Audio Equipment

Some audio gear will pick up a 60-cycle buzz through the speakers. It doesn't hurt the equipment, but it's annoying to the listener. There are too many models and brands to say specially which have this problem. We've had better luck with new equipment recently. Manufacturers are starting to put better power supplies into their gear. We can only recommend that you try it and see. Some top-of-the-line audio gear is protected by SCRs or Triacs. These devices are installed to guard against power line spikes and surges.

Computers

Computers run happily on modified sine wave. In fact most of the uninterruptible power supplies on the market have modified sine wave or even square wave output. The first thing the computer does with the incoming AC power is to run it through an internal power supply. We've had a few reports of the power supply being just a bit noisier on modified sine, but no real problems. Running your prize family-heirloom computer off an inverter will not be a problem. What can be a problem are large start-up power surges. If your computer is running off the same household inverter as the water pump, power tools, and microwave, you may have trouble.

Ceiling Fans

Most variable-speed ceiling fans will buzz on modified sine wave current. They work fine, without harm, but the noise may be annoying.

Radio Frequency Interference

All inverters broadcast radio static when operating. Most of this interference is on the AM radio band. Do not plug your radio into the inverter and expect to listen to the ball game; you'll have to use a battery powered radio and be some distance away from the inverter. This is occasionally a problem with TV interference when inexpensive TVs and smaller inexpensive inverters are used together. Distance helps. Put the TV (and the antenna) at least 15 feet from the inverter. Twisting the inverter input cables may also limit their broadcast power (strange as it sounds, it works).