Philmore S38 Vernier Control Knob

This is a sweet little control knob. I wasn't sure what to expect, since I had never bought one of these before, and the price was a little steep for something I wasn't at all sure of, but I'm glad I finally made the purchase (after a few months trying to decide). What this does is convert a 180 degree potentiometer/variable capacitor/whatever into a 3-turn device by way of gearing inside the knob assembly. When you want finer control over the exact position of a tuner knob or whatever, this is kinda like a super magnifying glass for knob position, so that a full revolution of the knob only actually moves the underlying control 1/3 of its extent - and the 0-100 scale on the front of the control only moves by the portion of 180 degrees that the underlying control has been moved.This will be great on my homebrew Ham Radio. Instead of fidgeting with the knob trying for 1/32 of and inch rotation to dial in a station perfectly, this will make that same tiny span into something very much more manageable and pleasant to work with. The control is very tightly built with no detectable play in the gears. It is smaller than I expected it to be - the black center knob is not much bigger than an American Nickel or a bottle cap. Somehow, I thought it would be bigger and was concerned that it would be too bulky to be useful. As is, I think it is almost exactly as small as it could be before it became too small to be useful. Of course this is all subjective, but, after all, this is an opinion piece - my impression of the product.I am very happy that my hesitation finally gave way and I spent the money on this. You are unlikely to be disappointed if you do the same.

I've bought about 8 of these so far and aside from the plastic being brittle (don't tighten the screws too tight - I broke a leg off one) they work ok. I wish there were some of these that had the dial reversed. Most tuning caps increase COUNTERclockwise. These all increase CLOCKWISE. There are variations in their ease of turning indicating they are on the cheap side.

I used two of these in a crystal radio build and they gave me it a very nice feel and look. These worked beautifully and really made a primitive radio look like a vintage one - minus the wear and tear of use over time.

Very small and will drive only a very small capacitor. It slips and won't stay aligned at all. I have built many magnetic loop antennas and this vernier is the worse I have ever used. It's also made of very old Bakelite plastic. As soon as I find a better drive, this one is going in the trash.

I used it for finer tuning of the variable capacitor for my mag loop. 1:3 gearing ratio it has improved tuning enough. Now downsides: the shaft needs to be carefully aligned with the shaft it attaches to, otherwise, any eccentricity, even a small one, will cause it to block and stop turning the shaft mid-way. You can even see the surface of the dial move up and down as you turn. And this was a very slight misalignment. Another thing is that the torque it can produce is not very high. So, if the shaft you're turning is not very easy to turn on its own, this may not work as the Vernier dial will slip inside.

I used it for a radio kit I am building. It is smaller than I thought it would be, but it seems to be a good product (I have 2 of them). When you need a vernier dial, this is the only one I have found on line.

I purchased this item to replace a tuning knob on a small magloop antenna. The smooth vernier action on this knob makes all the difference in the world.

Too small for my needs