Thoughts (?) about tinning "tip" of stranded #12 awg wire.

[synchro]

I started in electronics building crystal radios when I was six years old.

Did you use a 1N34 germanium diode, or a "cat whisker" on a galena crystal, Gillette blue blade, etc.?

 

[jim dungar]

Square D says to put that stranded white wire into the screw terminal hole of the neutral bar and tighten the screw. If they thought it would not work, they would have designed it differently over the 35+ years they have been selling them.

The QO family dates back to the late 50's, I want to say 1958. I agree, if there were inherent problems with the design, changes would have been made. Their Homeline family is about 40 years old.

 

[LarryFine]

Did you use a 1N34 germanium diode, or a "cat whisker" on a galena crystal, Gillette blue blade, etc.?

Actually, my first one was a foxhole radio with the detector made with a blue blade and a pencil lead tied to the point of a large safety pin, and 100 turns of wire on a paper towel tube. I later added a 365uuf variable cap I removed from a broken radio.

 

[Todd0x1]

Someone may have already pointed this out, but NEVER solder or tin a wire that will be used in a pressure terminal. Solder cold flows under pressure and you will end up with a loose connection that will fail.

 

[synchro]

Someone may have already pointed this out, but NEVER solder or tin a wire that will be used in a pressure terminal. Solder cold flows under pressure and you will end up with a loose connection that will fail.

Yes. In contrast, copper works very well in crush washers that maintain the forces needed to seal high pressure hydraulic connections.

 

[Danielt]

I was taught, when terminating small stranded wires, to strip what you need, then take about a quarter-inch of insulation to the end of the wire. It keeps the strands from spreading.

 

[K1GMB]

I started in electronics building crystal radios when I was six years old.

One advantage of solid wire is it makes dressing panels a little easier.

Yea good old days of building electronics, dating myself but I loved building Heath kits, a simpler era!!!

 

[LarryFine]

Yea good old days of building electronics, dating myself but I loved building Heath kits, a simpler era!!!

SWTPc and Dynaco builder here.

 

[Little Bill]

I was taught, when terminating small stranded wires, to strip what you need, then take about a quarter-inch of insulation to the end of the wire. It keeps the strands from spreading.

Be kind of hard to stick the wire in a neutral slot with a piece of insulation on the end of it. That's what we are discussing here. Now that method works good when wrapping around a screw.

 

[synchro]

SWTPc and Dynaco builder here.

Stereo 70 amp with EL34's?

 

[LarryFine]

Stereo 70 amp with EL34's?

No. PAT-5 preamp, AF-6 tuner, and a pair of SWTPc original Universal Tigers pushing Rectilinear IIIs.

Dual 1229 w/ Shure V-15 Type 3 cartridge, SWTPc Class A headphone amp, Koss Pro-4 AAA 'phones.

That is nothing compared to the home theater system I have in my basement, with 2,200 watts RMS.

 

[Sea Nile]

twisting the wire snugly in the 'reverse' direction, so that under the screw head the 'rope' tightens rather than loosens.

Never thought about doing it like that, but thank you for sharing this, I'll add it to my bag of tricks and try it next time.

 

[LarryFine]

I usually hold the hook or loop of stranded wire closed with needle-nose pliers while tightening the screw.

 

[Jpflex]

Hi Folks, got a construction/installation question. This is my individual home wiring project, so I have plenty of time to think and try to do my electrical work safely and neatly. I am installing a 100-amp sub-panel with 20-amp Square D QO CAFI breakers. What are your thoughts about "tinning" the tip of the stranded #12 awg neutral wire, that will attach to the neutral buss bar in the panel. Traditionally when tightening down, the strains tend to spread out under the torque of the screw. Lots of articles about not tinning the wire completely because mechanically it "softens" the connection over time. Electrically this works, but yea I'm being very picky. Thoughts and field experience feedback is greatly appreciated. Thanks!!

Not sure about tinning but I’m curious about the AFCI compliant breakers you found. Where do you , find these, cost, verify they meet code?

 

[Jpflex]

Actually I will make a small comment about tinning since I’ve done a lot of automotive soldiering. The NEC says connections must be mechanically secured before soldiering tinning wire. Since you are tinning before mechanical compression connection perhaps this won’t be code compliant

 

[LarryFine]

Actually I will make a small comment about tinning since I’ve done a lot of automotive soldiering. The NEC says connections must be mechanically secured before soldiering tinning wire. Since you are tinning before mechanical compression connection perhaps this won’t be code compliant

The concern is about splicing wires in such a way that the wires could separate if the joint got warm enough to soften the solder. Both the mechanical and electrical qualities of the joint must be well made independently of the soldering.

That refers primarily to the days of knob-and-tube wiring, where most splices and joints were twisted, soldered, then covered with rubber and friction tapes. To simply solder two wires laid together has been done, but is certainly unreliable.

 

[Danielt]

Be kind of hard to stick the wire in a neutral slot with a piece of insulation on the end of it. That's what we are discussing here. Now that method works good when wrapping around a screw.

Definitely works on the neutral bar for #12 and #10. But it is a little off-topic from tinning

 

[Speedskater]

I too built some Dynaco kits, Stereo 70 amp, tube and transistor pre-amps and FM tuner. Later a Hafler (sp) mfg pre-amp.
Worked at a electronics parts store so I got the first on at a discount.

 

[PaulMmn]

SWTPc and Dynaco builder here.

I built the Dynaco FM Tuner-- you received the chassis, some brackets, and (IIRC) 2 circuit boards and the tuning capacitor assembly. The boards were pre-loaded and soldered, and the 3 modules were factory-tested as a unit. AllI had to do was the mechanical assembly (including stringing the indicator dial). Great unit!

 

[synchro]

I built the Dynaco FM Tuner-- you received the chassis, some brackets, and (IIRC) 2 circuit boards and the tuning capacitor assembly. The boards were pre-loaded and soldered, and the 3 modules were factory-tested as a unit. AllI had to do was the mechanical assembly (including stringing the indicator dial). Great unit!

I imagine they had to preassemble those boards because aligning IF strips, etc. would take specialized equipment.

I too built some Dynaco kits, Stereo 70 amp, tube and transistor pre-amps and FM tuner. Later a Hafler (sp) mfg pre-amp.
Worked at a electronics parts store so I got the first on at a discount.

I put together a Hafler power amp and pre-amp. The power amp used MOSFETs on the outputs. They were biased more heavily than a normal class AB and so the heat sinks got quite warm even without any drive signal.

Did you work at an Olson Electronics parts store? Just asking, because I know they had a number of them in Ohio.
To get back to the soldering topic, at an Olson's I saw a kid returning a simple kit that he'd assembled because it didn't work. The counterman took a quick look, and then he told the kid it was because he'd soldered all the resistors in backwards.