EEVblog Electronics Community Forum
Products => Test Equipment => Topic started by: saipan59 on January 12, 2020, 08:38:29 pm
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Hi, my first post here.
Just acquired a Type W plugin (for 500-series mainframes), paid $3 for it, but it is missing the three 8416 tubes, which are expensive.
Has anyone modified a W to use 6DJ8's instead (I have some of those)? The filaments in the W are in series, and driven from a DC rail. I'm thinking that an appropriate series R, plus a shunt R might work (the shunt R is because I assume the filament current in the 6DJ8 is double the current in the 8416, and there are a pair of Nuvistors in the chain also).
So, just wondering if anyone has bothered to mod something to replace an 8416 with a 6DJ8, or has another clever solution...
I should mention that I don't have a 500-series box to run the W in, so I don't want to "buy" tubes and such, but in case I get the mainframe someday... I also have an H and a P plugin, that were also $3 each at a local junk shop.
Thanks,
Pete
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Yes vacuum tubes.net wants $18 for them. However with no mainframe, you might as well put it on shelf so you can admire it.
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Better, you modified it to 12AT7 or similare double triode.
It needs high stable filament current/voltage for high gain & stable DC amplifier.
I have luck with 8416 tube, i have buyed all 8416 in one shop, 8€/ piece.
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European eqivalent to 8416 or 6DJ8 is the E88CC which is a special quality version of the ECC88.
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Yes, 6DJ8=E88CC=ECC88, but those are all 6V tubes, while 8416 is 12V. That's the issue - there is no easy direct sub for the 8416, except maybe a 12DJ8, which I've never seen an example of.
Pete
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some of the tubes there are serial heating from the 150mA (75V)
take care from that please