Re: Restoring 9A1 plugins: need a foto
(continued, last time I hope, grrr...)
I found the 9A1 now in Stan's book and in the 1964 catalog. Being designed for the 506, the plugin has BW 23 MHz (as opposed to 10 MHz for 3A1). Hence those resistors might have a different value in the 9A1.
Albert
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(continued)
Not 3A6 but 3A1. You probably have a 3A1 yourself. The internals (left picture) are exactly those of a 3A1. Obviously the big flat 1.5k resistors (310-596) have been replaced.
Albert
Hi Martin,
What a strange type designation, does this plugin have a dedicated purpose?
The front looks identical to that of a 3A6. The schematics of the 3A6 might help?
Albert
hello friends,
I am restoring a 561A with, a 9A1 plugin.In this 9A1, I am not sure if that is original, so I need please a picture made from another 9A1,upside, back, where is the deflection tubes E55L, there are some power resistors mounted.
I want to see them on a picture, and please how many ohms they have, I have no application of this 9A1
greetings from germanyMartin
- picture: my 9A1 -
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Re: Restoring 9A1 plugins: need a foto
(continued)
Not 3A6 but 3A1. You probably have a 3A1 yourself. The internals (left picture) are exactly those of a 3A1. Obviously the big flat 1.5k resistors (310-596) have been replaced.
Albert
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Hi Martin,
What a strange type designation, does this plugin have a dedicated purpose?
The front looks identical to that of a 3A6. The schematics of the 3A6 might help?
Albert
hello friends,
I am restoring a 561A with, a 9A1 plugin.In this 9A1, I am not sure if that is original, so I need please a picture made from another 9A1,upside, back, where is the deflection tubes E55L, there are some power resistors mounted.
I want to see them on a picture, and please how many ohms they have, I have no application of this 9A1
greetings from germanyMartin
- picture: my 9A1 -
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I have no idea Albert. I also do not have so much space.
I still have an 2467 and this Iwatsu SS-7635 where it is
nearly impossible getting valuable hints for needed adjustments.
Matthias
Am 15.07.2012 11:07, schrieb Albert:
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?
Is that $40 a buy-it-now price or a starting price? Just
curious, fortunately too far away since my attic is
overcrowded already.
Albert
> looks very nice. Unfortunately too far away for me
> living in germany.
>
> Matthias
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Re: Restoring 9A1 plugins: need a foto
Hi Martin,
What a strange type designation, does this plugin have a dedicated purpose?
The front looks identical to that of a 3A6. The schematics of the 3A6 might help?
Albert
toggle quoted message
Show quoted text
hello friends,
I am restoring a 561A with, a 9A1 plugin.In this 9A1, I am not sure if that is original, so I need please a picture made from another 9A1,upside, back, where is the deflection tubes E55L, there are some power resistors mounted.
I want to see them on a picture, and please how many ohms they have, I have no application of this 9A1
greetings from germanyMartin
- picture: my 9A1 -
|
Is that $40 a buy-it-now price or a starting price? Just curious, fortunately too far away since my attic is overcrowded already.
Albert
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looks very nice. Unfortunately too far away for me
living in germany.
Matthias I have no affiliation with the seller.
-Kurt
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A nearly working 7B80 (S/N B058022)
Put in an offer and got a good looking 7B80 TB from ePay. Seller said untested. Unusually for me it seemed to work fine too, but when doing a CAL check found sweep slightly out and front panel "Sweep Cal" having no effect. Downloaded manual (070-1959-00) shows a 741 op-amp buffering the sweep cal pot input to the time base with a variety of catching diodes and resistors twixt this control and pin 3 of the op amp.
But the op amp number on schematic is U722 while the IC marked on the board drawing is U842 and referencing the parts list shows no mention of a S/N affected U number for this one. U416 (the buffer for HOR Shift) is correct both on Schematic and board drawing so it seems that the U842 reference should read U722.
Tne fault found: FP SWEEP CAL pot had correct voltages in and out (+50v in and varying dc out) but no changes in voltage at pin 3 of (U722)
10mS and 10uS timing cal pots were affecting timing as they should, so checked CR117,116 and resistors R717,R716, cap C712 all OK .
Of course, the very last res checked R706 357K was found open, so Murphy's still not evicted from the place.
Found a 357k from my 360k 1% MF stock and replaced. Now all is fine.
Hope this may be of use to others, at some time.
John Byers
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Re: Restoring 9A1 plugins: need a foto
hello friends,
I am restoring a 561A with, a 9A1 plugin. In this 9A1, I am not sure if that is original, so I need please a picture made from another 9A1, upside, back, where is the deflection tubes E55L, there are some power resistors mounted.
I want to see them on a picture, and please how many ohms they have, I have no application of this 9A1
greetings from germany Martin
|
looks very nice. Unfortunately too far away for me
living in germany.
Matthias
Am 15.07.2012 02:18, schrieb
sipespresso:
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?
I have no affiliation with the seller.
-Kurt
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Re: 535 in Northern Virginia
nice, i want have hin.
But i am in Germany :-(
I has one 531 in grey square corner.
Regards
Matt
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--- In TekScopes@..., "sipespresso" <sipespresso@...> wrote:
I have no affiliation with the seller.
-Kurt
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Re: Polish out scratches in blue filter
I can fabricate new blue filters for the 2467x series or the 2465x series like Tom Jobe said.
Please contact me offline if interested.
--Victor
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--- In TekScopes@..., "KenS" <ken@...> wrote:
Hi,
I have a 2467 with some minor scratches in the blue filter. I found out the hard way with another Tek scope that you can easily make problems worse if you try to remove scratches with a plastic polish, so I am cautious. There appear no sources of NOS blue filters out there. Anybody know of any that wouldn't come up in Google? Or, a sure-fire way to polish out scratches from these blue filters?
Thanks!
- Ken
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I have no affiliation with the seller.
-Kurt
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I have no affiliation with the seller.
-Kurt
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Hi
I got this scope used and when i started it i couldnt get a trace, after some fiddling i discovered that the trace was as wide as the screen.
There is some reaction from the controls and i can move the light on and off screen.
I repair and build tube amps so i have some basic electronic skill.
Anyone had this problem or similar please help.
Thanks in advance/Roger
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Re: OT: Question about LM334 and 1N457
David,
In theory that may be so, but try telling *all* my 7071 and 7081 meters that this is the case - the AC buffer amplifier drifts for a lengthy period after power on. Before the latest change (C714 replacement) this has typically been over 24 hours before it stabilised. I'm still waiting to see how much better this might be after replacing C714. First signs are encouraging, but I've been misled before.
Regards,
David Partridge
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-----Original Message-----
From: TekScopes@... [mailto:TekScopes@...] On Behalf Of David
Sent: 14 July 2012 21:05
To: TekScopes@...
Subject: Re: [TekScopes] OT: Question about LM334 and 1N457
Every time I read the LM334 data sheet, I wonder the same thing. The
1N457 is not particularly fast or low leakage so I do not know what distinguishes it for this application other than the data sheet recommendation and comment about temperature coefficient which is not all that helpful in finding a replacement without testing.
The LM334 data sheet and application notes have enough information to calculate the required temperature coefficient. I would just build a circuit and fixture to test a variety of diodes including common transistor junctions.
The temperature coefficient of the current source for the 7081 AC Buffer should not affect the output anyway. If it does, then something else is wrong.
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Re: OT: Question about LM334 and 1N457
Every time I read the LM334 data sheet, I wonder the same thing. The 1N457 is not particularly fast or low leakage so I do not know what distinguishes it for this application other than the data sheet recommendation and comment about temperature coefficient which is not all that helpful in finding a replacement without testing. The LM334 data sheet and application notes have enough information to calculate the required temperature coefficient. I would just build a circuit and fixture to test a variety of diodes including common transistor junctions. The temperature coefficient of the current source for the 7081 AC Buffer should not affect the output anyway. If it does, then something else is wrong. On Sat, 14 Jul 2012 19:18:04 +0100, "David C. Partridge" <david.partridge@...> wrote: The LM334 datasheet specifies the use of a diode to cancel the temperature coefficient of the LM334, saying:
"The recommended diode for use in this circuit is the 1N457 because its tempco is centered at 11 times the tempco of the LM134, allowing R2 = 10 R1."
All well and good, but the 1N457 datasheet doesn't specify the TC, and anyway the 1N457 is getting rather hard to find.
Can anyone recommend a suitable substitute? Ideally in a surface mount package.
Thanks
David Partridge
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Re: OT: Question about LM334 and 1N457
Perhaps better for David, Farnell have them as well.? Since they are made by Fairchild, they should be using the correct ex-National process.
I don't know a surface mount equivalent.
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On Sat, Jul 14, 2012 at 12:47 PM, Leon Robinson <leon-robinson@...> wrote:
David,
Mouser has buckets of 1N457's at $0.14 each.
Leon Robinson ?? K5JLR
Political Correctness is a Political Disease.
--- On Sat, 7/14/12, David C. Partridge <david.partridge@...> wrote:
From: David C. Partridge <david.partridge@...>
Subject: [TekScopes] OT: Question about LM334 and 1N457
To: TekScopes@..., hp_agilent_equipment@...
Date: Saturday, July 14, 2012, 1:18 PM
?
The LM334 datasheet specifies the use of a diode to cancel the temperature coefficient of the LM334, saying:
"The recommended diode for use in this circuit is the 1N457 because its tempco is centered at 11 times the tempco of the LM134, allowing R2 = 10 R1."
All well and good, but the 1N457 datasheet doesn't specify the TC, and anyway the 1N457 is getting rather hard to find.
Can anyone recommend a suitable substitute? Ideally in a surface mount package.
Thanks
David Partridge
|
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Re: OT: Question about LM334 and 1N457
David,
Mouser has buckets of 1N457's at $0.14 each.
Leon Robinson ?? K5JLR
Political Correctness is a Political Disease.
|
--- On Sat, 7/14/12, David C. Partridge wrote:
From: David C. Partridge
Subject: [TekScopes] OT: Question about LM334 and 1N457
To: TekScopes@..., hp_agilent_equipment@...
Date: Saturday, July 14, 2012, 1:18 PM
?
The LM334 datasheet specifies the use of a diode to cancel the temperature coefficient of the LM334, saying:
"The recommended diode for use in this circuit is the 1N457 because its tempco is centered at 11 times the tempco of the LM134, allowing R2 = 10 R1."
All well and good, but the 1N457 datasheet doesn't specify the TC, and anyway the 1N457 is getting rather hard to find.
Can anyone recommend a suitable substitute? Ideally in a surface mount package.
Thanks
David Partridge
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Re: Polish out scratches in blue filter
Good Day,
based on experience with CRT-filters in my 5000 series and a 7704A I can recommend some milder car polish.
The product I use is named SONAX NANO car polish, which is intended for new cars and I use great care when applying it.
Hint: What I have found out myself is that the follwing works well:
I use a common sanding block, which I clean very thoroughly. Then, I use a clean cotton cloth and wet it. I wrap it carefully and tightly around the sanding block and use a small amount of the car polish at a time. I mark the worst scratches with some car polish first and make only circular moves.
The sanding block allows me to apply pressure much more evenly than when doing it by hand. And the handling becomes very ergonomical, too.
I excessively clean the CRT filter between using plain soap and water.
Then, I re-inspect the surface and continue with those spots which need another round of polishing; until all areas are shiny again.
For the final clean, I use some distilled water and cotton cloths to dry.
Cheers,
Magnus
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I have no affiliation with the seller.
-Kurt
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OT: Question about LM334 and 1N457
The LM334 datasheet specifies the use of a diode to cancel the temperature coefficient of the LM334, saying:
"The recommended diode for use in this circuit is the 1N457 because its tempco is centered at 11 times the tempco of the LM134, allowing R2 = 10 R1."
All well and good, but the 1N457 datasheet doesn't specify the TC, and anyway the 1N457 is getting rather hard to find.
Can anyone recommend a suitable substitute? Ideally in a surface mount package.
Thanks
David Partridge
|
David C. Partridge
David Hess