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Re: First post - Hello and a question

Richard W. Solomon
 

I have repaired many a TEK scope, most of the 7603's were the result of
human destruction not circuit failure. And of those not needing repair, I
have found most of them to be within tolerance and NOT needing re-cal.
Detroit should make cars as well designed and built as the 7603.

73, Dick, W1KSZ

-----Original Message-----
From: Kuba Ober <ober.14@...>
Sent: Feb 6, 2007 11:25 AM
To: TekScopes@...
Subject: Re: [TekScopes] First post - Hello and a question

On Monday 05 February 2007 19:54, you wrote:
I would recommend the 7603 with a 7B53 Time Base and a couple of 7A18
Vertical Amps. You can get that combo for $125 or less. With the plethora
of other plug-ins available you would have a versatile system that is
easily repairable
Assuming you have approxv $1000 worth of other test equipment needed to
recalibrate said 7603 :)

It's an easily snowballing hobby.

Cheers, Kuba



Yahoo! Groups Links



Re: old fashioned 535 - first start after 35 years

Michael Petereit
 

Stan,

I checked the voltages:
+100V = 124V
+225V = 203V
+350V = 306V
+500V = 464V
-150V = -144V

A lot voltage is below the limits. The main supply is switched to 234V,
the current standard voltage is 235V on the power line.
I assume the rectifier might be broken. Since the hartley oscillator is
powered by the +350V line and coupled with the +340V line according
schematics the tube might not run as expected. The frequency must be
aroung 50kHz but I do not have a AM receiver to check ans again the dirt
inside the scope is expecially around the HV and this oscillator horrible.

Any other ideas about the lower voltages ?

BR,
Michael


Stan and Patricia Griffiths said the following on 05.02.2007 22:02:


Hi Michael,



If the relay is opening again after closing, it is not getting coil
voltage from its own contacts. If you burnish (clean) the relay
contacts, it will probably hold in until the power switch is turned off.



It is not usually necessary to check the +8650 volts on the CRT
anode. If the -1350 is present, then the +8650 will be OK. All of
the other power supplies must be working properly before you bother to
measure the -1350. The other supplies are: -150, +100, +225, +350,
and +500.



Stan



------------------------------------------------------------------------

*From:* TekScopes@... [mailto:TekScopes@...]
*On Behalf Of *Michael Petereit
*Sent:* Monday, February 05, 2007 8:19 AM
*To:* m38a1_1962
*Cc:* TekScopes@...
*Subject:* Re: [TekScopes] Re: old fashioned 535 - first start after
35 years



I tried again. Since the CRT is completely covered I cannot see any
filament working.
Shortly before the tube's diameter gets wider some connectors for
deflection I guess. Even there some color avoid having a look onto any
filament.
Is it really colour or might it be dirt ?
The tube is such long you can't have a look from the back unless you
remove the backcover. But I would like to avoid as much disassembling as
possible unless it worked once. Then any other cleaning will happen and
I try to "renovate" the item.

I'll try to get a high voltage adapter for my Gossen multimeter. Then
I'll check the -1350V and the 8960V.

br,
Michael

m38a1_1962 said the following on 05.02.2007 03:35:

Before you go too far with the chassis cleaning and wholesale tube
testing, check and repair the low voltage power supplies first (be
especially wary of the bypass capacitors across the precision voltage
divider resistors). If the voltages are all in tolerance, look at the
high voltage rectifier tubes under the top HV cover to see if their
filaments are glowing. This will tell you if the HV oscillator is
working. If they are glowing, the CRT filament should also be glowing.
You won't be able to fix anything else until the power supplies are
working. BAMA has a 535_545 manual listed for free download if you are
in for some troubleshooting. Good luck.

--- In TekScopes@... <mailto:TekScopes%40yahoogroups.com>
<mailto:TekScopes%40yahoogroups.com>,
Artek Media <manuals@...> wrote:


__________ NOD32 2040 (20070206) Information __________

This message was checked by NOD32 antivirus system.


Re: First post - Hello and a question

arthurok
 

he needs something simple
he is at 0 right now
im not sure he could even repair an o scope
even a chinese 20 mhz no delay line scope would do for his needs.
i think he should buy the newest most reliable scope that he can find for his money thats also easy to repair
the 422 is a great audio scope but old

----- Original Message -----
From: Kuba Ober
To: TekScopes@...
Sent: Tuesday, February 06, 2007 10:25 AM
Subject: Re: [TekScopes] First post - Hello and a question


On Monday 05 February 2007 19:54, you wrote:
> I would recommend the 7603 with a 7B53 Time Base and a couple of 7A18
> Vertical Amps. You can get that combo for $125 or less. With the plethora
> of other plug-ins available you would have a versatile system that is
> easily repairable

Assuming you have approxv $1000 worth of other test equipment needed to
recalibrate said 7603 :)

It's an easily snowballing hobby.

Cheers, Kuba


Completely free stuff, tek and others, but you have to pick it up.

wshawlee2
 

I am doing a big clean up and toss-out over the next month or two, and
a lot of tek bits are going to hit the dustbin (especially 7K ad 5K
stuff). I just have to have the space back for other things. Also
lots of fluke and HP left overs, etc. I found a big box of switching
power supplies for 7K frames, for example.

I don't have time or desire to pack and ship it, but for anybody
thinking of trip up this way to beautiful BC (Kelowna), let me know,
and I will start a pile for you. contact me off list for more
details. even with thousands of feet of space, and two storage
buildings, we are just out of space, so some stuff has to die. This is
the moment.

all the best,
walter
sphere research


11K Series question, is there anything other than 11A plug ins?

wshawlee2
 

I have never seen one, but I can't help but wonder, does any plug in
exist for the 11K series of frames OTHER than a simple vertical
11A-series unit?

sweep is internal to the frame, so I can't see any use for a sweep,
but curve tracer, logic analyzer of spectrum analyzer, maybe? Has
anybody run 7K plug in there with much luck? I have noted some
earlier postings with comments that they do function, but with no
remote control or readout.

Anyway, I got a few 11K frames and plug ins, and am going to start
tinkering, so I'm happy to hear from anybody that has experience with
these.

ALSO, still trying to find 2505 software and 25A series plug-ins, if
you can help, please let me know,
all the best,
walter
sphere research


Re: First post - Hello and a question

Kuba Ober
 

The 7000 series was the premium line of its day. They were built for
pure performance, not to fit a modest budget.

The only thing against them today is the fact that they're getting a
bit old, and failures in the scope mainframe power supplies are pretty
common now. Those failures are cured by replacing the tantalum caps
in the switch mode power supply more often than not. It's a pretty
simple repair that costs just a few bucks plus your labor.
I'd suggest staying away from switcher-based mainframes for a casual user not
interested in playing with a disassembled scope that much :)

7603 has a benign linear power supply, big screen, and with two 7A22s and a
time base is more than enough for serious audio work (checking CMRR, noise,
what have ya).

Cheers, Kuba


Re: First post - Hello and a question

Kuba Ober
 

On Monday 05 February 2007 19:54, you wrote:
I would recommend the 7603 with a 7B53 Time Base and a couple of 7A18
Vertical Amps. You can get that combo for $125 or less. With the plethora
of other plug-ins available you would have a versatile system that is
easily repairable
Assuming you have approxv $1000 worth of other test equipment needed to
recalibrate said 7603 :)

It's an easily snowballing hobby.

Cheers, Kuba


CRT differences

 

I have often wondered about the actual differences in Tektronix CRTs.
Within a basic class the tubes appear to be identical except for the part number.
Please cut me lots of slack on the word appear.
Just for example take the 465/a/b/m, 2213/3a/15/15a,and many others.
Quite some time ago, I got a nice 465B for almost nothing and it had a dead crt.
I had almost nothing to lose so I tried a jug from a 465M which had a badly
broken case.
It has been running fine for about four years now.
Any thoughts?


Re: Tek 2235 HV Multiplier

georgeplhak
 

TEK obviously had a second source for these.
The actual U975 in my 2235 (that may need one) is labeled:

"152-0806-00
MSL8513
MURATA
8544"

The 8544 is probably the date code.

A quick search of MURATA and UNITRODE websites doesn't get any hits on
either the TEK pn or the mfr pn. Sphere doesn't seem to have any.

George Plhak, Acton, Ontario, Canada

--- In TekScopes@..., "georgeplhak" <ffwd@...> wrote:

I may need one of these also.

The Tek pn is 152-0806-00
Mfr is Unitrode Corp. Watertown, MA Their pn CMX647

It is described in the TEK circuit description as:

"High voltage mutiplier U975 utilizes the 2-kV winding of T948 to
generate 12 kV (so it is 6X) to drive the crt anode. It also uses an
internal half wave recifier diode to produce -2 kV for the crt cathode."

George Plhak, Acton, Ontario, Canada


Re: Tek 2235 HV Multiplier

georgeplhak
 

I may need one of these also.

The Tek pn is 152-0806-00
Mfr is Unitrode Corp. Watertown, MA Their pn CMX647

It is described in the TEK circuit description as:

"High voltage mutiplier U975 utilizes the 2-kV winding of T948 to
generate 12 kV (so it is 6X) to drive the crt anode. It also uses an
internal half wave recifier diode to produce -2 kV for the crt cathode."

George Plhak, Acton, Ontario, Canada



--- In TekScopes@..., "Deane E. Kidd" <dektyr@...> wrote:

Hi from Deane:
Yes, I am still alive and well and still rather sarcastic as
follows. You want the HV multiplier from the 2235 scope but you don't
include the Tek part number. Yes, I can go find the manual and then
the schematic and thefile number and then the part number, but you
have the part in your hand. All of us that have parts for Tek items
use the same part numbers and it sure makes it easier to help. I have
about one hundred multipliers and I know that I don't have the 465M
multiplier but I don't know the number for the 2235.
Deane

----- Original Message -----
From: Kevin John Chadwick
To: TekScopes@...
Sent: Monday, February 05, 2007 4:17 PM
Subject: [TekScopes] Tek 2235 HV Multiplier


Hi All,

Two questions:

Anyone heard from Deane Kidd recently? Is he still answering e-mails
(vacation?).

I am looking for an HV multiplier for a really good 2235. If I cannot
locate one at a reasonable price I would like to build one using
discrete diodes and capacitors (12 kV for HV and -2kv for focus).
Anyone know what is inside the original multiplier circuits? - or has
a scrap 22xx complete with multiplier for sale?

I have checked the archives but can find very little on the 2235
multipliers just lots about 547s. Trying to remove the potting from
the failed unit seems to be just about impossible. The existing HV
multiplier still works but loads down the power supply and prevents
the -8.6 v from getting past -8.3 before the current limiter kicks in.
Presumably the existing multiplier is leaky when the high voltage is
generated.

Thanks for any information.

Kevin C
Ottawa ON





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Re: First post - Hello and a 335 paean

Ashton Brown
 

While Stephen did not elaborate on "other desirables" -
When covering the field, it is good to point out the surreal nature of the test equipment market in Murica, as it moves from engineering excellence on to the (ever slightly-sleazy.. like Babbitt) milieu of marketers, of mere repackagers of goods created by less lazy minds. Imagine.. Gigahertz 7104s, for a few $hundred. Items our Lab could not afford are now literally:
pearls before swine. By the pallet-load. A Rorshach ink blot proof of a declining civilization, I wot.

{Oink..}

ie you can afford Two scopes, at least! - when a 500 MHz scope can oft be had for ~100ish or a bit more, if it is shown with a trace.
Of course: a 7000 series, at very least a 7603, but frequently the higher bandwidths will be just as absurdly priced - a daily eBay crap shoot.

I nominate though, for portability - the magic of Tek, executed in the land of Seiko (and of most autos on US roads today) -- the Sony-Tek 335 - weighing a tad over Ten Pounds (4.7 kg.) 35 MHz nom. 1 mV/DIV @ 25 MHz for those audio preamp thingies.

All the delayed sweep bells & whistles of a Titanic-sized, utterly unportative 545 ... shrunk to the size of your average 5+ digit lab dvm. Capable of operation on most any AC or DC voltage around. Of course too, one needs a watchmaker's patience for certain (rare) maintenance efforts - the price of miniaturization. Still, it is a marvel - and in its gold plated attenuator area - a work of art. Even if it didn't work.

It does, however. And because of this ongoing fire sale of our superfluous engr'g. tools: again, buy Two.
(Thus have spare parts for as long as the power grid stays up. Then go solar (or put a paddle on a car alternator and use the creek by your house: 2 amps at 12V is all you need.))


My 1000 ???,


Ashton - who has not yet fully assimilated the pewling surrender of a civilization to Suits, to the crass marketing of megatons of mindless trinkets - and to corporate cubicles with hamster wheels provided for the fungible inmates.
(Y'see ... I once watched someone at Beaverton assembling a 1A1 preamp, way-back, way before terminal National Dumbth had set in.)


O/T: Cherenkov Radiation

Dave Casey
 

Since there was some discussion about this awhile back, I'd like to point out that there's a neat picture of Cherenkov radiation in the February 2007 issue of IEEE Spectrum. It can be found on pages 38-9.

Dave Casey


Re: Replacement to DS1230AB Lithium backed NVRAM

 

ST pioneered built-in battery backed up SRAMs with their MK48Z products many
years ago.

The Dallas parts were interesting inside. Seemed to work OK but I'm betting
most of the engineers in this group wouldn't have been happy with the sloppy
pre-encapsulation construction techniques (through-hole components on a PCB
in those days).

Eventually a third vendor, Benchmarq (later bought by Texas Instruments),
introduced their version of the products.

For a long time, ST offered the only Surface Mount version (heat from reflow
soldering plus coin cell battery was a bad combination). They came up with
their SnapHat product where the the battery (can't remember if any of the
control electronics are in it as well) is "snapped" onto the surface
mountable main portion of the component after the soldering process is
complete, etc. Maxim/Dallas now has their PowerCap version. I assume TI
has something similar.


A couple of other approaches:

Use a Dallas Smartsocket. Has the battery backup and associated electronics
in an IC Socket. One adds the low power SRAM of one's choice.

Simtek offers non-volatile SRAM products which don't require a battery.
During power-up the data in the non-volatile memory is written to SRAM and
vice-versa during power down. The rest of the time one is reading/writing
to the SRAM so the wear out issue present in the attempted Ramtron solution
is not present. Their current product offering is vastly improved over
their older product offering. Their original fab, ZMD, eventually produced
their own competing products for sale and later sold that portion of their
memory business to Simtek. Gave them products with increased densities and
SRAM compatible footprints.



- Greg




_____

From: TekScopes@... [mailto:TekScopes@...] On Behalf
Of John Miles
Sent: Monday, February 05, 2007 4:00 PM
To: TekScopes@...
Subject: RE: [TekScopes] Re: Replacement to DS1230AB Lithium backed NVRAM



Well, what fun would it be otherwise? Heh...

Would be nice if someone could X-ray one of those puppies to determine where
the cell actually is. But the equivalent part numbers are even more useful;
thanks for posting those.

-- john, KE5FX

-----Original Message-----
From: TekScopes@yahoogrou <mailto:TekScopes%40yahoogroups.com> ps.com
[mailto:TekScopes@yahoogrou <mailto:TekScopes%40yahoogroups.com> ps.com]On
Behalf Of Victor Silva
Sent: Monday, February 05, 2007 1:54 PM
To: TekScopes@yahoogrou <mailto:TekScopes%40yahoogroups.com> ps.com
Subject: [TekScopes] Re: Replacement to DS1230AB Lithium backed NVRAM


Be very careful here. There's a reason the Postal Service will not
even ship Lithium cells and it is illegal to ship them via air cargo.

If you happen to dremel into the cell, not only are you getting the
caustic material flung all over, the cell will most likely short-
circuit when it is cut into. Lithium cells can start fires if they
are shorted.

ST has equivalents to the DS devices used in both the 2465B and the
243X/40. The ST devices are slightly lower priced.

ST Micro 8Kx8 DS1225AB equiv. M48Z58Y-70PC1
ST Micro 32Kx8 DS1230 (DS1235) equiv. M48Z35Y-70PC1

--Victor


--- In TekScopes@yahoogrou <mailto:TekScopes%40yahoogroups.com> ps.com,
"John Miles" <jmiles@...> wrote:
Is it practical to
Dremel the Dallas part open and replace its integral lithium cell
with an
outboard cell?

-- john, KE5FX




Yahoo! Groups Links




Re: First post - Hello and a question

 

If you will be aligning Tuners, the 5000 series won't do. You will
need something that will get out there. I've read that one needs to
have three times the bandwidth of the observable measurement. So for
FM, ya gotta get out there! [snip]
Just to stick up for the 5000's, there _is_ a 1Ghz sampler, the 5S14N,
basically a 7S14 repackaged slightly. But I am not familiar with
aligning sets, so I don't know if sampling would work for that
application.

BTW, anyone have a spare 5S14N they don't need? :)


Re: Schematic for the 465M as in Military not the 465 or 465B

Deane E. Kidd
 

Hi Charles:
The 465M is not a variation of the 465 or 465B but is a vertical amplifier change from the 455/A2/B2 scope. I just copied the schematics for the 465M for you but I have not heard from you since I made the offer to copy them for you. There are 9 pages 11 x 17. The cost is $3.00 with postage prepaid in the USA. Please advise with your mailing address if you want this set.
Deane

----- Original Message -----
From: Charles A. Pratt
To: TekScopes@...
Sent: Monday, February 05, 2007 9:27 PM
Subject: [TekScopes] Schematic for the 465M as in Military not the 465 or 465B


Hi,

I would really like the schematics for the 465 Military, I am trying to
trouble shoot my scope -5 is gone I have replaced the caps.

I have downloaded the avalible manuals and they are helpful but no
schematics.

I need the M series schematic not the B or the standard 465 they are
different.

Regards,

Charles





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Re: 7D20 input attenuator

arthurok
 

deane kidd might have the parts

----- Original Message -----
From: Lawrence Glaister
To: TekScopes@...
Sent: Monday, February 05, 2007 11:32 PM
Subject: [TekScopes] 7D20 input attenuator


Greetings to the list.

I have been working on restoring a 7D20 module in my R7704 mainframe. I
have everything working except the CH1 input attenuator (A12 hybrid
board on the A4 preamp module). The 2 latching relays on this board are
dead... they are intermittent and look like they have overheated. Does
anyone have a junked 7D20 that I might be able to salvage this assembly
from? Everything is so close to working, but the broken input attenuator
makes CH1 pretty much useless.
cheers

--
=================================================================
Lawrence Glaister VE7IT ve7it@...
1462 Madrona Drive
Nanoose Bay BC
Canada V9P9C9
=================================================================


7D20 input attenuator

Lawrence Glaister
 

Greetings to the list.

I have been working on restoring a 7D20 module in my R7704 mainframe. I
have everything working except the CH1 input attenuator (A12 hybrid
board on the A4 preamp module). The 2 latching relays on this board are
dead... they are intermittent and look like they have overheated. Does
anyone have a junked 7D20 that I might be able to salvage this assembly
from? Everything is so close to working, but the broken input attenuator
makes CH1 pretty much useless.
cheers

--
=================================================================
Lawrence Glaister VE7IT ve7it@...
1462 Madrona Drive
Nanoose Bay BC
Canada V9P9C9
=================================================================


Re: First post - Hello and a question

J Forster
 

From: "jones_chap"

[Snip]

If you will be aligning Tuners, the 5000 series won't do. You will
need something that will get out there. I've read that one needs to
have three times the bandwidth of the observable measurement. So for
FM, ya gotta get out there! [snip]

You don't need much BW to align FM tuners. All you need is an RF (diode)
probe and a sweep generator that covers the RF and IF frequencies
(markers are a plus). You have to sweep the IF and adjust the IF
transformers for the correct envelope response. If you don't want to
use an RF probe, you only need something that will see and be fairly
flat across the IF frequency.... usually 10.7 MHz. In receivers with
ceramic IF filters, alignment is essentially moot. A 60 MHz scope
(think 7603 or 465) would do fine, IMO.

-John


Schematic for the 465M as in Military not the 465 or 465B

Charles A. Pratt
 

Hi,

I would really like the schematics for the 465 Military, I am trying to
trouble shoot my scope -5 is gone I have replaced the caps.

I have downloaded the avalible manuals and they are helpful but no
schematics.

I need the M series schematic not the B or the standard 465 they are
different.

Regards,

Charles


AM501 Stuff.

jones_chap
 

Beside collecting TM500 plugins, anyone actually usem, in particulars,
the AM501. Just got two of em.

I'd like to use a FG504 & FG501A plus other signal generators to
create all different types of waveforms. Integrating,
differentiating, ...

Any suggestions? Any neat experiements?

Specificatioins of the AM501? Comparisons with modern OP-Amps?

Thanks.