Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: frank57 on December 14, 2010, 02:46:08 pm
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I'mhaving some problems with this Hiwatt layout.
See here for the back story:
http://www.el34world.com/Forum/index.php?topic=10265.0
I had everything wired up but then I put in the tubes and whoops...
the heaters are touching the el84 tube and there doesn't seem to be a way around it unless I drill a new hole for them. There is little slack in the wires so not much room to move things.
I'm going to post a better picture with the board in place,
but generally what would be a good place to put a hole for the heaters and how big should it be?
Only other idea maybe make the current hole bigger.
I'd like to test it to see if this board idea works already but I'm sure these wires would burn.
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Are you saying that the existing wires for filament power are too short?
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yes, that's it.The yellow wires barely reach the turrets.
When they are wired up they touch the tube.
Maybe these photos will clear it up.
Unless there's a way to replace the wire itself?
Unless dc power setup might help here?
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yes, that's it.The yellow wires barely reach the turrets.
When they are wired up they touch the tube.
Maybe these photos will clear it up.
Unless there's a way to replace the wire itself?
There's no reason why you couldn't lengthen those wires by splicing more wire onto them. Then you have choices as to where to route the wires.
Make sure you use at least the same gauge (and probably colour too for convenience). There are a few techniques you could use, but I go for "twist, solder and heat-shrink". Here's a well documented method:
http://www.instructables.com/id/Master-a-perfect-inline-wire-splice-everytime/
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Are there any problems that could arise from it?
The only problem is I probably would have to buy some new wire.
It's 22awg 105 600v LL984a51 type tew. I have a lot of teflon cable. I might have some I'll have to check.
Is it better to do that inline splice or drill a hole?
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I bet they will reach if you simply untwist them.
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Does the twist make any difference hum wise?
They are twisted as you can see in the photo going to the tube from the turret.
( the green wires)
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Yeah, I was gonna recommend untwisting too. It's bailed me out a few times. It's not going to make any difference where they're at.
Or, pull that tube and put the wires on the other side (between the sockets). Mebbe you'll have enough slack to grab and hold the wires in place with a clip.
Or use a terminal strip inside the chassis. Shorter standoffs under the board might get you like a 1/4". Or drill a hole in a better location. Or just lengthen the wires.
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I'll try untwisting and report back.
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Okay so untwisting doesn't work.
You're still up against the tube.
I gained a little but not much.
This amp refuses to cooperate eh?
I think I have some green wire that will do the job, so we'll go the splice route.
TEW is the same as UL1015 I believe, just different designations for the same thing.
I think I'll extend the black wire as well because that's pretty tight too.
I think Antique radio has the wire under hookup
http://www.tubesandmore.com/
There's no url for the exact page but I thinkk the 600v tinned is the right one.