Date   
7586 Nuvistors on sale

Dr. Charles E. Morris <charlesmorris@...>
 

FYI, Antique Electronic Supply (tubesandmore.com) has new-in-box 7586
Nuvistors on sale for $11.20 each, through July 15.

I just bought two for a plugin repair and to have a spare. They are
Sylvania, date coded 1978. This is much cheaper than the $25-$30 most other
places (including AES, normally $30.25). There is allegedly a supply of
Russian-made ones for $3.50 each from a guy in Lithuania but who knows.
Stock up now!

-Charles
(no connection to the company).

Re: Input Capacitance and using new probes on older scopes.

Craig Sawyers <c.sawyers@...>
 

3.The P6055 probes mentioned by Craig are 35 MHz and are for 20 to
27pF.
Groan. The bandwidth of the P6055 is 60MHz not 35MHz. Looks like another
minor typo on Stan's site.

Cheers

Craig

Re: Input Capacitance and using new probes on older scopes.

Craig Sawyers <c.sawyers@...>
 

3.The P6055 probes mentioned by Craig are 35 MHz and are for 20 to
27pF.
Just noticed that one. I'm fairly certain that is a typo on Stan's site (I
guess that is where you got that data?). The P6055 is good for 20pF - 47pF
input C, and was the original recommended probe for the 7A22.

Cheers

Craig

Re: Input Capacitance and using new probes on older scopes.

Craig Sawyers <c.sawyers@...>
 

1. Can anyone confirm input C of a 7A26? (I think it is also 20 pF
like the 475 so I could use the same probes.)
1M, 22pF

2.Do any of the 7000 series vertical plug-ins have built in power for
the P6201, or was that probe unique to the 475 and 475A?
The probe power comes from the mainframe. Just about all of them have two
probe power outputs on the rear panel, except I think the original 7704 (go
for the 7704A instead).

3.The P6055 probes mentioned by Craig are 35 MHz and are for 20 to
27pF. The input of the LA22 says 1 Meg+47pF. Can you help me figure
that one out. Can one use regular, higher bandwidth probes like the
6106A in that LA22 with good results or do I have to go on a quest
for a pair of 6055's.
Well, a matched pair of P6055's will maintain the CMRR through to the
measurement. However, other useful probes that will compensate to 47pF are
the P6101A (1x, 15-ishMHz with 2m cable), P6105A (10x, 100MHz), and P6062B
(1x/10x switchable, 6MHz/100MHz with 2m cable). Also the P6135A, in current
production, is the development of the P6055, goes to 150MHz and compensates
to 47pF, and is available in matched pairs. On the Tek site the prices say
"contact us", so it *may* be about to go out of production. They do
occasionally crop up on eBay though (you need a set of "blue" tips to handle
47pF scope input C).

4. Most of the newer, wider bandwidth probes like the P6138 are
designed to compensate for lower input C of newer scopes (12 to 18pF)
Can the 20 pf input C of the 475 and some of the 7000 series vertical
amplifiers be modified to lower the input C to work with the newer
probe, (In other words, is there a pad capacitor in parallel with the
input connector that could be made even a few pFs smaller to bring
the total input capacitance into, say, the 15pF range instead of
20pF.
Well, just looking at the 7A26 schematic (22pF), the only padding capacitor
is a 0.2-1.5pF trimmer - so the nominal 22pF input capacitance is what you
get from the attenuators themselves, trace capacitance, the input FET (and
associated circuitry) and the BNC connector. So I think that the answer is
"no".

Or just stick with the older probes. I've stocked up with NOS ones where
possible, or excellent used ones from eBay - and trust me, age is no
disadvantage. Newer ones might be slightly smaller at the probe tip, but
the P6055, P6101 and P6105 are pretty darn small (tricky to probe surface
mount chips though - only the newer probes have tiny clip accessories to
grab a SM pin).

Cheers

Craig

Re: Input Capacitance and using new probes on older scopes.

fjh001 <javier2945@...>
 

--- In TekScopes@..., "tss_steve_990" <stevehogan@s...>
wrote:


1. Can anyone confirm input C of a 7A26? (I think it is also 20 pF
like the 475 so I could use the same probes.)
I've two 7A26, one is marked 20pF and the other is marked 22pF

2.Do any of the 7000 series vertical plug-ins have built in power
for
the P6201, or was that probe unique to the 475 and 475A?
Power connector for P6201/P6202 probes is on the mainframe, not in
the plugins. I think that some mainframes has two outputs (like the
7904), and others has only one output connector.

Regards,

Javier

Input Capacitance and using new probes on older scopes.

tss_steve_990
 

I am awaiting the arrival of a late model, excellent condition 475
scope which will be my portable. Thanks to all of you who pointed
out the value and flexibility of the 7000 series products, I am also
going to start putting together a mainframe for the shop. The 7A22
plug-in that Craig Sawyer pointed out really does look useful for
audio. The 7A26 Plug ins look like the standard 200 Mhz vertical amps.
I'm searching at the present time for some P6106A probes which seem
to be a good match to the 1Meg + 20 pF input of the 475. The P6201
FET probes have built in powering from the 475, so they look like a
good thing to have, too.

I have a few questions:

1. Can anyone confirm input C of a 7A26? (I think it is also 20 pF
like the 475 so I could use the same probes.)

2.Do any of the 7000 series vertical plug-ins have built in power for
the P6201, or was that probe unique to the 475 and 475A?

3.The P6055 probes mentioned by Craig are 35 MHz and are for 20 to
27pF. The input of the LA22 says 1 Meg+47pF. Can you help me figure
that one out. Can one use regular, higher bandwidth probes like the
6106A in that LA22 with good results or do I have to go on a quest
for a pair of 6055's.

4. Most of the newer, wider bandwidth probes like the P6138 are
designed to compensate for lower input C of newer scopes (12 to 18pF)
Can the 20 pf input C of the 475 and some of the 7000 series vertical
amplifiers be modified to lower the input C to work with the newer
probe, (In other words, is there a pad capacitor in parallel with the
input connector that could be made even a few pFs smaller to bring
the total input capacitance into, say, the 15pF range instead of
20pF. Such a modification might totally mess up the attenuator
frequency response or it may not. I have no idea, but
I am guessing that the people in this group do know, and perhaps will
be willing to clue me in.

Thanks,

Steve Hogan
One last

Re: 7603

Robert Morein <morepub@...>
 

The driving amplifier won't be bothered by a shorted load?

----- Original Message -----
From: Stan & Patricia Griffiths
To: ukcartman
Cc: TekScopes
Sent: Saturday, July 12, 2003 12:43 PM
Subject: Re: [TekScopes] 7603


On the off hand chance that your beam finder is also broken or the trace is
SO FAR OFF screen that the beam finder won't find it, try shorting the CRT
vertical plates together right at the CRT and see if that gives you a trace
or not. It should (if your sweep is running and the horizontal amp works).
This should cause no damage to the instrument if you don't brush one lead of
the shorting wire against ground as you do this . . .

Stan
w7ni@...

----- Original Message -----
From: "ukcartman" <johnbloom@...>
To: <TekScopes@...>
Sent: Monday, July 07, 2003 3:05 PM
Subject: [TekScopes] 7603


> Hi,
> Can anyone help with the fault on this one? I have readout but no
> trace on screen, this is the same on the beam find switch so it
> appears that the trace is not there, not just off screen.
> Thanks,
> John.
>
>
>
>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>
>


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Re: Falcon on the launchpad.

Stan & Patricia Griffiths <w7ni@...>
 

You definitely need a manual set for this system. Timebase A not working
will be a serious problem since there is no sawtooth output from timebase B
and you definitely need it to make the L20 work.

90% of all scope problems are in the power supply so you should start there
by checking to see if you have -150, +100, +225, +350, and +500 within 2%
and regulating properly. The procedure for doing this is in the manual . .
. Once you know the power supplies are working, then you can proceed to the
rest of the scope. By the way, a plugin MUST be installed in the scope to
put the proper load on the power supplies to make them regulate. There was
a "Test Load Plugin" made by Tek for this very purpose but you don't really
have to have one of those to make the scope work. It just helps to make
sure it is working 100% correctly.

Also, I faintly recall that some modifications may need to be installed in
the 585 to make the sawtooth compatible with the L20 but this will require
some research on my part to be sure. No point in doing this until you get a
set of manuals and get the A sweep working again.

Another useful trouble-shooting technique is to locate someone with a known
good scope to test the L20 in separately. If it doesn't work in that one,
you probably have an L20 problem, too, however, don't overlook that this
other scope may need sawtooth out mods, too, for the L20 to work in it.

Good luck on this and ask again when you have verified the 585 power
supplies and have A sweep working. By the way, if the power supplies are
working and A sweep is not, it is very probably a bad tube in A sweep
somewhere . . .

Stan
w7ni@...

----- Original Message -----
From: "eternalesquire" <eternalsquire@...>
To: <TekScopes@...>
Sent: Saturday, July 12, 2003 8:10 PM
Subject: [TekScopes] Falcon on the launchpad.


Hi everyone!

Thanks for all the advice so far. I've located the sawtooth
source on the 585, but got no signal from there. I put back
the original 82 plugin to test the 585 as a scope, and have
discovered that timebase A is not working, but that timebase B
however is.

Does anyone have suggestions for how I should begin debugging
timebase A?

Thanks again,

The Eternal Squire







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Re: Falcon on the launchpad.

Craig Sawyers <c.sawyers@...>
 

Does anyone have suggestions for how I should begin debugging
timebase A?
OK. First try free-running the timebase by setting the "Stability" control
fully clockwise. If there is still no trace when the "Horizontal Display"
switch is in the "A" position, then there is a fault in the A timebase
generator circuit. Here is what the manual says (you absolutely *must* get
a manual! It is the only way to ensure sanity with one of these units)

"No Horizontal Sweep
====================
If the Time-Base "A" generator is not producing a sawtooth sweep voltage
when the Stability Control is adjusted for a free running sweep, some defect
in the generator is holding the Miller Runup circuit. Depending on the the
on-off states of the Disconnect Diodes V152 (6AL5), the Miller Runup circuit
may be held at either the high end or the low end of the sawtooth. The
manner in which it is held may be determined by measuring the voltage at the
Sawtooth A binding post. If the Miller Runup circuit is held at the high
end of the sawtooth the front panel binding post may measure about +300V; if
held at the low end the voltage at this point will measure anywhere between
ground and -20V, depending on the cause. If it rests at -20V, the trouble
probably is non-conductance of V152A, and it should be replaced. It could
also mean that R151 (1k, between pins 7 and 8 of V152) is open.

If the Miller runup circuit is held at the high voltage end of the runup,
replace V152 as it can mean that both heaters can be open or its cathode can
have low emission and give the same effect. Usually if V161 (6CL5) is not
conducting, B167 wil be glowing brightly.

In the event the front panel Sawtooth A connector voltage rests at +350V,
there is probably a plate to grid short within V173 (6DJ8); replace it.
When this occurs B167 glows brightly at the electrode attached to pin 6 of
V161. If this reverse conduction condition is permitted to contine for
longer than about 15 minutes it may be necessary to replace B167 with a new
neon glow tube. The reason for this is that B167 may be unstable
thereafter.

If the heater of V173 is open, both neon glow tubes will be glowing brightly
and there will be no sweep.

If all the tubes have been checked, then check for open plate or cathode
resistors in the Sweep Gating Multivibrator circuit, the Hold-Off circuit or
the runup CF circuit. Also check that the Stability control can vary the
voltage at the grid of V135A"

Good luck!

Craig

Re: Falcon on the launchpad.

Robert Morein <morepub@...>
 

The pulse shaping tubes in the timebase frequently fail to work without testing bad.
Any tube with less than 90% emission should be swapped.

----- Original Message -----
From: eternalesquire
To: TekScopes@...
Sent: Saturday, July 12, 2003 11:10 PM
Subject: [TekScopes] Falcon on the launchpad.


Hi everyone!

Thanks for all the advice so far. I've located the sawtooth
source on the 585, but got no signal from there. I put back
the original 82 plugin to test the 585 as a scope, and have
discovered that timebase A is not working, but that timebase B
however is.

Does anyone have suggestions for how I should begin debugging
timebase A?

Thanks again,

The Eternal Squire




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Falcon on the launchpad.

eternalesquire <eternalsquire@...>
 

Hi everyone!

Thanks for all the advice so far. I've located the sawtooth
source on the 585, but got no signal from there. I put back
the original 82 plugin to test the 585 as a scope, and have
discovered that timebase A is not working, but that timebase B
however is.

Does anyone have suggestions for how I should begin debugging
timebase A?

Thanks again,

The Eternal Squire

Re: 7904 Mainframe production dates

Stan & Patricia Griffiths <w7ni@...>
 

I guess I need to step in here and explain a little about Tek's serial
number system. It is covered pretty well in my book on page 39, but here is
some helpful info.

The earliest Tek instruments started with 3 digit numbers and Tek always
skipped the first 100. That means the first one off the line was s/n 101.
Numbers below 101 were used for protypes and only a few of them made it to
the surplus market, mostly through Tek employees taking them home (with
permission) after the design was complete. They stamped these numbers
directly on the panel. Later, the numbers were stamped on an aluminum
insert and leading zeros were added to make the number 6 digits. Sometimes
at the introduction of a newer model like when the 545A replaced the 545, a
bunch of numbers were skipped and the new instrument started serial numbers
at a higher convenient place like 0200001 for the first 545A. The 310/310A
transistion was like that also, going from stampling the number directly on
the front panel to an aluminum insert and skipping up to 0100001 for the
first 310A.

At some time later, a "B" was added in front of the serial numbers of
instruments built in Beaverton and an entirely new scheme of serial
numbering began. The first two digits following the "B" represented the
first major form of the instrument. So the first 465, for example, would be
B010101: "B" = Beaverton, "01" = the first major form of the instrument,
"0101" = the first unit off of the line. If a "major" change was introduced
into the instrument, the first 3 characters of the serial number were
incremented to "B02" and the following 4 digits continued on from where the
last "B01" serial number had stopped. (Don't ask me what a "major" change
was that triggered a new series of numbers . . . I don't know . . . ) This
scheme works fine until you get to B0?9999 and then you run out of numbers.
I think then, Tek just incremented the B0? to the next one and started again
at "0101" (or maybe "0000", I don;t know for sure . . . ) So, generally, if
you see a s/n starting with something like B26...., then it means either
that Tek built a LOT of them or they made a lot of major changes in the
design along the way . . . major enough to cause them to roll the "B" number
up to the next one.

Regarding how many of any particular model that Tek built, I have been asked
many times to provide that info. It is not readily available but some good
guesses can be made by studying the serial numbers found in the Modification
Summary for each instrument. The 570, for example, numbers about 1500
instruments, total. The 7A26 is the most common instrument Tek ever made
with something like 130,000 made. I would be surprised if Tek made more
than 10,000 or so 7904's and maybe only 5000 or so 7104's. The CA plugin
numbers about 75,000.

The point is that Tek skipped a LOT of serial numbers and it probably was
not to confuse the enemy. More likely it was so that by reading the serial
number, a service technician would have a good idea what to expect when he
took the covers off.

I hope this helps a little . . .

Stan
w7ni@...

----- Original Message -----
From: "Miroslav Pokorni" <mpokorni2000@...>
To: "washesmelon" <vwthingy@...>; "Fred Olsen" <fwolsen@...>
Cc: <TekScopes@...>
Sent: Thursday, July 10, 2003 11:25 AM
Subject: Re: [TekScopes] 7904 Mainframe production dates


Hello Fred,

When you expressed doubt that Tektronix built over a quarter million 7904,
I
did agree, but did not think it was worth commenting. Now that Craig asked
a
question about 7A21 (a direct access unit), I went and looked at my copy
of
plug-in. The serial number was in 40000. That is really hard to believe. A
direct access unit did not have so much applications that 40000 units
could
have been stamped out. I think that was time when reason departed
Beaverton
and scheming got into swing, 'to confuse competition' or to retain job of
the guy who was dreaming up schemes.

Regards

Miroslav Pokorni

----- Original Message -----
From: "Fred Olsen" <fwolsen@...>
To: "washesmelon" <vwthingy@...>
Cc: <TekScopes@...>
Sent: Wednesday, July 09, 2003 6:54 PM
Subject: Re: [TekScopes] 7904 Mainframe production dates


Jeff, the only one I can address at the moment is the early 7904. It
would be reasonable to assume that early production exceeded the 250k
point, hence the restart at 260k rather than 250. Mine is a "late
early", at B2464xx. That said, I still would find it difficult to
comprehend that Tek built over a quarter-million 7904s!

Fred
--
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--
Outgoing checked by Norton AV






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Re: 7603

Stan & Patricia Griffiths <w7ni@...>
 

On the off hand chance that your beam finder is also broken or the trace is
SO FAR OFF screen that the beam finder won't find it, try shorting the CRT
vertical plates together right at the CRT and see if that gives you a trace
or not. It should (if your sweep is running and the horizontal amp works).
This should cause no damage to the instrument if you don't brush one lead of
the shorting wire against ground as you do this . . .

Stan
w7ni@...

----- Original Message -----
From: "ukcartman" <johnbloom@...>
To: <TekScopes@...>
Sent: Monday, July 07, 2003 3:05 PM
Subject: [TekScopes] 7603


Hi,
Can anyone help with the fault on this one? I have readout but no
trace on screen, this is the same on the beam find switch so it
appears that the trace is not there, not just off screen.
Thanks,
John.





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Re: fast storage vs. slow storage?

Stan & Patricia Griffiths <w7ni@...>
 

The main difference between fast and slow storage tubes is contrast. Better
contrast in the slow ones.

Stan
w7ni@...

----- Original Message -----
From: "Robert Morein" <morepub@...>
To: <TekScopes@...>
Sent: Sunday, July 06, 2003 9:22 PM
Subject: [TekScopes] fast storage vs. slow storage?


The Tek 434 has much slower writing speed than the "fast" scopes.
I notice there was an almost free option to supply a faster writing CRT.
From this, I'm guessing there is some advantage to a CRT with slow
writing speed.
Durability, perhaps?
Resistance to burn?
Does anyone have any figures for number of storage hours for the various
tubes?







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Tek Serial Number Scheme

tss_steve_990
 

Deane Kidd has kindly supplied the following understanding of the
Beaverton Serial numbering scheme.

On Any Given Model of Scope:

The first Letter "B" stands for Manufactured at Beaverton Plant
The next two digits are the Bill of Materials for that scope model
The next 4 digits are the actual serial number of that scope

Thus an introductory model B010100 is serial number 100 built from
the first production BOM

B02xxxx is the first revision after BOM B01xxxx
B25xxxx uses bill of materials #25 etc.

No guesses as to the scopes made in Holland except that the first
number is 7.

This concludes my quest for understanding Tek Serial Numbers unless
someone has some insight into the Dutch numbering scheme.

Some of you have rightly questioned whether the S/N (i.e. date of
manufacture) is really that important relative to the present
condition of the scope. Obviously a perfect condition earlier unit is
better than a later unit that has much more "mileage" on it. I am
using the S/N as only one data point in selecting a used scope.
Given the Tektronix philosophy during the period when the scopes I am
considering were built, I am making the assumption (perhaps not
correct in all cases) that the later models had fixes and
improvements over earlier models. And a perfect condition 20 year
old scope might have more life left in it than a perfect condition 30
year old scope of the same model. I have just now becoming aware
(with the help of many of you who have responded to my inquiries) of
the wide variety of choices available in the Tek line, including the
9000 series, which I really didn't know much about. Remember my only
scope is a 535 with a CA plug-in, used mainly to heat the garage in
the winter.
Thanks to this group I have met many of you who know Tek equipment
far better than I do. I have learned about the DSESR meter to locate
failing caps in vintage gear. I have gotten a lot from you all.

Thanks,

Steve Hogan

Falcon on the launchpad.

Andrew Jonathan Fine <eternalsquire@...>
 

I did a few "idiot tests" on my setup, the most important one being to
check that all tubes were glowing in the L20, the 585, and the 81.
I was assured by the vendors of both the L20 and the 585 that they
were recently in good working order.

The only unknown quantity was the 81 Adapter, that was bought in
unknown condition. but those are much less expensive to replace.

I disconnected my boxes and found the switch on the back of the L20.
There is a selection of 100 V Sawtooth vs 150 V Sawtooth. I also found
a sweep input on the front of the L20. I assume that's where the sawtooth
goes. But where do I get the sawtooth from the 585?

Oh, my kingdom for some manuals!

The Eternal Squire.

----- Original Message -----
From: Richard Solomon, W1KSZ <w1ksz@...>
To: eternalesquire <eternalsquire@...>
Sent: Friday, July 11, 2003 6:01 AM
Subject: RE: [TekScopes] getting my millennium falcon to fly.


If I remember correctly, now this was back in the Mesozoic era,
you needed to connect a sweep signal to the L20 input. There was
a pin jack on the L20 that connected to the external sweep BNC on
the scope. On the back of the L20 was a slide switch that set the
sweep voltage. Since all that stuff is long gone, this is all from
a fuzzy memory.
Hope this helps,

73, Dick, W1KSZ

-----Original Message-----
From: eternalesquire [mailto:eternalsquire@...]
Sent: Friday, July 11, 2003 4:56 AM
To: TekScopes@...
Subject: [TekScopes] getting my millennium falcon to fly.


Hi everyone!

I'd like to ask some advance on debugging a scope configuration.
I've put together a Tek 585, 81 Adapter, and L20, all tubes.
I'm getting a wierd readout on my CRT, and I would like to know
if anyone understands immediately what I am doing wrong based
on what I am describing:

There is a vertical fuzzy bar in the middle of the CRT.
On the upper and lower right hand side of the CRT I
am seeing "fluffy angels wings". The horizonal position
moves the fuzzy bar from left to right. I get this on
channel A only, I get no readout from channel B.

Injecting a signal into the main L20 input makes no difference.
The bar is still fuzzy even through I brought it into focus
as much as I could.

Does anyone have any advice as to how I might need to operate
different, or what area I should begin debugging?

Thanks in advance,

The Eternal Squire.





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Re: Ebay item

Andreas Troschka - IK2WQI <signupbox@...>
 

Thanks for the hint, Craig!
It is exactly what I'm looking for.

It is really interesting to have the signals on the rear connectors.

This is a series that leaves some free space for experimenting.

--

Cheers.

Andreas Troschka - IK2WQI - JN45OL

--

Re: 575

Stan & Patricia Griffiths <w7ni@...>
 

Hi Morris,

There was a kit made by Tek to modify a standard 575 to a 122C. I
personally installed this kit a few times. It took a couple of days . . . !
Anyway, I have the kit instructions for this which include updated pages for
the standard manual. Would copies of the manual update do? If so, it will
take me some time to get them made and I will quote you a price. Let me
know.

Stan
w7ni@...

----- Original Message -----
From: "Morris Odell" <morriso@...>
To: "Tekscopes (E-mail)" <TekScopes@...>
Sent: Sunday, July 06, 2003 4:47 PM
Subject: [TekScopes] 575


Hi all,

A friend of mine is restoring a 575 curve tracer mod 122C. It's a bit
different from the non-mod 122C manual we have. Is anyone able to help me
with a copy of the schematics (or the whole manual)? Usual costs
reimbursed
etc..

Thanks,

Morris




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Re: 3RP1 for a 310A

Stan & Patricia Griffiths <w7ni@...>
 

I have never actually tried a 3RP1 in a 310 or 310A but it is not the one
Tek recommends. Tek wants you to use a 3WP2 or one with a Tek Part Number.
You can check that out on the following web page:

www.reprise.com/host/tektronix/reference/default.asp

I think I have a spare 3WP2. If you need one, I can quote you a price.

Stan
w7ni@...

----- Original Message -----
From: "Robert Morein" <morepub@...>
To: <TekScopes@...>
Sent: Thursday, July 03, 2003 7:59 PM
Subject: [TekScopes] Re:3RP1 for a 310A


3RP1 for a 310A

Will this CRT fit this scope?








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Re: 475/A not really ideal for audio, and some noise thoughts.

Robert Morein <morepub@...>
 

For audio, why not a 434?
It has 1 mv sensitivity.
With a sweep oscillator and the storage tube, you can get a nice graph of frequency response.
The scopes are cheap. Although speced at 25 mHz, they measure out to about 38 mHz.
They weigh 24 lbs, and were stated by Tek to be designed for rugged environments.

I think one has to really think twice about the "one scope fits all" idea.

Although this is a Tek scope group, I'd like to point out that there are other worthy scopes out there. I purchased a Leader LBO-518 at a Verizon auction for $55. It looked like a trashcan, but cleaned up nicely. Surprisingly, it was perfectly functional.
It's a 100 mHz scope with FOUR channels, dual time based, delayed sweep, and 1mv sensitivity.
Surprisingly, the scope does not appear to have a switching power supply, which is probably why it still works perfectly. Weight is under 20 lbs, and the knobs and feel are very familiar.

Sorry, Tek lovers. I couldn't help but mention it.

----- Original Message ---