On Sat, 3 Nov 2018 04:16:17 +1000, you wrote: You'd be surprised that the basic difference (perhaps) in the MIL units vs. the commercial units is the ability to remove subsystems. This does not always follow with (for instance), TM500 and TM5000 series. Scopes, however, I'm willing to go with a different model. Having said that, the schematics are often quite similar, and if you can repair a MIL unit without black boxing it, you can repair a civilian unit (especially by swapping boards.... <innocent look>). The similarity happens when you do what's equivalent to depot level test (and my job was mostly designing flightline test equipment). Regardless of the complexity of the item, once you start to diagnose down to a component (if possible), it's really the same thing, regardless of where it happens, depot, manufacturer's testing and rework, or your own lab. Harvey 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
-----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
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