- V10206
Hi Colin (laughing)..yes but Dr Watson was the diagnostician, Raymond may have been doing some spin on the blundering Watson who nevertheless
sometimes got Holmes back on track through some seemingly asinine mumble. Watson, who'd been through the Indian campaigns as a surgeon
was nevertheless grievously hurt when he felt Holmes was displeased with him or mocking him or his chronicles.
I think the Tektronix CRO, an arcane thing , a Pandora's box one might argue , may have been designed by Moriarty.
My regards
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-----Original Message----- From: Colin Herbert via Groups.Io Sent: Saturday, November 3, 2018 4:20 AM To: [email protected]Subject: Re: [TekScopes] N channel fet 151-1121-00 -- V10206 Hmmm.. I think there was a small clue in the fact that the scope was a 7633. I might also point out that the Great Detective was Sherlock Holmes - Doctor Watson was his sidekick... Colin. -----Original Message----- From: [email protected] [mailto: [email protected]] On Behalf Of Raymond Domp Frank Sent: 02 November 2018 17:43 To: [email protected]Subject: Re: [TekScopes] N channel fet 151-1121-00 -- V10206 On Fri, Nov 2, 2018 at 06:37 PM, Dennis Tillman W7PF wrote: Hi Dennis,
COMMON MISTAKE: Your photo shows you did not switch the Drain and the Gate
leads when you were using the 7CT1N. I believe when you do switch them that
you will see there is nothing wrong with the FET.
So a 7CT1N was used. Well done mr. Watson! Raymond -- Jack
|
Re: N channel fet 151-1121-00 -- V10206
On Fri, Nov 2, 2018 at 11:20 AM, Colin Herbert wrote:
Hmmm.. I think there was a small clue in the fact that the scope was a 7633. I
might also point out that the Great Detective was Sherlock Holmes - Doctor
Watson was his sidekick...
Colin.
-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of Raymond
Domp Frank
Sent: 02 November 2018 17:43
To: [email protected]
Subject: Re: [TekScopes] N channel fet 151-1121-00 -- V10206
On Fri, Nov 2, 2018 at 06:37 PM, Dennis Tillman W7PF wrote:
Hi Dennis,
COMMON MISTAKE: Your photo shows you did not switch the Drain and the Gate
leads when you were using the 7CT1N. I believe when you do switch them that
you will see there is nothing wrong with the FET.
So a 7CT1N was used. Well done mr. Watson!
Raymond
Dennis You are exactly correct. More user failure on my part. Thank you for pointing that out.
|
Re: No contribution from David Hess since July 18th
On Fri, Nov 2, 2018 at 07:06 PM, Dennis Tillman W7PF wrote: Hi Dennis,
My records show he has never posted on TekScopes since we switched to
Groups.io in Dec 2017. There were no posts from him on July 18 of this year
either.
I pm' ed my copy of his message on July 18th as I have it to you. Raymond
|
Re: N channel fet 151-1121-00 -- V10206
Hmmm.. I think there was a small clue in the fact that the scope was a 7633. I might also point out that the Great Detective was Sherlock Holmes - Doctor Watson was his sidekick...
Colin.
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Show quoted text
-----Original Message----- From: [email protected] [mailto: [email protected]] On Behalf Of Raymond Domp Frank Sent: 02 November 2018 17:43 To: [email protected]Subject: Re: [TekScopes] N channel fet 151-1121-00 -- V10206 On Fri, Nov 2, 2018 at 06:37 PM, Dennis Tillman W7PF wrote: Hi Dennis,
COMMON MISTAKE: Your photo shows you did not switch the Drain and the Gate
leads when you were using the 7CT1N. I believe when you do switch them that
you will see there is nothing wrong with the FET.
So a 7CT1N was used. Well done mr. Watson! Raymond
|
Re: 425 Mil vertical module needed....seeking
Hi thanks Harvey....yes that's about it.....time saving with a good spares inventory ....replace the faulty aspect of equipment and then send through the system
to component level repairs. Repair was not always attempted and "U/S" tags were plentiful. Reliability and cost were a decision. I recall when aircraft mods were
done in Vietnam conflict we just dumped $millions in unusable inventory, even here. Our (Defence's) vibration and environmental equipment was given to AWA,
which then charged Defence for the use of it. I found that..a kind-of peculiar arrangement. Labour costs yes, but use of the gear wasn't confined to us.
Component level was not always done at Echelon...a level of testing might be done and a decision made whether to send to the manufacturer but at the card level
when it was a card....it may more likely have been tagged 'U/S' scrupulously recorded then binned, later ...perhaps many years later and when security allowed it and the
conflict was over.....go through the 'disposals auctions'. The equipment need to ensure the gear met services' specs was too complex and expensive in some cases.
Reliability warrantied as being certain is primary especially in weaponry and radar you mentioned demands manufacturer-level accuracy. My recollection is that
it was not until after 'Korea' thatmodularisation became common...the TRC77 for example in a small way. Until then changing tubes was the field level repair.
Owing to advice from Dinos I was able to realise what I thought a nightmare, highly inefficient teardown for a small repair was in fact simple...It took about 10 minutes
pull the module once the advice I was given made sense...in the field with spares available it was probably a half hour turnaround. Edgar Allen Poe's fear of the Raven
tapping at his door was no greater than my fear of Tektronix CRO's tapping at my confusion of fear and lust when a Tektronix came sashaying into view. "The best way
to get away from temptation is to give into it" wrote Oscar Wilde,,,"Resist it, and your soul grows sick with longing for the things it has forbidden to itself "
That is mankind's Achille's heel.
One look inside a Tektronix when I was 20 scared me into a sort of misty coma...Milspec radio's...ok....general test equipment ok...BWD CRO's....well ok. Tektronix
aaaaaaaaaaaaagh!! A contact with Tektronix supervisor out at Nth Ryde forty years ago led to hair-raising information on repair costs. I can only thank heaven and
Dinos and Fabio that I bought a Mil unit, unwitting of its advantages. What I thought would be a simple repair isn't at component level but IS at module level.
Reading some of the problems raised even in my brief experience with tekscopes made it clear that this group is an essential part of dealing with Tektronix gear.
One day I suppose, the manufacturers of Prozac and Zoloft will try to buy it out, owing to the business they are losing through the support given each other in forum.
Voila
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-----Original Message----- From: Harvey White Sent: Thursday, November 1, 2018 9:38 AM To: TekScopes@groups. Cc: [email protected]Subject: Re: [TekScopes] 425 Mil vertical module needed....seeking On Wed, 31 Oct 2018 08:56:47 -0700, you wrote: Many of the functions of a Mil qualified piece of test equipment (or flightline, I'm extrapolating from that) are as follows: 1) mil qualified parts (for TTL, for instance, expanded temperature range and +/- 0.5 volt tolerance on VCC rather than 0.25 volts) 2) vibration and temperature tolerances 3) (perhaps most important): the ability to repair a unit by (on the flightline) by replacing an whole unit, for instance, a complete power supply, or a vertical channel, or a CRT/display unit, that kind of thing. This is, I suspect, where the (apparently) massive difference in physical construction might come from. Diagnostics wise, you'd go out to the aircraft, diagnose the radar, and find out what is malfunctioning (transmitter, receiver, processor, etc). You'd black box replace the entire unit. That unit would go back to the depot. At the depot, special test equipment (bought from the radar's manufacturer) would diagnose the failing unit to a particular board. That board would be replaced and the unit would be re-tested. The failing board would go back to the manufacturer for testing and repair. Sound familiar? I'm suspecting that the physical construction of this scope allowed this kind of repair. Not sure, though. Harvey Hello Jack,
What you refer to as 425 Mil is, for correctness sake, a 465M or an AN/USM 425.
It confused me at first, as I didn't recall there was ever a 425 oscilloscope.
For what I know, the 465M is electronically similar to the civilian 465 (but even at electronic diagram level, there ARE differences), but, for the sake of assemblies or sub-assemblies, they're essentially two completely different oscilloscopes (i.e the boards are physically different).
As mentioned on this () page of the TekWiki website, the 465M is more similar to the civilian 455, than it is to the 465.
I can't really tell by how much they are similar, but you may be able to compare them by yourself by looking at the service manuals of both, which are available on the TekWiki website.
The page for the civilian 455 is here:
I don't know much of either (455 or 465M) but, coincidentally, there's a seller on a Brazilian auction site, selling the modules of a Tektronix 455:
I can't tell how similar those modules are (to your 465M) and if they can serve as parts donors, but if you find out that they may help, you can try to contact the seller, or I can help you with the purchase and shipping of the module (or the parts) to your location, for their advertised cost and shipping expenses to your place.
Note: I have no affiliation with the seller (and don't even know if I know them, since the auction site only reveals the seller after you purchase the item).
I normally wouldn't even make this offer, as shipping from Brazil is usually prohibitive and the parts are not even mine... But since you're so far away down under, I think that shipping from anywhere will be just as difficult.
Please let me know if you want my help, or maybe some other folks in the group will chime.
Krgrds,
Fabio
On Tue, Oct 30, 2018 at 06:52 PM, Jack wrote:
Hi. I'm a new member finding my way. I bought a lot of Tektronix scopes for
the services when with Defence during Vietnam era and visited Tektonix at
North Ryde (NSW)
to see about repairs to (I think it's a 564) I still have....still not working
I guess after having a new very high voltage insulated transformer wound for
CRT filament...two actually, the other must be around "somewhere". I
developed a healthy fear of Tektronic CRO's owing to the prices Tektronix
charged for repairs..
I have a 425 Mil with broken switch.in Vertical section It's unrepairable.
Whilst I could sooner or later find a parts CRO, sight unseen on eBay for
example, it may also be on the way out. I think the plastic used in Tektronix
may be the lowest quality amongst high quality devices , or maybe they just
specify 'shall be or a type formula and manufacture which will maintain all
utility until the end of time'
I was directed to your group (Hi...there) . To get to the essential point
Would some person have a reasonably low mileage vertical module, complete,
which I could buy? Please advise me if so....Australia would be best of course
but 'anywhere'. Also...to undo some confusion...I've been told 425 and 465 are
"intrinsically" the same CRO...obviously without the Mil labelling... . Does
that mean parts are interchangeable?
One reason I ask is that I was also told that the 425 being Military contract
and Mil Spec was built to be readily pulled down for field repairs. Is that
true?...Is that a quality the 465 does not replicate? if so it may mean that
...just as an example...the vertical amp module from a 465 may have some
mounting differences from the 425.
On the other hand it may not. Perhaps someone familiar with this type will
bring me to a state of awareness even wisdom regarding my CRO. ...oh... other
than having one channel down it seems to work ok and 'oh' again...when I
originally pulled it down a piece of curved springy metal fell out. Whence it
exactly originated I have no idea...'somewhere inside'. .It may be a method
of maintaining the case at frame potential, under pressure as one reassembles
the CRO...so perhaps it 'jammed' between a plate on the chassis and the
bottom cover. It could have come from elsewhere or it might not be from the
CRO at all.....That said, Im pretty sure I saw an exploded view one time where
this curved metal piece as shown hanging in mid-air underneath the chassis.
Have I been able to find that particular exploded view again (that was 3 years
ago)...of course not!!
Any passing of knowledge wisdom common sense mindfulness and most of all
perhaps a complete vertical amplifier will be very well received.
--
Jack
-- Jack
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Re: No contribution from David Hess since July 18th
Hi Raymond,
My records show he has never posted on TekScopes since we switched to Groups.io in Dec 2017. There were no posts from him on July 18 of this year either.
Dennis Tillman W7PF
toggle quoted message
Show quoted text
-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of
Raymond Domp Frank
Sent: Friday, November 02, 2018 10:54 AM
To: [email protected]
Subject: [TekScopes] No contribution from David Hess since July 18th
FYI:
I'm missing contributions from our long time, very active, helpful and
knowledgeable member David Hess. As far as I can see, his last message on
this forum is from July 18th. On October 7th, I sent him a pm but got no
response. No contributions on the HP_... forum either.
Raymond -- Dennis Tillman W7PF TekScopes Moderator
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Raymond Domp Frank
Michael A. Terrell
Jeff Urban