The History of the Tektronix Corporation
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Re: 7904 pre-260000 PSU crackling
Oh, no smell of ozone either Jon. The trafo runs at 51 degrees, the caps at 31, this relative to a room temp of 20C, all limited by DIY equipment...
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Re: 7904 pre-260000 PSU crackling
Jon, Ed, Mark and everyone else, thank you so much! I had to go to work today, an "occupational hazard".
Tonight I clarified a couple of things. The neon stays on for a good 30 seconds, but I need a dark place to see it in, so my bad that I didn't see it before, apologies. Second, the noise comes from the middle of the PSU. I'd love to say from the trafo or the caps but it's too tight in there to tell, definitely in there. Sounds like both ends of the unit. Sorry for the lack of certainty. Voltages say tight, the ripple is of variable frequency across voltages if that matters, this with a vertical and horizontal unit inserted. There are snaps, crackles, and pops from the hv cable when wiggled so this needs further cleaning as well, but it sounds different.
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Re: Adapter PCBs for 148-003x-00 relay replacement
Hi Wolfgang,
I understand. I plan to pursue those relays on my own but just wanted to ask just in case.
I'm still interested in getting a few of your boards as I have two 7A13s and I think the 7A12 also uses some of those types as well.
Thanks again,
Barry - N4BUQ
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Hi Barry,
sorry for the confusion regarding the 148-0063-00. I didn't know the part number
and just googled the part. From the pictures I found I thought it was just as
simple DPDT relay (like 148-0034-00) with an additional internal connection.
As it turns out, this is not the case. It might be possible to build an PCB
adapter for this one as well. But as it is only used in the 7A12 and nowhere
else it might not be feasible to go through this effort.
Bye,
Wolfgang
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Re: Tektronix 106 Square Wave Generators for sale on eBay New in Box
On Sun, Jan 5, 2025 at 05:23 PM, John Williams wrote:
If you don’t have one you need one!
I don't think I have one. I don't think I need one. Is this a "collector's passion" ... or am I missing something? -- Roy Thistle
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Re: Tek T-130 LC - add mains/EMC filter or not?
Over the years I have heard that the meter scales on certain HP gear were custom ruled as part of initial calibration, so specific to the individual instrument, but I have no idea of which ones are this way. I don't know if any Tek ones are, but I doubt it. If anyone gets to a point where they need to take a meter apart for repair, it's a good idea to take an accurate picture or flatbed scan of the face just in case, for future reference and use.
Ed
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Re: Burned diode on CRT driver board CSA803A
Hi Evan, Thanks for replying. The CSA803A has a color display. I have put some pictures of the A8 video driver board in the photo album under: /g/TekScopes/photo/299921/3873248?p=Created%2C%2C%2C20%2C2%2C0%2C0I realized that my 11403A has the same A8 video driver board. Fortunately, I could make a picture of this diode without removing the board (Pic4 in the album). It is a glass diode with thick wires and a white ring at the kathode and partial identification "H-7". Kind regards, Gerard
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Re: 7904 pre-260000 PSU crackling
James: "What is the dog house hole? Is it the slot in the middle of the PSU panel where the HV lead
The HV section has a metal cover (doghouse) with a 3/8" hole where HV U;tpr 21 kV connector exists from HV multiplier.
Adding insulation is useless.
Just be sure the cable and Alden connectrs are clean and ry.
Ozone: even0. 1 PPM is easily penetreating smell
No tube needed.
Jon
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Re: Adapter PCBs for 148-003x-00 relay replacement
Hello Wofgang,
Thanks for the initiative. I would also be interested in two sets of boards. I have 2 7A13's that I would like to repair.
with best regards,
Patrick Vandenberghe
(Belgium)
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Re: Adapter PCBs for 148-003x-00 relay replacement
Hi Barry,
sorry for the confusion regarding the 148-0063-00. I didn't know the part number and just googled the part. From the pictures I found I thought it was just as simple DPDT relay (like 148-0034-00) with an additional internal connection.
As it turns out, this is not the case. It might be possible to build an PCB adapter for this one as well. But as it is only used in the 7A12 and nowhere else it might not be feasible to go through this effort.
Bye,
Wolfgang
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Re: Tek T-130 LC - add mains/EMC filter or not?
When I started working on mine, I found that bits of the meter scale were flaking off; so, I made an accurate photo of it. (I have a fairly good digital macrophotography setup). If the scale gets bad enough to need replacement, I'll edit out the bad parts of the photo
with gimp or photoshop (for Windows users), and print out a new high quality scale with a photo printer.
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Re: Tektronix 106 Square Wave Generators for sale on eBay New in Box
Would love to have one but it would make all my other Tek stuff look bad even though I've put a lot of effort into spiffing all of them up!
Tracy
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Re: Tek T-130 LC - add mains/EMC filter or not?
Wow - I had spotted my scale is non-linear but had not appreciated that they were individual to the meter.
When you say 'meter' do you mean one scale for that particular range of meters as used in that piece of equipment, or do you mean individual to each meter and/or each piece of equipment?
I too need to re-do mine - the red has almost gone.
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Re: Tek T-130 LC - add mains/EMC filter or not?
Thanks for that and filed away. Here's a link to one I did 30 years ago in Freehand on Mac a running OS 9.2.2, Did the arithmetic and just drew it, in about half a day: Here's the front panel layout for a Quan-Tech Spot Noise meter which I've been working on because the stock, linear-reading meters have about 10Db of range and the thing is an endlessly-range-switching pita to run. In addition to making it log reading, I want to change the spot noise meter itself from a 10Hz-to-100KHz machine to a 3Hz-to-30KHz machine because I do tube audio and want to get a better look at 1/f as tubes tend to run to a 1/f-ish noise spectrum. Bill in BC, Canada There are several software programs for generating meter faces, paid or
free. Two are:
This link is now correct: Googling for meter design software will find other approaches or
comments and comparisons.
John??? KK6IL
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Re: Tek T-130 LC - add mains/EMC filter or not?
There are several software programs for generating meter faces, paid or free. Two are:
<>
Googling for meter design software will find other approaches or comments and comparisons.
John??? KK6IL
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On 1/5/2025 4:30 PM, Jean-Paul via groups.io wrote: Richard, many thanks glad I could help.
Ed, fine mod, I will do the same on my 130 LC. By the way are the meter scales hand calibrated?
Plan à similaire mod for à Tek 191 constant amplitude generator ( 50 kHz..100 Mhz).
Remarkable these 1960s units are still working, mine are in cal.
Jon
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Re: Tek T-130 LC - add mains/EMC filter or not?
I have to redraw the scale for mine, it's faded beyond readability. If those scales weren't individual to the meter the redrawn scale might be of some use to others.
Not happening anytime soon though, still moving and setting up.
Bill in BC, Canada
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Richard, many thanks glad I could help.
Ed, fine mod, I will do the same on my 130 LC. By the way are the meter scales hand calibrated?
Plan à similaire mod for à Tek 191 constant amplitude generator ( 50 kHz..100 Mhz).
Remarkable these 1960s units are still working, mine are in cal.
Jon
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Tektronix 106 Square Wave Generators for sale on eBay New in Box
Tektronix 106 Square Wave Generators for sale on eBay new surplus in Box. Preferred Air Parts have three of these left out of five. I just purchased one. If you don’t have one you need one! I will let you know my experience once it arrives. Sale has nothing to do with me.
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Re: Tek T-130 LC - add mains/EMC filter or not?
Richard, many thanks glad I could help.
Ed, fine mod, I will do the same on my 130 LC. By the way are the meter scales hand calibrated?
Plan à similaire mod for à Tek 191 constant amplitude generator ( 50 kHz..100 Mhz).
Remarkable these 1960s units are still working, mine are in cal.
Jon
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Re: 7904 pre-260000 PSU crackling
One of my 7904s just crapped out with HV arcing inside the PS unit - very loud and obvious. I had just fixed it (it had other problems not HV) back in November, and I'm convinced the failure was due to high humidity damp and cold conditions out in the garage.
If your new unit is quite filthy from what you've seen so far, the inside is probably pretty bad too. If it's working now but making discharge noises, you should open it up and clean the HV section (and the rest too as needed) thoroughly, then look for evidence of arcing or component damage. Chances are it should be good to go after cleaning.
I think that mine unfortunately ended up damaging something. I should have shut it down immediately but I thought it might clear by itself. No such luck. It still showed a messed up display at first, but then went blank - bad idea to let it go.
Ed
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Re: Tek T-130 LC - add mains/EMC filter or not?
I agree - no line filter is needed. I'd say also that no extra trim plate is needed either unless the metalwork has been messed up. I changed my 130s to IEC recently by filing out the hole periphery with a 3/8" D or so round file just enough clear the chamfer and rounded corner features of the IEC connector. The original hole shows a bit, but I don't mind since it's on the back. Here's what it looks like: /g/TekScopes/photo/296248/3803157?p=Created%2C%2C%2C20%2C2%2C0%2C0Ed
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Jean-Paul
Bill Perkins
John Williams