Re: OT! OT! --- E-bay fee change -- OT! OT! Cross posted with HP group.
Auctions have been around since at least 500 B.C. since they promise to fetch as high a price as possible for the seller while at the same time offering to the buyer the prospect of buying items at bargain prices or perhaps buying items that would be difficult to buy in any other way.
Complaining about the latest changes in eBay's fees, or requirements etc., as many members are doing, is a waste of time. The auctioneer, eBay in this case, is entitled to collect a fee for providing the auction venue and for running it. The shipping companies all charge virtually the same price (monopolistic competition) so there is nothing you can do about that fee.
A far more useful way to spend your time is learning how to get what you want at the lowest price (if you are a buyer) or how to sell it at the highest price (if you are a seller). Almost everything you need to know to be more successful can be found in "Snipers, Shills, & Sharks : eBay and Human Behavior", by Ken Steiglitz, ISBN-13: 978-0-671-12713-2 and ISBN-10: 0-691-12713-1, 381.177015193-dc28.
Dennis Tillman W7pF
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-----Original Message----- From: [email protected] [mailto: [email protected]] On Behalf Of - Sent: Friday, April 30, 2021 10:30 AM To: [email protected]Subject: Re: [TekScopes] OT! OT! --- E-bay fee change -- OT! OT! Cross posted with HP group. Dennis, I agree with everything that you said. However I think that what people truely object to are the *never-ending* price increases from E-bay. PLUS all of the other charges (PayPal and Global Shipping for example) for services that they force buyers and sellers to use. Personally, I've been a buyer and a seller on Ebay since the first year that they started I've seen their fees rise from a FLAT 2% to whatever the combined totals are today. I quit sellling on Ebay about 5 years ago after I sold ONE item for $200 and was charged slightly over $22 for Ebay and PayPal only and shipping not included. But as you point out Ebay is a private company and isn't beholden to it's buyer and sellers so they have decide if they want to use it or not. However, as far as I'm concerned, E-bay is still the only serious game in town if you want to sell something for a decent price. And it's also usually the only place where most individuals can buy the specialized test equipment or other items that we desire. Overall; despite it's constant cost increase, I'm very pleased to have seen the rise of Ebay. I've made a pile of money selling TE and other items that I would never have been able to sell without them and I've also been able buy books, TE and some other items that I would never been able to find, or have been able to afford, from the old regular TE suppliers such as Tucker Electronics. -- Dennis Tillman W7pF TekScopes Moderator
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Re: Tektronix Probe Replacement Parts and Accessories
On Fri, Apr 30, 2021 at 11:06 AM, Dennis Tillman W7pF wrote:
I assembled together a PDF for the Probe Replacement Parts and Accessories
for most of the Tek Probes.
Thank you!! larry
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Re: Tektronix Probe Replacement Parts and Accessories
Thank you Dennis!
By chance do you have the part number for the TeKProbe BNC with the 2 locking rings?
Shown here without the 2 locking rings.
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Re: TDS 380 Attenuator Resistor Replacement Specs
Quick update - I installed a pair of 1/4 watt resistors to achieve 49.5 ohm to match channel 2 ( /g/TekScopes/photo/263498/3217080?p=Created,,,20,2,0,0). I now have a good signal through the first relay. Still no CH1 display, so I'll have to do some signal tracing through the attenuator board and beyond to see where the signal dies. A note to anyone working on the TDS3xx series. The ceramic attenuator board is not easy to solder. My first attempts to attach the resistors to the trace betwee the two SMD capacitors in the photo was an epic fail using a T18-BR02 fine point bent tip . . . I ended up using my hot air station which worked better. Hopefully the next issue I find is beyond the attenuator board so work will be easier.
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Re: OT! OT! --- E-bay fee change -- OT! OT! Cross posted with HP group.
A couple of my bookmark searches are
?(datron,fluke,valhalla) (reference,calibrator) -prt -pressure -thermistor -loop -process
?tektronix? 1502 -1502b -1502c -1503b -1503c
limited to UK only or EU only or within a distance
most recent first
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On 01/05/21 05:16, Martin wrote: Dave,
On 30. Apr 2021, at 22:56, Dave Seiter <d.seiter@...> wrote:
...Creative search parameters can weed out unwanted listings, but not all the time... Some years ago Ebay "modified" its search algorithms, leading to a ban of wildcards that worked well before. Now the search is doing whatever it likes, its intransparent. VERY VERY OFTEN I get thousands of hits in the automotive sector for items that don't even share a single search term in their title... (searching for a FET from Tektronix, for instance).
The only way I figured out to avoid this is only searching for auctions...
cheers
Martin
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Re: OT! OT! --- E-bay fee change -- OT! OT! Cross posted with HP group.
"-" is what I use all the time, and it seems to produce the oddest results on ebay.? Sometimes I get more hits when limiting the results.
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On Friday, April 30, 2021, 10:13:29 PM PDT, - <rrrr6789@...> wrote: ? That sounds like Google's search results.? I can search for "doublewhammyjammertityflopper" and get hits for hundreds of sites that say "we sell doublewhammyjammertityflopper" but of course, they don't.? Neither Ebay or Google are as useful or as useable as they used to be. ? Liberal use of the - search directive helps considerably.? "FET" "Tektronix" -ford -chevy -audi -bmw -wv -toyota -nissan On Sat, May 1, 2021 at 12:16 AM Martin <musaeum@...> wrote: Dave,
On 30. Apr 2021, at 22:56, Dave Seiter <d.seiter@...> wrote:
...Creative search parameters can weed out unwanted listings, but not all the time...
Some years ago Ebay "modified" its search algorithms, leading to a ban of
wildcards that worked well before. Now the search is doing whatever it
likes, its intransparent. VERY VERY OFTEN I get thousands of hits in the
automotive sector for items that don't even share a single search term in
their title... (searching for a FET from Tektronix, for instance).
The only way I figured out to avoid this is only searching for auctions...
cheers
Martin
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Re: OT! OT! --- E-bay fee change -- OT! OT! Cross posted with HP group.
That sounds like Google's search results. I can search for
"doublewhammyjammertityflopper" and get hits for hundreds of sites that say
"we sell doublewhammyjammertityflopper" but of course, they don't. Neither
Ebay or Google are as useful or as useable as they used to be.
Liberal use of the - search directive helps considerably. "FET"
"Tektronix" -ford -chevy -audi -bmw -wv -toyota -nissan
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On Sat, May 1, 2021 at 12:16 AM Martin <musaeum@...> wrote: Dave,
On 30. Apr 2021, at 22:56, Dave Seiter <d.seiter@...> wrote:
...Creative search parameters can weed out unwanted listings, but not all the time...
Some years ago Ebay "modified" its search algorithms, leading to a ban of
wildcards that worked well before. Now the search is doing whatever it
likes, its intransparent. VERY VERY OFTEN I get thousands of hits in the
automotive sector for items that don't even share a single search term in
their title... (searching for a FET from Tektronix, for instance).
The only way I figured out to avoid this is only searching for auctions...
cheers
Martin
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Re: OT! OT! --- E-bay fee change -- OT! OT! Cross posted with HP group.
Dave, On 30. Apr 2021, at 22:56, Dave Seiter <d.seiter@...> wrote:
...Creative search parameters can weed out unwanted listings, but not all the time... Some years ago Ebay "modified" its search algorithms, leading to a ban of wildcards that worked well before. Now the search is doing whatever it likes, its intransparent. VERY VERY OFTEN I get thousands of hits in the automotive sector for items that don't even share a single search term in their title... (searching for a FET from Tektronix, for instance). The only way I figured out to avoid this is only searching for auctions... cheers Martin
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Thanks Dave for the reply. In my case, all the supplies are perfect. Even the Anode supply of 10kV is present. That is until the anode is connected when it blows the fuse. The way I see it, it is almost like the tube anode draws too much current. This is why I suspected the tube itself but even with the replacement tube, it does the same thing. It may be that something is not limiting the anode current. OR, may be the HV transformer is unable to take the load which is hard to test.
Like you did, I want to pull a bunch of parts in the vicinity and replace them just for the heck of it. If that test fails, it points the finger to the HV transformer in my opinion.
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I had a problem with my 465M that turned out to be C582, so I replaced it and C584 as well. I have another Tek scope that has a very similar HV circuit that kept blowing the equivalent fuse. The transistors equivalent to Q556 and Q553 got rather hot. I wound up replacing all the semiconductors in that entire circuit. and it seems to be happy now.
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Re: TM500/5000 plug-in failure modes.
My PS503 has a couple of OverVoltage SCRs on the +33 and -33 busses effective for S/Ns B022064 and below.
The +/-33V is also used to create regulated +/- 27V in a lot of other plugins, often by a pass transistor mounted in the plug-in, and +/- 5V via Zener but I would doubt it could draw that much current. I think the series resistor for that would limit the current sufficiently.
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Re: Tek DSA8200 help wanted
Hi There,
We have a scope at work with 80SJNB - I'll check to see if I have on CD - however it's pretty old (Windows 98).
Also, you can download 80SJNB for Windows XP scopes from the Tek website.
Which O/S is your scope running?
However, getting the software is just part of your challenge. You will also need a license code -> Google is your friend ;-)
Regards,
- Guy.
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Re: New to Tek 465B operation
On Fri, Apr 30, 2021 at 12:41 PM, Torch wrote: These are decent probes, good bandwidth, reasonably priced and have the Tek readout pin. 10x only though:
Note that this particular example has a broken cable jacket at each end, which would seem to indicate that the cable had been stressed at those points. That might be okay, or it might be a sign of a problem. The probe tip also appears to be bent; those usually break off when you try to straighten them.
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I've had orange lines on a color display when the display is powered up but not initialized properly.? There's supposed to be a clock input to the display.? When it's not correct, the duty cycle on the display LCD can give you that odd looking orange.
How you could get this on a monochrome display I don't know.? I do think that it has to d with bad connections to the display.
Harvey
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On 4/30/2021 4:19 PM, Pwrelectronics wrote: Yes orange lines... When slapped, the screen goes to the normal monochrome white and boot-up messages. The orange lines are in a specific pattern (these are horizontal lines) and it appears the back light is working.
I am presuming that the orange lines are what you get when there is no input to the display board from the motherboard? I am only assuming the issue is with the mother board because it goes to the boot up self test when shocked. If the issue was with the display board, I would expect that it would come up as "normal" with a mechanical shock well after the mother board booted and not see the self test messages at that point.
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On Fri, Apr 30, 2021 at 07:01 PM, Pwrelectronics wrote:
What should I look at? After the obvious with bad connections someplace
Does the scope have an optional I/O module e.g. GPIB ? If so, make sure it is seated as far as it goes. The pins on the motherboard are very short and if the module doesn't make good contact on all pins there could be boot problems. You could also remove the module completely and see if the problem persists. /H?kan
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Have you followed the oscilloscope repairman's motto? Thou shalt check voltages.
Begin at the beginning. Check the supply rails. If those are good then you can move on to check voltages at major components (like the CPU chip). For something this modern you might not even need a schematic: e.g. the voltage regulators may be pre-packaged parts so you can tell what they're doing just by looking at the part number (or a few components around them). Checking the power supply for the logic chips is as simple as finding an identifiable logic chip and probing its power pin.
The bigger trick may be getting it to perform the malfunction on demand (e.g. with the case off, though this does not sound temperature related).
For a problem like this one, which goes away when physical force is applied, you should suspect a bad solder joint, or something similar. That would actually be a best case outcome, as it would be easy to fix.
Also, it never hurts to do a simple visual inspection of the boards and components. It's unlikely, given your symptoms, but maybe something burned up or spilled its guts.
-- Jeff Dutky
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Re: OT! OT! --- E-bay fee change -- OT! OT! Cross posted with HP group.
That's what I hate about ebay- pages and pages of sellers trying to sell the identical useless junk from china.? I guess somebody must be buying it.? It's really annoying if the item you're looking for has a very generic name!? Creative search parameters can weed out unwanted listings, but not all the time.? I was looking for something a few weeks ago, and I'd get either 4 hits or over a thousand, depending on how I was searching.? Strangely, there were about 30 items that fit my search and shouldn't have been excluded by the exclusion list, but were anyway.? Never did figure out why.
-Dave
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On Friday, April 30, 2021, 11:22:04 AM PDT, - <rrrr6789@...> wrote:
?E-bay has now shifted their approach and are
trying to also attract retailers with large quantities of new identical
fixed-price items instead of individuals with a single used items.
Unfortunately for many of us, Ebay no longer attracts the sellers of used,
and originally very expensive when new, specialty items that we're looking
for.
On Fri, Apr 30, 2021 at 1:57 PM Roy Thistle <roy.thistle@...>
wrote:
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Yes orange lines... When slapped, the screen goes to the normal monochrome white and boot-up messages. The orange lines are in a specific pattern (these are horizontal lines) and it appears the back light is working.
I am presuming that the orange lines are what you get when there is no input to the display board from the motherboard? I am only assuming the issue is with the mother board because it goes to the boot up self test when shocked. If the issue was with the display board, I would expect that it would come up as "normal" with a mechanical shock well after the mother board booted and not see the self test messages at that point.
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Re: TDS 380 Attenuator Resistor Replacement Specs
Good luck. I seem to remember someone sketching the schematic of these attenuators, where this resistor was in-line with the signal. Presumably it's for dampening and/or a fusible cutout, and so the power rating shouldn't be a problem. I don't think the 380 or the 420 have a 50Ohm coupling option? On Fri, Apr 30, 2021 at 3:29 PM Richard Peterson <saaber1@...> wrote: Thanks Siggi. I found that article and it inspired me to dig into my
repair. Since Mark used an 0603 SMD resistor I assume the power
requirement is pretty low but i thought i'd ask others. I can probably
squeeze a 1206 in there, but it would be much easier scrape away the
remains of the old resistor and solder in a 1/4 watt resistor (or two in
series). I was mostly concerned about the power rating of the original
part, but given the size, I guess it's pretty low. I'll try the metal film
resistors, matched to the value of the resistor in CH2 and see what
happens. Hopefully nothing on the underside of the board is also blown.
I'll post my results . . .
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Re: TDS 380 Attenuator Resistor Replacement Specs
Thanks Siggi. I found that article and it inspired me to dig into my repair. Since Mark used an 0603 SMD resistor I assume the power requirement is pretty low but i thought i'd ask others. I can probably squeeze a 1206 in there, but it would be much easier scrape away the remains of the old resistor and solder in a 1/4 watt resistor (or two in series). I was mostly concerned about the power rating of the original part, but given the size, I guess it's pretty low. I'll try the metal film resistors, matched to the value of the resistor in CH2 and see what happens. Hopefully nothing on the underside of the board is also blown. I'll post my results . . .
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Richard Peterson
Martin
DaveH52
zenith5106