Fidelity Research FR-54 Tonearm. ANTI-SKATE???

You are confirming my belief, it's pulling out 2.5g.

Well, it sounds darn good 1.5g down/2.5g out, but I don't have any experience with playing Mono LP with Mono Cartridges*; This Cartridge; This Arm.

To add weight is easy. Bottom of weight is threaded. Optional weights were probably available back when ..

various length screws would add variations of extra weight. Any screw/ combo can be weighed easily enough.. I read weight has m6 threads, needs to be verified.
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The purpose is to play MONO records, for now I am sticking with 1.5g down.

a. remove weight, let stylus 'ride' the inner wall with 1.5g

b. leave weight, let stylus 'ride' outer wall +1g

c. make 1.5g weight as you suggest (I'll try that first)

d. grind weight down to 1.5g. (can add to that if needed one way or another)


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* No experience with Mono Cartridge, Except to instantly know using dedicated Mono Cartridge is clearly better than playing Mono LP with Stereo Cartridge as I used to do, in Stereo Mode or most often via Fisher or McIntosh Mono mode switches. I was happily surprised how much better on some, not all old LPs. Thanks to the thread here.

 The force with which the anti-skate weight is pulling outward on the tone arm is related not merely  to the weight in grams of the AS weight itself. It’s also dependent upon the distance of the connection between the weight and the arm wand from the pivot point. it’s a lever in principle. So if you can get out your old geometry text you can figure out how much AS force is actually pulling on your arm. And you don’t want so much as a 1.5g AS force for a 1.5g VTF. Much less will usually do.

To get you started, an AS device creates a class 3 lever. Where the tonearm is the lever, the pivot is the fulcrum, and the cantilever is the load.  See here: https://en.wikipedia.org/wiki/Lever
That's if the AS force is applied to the arm wand.  In some cases, the AS force is applied to the short arm that holds the counterweight, to the rear of the pivot, and the AS force pulls the short arm inward.  In that case, we have a Class 1 lever.

thanks.

Sometimes I'm glad I ain't too smart. I get the distance from pivot varies the force.

I had SME 3009: dangling weight on line, 'inside' toward lp. hung on various notches on rod behind the pivot, progressive distances behind the pivot increase the force gradually. 

I see arms with the rod on the outside, with the notched rod forward of the pivot. same thing reversed, got it.

Fidelity Research FR-54 has an outside weight, the difference is, there is only one location to suspend the line, on a wire outside the arm, and, the line connects to only one place, a bimp on the bottom of the arm, about 1/2" in front of the center of the pivot.

No way to lighten, only threads in the bottom of the dangling weight to add sub weights.

If it weighs 2.5g, and it is connected 1/2" forward of the pivot, what amount of outward force do you estimate is produces?

What makes most sense to me is that it was designed in the days of heavy tracking weights, 2.5g start, method to add more if needed.

Exactly. Make that lighter weight and see how it tracks the run out area between grooves. It should just barely drift towards the spindle.