Mike,
Here is a followup to your further question via email to me about the the stylus alignment gauge. Since you have a pre-drilled armboard on your SOTA, you already have one of the biggest issues solved. The rest is purely an exercise in logic once you understand the principles of the arm design, which I think you do.
The stylus reference gauge is very simple. It is only apiece of plastic with a hole drilled at one end to fit over the spindle and a line scribed from the center of that hole to the end of the piece of plastic. The value of this tool is that you can very gently lower the stylus onto the stylus gauge at various points along its length to check that the stylus is settling right onto the line at each point along the length. Once you accomplish this, you know the arm is tracking perfectly tangential to the groves -- its "in alignment."
Wally Malewicz (of "Wallytractor" fame) makes an alignment gauge for linear tracking toneams. Lloyd Walker includes one with each of his Walker Proscenium Gold turntables, which use a linear tracking arm. You could probably order one from Music Direct, see http://www.amusicdirect.com/products/detail.asp?sku=AWALTRACTOR, but the cost is $149 and you'll probably have to wait for Wally to make one for you. OTOH, you could call Lloyd Walker to see if he has one on hand that he'd sell to you. (http://www.walkeraudio.com) The advantage of the Wallytractor is that the lines are scribed on a reflective surface that makes checking for stylus placement much easier, and it also gives you a great tool for adjusting azimuth by eye when you get to that point. The Wallytractor is beautifully and very accurately made.
Cheaper alternatives may be available. In a quick web search just now I found the following: http://www.turntablebasics.com/index.html It is shown with a pivoted arm, but the line you see drawn from the spindle to the edge should work just fine for what you need to do. Also gives you a mirrored surface.
For $5, this Garrott Brothers Cartridge Protractor would probably work: http://shopping.netsuite.com/s.nl/c.ACCT106601/sc.9/category.-109/it.A/id.1108/.f
Now, here's the least cost alternative... Make your own. Take a piece of heavy stock paper (24lb or greater). Fold the paper exactly in half - lengthways by aligning the edges. Make it a sharp crease. At one end, use scissors to cut off a corner from the end of the folded edge. Unfold the paper and fold it back the other way - to make it lay flat. Your corner cut will now be a "V" at the end of the crease remaining from your fold. Set the "V" against your spindle and the crease should run from the center of the spindle to the outer edge of the platter. Bingo - you now have a stylus alignment gauge with the crease as your scribed line.
Hope this is helping some. It will be confusing the first time through, but hopefully it will get clearer as you work with it.
Here is a followup to your further question via email to me about the the stylus alignment gauge. Since you have a pre-drilled armboard on your SOTA, you already have one of the biggest issues solved. The rest is purely an exercise in logic once you understand the principles of the arm design, which I think you do.
The stylus reference gauge is very simple. It is only apiece of plastic with a hole drilled at one end to fit over the spindle and a line scribed from the center of that hole to the end of the piece of plastic. The value of this tool is that you can very gently lower the stylus onto the stylus gauge at various points along its length to check that the stylus is settling right onto the line at each point along the length. Once you accomplish this, you know the arm is tracking perfectly tangential to the groves -- its "in alignment."
Wally Malewicz (of "Wallytractor" fame) makes an alignment gauge for linear tracking toneams. Lloyd Walker includes one with each of his Walker Proscenium Gold turntables, which use a linear tracking arm. You could probably order one from Music Direct, see http://www.amusicdirect.com/products/detail.asp?sku=AWALTRACTOR, but the cost is $149 and you'll probably have to wait for Wally to make one for you. OTOH, you could call Lloyd Walker to see if he has one on hand that he'd sell to you. (http://www.walkeraudio.com) The advantage of the Wallytractor is that the lines are scribed on a reflective surface that makes checking for stylus placement much easier, and it also gives you a great tool for adjusting azimuth by eye when you get to that point. The Wallytractor is beautifully and very accurately made.
Cheaper alternatives may be available. In a quick web search just now I found the following: http://www.turntablebasics.com/index.html It is shown with a pivoted arm, but the line you see drawn from the spindle to the edge should work just fine for what you need to do. Also gives you a mirrored surface.
For $5, this Garrott Brothers Cartridge Protractor would probably work: http://shopping.netsuite.com/s.nl/c.ACCT106601/sc.9/category.-109/it.A/id.1108/.f
Now, here's the least cost alternative... Make your own. Take a piece of heavy stock paper (24lb or greater). Fold the paper exactly in half - lengthways by aligning the edges. Make it a sharp crease. At one end, use scissors to cut off a corner from the end of the folded edge. Unfold the paper and fold it back the other way - to make it lay flat. Your corner cut will now be a "V" at the end of the crease remaining from your fold. Set the "V" against your spindle and the crease should run from the center of the spindle to the outer edge of the platter. Bingo - you now have a stylus alignment gauge with the crease as your scribed line.
Hope this is helping some. It will be confusing the first time through, but hopefully it will get clearer as you work with it.