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2754p memory problems
jeb_brygider
I have two 2754 spectrum analyzers, one partially working, the other basically a parts mule. When starting the good one, it tells me it has memory faults and when stepping past it shows memory bad or missing. I have researched and am concerned I might do serious damage by swapping the memory board from the parts unit.
This is my first venture into spec analyzers, although I have been an instrumentation tech for almost all of my 74 years, and am what I consider to be an ancient measurement equipment archeologist with several hundred instrument collection ( I have lost count, could be over1000). I've also been a ham since 1959 W2JEB. My interests are mostly repairing and restoring equipment as opposed to purchasing new. I live in western Washington NW of Seattle in the Port Townsend area. I would appreciate any and all suggestions and assistance as I'd truly love to have this unit operational. Thanks in advance, Jeb Brygider
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Re: 2465 Fan Collet Thingy
EricJ
I am still getting my new machines set up, but I can probably run off a few soon.
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--Eric
On Nov 9, 2019 11:15 PM, Chuck Harris <cfharris@erols.com> wrote:
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Re: 2445 CH 3 and CH 4 vertical setting - volts/ div where ?
Chuck Harris
I prefer to think of channels 3 and 4 as external trigger inputs
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with full waveform display... because that is what they really are. -Chuck Harris TomC wrote:
The channel 3 and 4 volts/div for the 2445 can be anything you want as long as you
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Re: 2465 Fan Collet Thingy
Chuck Harris
As I said, there are dimensioned prints... prints are
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a 2D thing. You will have to use your own cad expertise to convert them into a 3D mesh for printing. I am not sure that an all plastic printed solution will work... tektronix didn't think so, and made a much more expensive metal/plastic hybrid. -Chuck Harris Tony Fleming wrote:
Where are the 3D files to print my own replacement?
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Re: 2445 CH 3 and CH 4 vertical setting - volts/ div where ?
TomC
The channel 3 and 4 volts/div for the 2445 can be anything you want as long as you want 0.5 volts/div or 0.1 volts/div. It is selected by a pair of push buttons, one for each channel, between the channel 3 and 4 vertical position controls.
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Tom
On 11/9/2019 6:36 PM, vaclav_sal via Groups.Io wrote:
Just adjured 2445 scope and trying to get familiar with the controls.
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anyone have 310 or 360 parts machine?
I am looking for a graticule lens for my Tektronix 360 indicator module. This is the old scope module for the 160 series with the round CRT.The 310 scope used the same part. Tektronix part #331-0027-00. I will gladly pay for it and shipping. Any help would be appreciated.
Thanks Phil Cirocco
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2445 CH 3 and CH 4 vertical setting - volts/ div where ?
vaclav_sal
Just adjured 2445 scope and trying to get familiar with the controls.
Not having much luck asking Mrs Google or reading text only ( no links / reference ) manuals. So - any owner of 2445 can tell me where / how to select vertical "Volts/Div" setting for CH 3 and CH 4? I can read the calibrator on CH3 OK , just cannot figure out how to set the vertical setting for it. Thanks
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TEK 2430A
frank carcia
Hi All,I have a clean 2430A that pulls faults in power on bit. I don't think the battery has ever been changes.One fault that comes up is attenuator and another is trigger related. I wonder if this could be battery related.I have not tried to clean any board contacts or troubleshoot. I just downloaded the service manual. Any advice welcome to avoid reinventing the wheel.Thanks,Frank WA1GFZ
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Re: 2465 Fan Collet Thingy
n4buq
That happened to me. It broke cleanly and rather squarely at the end/depth of the brass insert.
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I drilled and tapped the collet about 3/16" deep, used a very short length of #4-40 threaded rod (really just a cut off #4-40 screw), CA-glued the threaded rod into the plastic and then did the same into the brass end (with CA on the mating surfaces. I had to shorten the #4-40 on the threaded "puller" but it all went back together and appears it will hold (it doesn't take much "pull" to close the collet sufficiently. Just one way that might work to fix a broken collet. Thanks, Barry - N4BUQ
----- Original Message -----
From: "DaveH52" <ac2gl.dave@gmail.com>
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Re: 2465 Fan Collet Thingy
Tony Fleming
Where are the 3D files to print my own replacement?
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Thank you very much. Tony
On Sat, Nov 9, 2019 at 6:39 PM Chuck Harris <cfharris@erols.com> wrote:
More usually, the problem is someone turning the
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Re: 2465 Fan Collet Thingy
Chuck Harris
More usually, the problem is someone turning the
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slotted screw, thinking it loosens the collet. Turning the screw will break the collet every time. Tightening the nut is less likely to do that, as that is the intended way to apply force to the collet. It is the torque that causes problems. There are dimensioned prints for the collet in the files section of this group. A search on collet should find them. If you can't find them, contact me, and I will send them to you. -Chuck Harris DaveH52 wrote:
Are there any of the fan to motor collet thingies available anywhere?
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Re: 2440 nvram (was: NVRAM back-up battery change on a 2715..... avoiding disasters)
Hi Szabolcs,
Your and my latest posts bring things mostly in line. We may have had a misunderstanding where I thought you were saying that just pressing a few buttons would re-establish calibration after exchanging the NVRAM. If I misunderstood I apologize. I think we *can* agree that 1. Calibration constants, not just operational constants are stored in NVRAM 2. These constants are lost when the NVRAM is exchanged 3. An Ext Cal is needed to restore the calibration constants but the 'scope operates without restoring them 4. To perform an Ext Cal, some equipment (PG506 or the like, fixed attenuators) is needed 5. Doing it all is not a big deal if you've got suitable equipment and (mostly) know what you're doing If these points are no problem for Bob (OP), he would have no problem after exchanging the NVRAM. Raymond
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Re: Tek 485 short sweep
Abc Xyz
Michael,
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I was thinking the same thing. JR
On Sat, Nov 9, 2019, 3:54 PM Mlynch001 <mlynch002@gmail.com> wrote:
On Sat, Nov 9, 2019 at 04:25 PM, DaveH52 wrote:on the
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Re: 2440 nvram (was: NVRAM back-up battery change on a 2715..... avoiding disasters)
On Sat, Nov 9, 2019 at 11:16 PM, Szabolcs Szigeti wrote:
Hi Szabolcs, You wrote: It turns out that's correct. Note: Ext Cal stores "Internal Calibration Constants" in (some sort of?) NVRAM, which is exactly what I am talking about. Ext Cal is no big issue but you need some (calibrated) equipment to do it. Examples: General: Chapter 5 paragraphs 4.e and 4.f (page 5-19 in my SM) "Match Ch1 and Ch2 bw at remaining V/div settings". Sine Generator and 5x and 10x attenuators needed. Ext Cal (starting at page 5-23): - "1. Attenuator Gain Adjustments". Needs calibrated voltage generator and stores constants. - "2. Channel Delay Adjustments". Needs fast rise calibration generator, stores constants. I'd be surprised if a slow edge would be ok - "3. Trigger Adjustments". Calibration generator needed. Stores constants. - "4. Ramp (REPET) Calibration. Stores constants. - "5. CTE Calibration. Needs Fast Rise Calibration Generator. Stores constants. From the above, I'd say that (Ext) Cal is not only a matter of pressing some sort of "Self Cal" button(s). It involves connecting and using calibration equipment and pressing buttons. As said, no big deal (a PG506, possibly with TD pulser, will do as a generator and voltage source) but a large part of calibration *is* lost if NVRAM is exchanged. Whether that's serious is a matter of interpretation but I'd be surprised if an average 2440 will be "in spec" without re-establishing the NVRAM constants. Maybe deviation is 5% max, as I've seen with analog 24xx'es, don't know. Raymond
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Re: Tek 485 short sweep
On Sat, Nov 9, 2019 at 04:25 PM, DaveH52 wrote:
90V supply in a 465/465B or 475? Unreg +120/110,+110,-8,+5 +15 and +55 are the only ones that I have ever seen. Have I missed something? -- Michael Lynch Dardanelle, AR
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Re: 2440 nvram (was: NVRAM back-up battery change on a 2715..... avoiding disasters)
Szabolcs Szigeti
Hi,
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There are 3 calibration task for the 2440. The self cal and the ext cal and the procedure described in the adjustment section of the SM. The adjustment section ha two distinct part. One is the display geometry adjustment. This is completely separate from all other workings of the scope and deals about having the correct picture on the screen. You need to adjust horizontal/vertical gain and offset, crt bias, etc. The scope provides the test pictures. This only includes turning pots, a completely analogue process and has no affect to any other parts of the instrument. The other part is about setting the CCD gains, cocks and some other parameters. This is also mostly about turning pots and having the scope calculate values based on that. This is what you are referring to as saving when pressing the horiz A/B button if any change is made to the pots. But all contants are calculated b the scope, the are no hidden, magic constants somehow loaded in the factory. Therefore, if we suppose that one only replaces the nvram, then simply doing the self cal and ext cal, and possible the steps in the adjustment section requiring pushing buttos, the scope will be in spec as a result. If you decide to do the whole calibration, you can do that, you need some extra equipment, but nothing too fancy. It is true, that while the sope is doing the self cal, it builds on the previous cal constant but that is only to reach a quick result. If you start from an empy nvram, the self cal will usually take a long time, until the spope converges on a solution. Actually, if you turn of the scope during self cal, it will invalidate the cal constants and force you to do a self cal at next turn on. So, based on this, it is not necessary to save the content of the nvram when replacing, because it is very easy to do the steps to have the scope recalibrated. This is in contrast to the analogue 24xx scopes, where we can all read horror stories about how hard them to recalibrate without the proper equipment and skills. The 2440 can be recalibrated in an hour, even if you need to do internal adjustments. If you don't need internal adustments, because you assume that the pots were at the proper setting before losing the nvram, it's self cal and ext cal, and that is all. So this is why I'm saying that don't worry about saving the nvram. I think this thread is now getting a bit repeative, so base on my experience my advice is replace the nvram, don't bother with saving it. I did it several times and the sky hasn'T fallen on me. YMMV. But, If you open the scope anyway, you may as well do the whole adjustment procedure (at least very if you need it), because it is simple to do. The SM recomments verifying every 2000 hours if I remember correctly. It certainly won't hurt. Szabolcs Raymond Domp Frank <hewpatek@gmail.com> ezt írta (időpont: 2019. nov. 9., Szo, 23:32):
On Sat, Nov 9, 2019 at 11:16 PM, Szabolcs Szigeti wrote:Maybe none of the corrections done by storing in chapter 5 were necessary
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Re: Tek 485 short sweep
Abc Xyz
Dave,
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How did you Find the Leaky Capacitor? JR
On Sat, Nov 9, 2019, 2:26 PM DaveH52 <ac2gl.dave@gmail.com> wrote:
I had a similar issue with my 465. It turned out to be a 2uf capacitor on
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Nice 453 on CL Toledo
Paul Amaranth
No affiliation, etc ...
https://toledo.craigslist.org/ele/d/temperance-tektronix-oscilloscope-type/7013203618.html -- Paul Amaranth, GCIH | Manchester MI, USA Aurora Group of Michigan, LLC | Security, Systems & Software paul@AuroraGrp.Com | Unix & Windows
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Re: 2440 nvram (was: NVRAM back-up battery change on a 2715..... avoiding disasters)
On Sat, Nov 9, 2019 at 11:16 PM, Szabolcs Szigeti wrote:
Maybe none of the corrections done by storing in chapter 5 were necessary or relevant in your case. Maybe they're minimal, maybe not everything is in spec. This is all very intriguing. I cannot imagine the Adjustments according to chapter 5 that I mentioned not to go into (some sort of) NVRAM and I do not understand what they're for if just pressing a button outside of the Adjustments chapter will do the same. As you said, a little bit of mystery Can you point me to where it says that? It would negate the sense of the store-adjustments mentioned earlier. I've seen that happen in the analog models, about 5% off max. but I'm aware of the difference. Same with forced air cooling when out of case: A must with 2440, not with analog 24xx'es. Raymond
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Re: 2465 Fan Collet Thingy
Tom Gardner
On 09/11/19 22:04, DaveH52 wrote:
Are there any of the fan to motor collet thingies available anywhere?That happened to my 2445B recently. There are some possibilities for manufactured collets discussed in the archive. I've sent a model of the collet off for manufacture in SLA, but it will probably take the best part of a month to arrive. When it arrives I'll let you know if it looks like it works.
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