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Re: little bit O.T IGBT doesn't need snubber +ESR meter
Thanks! that is just what I'm looking for at this time, will order a few this week.
Mouser shows 995 in stock.
The application is in special purpose power supplies, small quantities.
Add to this that
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Thanks! that is just what I'm looking for at this time, will order a few this week.
Mouser shows 995 in stock.
The application is in special purpose power supplies, small quantities.
Add to this that
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By
Bert Haskins
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#112303
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Re: tek 465 no sweep question
Is this repeatable?
When you connect the calibrator to the scope in 'chop', does the sweep look right? E.g. is the signal in scale and linear?
The service manual specifies to measure these in
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Is this repeatable?
When you connect the calibrator to the scope in 'chop', does the sweep look right? E.g. is the signal in scale and linear?
The service manual specifies to measure these in
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By
Siggi
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#112302
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Re: little bit O.T IGBT doesn't need snubber
Bert,
There have been IGBTs out there for quite some time, that clamp overvoltage not by avalanching in the main device, but by intentionally turning the device partially on, by means of a zener
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Bert,
There have been IGBTs out there for quite some time, that clamp overvoltage not by avalanching in the main device, but by intentionally turning the device partially on, by means of a zener
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By
Manfred Mornhinweg
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#112301
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Re: 7704A -just a quickie
Hi,
p20G 7 to 9 should be a very small resistance but not zero. This the lamp circuit. The readings you gave look okay. Add 2 ohms from the +5v line to ground and see if the 7704a will power
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Hi,
p20G 7 to 9 should be a very small resistance but not zero. This the lamp circuit. The readings you gave look okay. Add 2 ohms from the +5v line to ground and see if the 7704a will power
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By
jerry massengale
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#112300
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Re: tek 465 no sweep question
Power supply voltages in test points are in tolerance.
+5v reads 4.99v
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Power supply voltages in test points are in tolerance.
+5v reads 4.99v
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By
Serge K
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#112299
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Re: tek 465 no sweep question
Power supply test points? Especially the +5.
Tom
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Power supply test points? Especially the +5.
Tom
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By
Tom Miller
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#112298
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tek 465 no sweep question
Hello to all the group members.
My tek 465 stopped working recently and I'm trying to find the offending circuit.
There is no horizontal trace on both channels on standard settings with auto
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Hello to all the group members.
My tek 465 stopped working recently and I'm trying to find the offending circuit.
There is no horizontal trace on both channels on standard settings with auto
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By
Serge K
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#112297
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Re: 7704A -just a quickie
HI Jerry,
It's all in the spreadsheet but it pretty much boils down to this:
P20G3 Ground
P20G6, -50v, 13.2k
P20G1, -15v, 124Ω
P20G2, +5v, 86Ω
P20G4, +15v, 124Ω
P20G5, +50, 1.7k
These were
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HI Jerry,
It's all in the spreadsheet but it pretty much boils down to this:
P20G3 Ground
P20G6, -50v, 13.2k
P20G1, -15v, 124Ω
P20G2, +5v, 86Ω
P20G4, +15v, 124Ω
P20G5, +50, 1.7k
These were
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By
Keith Smith
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#112296
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Re: Tek 2465 A9 HV module interchangeability ?
Is there a problem with the -15 Unregulated supply? There is a 180 uF cap, C1113 that could be bad and let the voltage sag. Maybe that is the problem with your old A9 board. I could not find any
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Is there a problem with the -15 Unregulated supply? There is a 180 uF cap, C1113 that could be bad and let the voltage sag. Maybe that is the problem with your old A9 board. I could not find any
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By
Tom Miller
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#112295
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Re: Tek 2465 A9 HV module interchangeability ?
With your old A9 board inverter work well, and voltage levels are ok?
I have the same exact symptom some time in the past. Please check the + 10 v reference voltage, and if is at half f.e. 4,5 - 5v,
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With your old A9 board inverter work well, and voltage levels are ok?
I have the same exact symptom some time in the past. Please check the + 10 v reference voltage, and if is at half f.e. 4,5 - 5v,
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By
Panos
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#112294
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Re: 7704A -just a quickie
Hi,
Please give the measured resistance from all the low voltage power outputs to ground and what plugins were present if any. This a ballpark value but the +5v should be less than 100 ohms the +-15v
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Hi,
Please give the measured resistance from all the low voltage power outputs to ground and what plugins were present if any. This a ballpark value but the +5v should be less than 100 ohms the +-15v
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By
jerry massengale
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#112293
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Tek 2465 A9 HV module interchangeability ?
Hi there!
I have a 2465 with a bad A9 HV module--part# GB-7717-02.
I purchased another with a model# of 670-7277-08. This module was supposedly "removed from a working 2465" but seems to
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Hi there!
I have a 2465 with a bad A9 HV module--part# GB-7717-02.
I purchased another with a model# of 670-7277-08. This module was supposedly "removed from a working 2465" but seems to
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By
spinstar56@...
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#112292
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Re: 7704A -just a quickie
Well, I'm getting some time in on this today. During the week I made a
spreadsheet to help me get a grip on all of the inter-connects for at least
the +50, -50, +15, -15, and +5v supplies.
That
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Well, I'm getting some time in on this today. During the week I made a
spreadsheet to help me get a grip on all of the inter-connects for at least
the +50, -50, +15, -15, and +5v supplies.
That
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By
Keith Smith
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#112291
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Re: DC508 1GHz Counter
Thank you for all replies. It confirms what I suspected. I am missing the prescaler board. Henryk
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Thank you for all replies. It confirms what I suspected. I am missing the prescaler board. Henryk
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By
henasau@...
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#112290
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Re: TEK 2465 with screen issues.
Hi guys. Finally responsible for the problem with dot characters, is the A5 digital control board.
I know cause I said "have tested" in the past, when I exchange this with another working from my
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Hi guys. Finally responsible for the problem with dot characters, is the A5 digital control board.
I know cause I said "have tested" in the past, when I exchange this with another working from my
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By
Panos
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#112289
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Re: 2335 vertical issues (2335/2336/2337 service manual needed)
It is highly unlikely. Everything around it is biased and just waiting
on the push/pull of the preamp.
Dave Casey
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It is highly unlikely. Everything around it is biased and just waiting
on the push/pull of the preamp.
Dave Casey
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By
Dave Casey <dcasey@...>
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#112288
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Re: DC508 1GHz Counter
Henryk
I think you are missing the prescaler box, which is to the left of the
main board (looking from the front) and mounted on standoffs from the
main board and to the frequency switch. The metal
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Henryk
I think you are missing the prescaler box, which is to the left of the
main board (looking from the front) and mounted on standoffs from the
main board and to the frequency switch. The metal
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By
Christopher Hilton-Johnson
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#112287
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Re: DC508 1GHz Counter
Hi Henryk,
Option 1 is a better time base for the DC508 so that wouldn't account for
your missing board.
Unfortunately I only have DC508A so I can't help any further.
Dennis Tillman W7PF
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Hi Henryk,
Option 1 is a better time base for the DC508 so that wouldn't account for
your missing board.
Unfortunately I only have DC508A so I can't help any further.
Dennis Tillman W7PF
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By
Dennis Tillman W7pF
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#112286
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Re: 2335 vertical issues (2335/2336/2337 service manual needed)
I have powered the unit up with no 155-0220-00 IC in channel 1 for a minute, is it likely that any damage have happened to the unit ?
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I have powered the unit up with no 155-0220-00 IC in channel 1 for a minute, is it likely that any damage have happened to the unit ?
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By
Egberto Galas
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#112285
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Re: 2335 vertical issues (2335/2336/2337 service manual needed)
OK so the acetone trick didn't work as far as it seems, but a replacement vertical preamp chip is on the way !
Thanks !
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OK so the acetone trick didn't work as far as it seems, but a replacement vertical preamp chip is on the way !
Thanks !
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By
Egberto Galas
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#112284
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