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Re: Advice about buying a 7904
I have a 7904 and a 7934 (obviously different but I believe the PSU is very similar to the 7904A). I find the fan noise of the 7934 becomes a distraction after a while when you are trying to
I have a 7904 and a 7934 (obviously different but I believe the PSU is very similar to the 7904A). I find the fan noise of the 7934 becomes a distraction after a while when you are trying to
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By
Roger Evans
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#167595
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Re: Encouraging beginners: What are we accomplishing?
On Wed, May 27, 2020 at 10:52 AM, LarryS wrote:
I thought I had read somewhere the actual figure was 83%. You must be right!
larry
>
> 87% of all statistics are made up on the spot.
> :-)
>
>
On Wed, May 27, 2020 at 10:52 AM, LarryS wrote:
I thought I had read somewhere the actual figure was 83%. You must be right!
larry
>
> 87% of all statistics are made up on the spot.
> :-)
>
>
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By
Lawrance A. Schneider
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#167594
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Re: Mystery part Type 576 Curve tracer.
They are placed between the rectangular HV ceramic caps in the CRT HV module.
They are placed between the rectangular HV ceramic caps in the CRT HV module.
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By
Bob Koller <testtech@...>
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#167593
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Re: Advice about buying a 7904
The fan on my 7904A is very quiet, a non issue on mine at least. I suggest that the most important thing will be finding the best instrument available around your location. Packing properly is
The fan on my 7904A is very quiet, a non issue on mine at least. I suggest that the most important thing will be finding the best instrument available around your location. Packing properly is
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By
Bob Koller <testtech@...>
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#167592
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Re: Advice about buying a 7904
Thanks for all the responses. I also hate fan noise. That and more readily available parts make the 7904 preferable. However, I'll also look into the 7854.
As I have a Tek 11801 and HP 16702B and
Thanks for all the responses. I also hate fan noise. That and more readily available parts make the 7904 preferable. However, I'll also look into the 7854.
As I have a Tek 11801 and HP 16702B and
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By
Reginald Beardsley
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#167591
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Mystery part Type 576 Curve tracer.
All:
Now that I have got my 576 working reliably, I was going to start calibration and I found a pair of what appear to be silicone washers laying in the bottom of the unit. I have no idea where
All:
Now that I have got my 576 working reliably, I was going to start calibration and I found a pair of what appear to be silicone washers laying in the bottom of the unit. I have no idea where
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By
Michael W. Lynch
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#167590
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Re: 475 questions
Bruce,
There are 2 fundamental differences that need to be taken in to account when replacing “vintage” caps. And I use the term vintage loosely. One is tolerance. In the worst case I can
Bruce,
There are 2 fundamental differences that need to be taken in to account when replacing “vintage” caps. And I use the term vintage loosely. One is tolerance. In the worst case I can
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By
Eric
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#167589
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Re: Advice about buying a 7904
I had a 7904A recently for a short time.
The fan was one reason I sold it - the noise is obnoxious to me. I don't think there was anything wrong with the fan, but I'm sensitive to that white noise -
I had a 7904A recently for a short time.
The fan was one reason I sold it - the noise is obnoxious to me. I don't think there was anything wrong with the fan, but I'm sensitive to that white noise -
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By
saipan59 (Pete)
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#167588
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Re: 475 questions
It might help if I posted the values of the capacitors that were originally in the scope. I'll do this below in the quoted text.
To replace the tantalum I broke (C1091), and the other one I removed
It might help if I posted the values of the capacitors that were originally in the scope. I'll do this below in the quoted text.
To replace the tantalum I broke (C1091), and the other one I removed
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By
ciclista41@...
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#167587
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Re: Tek 4041 GPIB Controller
I just finished creating the binary files for each of the Option ROMs v2.1 and also a 16bit binary that could be used for disassembly and posted them in the ROMs folder on my github repository for the
I just finished creating the binary files for each of the Option ROMs v2.1 and also a 16bit binary that could be used for disassembly and posted them in the ROMs folder on my github repository for the
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By
Monty McGraw
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#167586
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Re: Advice about buying a 7904
I can speak of this from the 7904 perspective, since I have two that work, and some backup parts sources,
I had 7904's available, and no 7904As.
the 7A19 are the "appropriate" plugin for a 500 mhz
I can speak of this from the 7904 perspective, since I have two that work, and some backup parts sources,
I had 7904's available, and no 7904As.
the 7A19 are the "appropriate" plugin for a 500 mhz
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By
Harvey White
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#167585
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Re: 475 questions
As a precaution, some switching supplies don't work well with a voltage below the operating voltage.
For a linear supply, as the voltage to the supply rises, the regulator generally (if it has a
As a precaution, some switching supplies don't work well with a voltage below the operating voltage.
For a linear supply, as the voltage to the supply rises, the regulator generally (if it has a
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By
Harvey White
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#167584
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Re: probe.
I stand corrected. Sometimes you can teach an old dog new tricks! ;)
Thanks, Raymond!
Jim
I stand corrected. Sometimes you can teach an old dog new tricks! ;)
Thanks, Raymond!
Jim
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By
Jim Ford
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#167583
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Re: Advice about buying a 7904
Issues and features that I recall:
7904 has lots of tantalum caps, and a couple are bound to blow.
They are easy to find and fix.
7904 has a weak power supply that can't handle many of the
Issues and features that I recall:
7904 has lots of tantalum caps, and a couple are bound to blow.
They are easy to find and fix.
7904 has a weak power supply that can't handle many of the
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By
Chuck Harris <cfharris@...>
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#167582
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Re: 475 questions
Hi folks,
Here's my proposed parts order on Digi-Key, except that I haven't decided between the first or second set of tantalums. The caps below those are to replace the large C1412, 14, 42, 52,
Hi folks,
Here's my proposed parts order on Digi-Key, except that I haven't decided between the first or second set of tantalums. The caps below those are to replace the large C1412, 14, 42, 52,
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By
ciclista41@...
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#167581
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Re: Advice about buying a 7904
My email should have read “no well-known problems”.
I had both a 7904 and a 7904A; I gave the 7904 away to a good home when I moved across the country, reducing my collection to five 7xxx
My email should have read “no well-known problems”.
I had both a 7904 and a 7904A; I gave the 7904 away to a good home when I moved across the country, reducing my collection to five 7xxx
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By
Dave Daniel
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#167580
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Re: Advice about buying a 7904
Hi Reginald,
Advantages of the 7904A over the 7904:
- Newer, so possibly less failure-prone
- Easier to service because of split construction
- Front panel layout very much like the 7104 (or is that
Hi Reginald,
Advantages of the 7904A over the 7904:
- Newer, so possibly less failure-prone
- Easier to service because of split construction
- Front panel layout very much like the 7104 (or is that
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By
Raymond Domp Frank
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#167579
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Re: Tek 4041 GPIB Controller
We can get the 4041 service manual scanned from the vintagetek.org microfiche library of all Tektronix documentation - after COVID-19 is over. Right now Oregon is still in lockdown. They only charge
We can get the 4041 service manual scanned from the vintagetek.org microfiche library of all Tektronix documentation - after COVID-19 is over. Right now Oregon is still in lockdown. They only charge
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By
Monty McGraw
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#167578
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Re: Advice about buying a 7904
Reg,
As you may know from our prior conversations, I have both a 7104 and a 7904A. The 7904A is definitely my workhorse because, as you mention, I want to preserve and protect the mcp tube in the
Reg,
As you may know from our prior conversations, I have both a 7104 and a 7904A. The 7904A is definitely my workhorse because, as you mention, I want to preserve and protect the mcp tube in the
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By
Sean Turner
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#167577
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Re: Advice about buying a 7904
The 7904A is easier to wotk pne because it has the “kickstand” feature where one can split the display section up off of the lower section to make repairs. I’ve never compared the specs of a
The 7904A is easier to wotk pne because it has the “kickstand” feature where one can split the display section up off of the lower section to make repairs. I’ve never compared the specs of a
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By
Dave Daniel
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#167576
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