Shortwave - Your Ear on the World
August 1968 Radio-Electronics

August 1968 Radio-Electronics [Table of Contents] Wax nostalgic about and learn from the history of early electronics. See articles from Radio-Electronics, published 1930-1988. All copyrights hereby acknowledged.

Charles J. Vlahos' 1968 Radio-Electronics magazine article highlights the growing popularity of shortwave listening (SWL), still a popular pastime, with around 3,000 stations worldwide broadcasting diverse content - news, propaganda, language courses, and entertainment - often in English. SWL offers unique perspectives, from Hanoi's war coverage to Radio Tokyo's language lessons. Enthusiasts log stations using SINPO codes and collect QSL cards as verification. The article details receiver specifications, emphasizing selectivity, sensitivity, and stability, with price comparisons from budget kits (e.g., Heathkit GR-64 at $39.95) to high-end models (e.g., Galaxy R-530 at $695). Antennas, like long wires or whip antennas, are crucial for performance. Accessories such as headphones, 24-hour clocks, and crystal calibrators enhance the experience. Propagation depends on ionospheric conditions, sunspot cycles, and time of day, with higher frequencies (15-25 MHz) optimal in daylight and lower bands (3.9-7 MHz) better at night. SWL combines global connectivity with technical hobbyism.

Shortwave - Your Ear on the World

By Charles J. Vlahos

Short-wave radio has been bridging distances between continents - electronically - for decades. The popularity of short-wave listening (SWL) continues to grow as greater numbers of low-cost, quality receivers are marketed, and interest in other nations develops.

Today, some 3000 short-wave stations beam their broadcasts to the world. Operating at powers up to 500 kW, they fill the airwaves around the clock with a variety of programs that will suit anyone's taste.

At the right frequency and time you can hear Hanoi's interpretation of the war news from Vietnam. Twist the dial to another frequency and you'll hear world news reports from Switzerland - a different viewpoint from the American press and Hanoi. Take the trouble to learn Morse code and you can monitor press broadcasts while news services are receiving them.

Interested in propaganda? Radio Moscow, Radio Peking, Havana or East Berlin will provide all you want. Their broadcasts are slanted to give their viewpoint, not only on world affairs, but on how they feel people should live and govern themselves.

Many stations offer language courses. Tune in Radio Tokyo twice a week for a course called "Let's Talk Japanese," specifically slanted to English-speaking audiences. You can listen to a talk on West Indian wrestling, guided tours of foreign lands, folk music and opera. You'll find much of the SW programing is in English - particularly broadcasts beamed to the States.

For those with a spirit of adventure, there's excitement, too, in SWL. Hundreds of SWL'ers heard the distress call of the Andrea Doria when she went down off the New England coast in 1956. Police, fire and marine calls, airport control towers, government stations - all are within range of many short-wave receivers.

Then there's amateur radio. Amateur or ham radio stations are operated by private citizens in more than 250 countries. Amateurs talk to other amateur operators for personal pleasure or for experimentation. Listening to their chatter can be informative and educational. Commercial business transactions are not permitted over ham bands.

Logging Stations

But there's more to SWL than keeping your ear to a loudspeaker. Experienced listeners record what they hear. Log records can be set up in various ways. Typically, the arrangement includes columns for the date, time, call (station), frequency, quality of reception and remarks.

Reception quality is often logged with the SINPO code (signal strength, interference, noise, propagation disturbance and overall merit), which rates reception from 5 (excellent) to 1 (very poor).

Logging is a complete record of the signals heard at the SWL'er's station. Like a ship's log, it should be comprehensive and well organized - what you heard over your receiver. A log book can be an invaluable aid in your search for rare DX (distant stations), and can serve as a guide to quickly locate favorite stations.

In addition to logging, SWL'ers collect verification reports from SW stations. These highly prized confirmation reports are called QSL cards. To obtain a QSL card, the listener must of course first hear the station and log program details. This information is then sent to the station so it can check the report against its transmitting record.

What should you include in the report? Deutsche Welle (Germany Radio) asks that you submit at least these details: 1. Date and time of reception in Greenwich Mean Time, or your local time. 2. Frequency in kHz, MHz and/or meter band. 3. Program details that cover at least 10 minutes of broadcasting time. 4. Language of transmissions. 5. Quality of transmission. 6. Description of your receiver and antenna.

Most international broadcasting stations don't require return postage, but your best bet is to include an International Reply Coupon, obtainable at any post office.

Short-Wave Receivers

Receivers are often designed for reception only on certain types of broadcasting-such as two-way business radio or amateur-band receivers. A "short" wave is less than 187 meters, crest to crest, compared to about 200-550 meters for standard broadcast waves.

There are 14 international and domestic short-wave bands. The least expensive receivers cover three or more of these bands, and often include the AM or standard broadcast band and sometimes FM. The better receiver models offer continuous coverage from 550 kHz to 30 MHz, and usually designate this coverage in frequency rather than radio wavelengths. When wavelength is known, frequency can be determined by the formula f = 300/λ, where λ = the wavelength in meters and f = frequency in megahertz.

A short-wave band, say 25 meters, covers wavelengths that vary less than 1 meter (25.05-25.7), or from 11.7-11.975 MHz. Thus the 25-meter band covers frequencies in this 11-MHz range on the receiver dial. Short-wave bands will be discussed later in more detail.

First, let's look at some of the criteria that determine the quality of a receiver. Selectivity, sensitivity, stability and image rejection are a few - all, of course, are related to selling price. Expensive models offer the best of each of these characteristics.

Selectivity means just that: the inherent ability of a receiver to select a particular station from a crowded frequency band and reject all others adjacent to it. A receiver's overall selectivity depends on the selectivity of its individually tuned circuits. In super-heterodyne receivers, this selectivity is achieved in the i.f. amplifiers, and the higher the Q of these circuits (and their corresponding sharp resonance curves), the greater the selectivity.

Figure 1 shows a typical selectivity curve for a quality receiver. Although manufacturers seldom supply these curves, when two or more bandwidth figures are provided for receiver functions (AM, CW, SSB) the approximate shape factor of the curves can be determined.

Bandwidth figures are usually stated for the points on the selectivity curve where signal attenuation is 6 dB and 60 dB down. Shape factor is determined by dividing the former into the latter. Thus, for the curve shown in Fig. 1, bandwidth at -6 dB and -60 dB is 5 kHz and 15 kHz, respectively, and the shape factor is 3.

Facts About the Map Short wave bands are shown in megahertz for the listener's local standard time. The map applies only to listeners in the continental U.S., and is broken down for readers in the EAST and WEST. Example: A Chicago listener wanting to tune in Formosa this winter at 10 p.m. should check the EAST row in the Far East block and try the 15-MHz band. Predictions are for the best band, but at any time reception may be equally good one or two bands above or below the band shown. Where two bands are given in a time period, a sharp transition occurs within the 4-hour period.

The voltage scale also shown in Fig. 1 indicates the ratio of signal strength off resonance to signal strength at resonance to provide constant output.

When your receiver has a narrow selectivity curve, it's clear you'll have less interference from adjacent stations. But the bandwidth at -6 dB must be wide enough to pass AM signal sidebands or fidelity will be poor. With the aid of crystal and mechanical filters, receiver selectivity can be made very sharp for code and phone reception where fidelity is not so important. Many quality receivers can be varied in selectivity on all functions with variable selectivity filters.

Sensitivity determines how well a receiver responds to weak signals. When a signal originates from a distant transmitter, its strength is greatly diminished by the time it reaches your listening station - sometimes to a few hundredths of a trillionth of a watt. Your receiver must be able to pick up such signals and amplify them over the receiver's internal noise.

Specifications for sensitivity are given in microvolts in relation to the signal-to-noise ratio. That is, the input signal necessary to give an output signal at a specified ratio above the set's noise. A figure of about 5 to 6 μV at 10 dB S/N is an acceptable sensitivity level, although it's not spectacular. A microvolt value cannot be given for the entire frequency range of a receiver, since sensitivity varies from one band to another, and from the low side of the dial to the high.

A method for testing sensitivity is to turn on the set with the antenna attached. Turn off the avc and set the antenna trimmer to maximum response. Listen for background noise as you rotate the dial. Then disconnect the antenna and check for inherent noise. With the volume turned up, some low-level noise is acceptable.

Also look for an rf gain control. If there is one, you have an added feature to help prevent overloading by strong signals.

Another criterion of a good receiver is stability. This refers to the frequency stability of a receiver, or its ability to prevent a tuned signal from creeping along the dial. Stability is gained through sound electrical and mechanical design, and all manufacturers do their best to achieve it.

One way to check stability is to set the receiver at some known frequency standard (such as WWV, at 2.5, 5, 10, 15, 20 or 25 MHz). Let the receiver warm up, and after 30 minutes or so (if it is a tube set), it should cling pretty close to WWV.

Image rejection is still another important receiver characteristic. The high-frequency oscillator of a super-heterodyne can produce the receiver's i.f. from either of two incoming signals, one above and one below the oscillator frequency. One of these responses (twice the intermediate frequency away from the desired signal) is an image and can cause serious interference. The ability of a receiver to reject such images depends on its image ratio. This is the ratio of the receiver's output voltage from the desired frequency to that from the image frequency. A high image ratio can be achieved with good selectivity in the set's rf circuits (before the signal is heterodyned) .

More expensive receivers achieve higher image ratios by using a high i.f. (such as 3 MHz) or two i.f. amplifiers, one of which has a high i.f., since increasing the i.f. increases the separation between the desired frequency and the image frequency.

There are other features to look for in a quality short-wave receiver, and all are evident by studying the front of the set where the controls are. For example, look for:

Bandspread Dial. This extremely important feature is found on all good receivers. A separate control which may be described as ultra-fine tuning, it allows you to pick out and isolate stations impossible to separate with a conventional tuning control. In better-quality receivers, this dial is a geared affair. In many SW receivers the band-spread scale is labeled with arbitrary numbers and not in actual frequencies.

S-Meter. A useful feature which measures for the listener the relative strength of the signal, the S-meter serves as a useful tuning aid. It can also be used for reporting signal strength to SW stations, since the meter face is marked off in S-units and decibels, both of which are universally accepted and understood.

Antenna Trimmer. Mentioned before, this control helps peak the first (antenna) tuning stage in the receiver. You peak this stage by rotating the antenna trimmer to a point where the S-meter reads the highest.

Rf Gain. This control prevents overloading by strong signals.

Bfo Control. This turns on the beat-frequency oscillator, adds a tone to CW signals, and enables the listener to vary code tone to the most pleasing sound.

ANL Switch. This turns on the automatic noise limiter and, in the on position, reduces pulse type noises. Therefore, the signal reaches the loudspeaker practically unaffected by static.

Avc Switch. The automatic volume control helps prevent blasting when a loud signal appears. This switch disables avc for certain types of reception (CW, SSB).

Selectivity Control. This control selects or adjusts a filter for the appropriate bandwidth.

Other features, such as the main tuning control, phone jack, af or volume control, are self-explanatory.

Where and When to Listen

As mentioned earlier, there are 14 international and domestic short-wave bands. Three of these bands (120, 90 and 60 meters) are assigned for domestic broadcasting in tropical areas, and are used mainly by stations in Latin America, Africa, Southeast Asia and Oceania. These Tropical Broadcast Bands are best received when the transmitting station and the listener are in darkness.

The Nine Remaining Short-Wave Bands Are ------->

Reception of these bands, as well as the tropical bands, is primarily dependent on the electrified region or ionosphere encircling the earth. The density of the ionosphere and its height above the earth's surface vary due to several factors. Since radio waves are reflected from the ionosphere, short-wave reception also varies directly with these factors. Ultraviolet radiation from the sun has the most direct effect on the density of the ionosphere. Consequently, reception varies according to the time of day over the reception path and with the seasons. Broadcasting stations usually compensate for seasonal variations by changing their frequencies in March, May, September and November.

Generally, reception is better on the higher-frequency bands (15, 17, 21 and 25 MHz) during daylight hours (daylight at both transmitter and receiver) and especially during the listener's winter season. During evening and night hours, reception is better on the lower bands (3.9, 6, 7, 9 and 11 MHz). On winter nights 3.9, 6 and 7 MHz are particularly good.

Sunspots are another periodic fluctuation affecting short-wave reception. The number of sunspots varies approximately over a 11-year cycle. As the number of sunspots increases, ultraviolet radiation goes up, increasing the density of the ionosphere and improving reception. At present, we are in a peak of sunspot activity, and consequently there is excellent short-wave propagation, especially in the 15-,17-,21- and 25-MHz bands. R-E

General-Coverage Receivers to $100

Heathkit GR-64 4-Band Receiver Kit

Tuning range: 550 kHz-30 MHz. Selectivity, Sensitivity: NA. Antenna input: Connections for external systems. Controls: Main tuning, bandspread, bandswitch, volume, bfo, ANL, function with AM, STBY, and CW positions, S-meter. Circuitry: Vacuum tube; built-in speaker. Price: $39.95.

Knight Star Roamer 5-Band Receiver Kit

Tuning range: 200 kHz-30 MHz. Selectivity: 8 kHz at 6 dB down. Sensitivity: 10 μV for 10 dB S/N. Antenna input: Connections for external systems, unbalanced, 300 ohms nominal; internal loopstick for BCB. Controls: Main tuning, bandspread, bandswitch, antenna trimmer, volume, sensitivity (bfo), avc, ANL, S-meter. Circuitry: Vacuum tube; built-in speaker. Price: $44.95.

Lafayette "Explor-Air" Mark V 5-Band Receiver

Tuning range: 550 kHz-15.5 MHz. Selectivity, Sensitivity: NA. Antenna input: Ferrite loop for standard broadcast; connections for short wave. Controls: Main tuning, bandswitch, tone, volume. Circuitry: Vacuum tube; built-in speaker. Price: $49.95.

Hallicrafters S-200 "Legionaire" 5-Band Receiver

Tuning range: 550 kHz-15.5 MHz. Selectivity, Sensitivity: NA. Antenna input: Ferrite loop for standard broadcast, connections for short wave. Controls: Main tuning, bandswitch, volume, tone. Circuitry: Vacuum tube, built-in speaker. Price: $59.95.

Heathkit GR·54 5-Band Receiver Kit

Tuning range: 180 kHz-30 MHz. Selectivity: 3.0 kHz min. at 6 dB, 7.5 kHz max. at 20 dB. Sensitivity: (for 10 dB S/N). AM, Band A, 1.6 μV; B, 8 μV; C, 1 μV; D, 1.2 μV; E, 6 μV. SSB/CW, Band A, 0.7 μV; C, 0.4 μV; D, 0.5 μV; E, 4 μV. Antenna input: Connections for external systems, 30-75 ohms; rod antenna for broadcast band. Controls: Main tuning, band-spread, bandswitch, af gain, rf gain, antenna trim, mode with AM, USB and LSB positions, avc, ANL, OPR with REC and STBY positions, meter adjust on rear panel, s-meter. Circuitry: Vacuum tube; built-in speaker. Price: $87.95.

Olson RA-48

Tuning range: Band A, 550-1600 kHz; B, 1.5-4.5 MHz; C, 4-12 MHz; D, 11.5-30 MHz. Sensitivity: Band A, 2 μV at 50 mW; B, 5 μV at 50 mW; C, 10 μV at 50 mW; D, 20 μV at 50 mW. Selectivity: 20 dB, 10 kHz. Main tuning: 6:1 spread dial ratio tuning. Auxiliary circuits: Bfa pitch control, phone jack. Circuitry: Vacuum tube; built-in speaker. Price: $39.98.

Antennas

Even the best receiver will not perform satisfactorily on short-wave bands unless it is connected to an adequate antenna. A 100' length of wire strung at a high elevation will pick up signals over the short-wave band. The wire (with insulators at either end) should be positioned away from sources of man-made electrical noise. A shielded lead-in wire will prevent noise signals from being picked up.

Another type of long-wire antenna uses traps on the wire to make sections of the wire sensitive to selected bands. The Mosley SWL-7 kit is a 50' wire (with lead-in and insulators) that includes traps for the 11-, 13-, 16-, 19-, 25-, 31- and 49-meter bands.

If you don't have space to mount long wires, whip antennas are available that cover the short-wave frequencies. The Hy-Gain SWL-9 is designed for frequencies from 1.8 to 30 MHz, and can be mounted on a window sill.

Accessories

Several devices will enhance your enjoyment of short-wave radio listening. While they aren't essential, they do make SWL a bit easier.

First on the list is a good pair of headphones. These permit you to spend late hours listening without disturbing other members of the household. Chances are you'll be doing much of your listening at odd hours.

And speaking of time zones, another useful item is a time clock. Not the ordinary run-of-the-mill clock, but a 24-hour clock so you can report times correctly on the 24-hour system. (Five in the evening is 1700 hours. See Chart I.) If you have an old clock, set it so you can read time in Greenwich Mean Time (GMT).

Chart I Converting To GMT

A crystal calibrator is useful for pinpointing frequencies. Available in kit form, this easily assembled accessory generates a series of accurate signals (usually 100 KHz apart) through the complete range of the receiver that are heard as a tone when the bfo is turned on.

General-Coverage Receivers $100 to $200

Hallicrafters S-240 FM/AM 5-Band Receiver

Tuning range: 550 kHz-108 MHz; 88-108 MHz. Selectivity AM: 6-10 kHz at 6 db. I.F. Bandwidth FM: 120-185 kHz. Sensitivity: NA. Antenna Input: Ferrite core for AM; line cord for FM; telescoping whip for short wave; connections for external systems. Controls: Main tuning (dual concentric), bandswitch, volume, tone, bfo switch, FM-afc switch. Circuitry: Solid-state, built-in speaker. Price: $109.95.

Radio Shack Realistic DX-150 4-Band Receiver

Tuning range: 535 kHz-30 MHz. Selectivity: NA. Sensitivity: to 5 μV at 30 MHz. Antenna input: Connections for external systems. Controls: Main tuning, bandspread, bandswitch, ANL switch, bfo, SSB/AM/CW switch, avc switch, receive/standby switch, antenna trimmer, rf gain, volume, S-meter. Circuitry: Solid-state; built-in speaker; operates from 117 Vac or 12V dc. Price: $119.95.

Hallicrafters S-129 4-Band Receiver

Tuning range: 535 kHz-31.5 MHz. Selectivity, Sensitivity: NA. Antenna input: Connections for external systems. Controls: Main tuning, bandspread, bandswitch, rf gain, antenna trimmer, ANL switch, AM-CW/SSB selector, bfo, volume. Circuitry: Vacuum tube. Price: $154.95.

Hallicrafters SX-130 4-Band Receiver

Tuning range: 535 kHz-31.5 MHz. Selectivity: Crystal filter. Sensitivity: NA. Antenna input: Connections for external systems. Controls: Main tuning, bandspread, bandswitch, rf gain, antenna trimmer, crystal phase, selectivity, ANL switch, AM-CW/SSB selector, bfo, volume, S-meter. Circuitry: Vacuum tube. Price: $169.95.

General-Coverage Receivers over $200

Hammarlund HQ-145A Receiver

Tuning range: 540 kHz-30 MHz (11 crystal-controlled frequencies on 145-AX). Selectivity: Six positions: 0 for crystal filter disconnected. 1, 2, 3 for AM; 2, 3, 4, 5 for SSB; 4 or 5 for CW. Sensitivity: 1.0 μV produces 10:1 S/N ratio. Stability: Adjustable high-stability, temperature-compensated bfo for SSB and CW. Antenna input: Connections for external systems; nominal impedance 100 ohms. Controls: Main tuning, bandspread, bandswitch, rf gain, audio gain, crystal selectivity: OFF-1, 2, 3, 4, 5 positions, crystal phasing capacitor, antenna compensator, function switch (send-receive SSB/CW calibrate), slot frequency adjust, bfa, avc, dial-scale reset (bandspread scale only), S-meter. Circuitry: Vacuum-tube, double-conversion superheterodyne. Price: $312.95.

Heathkit SB-310 9-Band Receiver Kit

Tuning range: 3.5 MHz-27.4 MHz. Selectivity: AM: 5.0 kHz at 6 dB down, 15 kHz max. at 60 dB down. CW: 400 Hz at 6 dB down, 2.0 kHz max. at 60 dB down (with CW crystal filter, available as accessory). SSB: 2.1 kHz at 6 dB down, 5.0 kHz at 60 dB down (with deluxe SSB crystal filter available as accessory). 2.1 kHz at 6 dB down, 7.0 kHz max. at 60 dB down (with standard SSB crystal filter available as accessory). Sensitivity: Less than 0.3 μV for 10 dB S/N for SSB operation. Stability: Less than 100 Hz drift/hr after 20·min warm-up. Less than 100·Hz drift for ±10% line-voltage variation. Antenna input: Connections for external systems, 50 ohms nominal unbalanced. Controls: Main tuning, bandswitch, function switch, mode switch, age switch, af gain control/ANL switch, preselector, rf gain, meter adjust on rear panel, s-meter. Circuitry: Vacuum-tube, double-conversion super-heterodyne. Price: $249.00.

Hallicrafters SX-122 4-Band Receiver

Tuning range: 538 kHz-34 MHz. Selectivity: Three steps: 0.5, 2.5, 5.0 kHz at 6 db down. Sensitivity: NA. Stability: Temperature compensation of high-frequency oscillator circuits and crystal-controlled second-converston oscillators. Antenna input: Connections for external systems. Controls: Main tuning, band-spread, bandswitch, bfo, antenna trimmer, crystal calibrator switch, AM-CW/SSB selector, rf gain, volume, ANL switch, selectivity, S-meter. Circuitry: Vacuum-tube, double-conversion superheterodyne. Price: $289.95.

Galaxy R-530 Receiver

Tuning range: 5 kHz-30 MHz. Selectivity: 2.1-kHz crystal lattice filter, 1.8:1 shape factor, SSB. Optional filters for CW (0.5 kHz) and AM (5 kHz). Sensitivity: 0.1 μV for 6 dB signal-plus noise-to-noise ratio, SSB; 0.05 μV, CW; 0.5 μV, AM. Stability: No more than 100 Hz (including 20% line-voltage variation) from turn-on. Antenna input: 59 ohms unbalanced. Controls: AM, USB, LSB; bfo tuning, preselector tuning, main tuning, frequency synthesizer tuning, meter switch (af/rf), af/rf gain control, band switch, blanker/rf attenuator control, selectivity, agc (fast/slow) switch, headphone jack, function switch (OFF, STBY, OPR, CAL). Circuitry: Solid-state dual-conversion superheterodyne. Price: $695.

Squires-Sanders SS-IBS Receiver

Tuning range: 3.5-26.1 MHz. Selectivity: (A), 8 and 32 kHz at 6 and 60 dB down; (B), 5 and 25 kHz at 6 and 60 dB down; (C), 2.5 and 5 kHz at 6 and 60 dB down. Sensitivity: Less than 0.5 μV for 10 dB S + N/N in 2.5-kHz bandwidth (unmodulated carrier in SSB mode); less than 1 μV on 7-7.5-MHz band. Stability: Less than 500 Hz drift after turn-on; less than 100 Hz in any 1-hr. period thereafter, including ±10% line-voltage variation. I.f. and image rejection: Greater than 60 dB. Controls: Bandswitch, rf gain, tuning (manual and motor with digital readout to nearest kHz), selectivity switch, af gain, bfo tuning, AM/LSB/USB/bfo switch, OFF/STANDBY / OPERATE/CAL switch, ANL/noise-silencer controls, agc: SLOW/FAST. Circuitry: Vacuum-tube, double conversion. Price: $1255.

Drake SW-4A U-Band Receiver

Tuning range: 0.150-26.050 MHz. Selectivity: Bandwidth of 5kHz at 6 dB down; 16 kHz at 60 dB down. Sensitivity: S/N ratio of 10 dB with input signal of 1 μV when input signal is modulated 30% with 400 Hz. Stability: After warmup, will not drift more than 100 Hz. A ±10% change in line voltage will cause frequency shift of not more than 100 Hz. Antenna input: Connections provided for external systems; nominal input impedance 52 ohms, Controls: Main tuning, bandspread, volume, tone, preselector (changes tuning of antenna and rf circuits), S-meter. Circuitry: Vacuum-tube and solid-state dual-conversion super-heterodyne. Price: $289.00.

More Information

Here's a list of short-wave receiver manufacturers,

Allied Radio Corp., 100 N. Western Ave., Chicago, Ill. 60680

Ameco, Div. of Aerotron, Box 6527, Raleigh, N.C. 27608

Eico Electronic Instruments, 283 Malta St., Brooklyn, N.Y. 11207

Hallicrafters, 600 Hicks Rd., Rolling Meadows, Ill. 60008

Hammarlund Mfg. Co., Mars Hill, N.C. 28754

Heath Co., Benton Harbor, Mich. 49022

Lafayette Radio Co., 111 Jericho Turnpike, Syosset, LI., N.Y. 11791

National Radio Co., Inc., 37 Washington St., Melrose, Mass. 02176

R.L. Drake Co., Miamisburg, Ohio 45342

Radio Shack Corp., 730 Commonwealth Ave., Boston, Mass. 02215

Squire Sanders, Inc., Box B, Liberty Corner, N.J. 07938