When you get your kit can I check the socket wiring with you? Mine doesn't match the wiring for the 8SJ31J in the seller's datasheet, but is pre-soldered & heatshunk and already on the tube. I'm worried they made an off-by-one error wiring it up.
On Saturday, 15 May 2021 at 05:53:11 UTC+1 gregebert wrote: > Most likely, the error is in the text description in the instruction > manual. From the datasheet, pin 9 is the multi-anode connection, and pin 5 > is the single anode. I am more likely to follow the connections to specific > pin numbers in the instructions, rather than the text-description. Pin 9 is > the higher-voltage (1500V) anode, and it should not be difficult to verify > that in the schematic. > > As far as the power is concerned, I cant figure out where 7-10 watts is > going. The filament is 6.3V / 150mA so that's less than 1 watt. The > electron-beam current is probably less than 100uA, so that is also less > than 1 watt. For comparison, a NIMO tube uses 30uA. Even if the anode > current was a whopping 1mA, that would still be only 1.5 watts. So that > leaves the grid and focus anode as the only other source of power > dissipation; maybe some clues will be in the schematic. > > My kit arrived in the US earlier this week, so I hope it will get > delivered to me next week. I will be placing a 250mA fuse in series with > the filament for added protection. I'll post an update after I've either > finished it, or ran into a problem. > > On Friday, May 14, 2021 at 5:15:45 PM UTC-7 John Snow wrote: > >> Found a conflict between the documentation (both before and after google >> auto-translation). The conflict is between Anodes A1,A2,A3 in the sellers >> documentation. >> >> The seller's documentation lists: >> >> A2 (Focusing Anode) - pin 5 >> A1,A3 (first and third anodes) - pin 9 >> >> I've found a separate pinout for the 8SJ31J tube that lists: >> >> Focusing Anode,A2 - pin 9 >> A1 - pin 5 >> >> The second pinout is from >> http://www.spectrum-scientifics.com/v/vspfiles/pdf/Properties_of_Electrons_Apparatus.pdf >> >> >> It looks like the tube in the spectrum-scientifics is the thin-pin >> version of the 8SJ31J, and the kit uses the thick-pin version of the >> 8SJ31J, but I'd like a second opinion. >> >> I know they have different power requirements - the thick-pin (old) is >> around 10W, and the thin-pin (new) is around 7W (I'm assuming which are old >> and new based on the design of the base socket). The rest of the pinout >> agrees, is this another difference between the old and new designs of >> tubes? >> >> Tl;DR I'm not clear on the anodes of the 8SJ31J, which pin is the >> focusing anode, and why the other two of the three anodes are joined >> together. >> On Saturday, 15 May 2021 at 00:06:33 UTC+1 John Snow wrote: >> >>> I'm trying to figure out how it's put together before I start soldering. >>> >>> As Paolo mentioned the only mystery part is the transformer T-SC-1 on >>> the parts list - it looks like a custom order. I don't know how to >>> characterise it without destructively pulling it apart, and unfortunately >>> they don't sell them separately. >>> >>> There's another four without the tube now listed: >>> https://www.ebay.co.uk/itm/265151344483 >>> >>> The kit is listed as configured for 8SJ31J by default, and the >>> documentation linked further up lists the wiring for 3SJ1J/5SJ38J/7SJ32J. >>> No idea if the power requirements differ and requires resistors changing on >>> the circuitboard(s), or if they are plug-and-pray drop-in replacements once >>> you've changed the pinout. >>> >>> The auction page says it can be used with >>> 3LO1I/7SJ33J/8SJ31D/8SJ40/8SJ42J/8SJ40D/9SJ105Y14/12SJ102J/13SJ38J/13SJ38D. >>> Unfortunately without knowing the transformer operating characteristics >>> I'd be hesitant to plug in anything else. >>> >>> I'll probably try to replace the fuses with polyfuses in the future, >>> socketing them for now, and taking measurements while unpopulated for >>> easier case design later. >>> >>> >>> On Wednesday, 28 April 2021 at 20:25:12 UTC+1 John Snow wrote: >>> >>>> Huh, ebay auction says 12V 5A, a previous aliexpress page gives much >>>> lower values for amperage: >>>> >>>> https://www.aliexpress.com/item/4001142939399.html >>>> >>>> I'm assuming it's the same design from the pictures >>>> >>>> On Wednesday, 28 April 2021 at 20:18:53 UTC+1 John Snow wrote: >>>> >>>>> The kit was previously 'avalible' from aliexpress for £56.44, but it >>>>> was from a seller that held no stock - got refunded as unable to ship. >>>>> >>>>> That was minus the tube though, the current ebay link includes the >>>>> 8SJ31J but lacks a power supply (12V 5A centre+) >>>>> >>>>> Unsure on lifespan of tube. >>>>> >>>>> On Wednesday, 28 April 2021 at 19:46:03 UTC+1 Paul Andrews wrote: >>>>> >>>>>> They actually seem very cheap to me... >>>>>> >>>>>> On Wednesday, April 28, 2021 at 12:56:00 PM UTC-4 John Snow wrote: >>>>>> >>>>>>> There's another 4 of the 8SJ31J kits listed at >>>>>>> https://www.ebay.co.uk/itm/265139148431 , I've ordered one on the >>>>>>> offchance they have them in stock, also the seller has feedback for >>>>>>> selling >>>>>>> them previously. >>>>>>> >>>>>>> Bit of a premium tho, and only avalible with tube. >>>>>>> On Wednesday, 16 December 2020 at 11:40:02 UTC Collin Smith wrote: >>>>>>> >>>>>>>> Have you looked at these kits? >>>>>>>> >>>>>>>> https://oscilloscopeclocknixiecrt.com/Kit.htm >>>>>>>> >>>>>>>> >>>>>>>> Sent from my iPhone >>>>>>>> >>>>>>>> On Dec 16, 2020, at 00:17, John Snow <[email protected]> wrote: >>>>>>>> >>>>>>>> I've tried to get that one from Aliexpress previously, but they >>>>>>>> later refunded me saying they weren't getting any more stock. >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> On Friday, 11 December 2020 at 21:42:35 UTC Pramanicin wrote: >>>>>>>> >>>>>>>>> Did anyone else on the list buy one of those recent CRT clock kits >>>>>>>>> that was listed on eBay? >>>>>>>>> >>>>>>>>> like this one... >>>>>>>>> >>>>>>>>> >>>>>>>>> https://www.aliexpress.com/item/4001330655526.html?spm=a2g0s.9042311.0.0.1a084c4d8VxYDr >>>>>>>>> >>>>>>>>> I have a kit, but they never shipped the instructions, so if >>>>>>>>> anyone has some that would be great. >>>>>>>>> >>>>>>>>> Thx, >>>>>>>>> >>>>>>>>> Nick >>>>>>>>> >>>>>>>> -- >>>>>>>> >>>>>>>> You received this message because you are subscribed to the Google >>>>>>>> Groups "neonixie-l" group. >>>>>>>> To unsubscribe from this group and stop receiving emails from it, >>>>>>>> send an email to [email protected]. >>>>>>>> >>>>>>>> To view this discussion on the web, visit >>>>>>>> https://groups.google.com/d/msgid/neonixie-l/3aacb083-5cbf-4b96-96ee-6e8e13744159n%40googlegroups.com >>>>>>>> >>>>>>>> <https://groups.google.com/d/msgid/neonixie-l/3aacb083-5cbf-4b96-96ee-6e8e13744159n%40googlegroups.com?utm_medium=email&utm_source=footer> >>>>>>>> . >>>>>>>> >>>>>>>> -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. 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