4th Sep 2017, 11:22 am | #1441 |
Octode
Join Date: May 2009
Location: Linkoping, Sweden
Posts: 1,465
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Re: The "Sussex" Homebrew Valve Tester.
The small PCBs for the LR8 arrived today and they fit nicely on top of the mainboard, they will have to be mounted on small standoffs so the pins and tracks don't short against the bottom PCB.
As you see they come with two mounting holes for those who wish to use them with older Sussex designs, I couldn't fit more holes onto the size of the PCB as it would have cost a lot more to manufacture then. When mounting them on top of the Sussex board you just break off the edge with the hole and grind down the small protrusions from the milling holes. I'll ask G8UWM-MildMartin if he is willing to distribute these to interested people. I'll post an updated schematic as soon as I have tested them out myself, but since I regularly use them in other designs I don't foresee any problems.
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Martin, Sweden |
5th Sep 2017, 10:34 pm | #1442 |
Octode
Join Date: May 2009
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Re: The "Sussex" Homebrew Valve Tester.
Now I have built one of the small PCBs and it works just as designed, I've included a few photos here (I only had 350V electrolytics so I didn't go any higher than 339V in my test).
For this build you will need: R3: 2.4k R7: 180k R29: 390k TM1: 50k Bourns 3296 Multiturn trimmer D18: 1N4007 C16 & C17: 4.7uF/400V electrolytic U1: LR8 (Microchip LR8N3G) and the small PCB - schematic and PCB will follow soon.
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Martin, Sweden |
6th Sep 2017, 5:31 pm | #1443 |
Octode
Join Date: May 2009
Location: Linkoping, Sweden
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Re: The "Sussex" Homebrew Valve Tester.
Here are the PCB-files, the Gerber files will make two PCBs side by side as it fits best for the PCB manufacturer I use to produce the cheapest PCBs.
There are also two PDF-files that can be used for those of you who want to make your own PCB, it too has two PCBs side by side - there is a "reversed" and a "normal" version of these and they were printed in 1:1 scale but i might of course differ somewhat on your printer. The ZIP-archives contains the Geber files necessary to produce PCBs and also the files for the PCB and schematic (with no connection in between them). Observe that the PCB file has the component text added as just text on the right PCB as it is not possible to use two components with the same text in Designspark! I will ship some PCBs to G8UWM-MildMartin, please contact him for a PCB.
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Martin, Sweden |
15th Sep 2017, 5:33 pm | #1444 |
Tetrode
Join Date: Sep 2017
Location: Luton, Bedfordshire, UK.
Posts: 53
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Re: The "Sussex" Homebrew Valve Tester.
I have just joined this forum with the initial main intention of building the Sussex VT. I'm very happy to find that both the boards and transformers are thankfully still available for this wonderful design. Thanks to Martin and Ed for providing a great service.
I found also that the LCD displays are still readily available, if anyone is struggling to find these please PM me and I will send details of my source. |
20th Oct 2017, 9:05 pm | #1445 |
Triode
Join Date: Mar 2011
Location: Bristol, UK.
Posts: 44
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Re: The "Sussex" Homebrew Valve Tester.
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20th Oct 2017, 10:39 pm | #1446 |
Tetrode
Join Date: Sep 2017
Location: Luton, Bedfordshire, UK.
Posts: 53
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Re: The "Sussex" Homebrew Valve Tester.
Following my previous post I have had a couple of PMs asking for my source of the blue LCD meters, so here is a link to one of the Ebay listings for these, all of the different types required for the Sussex Tester were available when I purchased a few weeks back.
Link: http://www.ebay.co.uk/itm/3-1-2-Blue...53.m2749.l2648 |
14th Nov 2017, 3:14 am | #1447 |
Retired Dormant Member
Join Date: Nov 2017
Location: Heflin, Alabama, USA.
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Re: The "Sussex" Homebrew Valve Tester.
... and for the forum readers "across the pond" in the USA, here is a link to what appears to be the same 199vdc dvm module, listed at ebay.com with free shipping to the states...
https://www.ebay.com/itm/191168661014 ... if you're not in a particular hurry to receive it: "Delivery: Estimated between Tue. Nov. 28 and Wed. Jan. 3" 73, Steve / K4KM |
14th Nov 2017, 10:19 am | #1448 |
Moderator
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Re: The "Sussex" Homebrew Valve Tester.
Just a reminder that there are strict forum rules forbidding the discussion of eBay auctions and sellers, though you may post a link to satisfy a specific requirement (as is the case here).
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14th Nov 2017, 10:41 am | #1449 |
Rest in Peace
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Location: Harlaxton, Lincolnshire, UK.
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Re: The "Sussex" Homebrew Valve Tester.
Thanks for the link Steve, unfortunately the page, as displayed here, is marked "Does not ship to United Kingdom"
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14th Nov 2017, 11:46 am | #1450 |
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Re: The "Sussex" Homebrew Valve Tester.
Steve's link was for people in the US.
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20th Nov 2017, 11:46 am | #1451 |
Retired Dormant Member
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Re: The "Sussex" Homebrew Valve Tester.
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20th Nov 2017, 12:55 pm | #1452 |
Moderator
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Re: The "Sussex" Homebrew Valve Tester.
Presumably by sending him a Private Message (PM).
You can do this by clicking on his username to the left of his post and selecting the option from the drop down menu.
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Graham. Forum Moderator Reach for your meter before you reach for your soldering iron. |
4th Dec 2017, 10:51 pm | #1453 |
Octode
Join Date: May 2009
Location: Linkoping, Sweden
Posts: 1,465
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Re: The "Sussex" Homebrew Valve Tester.
I'm interested in hearing some comments/feedback on the small LR8 PCB's that I sent to G8UWM-MildMartin which he sold off quickly - has anyone built them and used them for the Sussex or did they go to other projects?
I need this feedback before I incorporate the LR8 design on the mainboards. /Martin
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Martin, Sweden |
5th Dec 2017, 8:52 am | #1454 |
Tetrode
Join Date: Sep 2017
Location: Luton, Bedfordshire, UK.
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Re: The "Sussex" Homebrew Valve Tester.
Firstly, thank you so much for the dedicated work that you have put into the tester.
I intend to use the LR8 version on my tester in preference to the Zener chain. I did not think of obtaining the LR8 board at the time as I overlooked the usefulness of the modification. I do intend to make or have made the board now that the initial supply had been sold. I hope that my comment helps. Alan |
29th Dec 2017, 3:03 pm | #1455 |
Tetrode
Join Date: Sep 2017
Location: Luton, Bedfordshire, UK.
Posts: 53
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Re: The "Sussex" Homebrew Valve Tester.
I have just received a batch of 20 PCB's for the LR8 modification. This was the minimum order quantity, I had in mind to help others who would like to do this mod but were unable to obtain one from the previous batch, so as I only need one for myself, I will offer the remaining ones at a rough "cost price" of £2.00 including postage.
If you would like one please PM me and we can make arrangements. |
3rd Jan 2018, 12:52 pm | #1456 |
Octode
Join Date: May 2009
Location: Linkoping, Sweden
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Re: The "Sussex" Homebrew Valve Tester.
Here are the promised files for the main PCB combined with the LR8 board.
Please bear in mind that I haven't tested this main PCB myself but since the old design works and the loose small LR8 PCBs work by themselves and the combined board uses both designs I am confident that it will work. Component values for the extra LR8 parts can be found in post #1442 here: https://www.vintage-radio.net/forum/...postcount=1442 /martin
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Martin, Sweden |
3rd Jan 2018, 1:42 pm | #1457 |
Nonode
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Location: Resolven, Wales; and Bristol, England
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Re: The "Sussex" Homebrew Valve Tester.
Hi Martin,
I'm just assembling one of your PCBs with the new LR8 mod. I'm pleased you've altered the layout for the two pots, I'm having trouble finding ones to fit the older design! If you do another iteration, could you try to fit alternative bridge rectifiers, the in-line ones are quite hard to find, most 1A devices seem to be circular with four-square pinout. Thanks for your work so far....
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Richard Index: recursive loop: see recursive loop |
3rd Jan 2018, 4:18 pm | #1458 |
Octode
Join Date: May 2009
Location: Linkoping, Sweden
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Re: The "Sussex" Homebrew Valve Tester.
I did a quick check on the PCB and I think that it is too big a project to incorporate round rectifiers, I will have to move many components and traces to accommodate them and it will take too much time.
Where I buy components I have a free choice of either straight or round rectifiers for these small types, even with different pinouts (Mouser, DigiKey, ELFA, Farnell, Conrad, Reichelt and RS-Online and so on). You can always use isolating sleeves on the pins of a round rectifier and then just bend the pins so they fit the straight rectifier design, you can even bend the rectifier and its pins putting it 90 degrees sideways if you want. /Martin
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Martin, Sweden |
9th Jan 2018, 11:57 pm | #1459 | |
Hexode
Join Date: Aug 2014
Location: Dartford, Kent, UK.
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Re: The "Sussex" Homebrew Valve Tester.
Quote:
Kind regards John |
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10th Jan 2018, 9:48 am | #1460 |
Heptode
Join Date: Jan 2004
Location: Stockport, Greater Manchester, UK.
Posts: 827
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Re: The "Sussex" Homebrew Valve Tester.
Yes, there are some of the originals left, but the newer ones are better and cheaper:
Main board + LR8 add-on board + 4 switch boards for £8.76 including postage. |