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Hello to all
I thought I'd replace the transistor BC517 (untraceable) with BC547-BC337 couple in Darlington configuration audio amp.
you think you can do?
I'm building IDXpro Silverdog pcb.
Thank you all
Hello to all
I thought I'd replace the transistor BC517 (untraceable) with BC547-BC337 couple in Darlington configuration audio amp.
you think you can do?
I'm building IDXpro Silverdog pcb.
Thank you all
No,u can't.
Because mpsa13/bc517 is darlington type.
Hello
I explained bad, practically the BC517 is replaced by 2 transistors (BC547-BC337) mounted and connected in a darlington configuration.
hfe the gain is the sum of the 2 transistors.
Last edited by gallico58; 04-05-2017, 03:51 PM.
Reason: image
I remember, that some years ago for another project, I replaced a MPSA13 by only BC337 and it was working very well. Even until today, I never changed this transistor.
Of course you will find the layout in the thread here, but here is the same version like Nándor's pcb. The first file is what I have made and also with VDI connection. Well like always, I changed the pad sizes. The detector is one of my favorite.
Very nice done Nandor, could* you or someone else please explain more details about shilding the coil with graphite? I saw different designs with gaps and also without. Which homemade graphite mixtures are working well? Which resistance per centimeter is at least necessarry?
I remember, that some years ago for another project, I replaced a MPSA13 by only BC337 and it was working very well. Even until today, I never changed this transistor.
thanks Blobber
I try BC337 hfe looking for a good gain.
Hello Blobber, thank you ! I have mixed lacquer(for wood) with graphite and covered the housing 2x with it and glued a drain wire to the housing. I have seen this technique here on the forum. The resistance of the shielding was less than 1kOhm from one end to another. Than I placed the coils than the epoxy resin just to cover the coils than another layer of graphite and a final resin layer. You can paint the outrside of the housing with graphite to have a better shielding but you have to connect drainwires. Check this thread it's very informative on building a graphite shielded coil "http://www.geotech1.com/forums/showthread.php?21305-XP-deus-coil-modification&highlight=henrikas"
Thats very nice man ! We hade the same idea even the foam grip is the same black with red! Is your stem made of 2 piece's can you separate them? Thats what I wanted to do but have no idea how to make it. I like the coil thats my favorite of the White's design. You helped me a lot thanks again!
Thanks!
Yes I have made 2 gaps so the layer is not continuous. Well with a 50 eurocent ( I have no 1euro at home) it's almost 33cm. It performs a bit better than my TGSL in air test.
Thanks!
Yes I have made 2 gaps so the layer is not continuous. Well with a 50 eurocent ( I have no 1euro at home) it's almost 33cm. It performs a bit better than my TGSL in air test.
Hi, did you make some soil depth & disc test? I have Igsl and I am thinking about IDX as next project (after finishing magnum)... And air tests of IDX looks realy well, but I do not find any comparsion in soil so far.
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