Had occasion to try listening to a baseball game on the radio in my shop while using my G0766, a local AM station. All good with the lathe "on" and direction control in 'neutral' but was quite startled when I started a bowl spinning and the radio was drowned in white noise. Is this normal for a VFD? Or does my lathe just not like Cardinals baseball (in which case I may have to rethink my love affair with my G0766).
No, it's not characteristic of all VFDs. However its can happen if grounding isn't adequate. In my garage, my radio gets a lot of static when I turn on the fluorescent lights. I jus live with it but I could fix it if I took the time to check every ground connection back to the panel. Grounding can be perfectly safe but electronics characteristically add "noise" to the system. Not dangerous just annoying. fluorescent ballasts like vfd's are electronic.
Sounds like you should have all the grounding checked out, John. I think the more circuits/electronic devices on any "system" the more chance for interference on radio signals. I doubt you will find any lathe with the capabilities of the 0766 and the value you got for features that will give you any better than you have with this unit. You might possibly get less with a $10K lathe like the Robust AB or the Oneway 2436..........not sure it would be better for sure, but perhaps worth a try if your listening to the baseball is that important to you? My table saw will cause white noise to AM signals in the shop when running, and it does not have a VFD on it. FM signals seem to be clearer sounding.
Part 1: AM radios are extremely vulnerable to electrical interference from power tools. Inverters are notorious for generating electrical noise. Locating the receiver (your headphones) immediately next to the source of interference, is the worst-case situation. There are things that can be done to reduce some of the interference, but it is going to be a trial and error sort of thing. First you'd need to figure out if it was radiated or conducted interference - - or some of each. Then you may end up needing to put in RF filters, toroid inductors, capacitors, shielding on cables, etc. etc. That's a lot of work and no guarantees that you'll be able to reduce the interference to acceptable levels. continued...
Part 2: If you don't have objectionable interference on a regular AM radio (with speakers) located at the other side of the shop, I'd suggest using that and just turning up the volume. If you can find an FM station with the desired programming, I doubt that you'll have a problem. My G0766 messes up my AM reception major league also. My power/grounding is correct. BTW, I am am electronic engineer and an amateur radio operator.
Don't feel bad, my 0766 don't like the Giants.
what I did to clear up static was to use a car radio and extended the antenna outside, yes I had to use a 12 volt d.c. source for power which is a solar panel and a 12 volt battery. But on the plus side it works when the power goes out and no static. As a note the old magnetic ballasts seem to make far less noise than the newer electronic ballasts of florescent lights.
Grounding is good, and it's a dedicated circuit for the lathe. The radio is at the opposite end of a 30 ft deep shop space. I'll just not turn when the Cards are playing.
John, my lathe "blankets" my entire workshop with AM noise. FM = no problem. I like Dave Privett's solution of using an outdoor antenna. Another solution would be to buy an FM broadcast transmitter (e.g., from Ramsey electronics or equiv.). You would locate an AM receiver (which is located far enough from your shop that it doesn't pick up the interferencee) tuned to your baseball game and then broadcast, via FM, to your FM headphones. FM is immune to that sort of electrical noise. I have one of their transmitter kits and it works fine. I'm not endorsing their products - - just offering an alternative.
Brice has some good comments (I don't pass through here often) RFI/EMI is common with the electronics from lathes, the FCC considers them "commercial" items and thus exempt from the higher standards that "consumer" items have to meet (FCC part 15) A way to determine if grounding is the issue use a battery powered radio, like a car radio. If you get the same "noise" it's not grounding, it's emissions by the lathe (the issue with every lathe I've tested). The only real solution is better shielding in the lathe electronics, which is certainly not simple. Me, I listen to FM or the iPod. (by way of background I have a BS in Electronic Engineering and hold an Extra class Ham license)
