FS: 17 lb. Power Transformer for Tek 545A
Over on the Facebook Vintage Electronics Group, a group member has posted that he has a transformer for a Tek 545A. Here's the text of his post. I have purchased 3 items from this seller before and he is very trustworthy.
Text of post:
This beast is Tek part no. 120-120, the power transformer for the 545A 'scope. It weighs 17 pounds, has 12 secondary windings, and other than scratches on the case looks unused.
I got it a few years ago when I was thinking about building a beefy audio power amp. Combined, the four high-voltage windings will supply more than 650 volts and run cool at 400 mA. It has seven 6.3 VAC windings, two rated at 8 amps, one at 6 amps, two at 4 amps, one at 1 amp and one with no rating I can find.
I've checked all windings and they're good.
I want to pass it along to somebody who will make use of it. I paid something like $45, as I recall. I'll sell it for $20 plus shipping. It will fit into a medium Flat Rate Box ($13.65), for a total of $33.65. Add a buck if paying by PayPal. Pickup in the Maryland suburbs of Washington DC would be fine.
I'll include a table that calls out all the windings by lug number, voltage based on the 545A schematic, resistance, estimate current and power rating, and estimated loss.
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Re: Up to date capacitor list for Tek 2465A and 2465B scopes (2018)
Ron "I don't think the repair pads will do well with a leaded cap hanging on it." I have done many PCB repairs, replacing the SMD components with Leaded. See here: /g/TekScopes/album?id=60615This is of a Bose Music system - CD-Control PCB - before and after. There is very little vertical clearance, so they lay horizontal. The SMD pads are more than large enough to accommodate the soldered leads, and as long as the soldering is kept to the same standards as for SMD caps (less than 2 secs, at 270¡ãC), there is no danger of lifting the pads. This is my standard way of working with SMD PCB's now; same process on all the TV T-Con PCB's which I work on (TV PSU PCB's are still Through-Hole). I find it super-reliable, even if it won't win any aesthetics awards, and have not experienced any comebacks at all, on any of the hundreds of SMD PCB's which I have overhauled in this way.
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Hi Russ,
You may have overlooked my message #149053 saying
"You probably downloaded more manuals now (as indicated by Dennis) if you hadn't done so already. Note that you need the manual corresponding to your S/N, below or above B250000, though the later manual shows more voltage and waveform details which may or may not be applicable to the earlier version.
The requirements for regulated voltages are always in the first steps of a calibration procedure; same here.
It's difficult to find the proper pages in the pdfs compared to paper manuals. Strange enough the tab "Adjustment Locations 1" in my late manual shows arrows pointing to all LV test points whereas these are missing (except +55 V) in some or all pdfs Fig. 8-19. You might consult Fig. 8-18, pdf page 236 in "tektronix_465_oscilloscope_full_sm.pdf"."
You'll have to do with the available B25-up manual. There may be some minor changes in your B317000 'scope which are not yet shown in that manual, but for the present purpose don't bother about that.
As said the LV requirements are always in the calibration section, here pdf page 78 of "tektronix_465_oscilloscope_full_sm.pdf".
The test point locations are shown (very vaguely) in the board layout I mentioned, Fig. 8-18. Note also that the table of board grid locations below the figure. Mostly theseTPs are indicated at the board itself with description or number, like "+15V" or "TP1234".
Albert
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On Wed, Jun 20, 2018 at 05:44 pm, <musicamex@...> wrote:
Lol pol,
Thanks for the reply. Do you know where I can find a list of the lv test
points and what they should read?
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Re: 2430a power indicator lamp
At 10:08 PM 6/20/2018, Dave Casey wrote: I don't recall it having a lamp; I thought it just has a mechanism on the
button that exposes a bright green/yellow disc when the button is depressed. That is a Schadow switch (the line is now owned by ITT), often seen incorrectly spelt as "Shadow" switch. Dale H. Cook, Radio Contract Engineer, Roanoke/Lynchburg, VA
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Re: Tek 1502 Handle: How is the Blue Plastic Cap Removed?
Thank you both for your thoughts and efforts.
Yes it is item #30, but the hole is larger than bolt #31. Bolt #31 directly compresses the washer #32. Since there is considerable compressive force exerted by the bolt, this avoids that force compressing plastic.
I initially expected completely removing the bolt would allow the hinge to simply fall apart so I could see what was inside.? But the hinge remains intact.
Then I expected the cap to be snap on, but my deliberately gentle attempts to prise it off don't move it in the slightest.
I expect it probably is snap on, but given the plastic's age I'm worried that a hidden nib (etc) would break rather than deform.
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On 21/06/18 02:39, Artekmedia wrote: Looking at the service manual, Figure 1, Exploded View in the mechanical parts section, if we are talking about item #30 the view shows that the bolt is all that holds it on
-DC
manuals@...
On 6/20/2018 9:13 PM, Merchison Burke via Groups.Io wrote:
If you loosen the hex-head screw in the centre of the cap, does the cap loosen?
Does the cap look like a snap-on cap?
On 2018-Jun-20 5:25 PM, Tom Gardner wrote:
On 20/06/18 22:12, Raymond Domp Frank wrote:
On Wed, Jun 20, 2018 at 01:40 pm, Tom Gardner wrote:
So what is the right technique for removing the cap?
Sorry, I didn't read your question, although I quoted it... Are you sure that by completely removing the bolt, you can't pull off the handle and then remove the cap "from the inside"? It would have helped if I had noted why I wanted to remove the cap!
But no, unfortunately that doesn't help.
The 1502 is (or ought to be) thoroughly sealed up so that it can be operated in rain and actually underwater[1]. For the hinge-case joint this means there are four bolts coming through the case from the outside, and they are thoroughly "gunked" to the case.
[1] Yes, the 2kV coming to the intensity/focus pots on the front panel would make me a little twitchy (ahem) under those circumstances.
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Re: 2430a power indicator lamp
I don't recall it having a lamp; I thought it just has a mechanism on the
button that exposes a bright green/yellow disc when the button is depressed.
Dave Casey
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On Wed, Jun 20, 2018, 8:00 PM Dewey Wyatt <kn4wddewey@...> wrote: anyone here ever replaced a 2430a indicator light? I cannot find it in the
sm or user manual.
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Re: Tek 1502 Handle: How is the Blue Plastic Cap Removed?
Looking at the service manual, Figure 1, Exploded View in the mechanical parts section, if we are talking about item #30 the view shows that the bolt is all that holds it on
-DC
manuals@...
toggle quoted message
Show quoted text
On 6/20/2018 9:13 PM, Merchison Burke via Groups.Io wrote: If you loosen the hex-head screw in the centre of the cap, does the cap loosen?
Does the cap look like a snap-on cap?
On 2018-Jun-20 5:25 PM, Tom Gardner wrote:
On 20/06/18 22:12, Raymond Domp Frank wrote:
On Wed, Jun 20, 2018 at 01:40 pm, Tom Gardner wrote:
So what is the right technique for removing the cap?
Sorry, I didn't read your question, although I quoted it... Are you sure that by completely removing the bolt, you can't pull off the handle and then remove the cap "from the inside"? It would have helped if I had noted why I wanted to remove the cap!
But no, unfortunately that doesn't help.
The 1502 is (or ought to be) thoroughly sealed up so that it can be operated in rain and actually underwater[1]. For the hinge-case joint this means there are four bolts coming through the case from the outside, and they are thoroughly "gunked" to the case.
[1] Yes, the 2kV coming to the intensity/focus pots on the front panel would make me a little twitchy (ahem) under those circumstances.
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--
Dave
Manuals@...
www.ArtekManuals.com
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There is a hint in the "spec": "(It can't be used for measuring the AC power converted from a DC power with an inverter)"
Inverter often means square wave or modified square wave rather than sine wave voltage. A true RMS measuring meter won't care. Also notice the total lack of an accuracy specification. And what about power factor?
Dave
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On Wed, Jun 20, 2018 at 12:45 pm, Ed Breya wrote:
Michael A. Terrell wrote:
"
Durable-AC-80-260V-LCD-Digital-20A-Volt-Watt-Power-Meter-Ammeter-Voltmeter
US $7.99 plus shipping."
That's pretty slick for ten bucks, for common AC monitoring.
Unfortunately, the specs don't say if any measurements are true RMS or not.
For the voltage, average reading is sort of OK since the line will be "mostly"
sinusoidal, but current may be some nasty waveforms, and so will the power
that goes with it, so true RMS is best for accuracy. There are ICs that can
make the V and I measurements with ADCs, and properly calculate these and
other AC parameters. If they've used such a one, it could be a very cool
little monitor - especially for the price.
If anyone is planning to get some to try out, please let us know what you
find, and if they are capable of "true" measurements - it's easy to figure out
with a few experiments. If these are indeed capable, then I'd be interested in
getting some too.
Ed
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Re: Tek 1502 Handle: How is the Blue Plastic Cap Removed?
If you loosen the hex-head screw in the centre of the cap, does the cap loosen? Does the cap look like a snap-on cap? On 2018-Jun-20 5:25 PM, Tom Gardner wrote: On 20/06/18 22:12, Raymond Domp Frank wrote:
On Wed, Jun 20, 2018 at 01:40 pm, Tom Gardner wrote:
So what is the right technique for removing the cap?
Sorry, I didn't read your question, although I quoted it... Are you sure that by completely removing the bolt, you can't pull off the handle and then remove the cap "from the inside"? It would have helped if I had noted why I wanted to remove the cap!
But no, unfortunately that doesn't help.
The 1502 is (or ought to be) thoroughly sealed up so that it can be operated in rain and actually underwater[1]. For the hinge-case joint this means there are four bolts coming through the case from the outside, and they are thoroughly "gunked" to the case.
[1] Yes, the 2kV coming to the intensity/focus pots on the front panel would make me a little twitchy (ahem) under those circumstances.
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2430a power indicator lamp
anyone here ever replaced a 2430a indicator light? I cannot find it in the sm or user manual.
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Lol pol,
Thanks for the reply. Do you know where I can find a list of the lv test points and what they should read? After all of the hv warnings and having learned the hard way about hv working on tube amps, i dont want to smoke my remaining hair or my Fluke's fuses at best. If I had been inside of more than one scope[this one] and had a network of electronically competent amigos and parts at my disposal, I might not feel so overwhelmed with this repair. If you only had worked on classic hand wired tube amps and the next step was pulling the cover off a non functioning complexity like I have on the bench, you would understand how this seems to me. As an ex chemist and a charter member of 999 i am confident that i can learn how to fix this. But so far what I have downloaded from the manuals archives isn't fitting the bill by itself.
Thanks, Russ
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The fan requires the 15V rail to be working. I'm betting your LV test points are off. The 465 I just repaired was missing the 5V the 15V and the -8V the high voltage requires that those be working so hence no CRT, the 55V and the 110V were fine. As soon as I got those working the fan started and the CRT fired up. May not be the same for you but its worth checking the LV test points. Good luck
Hi all, thanks for the replies. My sn is B 317000. But i am not having much luck in finding the downloads for this later version. The scope has several small eylet tabs on the boards labeled TP followed by a number. It would be handy if there were a page identifying the testpoints and giving a range for acceptable values. Or for example, LV circuit test points, values and troubleshooting implications for out of range values. Any help finding this info would be greatly appreciated.
I will do the current measurement on the 120v input, perhaps on my off time this weekend, but as i mentioned, the power button does light the power on light and a few other lights on the front panel, and there is power to and through both fuses but there does not appear to be a filament glow inside the CRT and the fan doesn't turn on (temp activated?).
Thanks, Russ
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Hi all, thanks for the replies. My sn is B 317000. But i am not having much luck in finding the downloads for this later version. The scope has several small eylet tabs on the boards labeled TP followed by a number. It would be handy if there were a page identifying the testpoints and giving a range for acceptable values. Or for example, LV circuit test points, values and troubleshooting implications for out of range values. Any help finding this info would be greatly appreciated.
I will do the current measurement on the 120v input, perhaps on my off time this weekend, but as i mentioned, the power button does light the power on light and a few other lights on the front panel, and there is power to and through both fuses but there does not appear to be a filament glow inside the CRT and the fan doesn't turn on (temp activated?).
Thanks, Russ
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Hi Michael, How is the Display Module connected to the Base Module to measure values ? Can you hook an RMS meter and an averaging and this meter in parallel to determine if this meter is an RMS model and let us know ?
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Re: Tek 1502 Handle: How is the Blue Plastic Cap Removed?
On 20/06/18 22:12, Raymond Domp Frank wrote: On Wed, Jun 20, 2018 at 01:40 pm, Tom Gardner wrote:
So what is the right technique for removing the cap?
Sorry, I didn't read your question, although I quoted it... Are you sure that by completely removing the bolt, you can't pull off the handle and then remove the cap "from the inside"? It would have helped if I had noted why I wanted to remove the cap! But no, unfortunately that doesn't help. The 1502 is (or ought to be) thoroughly sealed up so that it can be operated in rain and actually underwater[1]. For the hinge-case joint this means there are four bolts coming through the case from the outside, and they are thoroughly "gunked" to the case. [1] Yes, the 2kV coming to the intensity/focus pots on the front panel would make me a little twitchy (ahem) under those circumstances.
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Re: Tek 1502 Handle: How is the Blue Plastic Cap Removed?
On Wed, Jun 20, 2018 at 01:40 pm, Tom Gardner wrote:
So what is the right technique for removing the cap?
I never use a screwdriver to lift caps, open hard disk cases, laptops etc. although every single manual suggests that. I always use the length of a regular breakfast knife. Maybe that's something to try. You can exert quite a lot of force on a large part of the plastic surface so very little risk of damage. Raymond
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Re: Tek 1502 Handle: How is the Blue Plastic Cap Removed?
On Wed, Jun 20, 2018 at 01:40 pm, Tom Gardner wrote:
So what is the right technique for removing the cap?
Sorry, I didn't read your question, although I quoted it... Are you sure that by completely removing the bolt, you can't pull off the handle and then remove the cap "from the inside"? Raymond
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Re: Tek 1502 Handle: How is the Blue Plastic Cap Removed?
On 20/06/18 22:00, Raymond Domp Frank wrote: On Wed, Jun 20, 2018 at 01:40 pm, Tom Gardner wrote:
So what is the right technique for removing the cap?
You don't remove the cap: Just very slightly tighten or loosen the Allen bolt. A small angle suffices. Thanks, but I do want to remove the cap from one 1502, so I can put it on another.
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Re: Tek 1502 Handle: How is the Blue Plastic Cap Removed?
On Wed, Jun 20, 2018 at 01:40 pm, Tom Gardner wrote:
So what is the right technique for removing the cap?
You don't remove the cap: Just very slightly tighten or loosen the Allen bolt. A small angle suffices. Raymond
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Tek 1502 Handle: How is the Blue Plastic Cap Removed?
How can I remove the blue plastic cap over the handle pivot, as visible in ?
Background: the Tek 1502 does not have a handle with the usual fixed detent positions; instead its handle is kept in position by the friction between plates. The plates are compressed together by a bolt, but that bolt apparently does not compress the blue plastic cap.
Looking at the service manual (Fig 9.1), I expected that if I removed the bolt then the entire hinge would spring apart, but it doesn't.
Now I could try and prise the cap off with a screwdriver, but I'm loathe to do that since it risks destroying the blue cap. So what is the right technique for removing the cap?
Thanks
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Dale H. Cook
Jon Batters
Raymond Domp Frank