Starting my Wreck board and I have a question

[M Fowler]

Holy crap how is it possible that you can build this amp if you can't even follow the wiring diagram for a power transformer?

Mark

[lgehrig4]

I have that already and unfortunately it doesn't. My knowledge isn't to the point where I would know where they go by the voltages. I guess if I knew how to read schematics it would be different, but at this point in time I cannot. Thanks though.

Oh jeez... Well, procede at your own risk!

1. The two wires that go to the bias board diodes (I'm thinking the yellows)
2. The two wires that go to pins 2 and 7 of V5
3. The wires that go to the ground lug
4. The remaining two wires that are not in the layout (snip & cap?)

1. Yellow
2. Brown
3. Yellow/Red, White/Brown
4. Yellow/Green Clip the stripped part off, fold the end over 1/2" or so, cover with heat-shrink tube, and coil them up. Secure with a zip tie.

Thank you! The one thing I do now is how to stay safe.

[lgehrig4]

Holy crap how is it possible that you can build this amp if you can't even follow the wiring diagram for a power transformer?

Mark

Common sense, patience and knowing when to ask questions. I already built a JTM45 and it came out great. Even did a number of modifications to it.

The layout tells you each part to use and where to solder it. When it comes to the transformers though the colors are different so a person who would rely on a layout naturally would have difficulties when they could no longer follow it.

Here's an example of why you can't just figure this stuff out. I'm looking at the schematic for "Kelly" and it says 6.3V to heaters. The Pacific data sheet for the PT shows the White/Brown as 6.3V and no values showing for the brown wires. Now based on Martin's reply I guess the browns are also 6.3V, but this could not be determined unless you have prior knowledge about how these things are written so I ask the question, get the answer and I will have a kick ass amp when I am done.

Thanks to all for your help so far! I will post some more photos as I get closer to the finish line.

p.s. let me know if I am asking too many questions. I realize this board is loaded with techs and engineers (I'm a finance guy)and I don't pollute it with rudimentary information that is not beneficial to anyone but me.

[jelle]

Please keep asking questions.

The reality is that most of us here expect people that work with a soldering iron, to be able to read a schematic and test basic stuff. Sounds like you are cautious, no worries.

[lgehrig4]

Please keep asking questions.

The reality is that most of us here expect people that work with a soldering iron, to be able to read a schematic and test basic stuff. Sounds like you are cautious, no worries.

Understood. Since I don't have formal education on the subject my knowledge is spotty. I don't know some things that I probably should know and I know other things that I don't have business knowing. Each build is a learning experience, especially this one.

[M Fowler]

Okay but ask questions please, we don't want anyone hurt.

[lgehrig4]

Ok, so I'm almost done but the rga174 cable is on back order. I went to radio shack and bought shielded wire and wanted to know if this would be a suitable replacement.

24 gauge
Shielded
Stranded 2 wire
Type CL2
Insulation thickness .25mm
Temp rating 60 degree C

I was thinking of just twisting the 2 wires together since they are so thin. Should this do the job or should I just find another supplier of the rga174 cable?

[Blackburn]

Apex Jr.

[jelle]

Does radioshack have video coax style stuff?

[lgehrig4]

Does radioshack have video coax style stuff?

The only thing they have is what I described. It's shielded. Does it have to be that specific coax? What do you think would be the result if I used this stuff?

Problem with ordering is that I would like to finish this project this weekend and I really don't need anything else so it would only be the coax. If thats the route I must take then I'll suck it up, but I just wanted to see what your thoughts were of this shielded wire. I can take a photo if that helps?


Edit: I just found an extra component cable for TVs. I cut the ends off the 3 wires and from the looks of it it may be a viable option. Can I use this? If so does it matter which of the cables (red, blue or green) to use? They each look slightly different as far as wire thickness and material surrounding the wire.

[cbass]

I've used audio/video cable .(Like the stuff for your TV) in a pinch before

[dobbhill]

Is this it?
http://www.radioshack.com/product/index ... Id=2062643
I would use it in a pinch. Twist the center conductors like you said before and move forward. You can always go back and retrofit later. That's half the fun with this hobby/obsession...
Enjoy, but be careful.
D

[JazzGuitarGimp]

Someone correct me if I'm wrong, but I think paralleling the inner conductors with double the capacitance of the cable, thus making the high frequency rolloff worse.

[vibratoking]

Someone correct me if I'm wrong, but I think paralleling the inner conductors with double the capacitance of the cable, thus making the high frequency rolloff worse.

No, it won't double the capacitance. Depending on the exact construction, the capacitance could actually be reduced. The capacitance will be the same in a first order approximation. The capacitance you are mainly concerned with is between the signal and ground, not signal and signal.

[cbass]

I think the Yellow tip video connector on RCA cables is single conductur.Its not Ideal but could be used till u get some rg-174