I have found that immersion silver plating corrodes (sulfates) quite nicely if not properly stored. Even the good stuff used in professional applications has to be stored in Silver Saver paper.
My PCB’s (in my job) were always parylene coated once populated and tested in production. They would then be immune to further corrosion. DIY audio PCB might not be conformally coated and would continue to corrode once constructed and put into service.
@hal4287 uses that with good results, see https://www.diyaudio.com/community/threads/need-advice-for-a-weird-project.352655/post-6433717
Silver does that, yes... 🙂
The MG Liquid Tin seems to tarnish as well. I wasn't super impressed with it. In the short term it made for a nice and solderable surface, but it was not as useful for longish storage (months). I didn't like it enough to buy another bottle of it and then I stopped etching boards anyway.
Conformal coatings are available in rattle cans from the usual suspects, so if the DIYer is concerned about corrosion there are options.
As pointed out above, polyurethane is great ... as long as you don't ever have to rework the board.
Tom
Immersion tin develops zebra stripes and tarnish. Even the good stuff (MacDermid or Shipley or Enthone). It’s the nature of the beast I’m afraid.
Tube voltages are high and current is low so pcb traces don't come into play. Heater wires should be at least 28ga for small tubes.
I used 28ga for 2 6922 as the twisting is tighter.
I used 28ga for 2 6922 as the twisting is tighter.
Good, me neither
Sure, should i ever need a PCB than I would convine myself to the layout and leave the manufacture to those being doing abetter job at
I just wanted you to tell me why, or where do you see advantages in using a multilayer PCB in a selfmade tubeamp . Sorry, I did not realiz that you are more interrested in serial production, PCB certainly offers advantages in that respect, but it is not "better". Point to point or PCB, one will choose what is best suitable according to ones needs. Yours surely differ from mine. But, please no more advice like the above, i am sure you do not need to be snappy, you know a thing or 2, but so do I. I turned 75 today and need to choose wisely what to learn and what not.
It is my experience that, as years go by, just about everything I ever made, I would at least know how to make better in some way . If i get some new idea I like to be able to put it to the test in reality. I am sure you understand my point by now, just like I now understand you a bit better by now. Massproduction and DIY needs are so differen they hardly can be met by the same means. I understand that DIY nowdays is so much different, for many it may be buying a kit, or PCB and go from there, and if you provide those ppl with what they need, offcourse its DIY too, just did not even cross mý mind that for many it migth be even the only option to build something for themself. Sorry, my mistake
We are on the same page then, good.
And sorry I was a bit snappy myself whith that performance/beauty contest thingy.
Looking forward to hear from you
Pete
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I use twisted pair wire salvaged from a big box of CAT5 cable that I have stashed away. It's copper, usually 22-24AWG, and stiff enough to keep it's shape when tucked away. Works well for small signal and low current filament wiring.
Blue pair for Left channel, Orange pair for Right channel, Brown for Filament, and Green for misc stuff.
I use Red, Black, Green, or Brown bulk solid core wiring for most everything else.
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For signal, I now use RG-174. I got tired of chasing hum and oscillation LOL
I once had issue with a PCB I could not explain. Distortion was at play that I could not trace.
By despair, I tried an older board and all was fine. I had traces 1mm apart and 485V running.
I believed it was the silks screen layer causing the issue but don't know for sure. I could measure a 2-3pf between trace is some area.
Nevertheless, I now always set my software for a 2mm trace alert, and I use the maximum trace size I can to comply with the 2mm rule.
I never had an issue since.
By despair, I tried an older board and all was fine. I had traces 1mm apart and 485V running.
I believed it was the silks screen layer causing the issue but don't know for sure. I could measure a 2-3pf between trace is some area.
Nevertheless, I now always set my software for a 2mm trace alert, and I use the maximum trace size I can to comply with the 2mm rule.
I never had an issue since.
I use it in my 6CW5 amplifier, it's interesting stuff. Good for feedback and input in a crowded chassis.
I still run the feedback with twisted #22 solid since it's low impedance compared to the input 🙂
Happy birthday Pete. Always glad to see someone around older than myself. You may be older than Jan, or maybe not, but jhs has the record I think.
All happy birthdays,
Chris
All happy birthdays,
Chris
Yes, this exactly was the way for me as a student to salvage tube sockets from 1960ies and 1970ies TV PCB's. After some cleaning in the diswasher they looked like new 😉 .
Best regards!
Back in 1971 and 1972 I made these primitive digital music synthesizer boards with RTL logic chips that were torched off of boards obtained from the trash dumpster at the Coulter Diagnostics (medical equipment) plant in Miami. Each round can contains a single gate or flip-flop. It takes a lot of these chips to do anything useful.
Attachments
Have done it that way on smaller scale, George...
But picking solder splash out of jeans w/ exacto knife is time consuming... So-
I believe chaps would be better that process- sure you're no stranger to those in Shenendoah river country... RIP John Denver
Jim