27th Apr 2016, 8:33 pm | #1281 |
Octode
Join Date: May 2009
Location: Linkoping, Sweden
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Re: The "Sussex" Homebrew Valve Tester.
Hi all!
A short while ago Martin (G8UWM-MildMartin) asked if someone could help with a new improved PCB since he had sold all of his. I offered to help and now I have a first (actually version 4) design that I am putting some pictures of here for everyone to have a look at and if possible check the circuit diagram so I didn't make any mistakes. Martin (G8UWM-MildMartin) and I have checked it against the original circuit diagram but there might still be mistakes made by me (I made a wrong symbol for the MJE350 and found an error in the bridge rectifier library!). I redraw the parts I need of the circuit diagram in Designspark V7.1 as I use that program for all of my PCBs. I did not draw the switches, buttons and other parts that are off of the PCB, only what's on the PCB as I did some of the switches as separate circuit diagrams (I'll show those in the next post). I have added one capacitor on the negative track as I was unsure if the relays would induce spikes when they were tripped as they are on the negative line for the oscillator and grid volts line, C20. I also put two LM317s on the board with their own heat sink, this will save one wafer on the heater switch and since only one will be used at any time they won't draw that much standby current not producing a lot of heat. I also added a heat sink to the MJE350, might be unnecessary but might be useful if something goes wrong. I also removed R3 as I couldn't find a reason for it - if there will ever be a need for a gate resistor and ferrite bead on the gate they should be mounted as close as possible to the gate anyway. I used connectors with a 5 millimeter spacing as those seems to be more common than other spacings. You can chose from a wide variety of connectors or solder the wires directly if you want, for the heater connectors and for the meter supply voltages I only used connectors for the wires coming from the transformer and solder pads for the other sides as I didn't know what connectors the meters might have, some come with wires and some without. All components have been put on one PCB, except for the resistors/capacitors found on the switches (Anode, Screen, Electrode and Function) as I made separate PCBs for Lorlin switches for those. You can use screw terminals or male-female sets for the connectors. Martin (G8UWM-MildMartin) said that he could try a first batch of these to check them, but before that I appreciate any input, especially if you find something wrong or if you have comments on stuff that I ought to change. I will post the Designspark files as well as Gerber files and a plot that can be printed on a laser printer for DIY people. I usually use Elecrow (www.elecrow.com) for my PCBs and Martin (G8UWM-MildMartin) might do that too as they are cheap and produce very good PCBs I think - I have used them a lot. This PCB will of course be free for anyone to use, I will not put any copyright on it nor will I ask for any royalty, I made It because I wanted to give something back to the forum and its users! So, here are the pictures for everyone to have a look at.
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Martin, Sweden |
27th Apr 2016, 8:37 pm | #1282 |
Octode
Join Date: May 2009
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Re: The "Sussex" Homebrew Valve Tester.
Hi All,
As I wrote above I made some separate PCBs for the switches and here they are. I didn't put any picture of the Function switch here as it only consists of a few wires. I made round PCBs as I think it looks good and it also save material and weight. I made these PCBs for the Lorlin CK1054 PCB mounted rotary switches but I can easily adapt them to other switches.
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Martin, Sweden |
27th Apr 2016, 8:45 pm | #1283 |
Octode
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Re: The "Sussex" Homebrew Valve Tester.
Hi All,
I've uploaded ZIP-archive of all of the pictures so you can view them in high resolution.
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Martin, Sweden |
27th Apr 2016, 8:55 pm | #1284 |
Dekatron
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Location: Newcastle upon Tyne, Tyne & Wear, UK.
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Re: The "Sussex" Homebrew Valve Tester.
Hi Martin, a great effort that I'm sure will be much appreciated.
I wonder what the grand total of Sussex's built is now? I've done over 70 transformers for them. Ed |
28th Apr 2016, 10:10 am | #1285 |
Nonode
Join Date: Aug 2010
Location: Resolfen, Wales; and Bristol, England
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Re: The "Sussex" Homebrew Valve Tester.
Hi Martin, I would be happy to try out one of the first batch.
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Richard Index: recursive loop: see recursive loop |
28th Apr 2016, 11:30 am | #1286 |
Hexode
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Re: The "Sussex" Homebrew Valve Tester.
Hi Martin
A very good job, Thanks. Bob
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Bob, BVWS member |
28th Apr 2016, 7:02 pm | #1287 |
Octode
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Re: The "Sussex" Homebrew Valve Tester.
Hi All,
Spotted one error today while doing a check of the rotary switches, the 3 Pole 4 Way switch had the wrong pinout at the center. I corrected it and have added the Electrode and Function switch PCBs here.
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Martin, Sweden |
9th May 2016, 8:47 pm | #1288 |
Octode
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Re: The "Sussex" Homebrew Valve Tester.
Hi all,
Finally! I've ordered the first batch of PCBs so that I can check the design to make sure that all components fit properly and show some photos of what I was thinking when I put them there. I've re-routed the PCB as I wanted to move the heater relay closer to the common ground point to reduce the length of the ground trace. When I was doing that I had to move other components to make space for the relay and the moving of the low voltage heater section with the two LM317s. So it looks like a new PCB compared to the old one. I just ordered the main PCB as I am not going to build a Sussex myself, I have to many other valve testers (which will be sold soon anyway) but I'll keep one PCB myself. I'll send the rest to Martin as soon as they have been checked by me.
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Martin, Sweden |
9th May 2016, 8:49 pm | #1289 |
Octode
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Re: The "Sussex" Homebrew Valve Tester.
Hi all,
Here's the ZIP-file with the high reslution screen shots.
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Martin, Sweden |
17th May 2016, 8:32 am | #1290 |
Octode
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Re: The "Sussex" Homebrew Valve Tester.
Hi all,
The boards have been produced and are en route to me, hopefully they'll be at my home in a few weeks time.
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Martin, Sweden |
18th May 2016, 10:41 am | #1291 |
Nonode
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Re: The "Sussex" Homebrew Valve Tester.
Good news! Please let me know when you have them, I'd like to use one in a rebuild of my Sussex.
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Richard Index: recursive loop: see recursive loop |
18th May 2016, 3:06 pm | #1292 |
Octode
Join Date: May 2009
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Re: The "Sussex" Homebrew Valve Tester.
I'll pass all PCBs, except one or two that I'll keep for reference, onto G8UWM-MildMartin so he can distribute them in the UK, it would simply be too costly to ship them from Sweden where I live, the Swedish Post have outrageous shipping costs.
G8UWM-MildMartin and I will keep you all updated on when the PCBs have arrived and at least one Sussex has been built and tested with them. As I've said before I won't build one myself as I already have too many valve testers.
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Martin, Sweden |
25th May 2016, 11:06 am | #1293 |
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Re: The "Sussex" Homebrew Valve Tester.
Hi all,
The PCBs have arrived! Now I'll ship ten of them to Martin (G8UWM-MildMartin) so he can build the first one and check it out. I just checked them so that the components fit, see the pictures.
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Martin, Sweden |
25th May 2016, 4:56 pm | #1294 |
Nonode
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Re: The "Sussex" Homebrew Valve Tester.
Let me know how they work out and I'll produce an update for the manual.
Keith |
25th May 2016, 10:17 pm | #1295 |
Hexode
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Location: Rustington, West Sussex, UK.
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Re: The "Sussex" Homebrew Valve Tester.
Hi Martin
Please let me know how to buy one of your new PCB's. Thanks, Bob.
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Bob, BVWS member |
25th May 2016, 10:52 pm | #1296 |
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Re: The "Sussex" Homebrew Valve Tester.
Bobdger, please contact Martin (G8UWM-MildMartin) regarding buying one of this first batch of ten (10) main PCBs, he will handle it in the UK. I live in Sweden and we unfortunately have crazy shipping costs to foreign countries. I don't know if all ten PCBs have been spoken for or not.
As soon as the first PCB has been built by Martin (G8UWM-MildMartin) and it works as intended I will publish the files here for anyone to use. If more people want professionally made PCBs we'll have to see how we set that up, maybe Martin (G8UWM-MildMartin) can order more directly instead of going through me (this time I wanted to make sure that all components fit properly, which they did before shipping the PCBs to him). Then we can also order the switch PCBs if people are interested in those, I didn't order them this time around as I couldn't afford them and didn't hear any comments on if anyone wanted them.
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Martin, Sweden |
19th Jun 2016, 1:19 am | #1297 |
Heptode
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Re: The "Sussex" Homebrew Valve Tester.
I have built a PCB and tested the oscillator, the screen grid and anode circuits (off load, not checked the current limit with the little heatsinks which were all I had) and the 1.4-V and 2-V regulated outputs.
The oscillator output increased by 5% as it warmed up and the HT outputs about the same. It is stable without electrolytics C101 & C102 on the outputs of the LM317s. I used BC327s instead of obsolete BC307s and R31 is 10K (as per post 1234) and D1 is two 1N4003s in series. I couldn't find presets to fit, so improvised. I haven't checked the functions of the two auxiliary relays, but the HT one is OK switching 330VDC. Martin-Dekatron in Sweden has done an excellent job of improving the original very good design! They are now released for sale and the cost is £6.70 + UK 2nd class postage of 75p, i.e. £7.45. I can be contacted by PM here and my email address is in Keith's handbook. |
19th Jun 2016, 5:06 pm | #1298 |
Octode
Join Date: May 2009
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Re: The "Sussex" Homebrew Valve Tester.
Thanks for building the first one Martin!
There is only one thing that is missing from the PCBs and that is the text layer, the manufacturer wanted a lot more money to add it to the component print since the PCBs were on the verge of being produced when they asked me (it was in a separate text layer) so I decided to skip that - in the latest revision (which hasn't been produced) I moved the text to the component print layer so there won't be any extra cost. As soon as a few of these PCBs have been built and no problems found I'll publish the Designspark files as well as 1:1 prints that can be used for making your own PCBs from.
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Martin, Sweden |
22nd Jun 2016, 12:36 pm | #1299 |
Hexode
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Re: The "Sussex" Homebrew Valve Tester.
I would be interested in the switch PCB's if there is enough interest to order a batch. I am planning to build it as this winters project.
Mark |
22nd Jun 2016, 1:22 pm | #1300 |
Octode
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Re: The "Sussex" Homebrew Valve Tester.
Mark, I'll let everyone know if I order any switch PCBs. Due to the cost of these I need at least ten people who want a set, otherwise it will be cheaper for people to make their own switch PCBs.
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Martin, Sweden |