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Re: Tektronix 475A intermittent / lazy sweep
Chris Smith
Hi,
On 19 Nov 2018, at 22:12, Jeff Urban <JURB6006@...> wrote: Thanks for the reply. Much appreciated. Just to note I¡¯ve eliminated U520. Expected waveforms at input and output are fine. I think this is somewhere between the tunnel diode drivers and U600. U600 is doing some weird stuff. I¡¯ve got a knackered 465 in the cupboard (shot attenuators but horizontal works!) so I will see if it¡¯s the same part in that and swap it out and see if it improves. Basically it¡¯ll jam with the triggered lamp on, single sweep doesn¡¯t work, auto doesn¡¯t appear to work etc. All external voltages make sense. Also remember this problem is obviously thermal. Got some Freon or even 91% alcohol ? Or solvent that is same on this thing ? you get it narrowed down and use a Qtip to apply an "evaporant" to cool the part. Shooting the stuff on 100 components tells you nothing. The trick is to catch it when it first acts up. Of course the problem has to be localized, so definitely try that once it is narrowed down.That¡¯s a good idea. I¡¯ve just ordered a can of freezer spray here. Will be here on Wednesday. That might actually narrow it down considerably. I have a few suspect parts. There¡¯s a thermistor (RT559) near the arming diode which feels a bit suspicious to me. From previous experience I replaced all the tants around the areas just to eliminate and weirdness there. That did nothing. Also, I assume by what you wrote that "auto" trigger does not result in a trace. This I believe is an important piece of information but to get into it will take a bit of time. I haven't yet found out exactly where the "auto" is accomplished, but I will. Sometime tomorrow probably I will get into that and come back with more. Maybe tonight. Who knows ? I might find a dead giveaway there. (once I find the damn thing)Looks like auto happens if there is no trigger event after 40ms. Now the trigger isn¡¯t happening every 40ms like it is supposed to even if there isn¡¯t a trigger event occurring. This has to be U600 thinking about it. Or possibly the IC socket? It¡¯s got one of those awful ones on it. I need to shelve looking at this for a couple of days now as I¡¯ve got a 2235 that needs some work on the power supply. Best regards, Chris |
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Re: OT: NEARC Jan/Feb/Mar 2018 Article "Matching Tubes For Audio Service"
Hi Dennis,
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Those articles sound very interesting, do you have links to them? Thanks, Geoff. On 20/11/2018 21:15, Dennis Tillman W7PF wrote:
Thanks to everyone who responded. |
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Re: OT: NEARC Jan/Feb/Mar 2018 Article "Matching Tubes For Audio Service"
Thanks to everyone who responded.
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I got the article I was looking for. Dennis Tillman W7PF -----Original Message----- -- Dennis Tillman W7PF TekScopes Moderator |
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Re: OT: NEARC Jan/Feb/Mar 2018 Article "Matching Tubes For Audio Service"
Hi...it may be something you know already of course... An article with that title, by Schoo, appeared in Tube Collectors Association Journal, noted in its 1999-2015 index p27. ()
The organisation might be an alternative source. -- Jack |
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OT: NEARC Jan/Feb/Mar 2018 Article "Matching Tubes For Audio Service"
Does anyone have access to the NEARC (Northeast Arc User Group) Journal?
I am looking for part 1 of "Matching Tubes For Audio Service" by Daniel Schoo which appeared in the Jan/Feb/Mar 2018 issue of their journal. I have part 2. Please reply off list to dennis at ridesoft dot com. Dennis Tillman W7PF |
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Re: TDS3032 Will not Finish Bootup
¡°Do you have room for a zif socket? I always use them in the 2430a when I
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replace the sram chips.¡± Oh I didn¡¯t think of that. I need to look as soon as I get back to the shop today. My first that is ¡°sure, plenty of space¡±, but that is close to where the GPIB/Serial/VGA module plugs in. I appreciate you looking. I can order a socket off of eBay/digikey/etc. that has to happen. I can¡¯t change the chip to many more times before I damage the board, no matter how careful I am. Thanks On Tue, Nov 20, 2018 at 6:15 AM Dewey Wyatt <kn4wddewey@...> wrote:
Do you have room for a zif socket? I always use them in the 2430a when I |
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Re: TDS3032 Will not Finish Bootup
Do you have room for a zif socket? I always use them in the 2430a when I replace the sram chips. In fact I may have one you can have if you got the room. I will be at work till 5pm today . I will check when I get off this evening and see for sure but I do think I have a few 28 pin dip sockets left.
Sent from Mail for Windows 10 From: David Kuhn Sent: Tuesday, November 20, 2018 12:05 AM To: [email protected] Subject: Re: [TekScopes] TDS3032 Will not Finish Bootup ¡° Don¡¯t faint when you see the price. I use a tl866-II plus to read and write these if it were the ds1230 series I have a few subs for them one is a smd on a card with ext. battery connects¡± I ordered one from their web site, about $39/$4 fedex ground shipping. I think, I¡¯ll solder lead carriers in when I pull the old chip again. I doubt I would have a proper sized socket. I used to love those gold lead carriers; although it may be hard to keep them all straight. Dave On Mon, Nov 19, 2018 at 9:31 PM Dewey Wyatt <kn4wddewey@...> wrote:
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Re: Tek 7623A started blowing mains fuse - Any specific tip or known failure mode?
from Tim P (UK)
I'm with Craig on this one - I had same problem with a 7613 blowing instrument fuse, and also a 'scope from 'The Other People' <g> Both had failed bridge rectifiers. I may have strained the 7613 by running a 7D20 in it, as discussed here previous. regards Tim On Mon, 19 Nov 2018 at 21:12, Craig Sawyers <c.sawyers@...> wrote: But then, after about 10 minutes it was on... all of a sudden, I heard a"pop", and all lights ofthe scopechance to open it). |
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Re: TDS3032 Will not Finish Bootup
On Mon, Nov 19, 2018, 10:11 PM David Kuhn <Daveyk021@... wrote:
¡°Well, I would not know. Hope it works. Just a warning, some of theseNo, not any of the places mentioned here, but some similar distributors sell military surplus and have asked me to certify where they will be used. Sorry for the confusion. Regards, Mark |
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Re: Tektronix 2430A Questions
¡°Do you actually have a 2430, or is it a 2430A? For a 2430A, you can
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request an HP/GL screenshot¡± Correction on my part, it is a 2430A. Dave On Wed, Nov 14, 2018 at 10:13 PM John Miles <john@...> wrote:
-----Original Message-----the |
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Re: TDS3032 Will not Finish Bootup
¡°Well, I would not know. Hope it works. Just a warning, some of these
distributors that sell military surplus will make you swear you won't resell or ship them to enemies of the free world! I had to fill in a form, sign it and send it back before they shipped¡± Hello Mark, are you talking that Nac store? I just selected one of the chips for $36 ( I think I said $38 in an earlier response ), and have them a PayPal payment. Web site said it will ship tomorrow. Do, I guess we¡¯ll see. I did not know it was military surplus. At least if it works, I won¡¯t be as afraid to dremmal in to the old chip to try and find the battery to wire to. Dave On Mon, Nov 19, 2018 at 9:35 PM Mark Goldberg <marklgoldberg@...> wrote: Well, I would not know. Hope it works. Just a warning, some of these |
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Re: TDS3032 Will not Finish Bootup
¡°
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Don¡¯t faint when you see the price. I use a tl866-II plus to read and write these if it were the ds1230 series I have a few subs for them one is a smd on a card with ext. battery connects¡± I ordered one from their web site, about $39/$4 fedex ground shipping. I think, I¡¯ll solder lead carriers in when I pull the old chip again. I doubt I would have a proper sized socket. I used to love those gold lead carriers; although it may be hard to keep them all straight. Dave On Mon, Nov 19, 2018 at 9:31 PM Dewey Wyatt <kn4wddewey@...> wrote:
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Re: 475 Comment/Question & Minor Reference To 465B
videoradioflyer
Hi,
I looked up the Tek part number 151-0271-00 in the Common Design Parts catalog from Tek, and found a number of cross references. The first JEDEC was the A5T4261, and the 2N4261. Unfortunately, NONE are stocked at Digikey, Avnet, or any other distributor, including Jameco. However, I did find the datasheet for the A5T4261 at . If interested, the crossreferences can be found at has a list of catalogs, and the one where I found the majority of info is at . It is titled Integrated Circuits, but contains LOTS of other semiconductors as well. contains a list of part numbers, and all equipment and locations they are found. This one indicates a JEDEC of SPS8236. If all else fails, you might find a transistor in another piece of equipment from that list, and use it. Good luck! |
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Re: TDS3032 Will not Finish Bootup
Well, I would not know. Hope it works. Just a warning, some of these
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distributors that sell military surplus will make you swear you won't resell or ship them to enemies of the free world! I had to fill in a form, sign it and send it back before they shipped. Pricing is a crapshoot with these places too. Negotiate as best you can. Regards, Mark On Mon, Nov 19, 2018 at 7:15 PM David Kuhn <Daveyk021@...> wrote:
¡°part says Green Tree Electronics has them:¡° |
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Re: TDS3032 Will not Finish Bootup
Don¡¯t faint when you see the price. I use a tl866-II plus to read and write these if it were the ds1230 series I have a few subs for them one is a smd on a card with ext. battery connects Sent from Mail for Windows 10 From: David Kuhn Sent: Monday, November 19, 2018 9:15 PM To: [email protected] Subject: Re: [TekScopes] TDS3032 Will not Finish Bootup ¡°part says Green Tree Electronics has them:¡° Those Maxim parts and not Dallas. I¡¯m sure it¡¯s not high speed and should work in place of the Dallas. Dave On Mon, Nov 19, 2018 at 9:08 PM Daveyk021 <daveyk021@...> wrote: ¡°don't know though if it will boot with blank or corrupted RAM chip but it --- This email has been checked for viruses by AVG. |
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Re: TDS3032 Will not Finish Bootup
Well, Maxim bought Dallas Semiconductor some years ago, IIRC.Jim FSent from my Verizon, Samsung Galaxy smartphone
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-------- Original message --------From: David Kuhn <Daveyk021@...> Date: 11/19/18 6:14 PM (GMT-08:00) To: [email protected] Subject: Re: [TekScopes] TDS3032 Will not Finish Bootup ¡°part says Green Tree Electronics has them:¡°Those Maxim parts and not Dallas. I¡¯m sure it¡¯s not high speed and shouldwork in place of the Dallas.DaveOn Mon, Nov 19, 2018 at 9:08 PM Daveyk021 <daveyk021@...> wrote:> ¡°don't know though if it will boot with blank or corrupted RAM chip but it> could be> worth a try.¡°>> Thank you for the suggestion Haken. I did try that with the ¡°new¡± battram> with no response.>> Dave>> On Mon, Nov 19, 2018 at 8:42 PM Mark Goldberg <marklgoldberg@...>> wrote:>>> On Mon, Nov 19, 2018 at 6:31 PM Dewey Wyatt <kn4wddewey@...> wrote:>>>> > Nac in Florida had 28 of them left. I bought two marked dallas semi from>> > them a few weeks ago. Counterfeit or not they worked for me>> > > On 11/19/18 5:09 PM, David Kuhn wrote:>> > > > Is the new Chinese DS1742W-150 bad?? There is only one supplier on>> > EBAY,>> >>> >>> Octopart says Green Tree Electronics has them:>>>> >>>> >>>> Green Tree claims to check obsolete parts for counterfeits. I have not>> bought from them but have bought from other similar distributors. Lately,>> any "new" parts from eBay or Amazon or from non distributors have been>> fakes, so I stopped getting parts from those sources.>>>> Regards,>>>> Mark>>>> >>>>
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Re: TDS3032 Will not Finish Bootup
¡°part says Green Tree Electronics has them:¡°
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Those Maxim parts and not Dallas. I¡¯m sure it¡¯s not high speed and should work in place of the Dallas. Dave On Mon, Nov 19, 2018 at 9:08 PM Daveyk021 <daveyk021@...> wrote:
¡°don't know though if it will boot with blank or corrupted RAM chip but it |
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Re: TDS3032 Will not Finish Bootup
¡° Green Tree claims to check obsolete parts for counterfeits. I have not
bought from them but have¡° Thank you Mark. I just put in an RFQ with them. Dave On Mon, Nov 19, 2018 at 8:42 PM Mark Goldberg <marklgoldberg@...> wrote: On Mon, Nov 19, 2018 at 6:31 PM Dewey Wyatt <kn4wddewey@...> wrote:Nac in Florida had 28 of them left. I bought two marked dallas semi fromOctopart says Green Tree Electronics has them: |
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