Why put short jumpers on eyelet boards?

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pompeiisneaks
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Why put short jumpers on eyelet boards?

Post by pompeiisneaks »

I've seen this in many of dumbles work, also in a fender I have now, but i'm at a loss as to why someone would do it.
Screen Shot 2017-10-24 at 7.59.20 AM.png
See area in image circled in red. red wires come in, connect to eyelets that then connect to a jumper to another eyelet that then connects to the actual Diode (that specific board uses it all over) but others do not use it.

What is the benefit to drilling and using several extra eyelets for a super short jumper like that? I don't see them, and figure it shaves a little time and a few eyelets off the build cost... not much, but to me every penny counts :)

~Phil
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xtian
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Re: Why put short jumpers on eyelet boards?

Post by xtian »

I choose not to “waste” turrets or eyelets like that also. But I can think of two reasons. It looks neater to have the wires exit the board from the edges, and ... ok, I can only think of one reason.
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Re: Why put short jumpers on eyelet boards?

Post by pompeiisneaks »

but you can really just cut the ends off the board and do something like this no:
Screen Shot 2017-10-24 at 7.59.20 AM.png
~Phil
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erwin_ve
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Re: Why put short jumpers on eyelet boards?

Post by erwin_ve »

I dont believe it's jumpered but the insulated wire throught the hole acts a as a strain relief.
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Re: Why put short jumpers on eyelet boards?

Post by frankdrebin »

maybe just in case of diode substitution you don't touch the main wire insulation,but...
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Re: Why put short jumpers on eyelet boards?

Post by martin manning »

I assume the reasons are to bring the flying lead connections to the edges of the board and to allow connecting/disconnecting the flying leads without disturbing the solder joints on the component leads. The strain relief holes are different... no eyelet, just a pass-through for the flying lead a short distance from the solder joint to prevent flexing of the lead near the solder joint.
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M Fowler
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Re: Why put short jumpers on eyelet boards?

Post by M Fowler »

Pass through hole like others noted.
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jelle
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Re: Why put short jumpers on eyelet boards?

Post by jelle »

Sometimes not all the leads fit one eyelet.

This fixes that.

Why not use a bigger eyelet, you ask?

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Re: Why put short jumpers on eyelet boards?

Post by pompeiisneaks »

I definitely have used pass through holes, but these aren't pass through holes. In the Fender I'm going to mod to be a Dumble, and in this dumble layout pic, it's a straight bare wire between two eyelets, on one end it connects to the component, and the other connects to the leads.

Silly, wasteful, and I don't get it.

~Phil
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Re: Why put short jumpers on eyelet boards?

Post by Charlie Wilson »

Those are not hook up wire, they are the transformer leads. Your suggestion to trim the board leaves out the fact that it needs be attached to chassis somehow. My guess at why Dumble did it is that Fender did it that way so why not. :D
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Re: Why put short jumpers on eyelet boards?

Post by pompeiisneaks »

Charlie Wilson wrote:Those are not hook up wire, they are the transformer leads. Your suggestion to trim the board leaves out the fact that it needs be attached to chassis somehow. My guess at why Dumble did it is that Fender did it that way so why not. :D
CW
I absolutely get that I met more room for the mounting hardware, just speaking more of the turrets. Ethan's that makes sense. It's odd fender did that though, Leo was a notorious penny pincher, unless this was a cbs design change

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Re: Why put short jumpers on eyelet boards?

Post by Charlie Wilson »

They did that in all the Blackface Twins I have been in. The people wiring in the circuit, mostly women I think, were great at being consistent and making them look nice but they were not electronic experts. Their task was to wire as many boards as they could in a short period of time. That particular board may have been done that way to help prevent them from overheating the diodes which are not as tolerant to that as resistors and capacitors. I think having to replace a burnt diode in parts and labor time would be more than a couple cents for eyelets. Just a guess.
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Re: Why put short jumpers on eyelet boards?

Post by M Fowler »

Jelle was speaking of why not using larger eyelets, well I did that on a few builds. I installed larger eyelet on the filter caps.

My eyelet assortment from Hobby Lobby didn't have the correct size I needed so it was just a wee bit too large of an eyelet. :D
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Re: Why put short jumpers on eyelet boards?

Post by talbany »

if the 124 layout has continuity throughout the board sets including preamp, it is not a jumper wire rather than an extra hole for the wire to pass under the board and connect on the opposite side of the eyelet where the components connect..i would assume this is mostly for strain relief and cosmetic reasons..As a side note here/ it does make it a bit easier to change the components if need be since you do not have to secure both wires and components down at the same time while you solder if you have to change or repair the board.This way the wire stays secured in the hole due to the insulator between the main board and the chassis.Not a big deal but thought i would mention it anyway IMO :D
BTW I did not design those boards on that layout, IcRacer did

Tony
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Re: Why put short jumpers on eyelet boards?

Post by pompeiisneaks »

Thanks all. The hole for the lead sounds like something I've done and liked in the past. I'm going to be building the boards myself and just wanted to be sure it made sense.

~Phil
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