Once again, Dr. Tekkie's mailbag is filled to overflowing (it's a small bag) with the usual: secret communications from powerful industrialists, marriage proposals from embarrassingly rich women, threatening letters from underworld kingpins and sincere requests for help from consumers struggling to master the vagaries of personal technology. Only the last is of interest to Dr. Tekkie's readers, of course, so the first envelope, please:

Q. I've seen several devices advertised making what I think is a dubious claim -- that they improve the sound quality of my compact disc player by reducing the effects of vibrations. Aren't CD players already vibration-free? Is this product a scam?

Dubious CD Lover, Washington, D.C.

A. This is a controversial subject among audiophiles. Most experts say compact disc players don't produce enough vibration to affect sound reproduction. But a few gadflies say they do and that these slight movements cause audible errors in the laser reading. One way to check your CD player for this possibility is to put not one but two compact discs into your machine. If the sound is significantly different from when just one CD is loaded, it may mean the extra weight is indeed dampening vibrations inherent in your machine. Thus you might benefit from a damping device -- really just a weight that sits on top of the disc -- the item I suspect you saw advertised. These devices sell for about $15 in audio specialty shops.

Q. We recently purchased an MS-DOS personal computer but find the choice of software confusing and overwhelming. All we want to start with is word processing, some graphics and a little drawing. We don't have the knowledge or the time to wade through voluminous manuals. Are there software companies that have produced good programs -- easy to learn and use -- for neophytes like us?

Bill and Marsha Ortega, Falls Church

A. Yes. More software companies are realizing that lots of new PC owners don't have the background, interest or patience to slog through manuals written in hieroglyphics, trying to decipher overpowered programs. Big business was the first target for software producers, but easier-to-use programs -- aimed at the home and small-business market -- are finally emerging.

Much of this software has the necessary instructions available on on- screen menus, eliminating the need to flip back and forth from the keyboard to a hefty manual. Here are some suggestions for good but relatively easy-to-use software:

Word processing: Take a look at First Choice and PFS: Professional Write (Software Publishing Corp.) and Webster's New World Writer (Simon and Schuster).

Graphics and drawing: These are more complicated to use, demanding that you spend more time delving into the program. How deeply you plunge in depends on how sophisticated you want your graphics and art to appear.

Easiest to use are Art Studio (Spectrum Holobyte), Print Master Plus (Unison World) and PC Paintbrush (Z-Soft). You should also consider Gem Draw Plus (Digital Research Corp.), Drafix 1 Plus (Foresight Resources Corp.) and EGA Paint 2005 (RIX Softworks). More powerful are Harvard Graphics (Software Publishing Corp.) and Freelance Plus (Lotus Development Corp.).

I haven't listed prices because discounts on software are widely available, particularly from mail-order houses. The best of these have toll-free telephone numbers for technical support. All offer a money-back guarantee on defective software, and a few will let you return the programs if you're not satisfied with their performance. Retail software shops have higher prices, but they also provide service -- people willing to answer your questions and a chance to try out programs in the store. One chain in this area -- Egghead Software -- even offers a 14-day no-questions-asked money-back guarantee on software.

Q. I'm looking for a device to edit my home video tapes. Several professional machines are available, but their prices are beyond my budget. Is there any reasonably priced video editing equipment out there for home use?

Alan Marshall, Washington, D.C.

A. DirectED, a computer-controlled home video editor ($499), was voted one of the most innovative products of 1987 at the summer Consumer Electronics Show in Chicago. The easy-to-use device, which works with any videotape format and almost all equipment, allows VCR owners to add titles, graphics (in 64 colors) and special effects (fades and wipes; text in graphics) to their productions. For more information, contact the manufacturer, Videonics Inc., 1129 Dell Ave., Campbell, Calif. 95008; 408/866-8300. :: Address questions to: Dr. Tekkie, The Washington Post Magazine, 1150 15th St. NW, Washington D.C. 20071.