Date   
Re: Digest Number 11490

 

Make sure there is no dust or carbon tracks near the HV supply.
 HankC, Boston WA1HOS

On Sunday, July 30, 2017 10:35 PM, "TekScopes@..." <TekScopes@...> wrote:


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9 Messages
Digest #11490 1a Re: BSM connectors by "David" david_william_hess 1b Re: BSM connectors by "Glenn Little WB4UIV" glennmaillist@... 1c Re: BSM connectors by big_sky_explorer 1d Re: BSM connectors by "Michael A. Terrell" michaelaterrell 1e Re: BSM connectors by "David" david_william_hess 2a Re: 2465A Filter, Implode shield, gray knob by "AncelB" mosaicmerc 2b Re: 2465A Filter, Implode shield, gray knob by spikeiskewl 3 475 Anode Lead Sparking by jeffrdavis 4a Re: WTB: Tek 475 Spares - (UK) by markjohanhatch
Messages

1a

Re: BSM connectors

Sun Jul 30, 2017 3:41 pm (PDT) . Posted by:

"David" david_william_hess
I have seen the BSM to BNC adapter Tektronix sold on Ebay but it was
expensive. I think the best thing to do is replace the BSM connector
on the 7T11A with an SMB connector and make or use an SMB to BNC
adapter.

On 30 Jul 2017 17:29:45 +0000, you wrote:

Does anyone know the name of the company that manufactured the mating male BSM connector used for the Pulse Output connector on the front of the 7T11A?
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1b

Re: BSM connectors

Sun Jul 30, 2017 5:19 pm (PDT) . Posted by:

"Glenn Little WB4UIV" glennmaillist@...
The BSM connector is also known as a MB connector.
This was used in the R390 and R390A receivers.

Glenn

On 7/30/2017 6:41 PM, David @DWH [TekScopes] wrote:
I have seen the BSM to BNC adapter Tektronix sold on Ebay but it was
expensive. I think the best thing to do is replace the BSM connector
on the 7T11A with an SMB connector and make or use an SMB to BNC
adapter.

On 30 Jul 2017 17:29:45 +0000, you wrote:

Does anyone know the name of the company that manufactured the mating
male BSM connector used for the Pulse Output connector on the front of
the 7T11A?

--
----------------------------------------------------------
Glenn Little ARRL Technical Specialist QCWA LM 28417
Amateur Callsign: WB4UIV wb4uiv@... AMSAT LM 2178
QTH: Goose Creek, SC USA (EM92xx) USSVI LM NRA LM SBE ARRL TAPR
"It is not the class of license that the Amateur holds but the class
of the Amateur that holds the license"
------------ --------- --------- --------- --------- --------- -

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1c

Re: BSM connectors

Sun Jul 30, 2017 5:29 pm (PDT) . Posted by:

big_sky_explorer
It's also known as an MB connector. I once had a large (7-foot rack) 24-channel Ampex IRIG recorder that used 1 inch tape that had these connectors for inputs on each record and outputs on each playback module. I saved the connectors some of which were still in sealed bags but cannot recollect as to where they are in my massive piles of parts.

You might try

http://www.surplussales.com/connectors/MB.html http://www.surplussales.com/connectors/MB.html
or-
http://www.hdcom.com/mbconn.html http://www.hdcom.com/mbconn.html

As a last resort a SMA connector would probably suffice although not sure about how it will affect the risetime of the output pulse.

Greg

[Non-text portions of this message have been removed]

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1d

Re: BSM connectors

Sun Jul 30, 2017 6:36 pm (PDT) . Posted by:

"Michael A. Terrell" michaelaterrell
www.surplussales.com/connectors/MB.html has some connectors and adapters.

-----Original Message-----
From: "Glenn Little WB4UIV glennmaillist@... [TekScopes]" <TekScopes@...>
Sent: Jul 30, 2017 8:19 PM
To: TekScopes@...
Subject: Re: [TekScopes] BSM connectors

The BSM connector is also known as a MB connector.
This was used in the R390 and R390A receivers.

Glenn

On 7/30/2017 6:41 PM, David @DWH [TekScopes] wrote:
I have seen the BSM to BNC adapter Tektronix sold on Ebay but it was
expensive. I think the best thing to do is replace the BSM connector
on the 7T11A with an SMB connector and make or use an SMB to BNC
adapter.

On 30 Jul 2017 17:29:45 +0000, you wrote:

Does anyone know the name of the company that manufactured the mating
male BSM connector used for the Pulse Output connector on the front of
the 7T11A?

--
----------------------------------------------------------
Glenn Little ARRL Technical Specialist QCWA LM 28417
Amateur Callsign: WB4UIV wb4uiv@... AMSAT LM 2178
QTH: Goose Creek, SC USA (EM92xx) USSVI LM NRA LM SBE ARRL TAPR
"It is not the class of license that the Amateur holds but the class
of the Amateur that holds the license"
-------- --------- --------- --------- --------- --------- -----


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

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


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

Yahoo Groups Links


Michael A. Terrell

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1e

Re: BSM connectors

Sun Jul 30, 2017 7:30 pm (PDT) . Posted by:

"David" david_william_hess
And I guess there is a 2 pin and 3 pin version.

On Sun, 30 Jul 2017 20:19:42 -0400, you wrote:

The BSM connector is also known as a MB connector.
This was used in the R390 and R390A receivers.

Glenn

On 7/30/2017 6:41 PM, David @DWH [TekScopes] wrote:
I have seen the BSM to BNC adapter Tektronix sold on Ebay but it was
expensive. I think the best thing to do is replace the BSM connector
on the 7T11A with an SMB connector and make or use an SMB to BNC
adapter.
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2a

Re: 2465A Filter, Implode shield, gray knob

Sun Jul 30, 2017 4:05 pm (PDT) . Posted by:

"AncelB" mosaicmerc
I might be able to help out. I have a parts hulk 2465. Which knobs do u
need?

I have the spare shield and the filter as well.

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2b

Re: 2465A Filter, Implode shield, gray knob

Sun Jul 30, 2017 4:39 pm (PDT) . Posted by:

spikeiskewl
Ancel B,

The row is the Intensity, Focus, Readout, scale Illum.

I guess they kind of slide a millimeter in and out slightly
and then stop. Pulling with gentle force. Eventually
they would come off, but then the grippers parts
would break off. The little concentric parts on the
inside of the knob.

This scope has been well used. The only other things
I'm not sure about, since I've not owned one before
are the SEC/DIV push pull switch
and the on/off switch.

SED/DIV seems to work sometimes when pulling
out but then stays in the same range etc when
pushed back in etc?

Same with the on/off, push it in and at there is
a delay before it starts to power up.

Sometimes a long delay? Anyone know whats
up with that?

That is getting ahead of myself. though.

I would imagine its probably a time for some new caps etc.

Thanks, let me know what you find out?
and what you might need for them also?

Spike

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3

475 Anode Lead Sparking

Sun Jul 30, 2017 4:51 pm (PDT) . Posted by:

jeffrdavis
Hi all,


I've been attempting to repair a 475 with a bad high voltage supply. I tracked the problem down to a bad high voltage multiplier - when disconnected, the high voltage comes back to -2470 just fine. After replacing the high voltage multiplier with one from a parts junker, the CRT anode lead sparks like crazy to any nearby path to ground.


Trying to eliminate operator errors before looking for other causes:
Could this be caused by powering on without the vertical preamp board installed? It doesn't seem like that should cause a problem, and I wanted to see if the parts queen hv multiplier worked before completely reassembling.


The scope has another problem, a bad filter cap in the +5v supply, so the +5 supply right now is about 4.4V. That doesn't seem to be affecting the HV regulation, however. The HV still reads -2470.


Is there something I could have missed in reassembly that might cause the sparking?


What would cause the CRT anode lead to spark like that?


Thanks,
Jeff N0DY

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4a

Re: WTB: Tek 475 Spares - (UK)

Sun Jul 30, 2017 6:49 pm (PDT) . Posted by:

markjohanhatch
If you were in the states, I could certainly help here. I toasted the motherboard on a B102xxx a few weeks back. It was working fine until I decided to replace the power supply caps "just because" ...

All my other 475's are newer, so the boards are not guaranteed to swap (i.e., timebase will not swap).


Happy to sell any of the boards (including knobs if available) for $15 each + postage + box (if required). Not sure of board cost/international shipments. But could explore that if you don't come up with another option. I would be shipping out of 94556, California.


Mark

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Re: 475 Anode Lead Sparking

Reed Dickinson
 

Hi:

I read, with interest, your plight concerning arcing after connecting
your CRT to the multiplier. In answer to your question, the anode lead
is an integral part of the CRT and not a replaceable item. Replacement
of the CRT is the only viable option. The arcing could also be coming
from inside the CRT! But, before you throw out your present CRT make
sure the grounding arm on the bottom of the CRT just forward of the
horizontal deflection pins is intact. There is a metal surface on the
CRT that must contact this arm. This arm provides a ground to the
helical high voltage gradient carbon path inside the CRT.

I have over 150 scopes in my garage and I am slowly selling them off as
I know I am at an age where I will never get to them all. I could send
you a good CRT for a 465, 465B, 468, 475 or 475A for $75 plus shipping
to your location. For more information please see my Craigslist ad for
Tektronix oscilloscopes on the Orange County , CA listing.

Reed Dickinson
1705 Stonehenge Drive
Tustin, CA 92780

714 838 1011

On 7/31/2017 7:01 AM, n0dyjeff@... [TekScopes] wrote:

So after thinking more about the arcing problem, it seems like the
most likely cause of arcing is a bad anode lead to the CRT, since
there's no arcing in or near the lead coming out of the HV Multiplier
module. It only starts after the connection to the CRT anode lead.

If that's the case, can the anode lead be replaced, or does this
require replacement of the entire CRT?


It just seems odd to me that the insulation would fail so
catastrophically. It's not just a tiny, occasional arc. It looks more
like a Van de Graaf generator.


How likely is it that I have secondary damage elsewhere as a result?
Some of the arcs hit the coaxial cables leading to the trigger
generator and z axis logic board.


Thanks in advance for your thoughts.

[Non-text portions of this message have been removed]

Re: WTB: Tek 475 Spares - (UK)

Malcolm Hunter
 

Hi Bob,

I'm in the UK too. I have a parts mule 475 that has intact knobs that
you're looking for, though the digits have rubbed off a little. If you can
collect, the scope is yours. Alternatively, I can send you the parts for
the cost of postage.

Malcolm

On 30 July 2017 at 17:23, mosfet10@... [TekScopes] <
TekScopes@...> wrote:



Hi All,

I've rescued a very nice, and almost working 475. I'm hoping this scope
will replace a 465 lost in a house move (long story)

Its quite an early serial no: B185xxx

The main problem; is the Ch2 Volts/Div knob (including the VAR insert) is
broken; most of the bits are missing; and the knob (whats left of it) just
turns freely (no clicks)

Does anyone have a spare 475 Volts/Div knob, and a spare VAR knob please,
that you don't mind sending to the UK. Naturally, your price paid and all
costs covered.

Also, does anyone have any hints as to the Volts/Div knob (whats left of
it) turning freely, any advice greatly appreciated, before I dive in.





Many thanks !


Rob



[Non-text portions of this message have been removed]



[Non-text portions of this message have been removed]

Re: 475 Anode Lead Sparking

Jeff Davis
 

Thanks for the responses, they are super helpful.

I've checked the HV regulation, and it's running -2470V, so we're good there.


The actual location of the arcing appears to be a few inches from the connection to the lead from the HV Multiplier module.So if a few layers of high quality electrical tape or some other added insulation would fix it, that would be great. Not sure I feel confident in my ability to unpot and repot the CRT anode lead, so if the "add some more insulation" fix doesn't work, I'm probably done. But I'm already much further ahead than I was yesterday at this time.


Thanks again for all the help!


Jeff

Re: 475 Anode Lead Sparking

Ed Breya
 

As Chuck suggested, first be sure the anode voltage is correct and under control of the HV regulation circuit. If it's way high, it can break through the insulations that normally are OK. I didn't see any mention of the location of this apparently obvious arcing, other than "when the anode lead is connected." Is it at the connector, off the wire itself, at the joint with the CRT, or inside the CRT?

The location will determine the cause and the required fix. So again, first be sure the HV is right, then make sure everything associated is as clean as possible, and that the HV lead is properly dressed throughout its trip from the multiplier to the CRT end - not pinched or folded around any sharp edges or other pointy things. The easiest fix is the lead itself, say if it's nicked or cracked somewhere - a few layers of electrical tape may help enough. The worst is if it's something inside the CRT itself, rendering it useless. If the problem is at the lead joint with the CRT, you'll probably have to pull the CRT to work on it. It should be easy to see where it was leaking, evidenced by burns or tracks - then clean it up and add extra silicone goop where needed.

Ed

For sale Tektronix 465B Analog Oscilloscope

camaro2172000@...
 

Hello All,

I am selling my Tektronix 465B that I bought a few months ago. I was hoping to learn how to use it but never got around to it. The 465B is in great looking condition and has the DM 44 voltmeter. The gentlemen I bought it from said it was in good working order. If anyone is interest I would be willing to send you photos of it turned on and working. Comes with owners manual. I am asking 150.00 plus shipping cost to lower 48 states only. My email address is edman44@...

Re: 475 Anode Lead Sparking

Chuck Harris
 

At its best, the 475 can barely contain its anode voltage.
I have seen many that went tick, tick, tick... as the anode
lead charged up, and arc'd to the chassis.

Any damage to the pink anode lead will result in a catastrophic
failure such as what you have witnessed.

The only solution is to remove the anode lead, which requires
unpotting the end that is fastened to the ceramic envelope
terminal, and potting in a new lead.

Remember, there is 18,000V between the anode and the cathode,
and the cathode is -2450V below chassis ground, so the anode
terminal is hovering around at 15.5KV. I don't think that pink
silicone insulation is rated for much more than that.

Also, if the voltage regulator circuit for the EHT is stuck full
on, the anode voltage will be up around 18-19KV, which is even
worse.

-Chuck Harris

n0dyjeff@... [TekScopes] wrote:

So after thinking more about the arcing problem, it seems like the most likely
cause of arcing is a bad anode lead to the CRT, since there's no arcing in or near
the lead coming out of the HV Multiplier module. It only starts after the
connection to the CRT anode lead.

If that's the case, can the anode lead be replaced, or does this require
replacement of the entire CRT?


It just seems odd to me that the insulation would fail so catastrophically. It's
not just a tiny, occasional arc. It looks more like a Van de Graaf generator.


How likely is it that I have secondary damage elsewhere as a result? Some of the
arcs hit the coaxial cables leading to the trigger generator and z axis logic
board.


Thanks in advance for your thoughts.


Re: U400 (155-0236-00) Channel Switch replacement

hjw2t7zlzaizqqddvktnnakr37glpdbz7w6j7ymb@...
 

Hi,


Would like to review schematic of the U400 and development.


sam

Re: 475 Anode Lead Sparking

Jeff Davis
 

So after thinking more about the arcing problem, it seems like the most likely cause of arcing is a bad anode lead to the CRT, since there's no arcing in or near the lead coming out of the HV Multiplier module. It only starts after the connection to the CRT anode lead.

If that's the case, can the anode lead be replaced, or does this require replacement of the entire CRT?


It just seems odd to me that the insulation would fail so catastrophically. It's not just a tiny, occasional arc. It looks more like a Van de Graaf generator.


How likely is it that I have secondary damage elsewhere as a result? Some of the arcs hit the coaxial cables leading to the trigger generator and z axis logic board.


Thanks in advance for your thoughts.

Re: 2465 ... While you have the cover off...

Chuck Harris
 

Evidence suggests that for much of tektronix's early life,
they didn't really consider their "foreign" customers to be
all that important... they had the US DOD, and all of US
industry, and it was already more than they could handle
sometimes.

That said, if you are one of tektronix's "marginal" customers
in the land of 200+ volt mains, you should take this as a
warning to use your own judgment to decide whether or not any
of the components that are connected to the mains voltages of
your country should be left alone, or replaced.

I always replace the "X2" capacitors attached to the mains
circuitry when I get a scope in for repair. I sometimes replace
the IEC power entrance filters on some equipment.

If I was in 220V land, I would always replace these parts, and
also make sure the fuse was appropriate, and the line voltage
selection mechanism was set for 220V.

-Chuck Harris





ulf_r_k@... [TekScopes] wrote:

Last night, when using my 2465 there was a loud >> BANG << and a lot of smoke
coming out from the scope.


On the power supply PCB where the AC mains filter connects, there
are two 68 nF "X2" capacitors. One of them was disintegrated.
Luckily, the content was not spread out and what was left of it
together with the other one was removed from the board.


The capacitors was made by RIFA and I had
been warned by ham radio friends that these are not very reliable.


So while you take the newly acquired 2465 apart to check for
dust rats and loose screws, pay attention to these caps.


73


Ulf - SM6GXV

Re: 2465 ... While you have the cover off...

Tom Gardner
 

While true, I'm not sure the analogy is helpful. SMPSs stress capacitors more
than mains, due to higher switching frequencies and higher transient currents.

The self immolation (including that of adjacent series resistor in my case) is
because they short circuit the mains for an instant!

On 31/07/17 10:14, esmond.pitt@... [TekScopes] wrote:

I'd like to comment on 'not very reliable'. I replace a lot of these Rifa
mains network capacitors in vintage hi-fi, where they have been sitting on
mains switches, across the mains, for forty or fifty years 24/7/52. Yes they
fail, but only ever in the mode specified: by self-immolation rather than
shorting out the mains. In the circumstances I think this is really pretty
good. Yes they are a known failure point, and yes they fail by smoking, but it
could be a lot worse. Same goes for tantalum caps: yes they fail, and yes they
fail short, but on the other hand they've been working for a lot longer than
most of us have.

Re: 2465 ... While you have the cover off...

Tom Gardner
 

On 31/07/17 09:28, Joe Laffey joe@... [TekScopes] wrote:

On Mon, 31 Jul 2017, ulf_r_k@... [TekScopes] wrote:

Last night, when using my 2465 there was a loud >> BANG << and a lot of smoke
coming out from the scope.


On the power supply PCB where the AC mains filter connects, there
are two 68 nF "X2" capacitors. One of them was disintegrated.
Luckily, the content was not spread out and what was left of it
together with the other one was removed from the board.


The capacitors was made by RIFA and I had
been warned by ham radio friends that these are not very reliable.


So while you take the newly acquired 2465 apart to check for
dust rats and loose screws, pay attention to these caps.
These are a known failure point, and should be replaced immediately when
you acquire such a scope.

Mine were already burst when I got my 2465.

Re: 2465 ... While you have the cover off...

EJP
 

I'd like to comment on 'not very reliable'. I replace a lot of these Rifa mains network capacitors in vintage hi-fi, where they have been sitting on mains switches, across the mains, for forty or fifty years 24/7/52. Yes they fail, but only ever in the mode specified: by self-immolation rather than shorting out the mains. In the circumstances I think this is really pretty good. Yes they are a known failure point, and yes they fail by smoking, but it could be a lot worse. Same goes for tantalum caps: yes they fail, and yes they fail short, but on the other hand they've been working for a lot longer than most of us have.

Just 2c

EJP

Re: 2465 ... While you have the cover off...

Joe Laffey
 

On Mon, 31 Jul 2017, ulf_r_k@... [TekScopes] wrote:

Last night, when using my 2465 there was a loud >> BANG << and a lot of smoke
coming out from the scope.


On the power supply PCB where the AC mains filter connects, there
are two 68 nF "X2" capacitors. One of them was disintegrated.
Luckily, the content was not spread out and what was left of it
together with the other one was removed from the board.


The capacitors was made by RIFA and I had
been warned by ham radio friends that these are not very reliable.


So while you take the newly acquired 2465 apart to check for
dust rats and loose screws, pay attention to these caps.
These are a known failure point, and should be replaced immediately when you acquire such a scope.

Mine were already burst when I got my 2465.


--
73
Joe

2465 ... While you have the cover off...

ulf_r_k
 

Last night, when using my 2465 there was a loud >> BANG << and a lot of smoke
coming out from the scope.


On the power supply PCB where the AC mains filter connects, there
are two 68 nF "X2" capacitors. One of them was disintegrated.
Luckily, the content was not spread out and what was left of it
together with the other one was removed from the board.


The capacitors was made by RIFA and I had
been warned by ham radio friends that these are not very reliable.


So while you take the newly acquired 2465 apart to check for
dust rats and loose screws, pay attention to these caps.


73


Ulf - SM6GXV

Re: 2465A Filter, Implode shield, gray knob

mosaicmerc
 

Those are the small knobs under the screen?

The other knobs on the control panel are ok?

Re: BSM connectors

Gary Robert Bosworth
 

I will gladly pay a reasonable price for them if you ever find them. I
could use them with or without a cable attached.
Gary

On Sun, Jul 30, 2017 at 5:29 PM, big_sky_explorer@... [TekScopes] <
TekScopes@...> wrote:



It's also known as an MB connector. I once had a large (7-foot rack)
24-channel Ampex IRIG recorder that used 1 inch tape that had these
connectors for inputs on each record and outputs on each playback module. I
saved the connectors some of which were still in sealed bags but cannot
recollect as to where they are in my massive piles of parts.

You might try

http://www.surplussales.com/connectors/MB.html
http://www.surplussales.com/connectors/MB.html
or-
http://www.hdcom.com/mbconn.html http://www.hdcom.com/mbconn.html

As a last resort a SMA connector would probably suffice although not sure
about how it will affect the risetime of the output pulse.

Greg

[Non-text portions of this message have been removed]




--
Gary Robert Bosworth
@grbosworth
Tel: 310-317-2247

Re: BSM connectors

Gary Robert Bosworth
 

I will check this out. Thanx.

On Sun, Jul 30, 2017 at 2:33 PM, hahi@... [TekScopes] <
TekScopes@...> wrote:



Does anyone know the name of the company that manufactured the mating
male BSM

P/N is 131-0579-00

The manual says: Speciality Conector Co Inc

The micro fiche says:
Berg Electronics
(Formerly Speciality Conector)
2100 Farlywood (or possibly Earlywood) Dr
PO Box 547
Franklin In
46131

/Håkan






--
Gary Robert Bosworth
@grbosworth
Tel: 310-317-2247


[Non-text portions of this message have been removed]

11301 - schematics needed or strip it.

Jerry
 

Does anyone have schematics for the 11301? This is my last shot at recovering this beast. I have the service manual as well as the calibration software.


I was given an 11301 in decent shape. I have a repair thread running on EEVBLOG as the primary issue, other than a loss of calibration data, is that the trace is wide. It seems to have main trace jitter related to the triggering. The character displays, cursors, etc are fine. I've tried a lot of debugging, spent probably 40 hours on it, no progress at all. I can get a decent trace if I do a super critical trigger setting where it just triggers at the very top or bottom of the trace cutting down on the number of jitter traces. But this is sort of faking it as the counter starts missing pulses as the sweep ramp goes unstable. I don't need the scope but wanted a 400Mhz analog scope for posterity.


If I can't locate the schematics I am going to strip out the cable, connectors and other parts. I've already used the vertical amps in my DSA602. There is a decent 10Mhz DOCXO in it as well. I'll keep all the cable as the delay line alone is probably around 60ft.


I'll post some photos starting with the problem in the photo section.


Thanks.


Jerry

Re: BSM connectors

 

And I guess there is a 2 pin and 3 pin version.

On Sun, 30 Jul 2017 20:19:42 -0400, you wrote:

The BSM connector is also known as a MB connector.
This was used in the R390 and R390A receivers.

Glenn

On 7/30/2017 6:41 PM, David @DWH [TekScopes] wrote:
I have seen the BSM to BNC adapter Tektronix sold on Ebay but it was
expensive. I think the best thing to do is replace the BSM connector
on the 7T11A with an SMB connector and make or use an SMB to BNC
adapter.