Equipment Reviews, January 1998
Last Updated on October 13, 2005 by Ralph Brandi
The Drake R8B Communications Receiver
A frequent complaint that SW listeners and DXers have had for years has been that receiver manufacturers don’t listen to what hobbyists say they need and want in receivers. I’m pleased to say that the R. L. Drake Company has invalidated that argument with their R8 series of communications receivers.
The initial offering, the R8, was a good receiver as regards basic performance, but had several ergonomic drawbacks, most notably the “carousel” or “step-through” method of mode and IF filter selection as well as the location of the passband shift and notch tuning knobs. These shortcomings were duly noted and addressed in the R8A, which followed the original by four years. The R8B represents a refinement of the “A”, with the major alterations being the incorporation of the sideband selectable synchronous detector that was introduced in the SW8 and increasing the number of memory channels from 440 to 1000. All the other feaures of the R8A were retained.
A Complete Receiver
The Drake R8B is fully configured and ready to go straight out of the box, with the exception of a decent antenna. That’s one reason that I consider the receiver to be such a good value, as there are no accessories that are actually “necessities”. The R8B is a general coverage receiver, with a frequency range of 100 to 30,000 kHz. The frequency coverage can be expanded to 35-55 and 108-174 mHz with the addition of the optional VHF convertor. All reception modes are supported including RTTY and FM. The R8B has a large array of features that make it very flexible, but the control interface is uncomplicated and easy to learn. This is not a receiver that requires keeping the manual alongside to use. The controls, filters and audio response permit all types of listening, from critical DX’ing to “arm chair copy” program listening. The R8B also has several types of control available, ranging from hands-on bandscanning, memory channel scanning and remote control via a computer.
An examination of the back panel shows thoughtful design, with attention to flexibility. There are two antenna inputs, one for coaxial cable and one for either a high or low impedance wire antenna. These antenna inputs are switchable from the front panel. There is a jack for an external speaker and switch to select either the internal, external or both speakers. There are two line level audio outputs for tape recorders, audio processors or decoders. A DIN connector provides the control line from the timer for unattended recording. There are connectors for an external DC power source (11-16 volts at 2 amps) for portable/mobile use. The AC cord is detachable (a welcome improvement over the original R8) and a switch is provided for using the receiver on a variety of AC voltages. The easily broken plastic elevation feet on the R8 have been replaced with a sturdy metal tilt bail.
This well thought out design also extends to the front panel. The R8B has been provided with nearly all of the interference-fighting features that a DX’er could want. There is a notch filter (which operates in the audio stages of the receiver) that provides a very sharp notch of up to 40 dB over the frequency range of 500 to 5000 Hertz. There is a passband shift control to allow for adjusting the passband of a selected IF filter for maximum intelligibility/fidelity. The R8B includes a full range of IF bandwidths: 6, 4, 2.3, 1.8 and 0.5 kHz @ -6 dB, all with shape factors (measured at –6 /-60 dB) of less than 2:1 with the exception of the 0.5 kHz filter, which is rated at 3:1. The new synchronous detector not only yields low-distortion audio reproduction, it can also be an aid to interference reduction due to its high degree of alternate sideband rejection. There is a 10 dB attenuator as well as a 10 dB preamp, either of which can be selected as necessary to handle strong or weak signals. The AGC has been improved for better response on SSB signals and either a fast or slow decay time can be selected. The AGC can also be configured to provide an “AGC Off” postion, for those who desire that listening option. For program listeners, the final audio amplifier provides a roomfilling 2.5 watts of power output and the tone control is a major improvement over that of the R8.
Operating Flexibility
The R8B has a very intuitive control interface and a variety of control options. The smoothly turning main tuning knob (although I was sorry to see that the heavy metal knob on the R8 has been replaced by a plastic one on the R8B) can be set to tune in 1, 0.1 and 0.001 kHz steps. The Up/Down tuning buttons will tune in 5 (9 or 10 kHz in the MW band in AM mode) or 100 kHz steps–quite handy for stepping through the international broadcast bands or for rapid tuning. The numeric keypad can be configured to allow for input in either mHz (decimal required) or kHz format. Unfortunately, the pushbuttons on the R8B retain the rubbery feel of the original R8. There are 1000 memory channels and each channel can be labeled with an eight character alphanumeric tag. The memory channels can be organized into “lists” of ten consecutive memory channels per list. Once configured, these lists can be linked for scanning purposes.
For those who prefer more automated methods of tuning, the R8B offers nine different scanning modes. Scanning can be of unlocked memory channels, “lists” of frequencies or between two user-defined frequency limits. Scanning can be set to either stop on active frequencies, pause for 5 seconds on active channels or hold on active channels until the carrier drops for five seconds. There is a RS-232 computer interface which permits remote control of all receiver functions, with the exception of those functions which are normally controlled by the front panel rotary controls (with the exception of tuning).
The R8B has two clocks which can be set to two different time zones and two independent On/Off timers for unattended program recording. The main display can be toggled between showing the tuned frequency or either of the two clocks. The user can set the level (in three steps–off, dim and bright) of the display/S-meter illumination for both the power on and off states. This is a small detail, but it shows the attention to flexibility on the part of the designers.
Operation/Performance
Operation of the R8B is in a word, flawless. Now that there are separate pushbuttons for mode and bandwidth selection, tweaking the receiver for best reception under varying conditions is quick and easy. Selecting some of the features, such as AGC times, preamp, etc. does require pressing the “Function” button to toggle the assignment of the six pushbuttons below the display window, but this is much simpler than the hierachical menus used on the AOR AR-7030. Using the selectable sideband feature of the synchronous detector involves selecting the sync detector by pressing the “AM/SYNC” button (if the receiver is in AM mode) and then pressing either the “LSB” or “USB” button to select the desired sideband. Returning the mode to regular LSB/USB requires two keypresses of the “AM/SYNC” button–one to put the radio into double sideband sync mode, the other to return to regular AM mode. The sync detector locks quickly and holds sync very well during signal fades. The behavior of the sync detector during passband tuner adjustment is very civilized as well. The sync loses lock for a split-second as the PBT control is turned, but this is manifested as a flashing of the sync indicator light–none of the howls and growls that accompany this manuever with the original R8.
I have always extolled the virtues of selectable-sideband synchronous detectors due to their ability to reduce adjacent channel interference. The R8B does a very effective job in this regards. My practical test for this feature is to tune to the CHU time signal which is transmitted as USB with carrier. With the R8B in LSB Sync mode, only the time pips (no voice announcements) were faintly audible. Listening tests on the international broadcast bands confirmed the detector’s usefulness. I have been less convinced of the other touted benefit of sync detectors–their ability to reduce distortion due to fading. However, I am pleased to relate that there is a definite audible benefit to using the sync detector with the R8B. It not only reduces the distortion due to selective fading, but also seems to reduce overall audio distortion. Subjectively, the overall sound quality of the R8B seems much better than the R8. There is less noise and the tonal range is fuller, even with just the built-in speaker. The R8B really shines when a good quality outboard speaker is connected.
The sensitivity of the R8B is more than ample–it is rated at 1.5 microvolts in AM mode, dropping to 1.0 microvolt with the 10 dB preamplifier engaged. On my R8 (which may be due to my location rather than the receiver itself) switching on the preamp introduces hum. This does not happen with the R8B. Selectivity is excellent, with ultimate selectivity rated at 95 dB. The variety of filter bandwidths available, coupled with the passband tuning control, allows the user to achieve the optimum balance between interference rejection and preservation of intelligibility. The only specification that is not top-notch on the R8B is the third order intercept point, which is listed as -20 dB at 5 kHz signal spacing. However, the filter bandwidth used for this measurement is not specified, so comparison with other receivers is impossible. I must say that I was unable to detect any instances of receiver overload during my time with the R8B.
Time To Upgrade?
With the series of upgrades that Drake has made in the R8 line, the R8B has evolved as a world-class tabletop receiver. In my side-by-side comparison with a very early R8, the R8B wins hands down. In short, the R8B owner won’t have to make any apologies for his equipment–if the signal is propagating, there’s an excellent chance this receiver will snag it. For those hobbyists looking for a receiver in the one to two thousand dollar price range, the R8B warrants serious consideration. I’d like to effusively thank fellow NASWAn John Wagner for loaning me his newly purchased R8B for this review. He had it shipped to me first–now that’s dedication to the hobby! Hmmm, I wonder if he’d notice if he got my R8 instead? The street price for the R8B is below $1200. Conatct the R. L. Drake Co. at 230 Industrial Dr., Franklin, OH 45005; (513) 746-4556; www.rldrake.com.
Hardware Bits
by Alan Johnson
MFJ 270 Lightning Surge Arrestor
MFJ Enterprises has introduced the MFJ-270 Lightning Surge Protector to protect radio equipment from damaging static electricity and lightning induced surges (but not direct lightning strikes). The ‘270 is designed to be used with 50 coaxial cable and has an insertion loss of less than 0.1 dB. It can handle transmitters up to 400 watts PEP and can be used at frequencies up to 1000 MHz. It sells for $29.95. MFJ Enterprises can be reached at 300 Industrial Park Rd., Starkville, MS 39759; (800) 647-1800; www.mfjenterprises.com..
Grove SP-200B Sound Enhancer
Although the packaging is the same, the SP200B has a completely new layout which is designed to provide lower noise and distortion product reduction. This outboard filter/amplifier/speaker combination sells for $199.95 and is available from Grove Enterprises, P.O. Box 98, Brasstown, NC 28902; (800) 438-8155; WWW.grove.net.
New Products From Kiwa Electronics
Kiwa has introduced a couple of accessories for the Pocket Loop antenna. The first is the Pocket Regeneration Module (PRM) which increases the gain and reduces the bandwidth of the Pocket Loop. The gain increase is to the order of 18 to 24 additional dB of gain. The PRM is usable to 10 MHz with the whip antenna coupler and to 17 MHz if a direct antenna conncetion is used. It sells for $48.00 and attaches to the front vertical surface of the Pocket Loop. The second is the Pocket Loop Car Radio Coupler that connects between the car radio and car antenna and allows the Pocket Loop to enhance weak signal reception. It uses Motorola type connectors (the usual car radio standard) and sells for $35.00. Kiwa Electronics, 612 South 14th St., Yakima, WA 98902; (800) 398-1146 (orders) or (509) 453-5492 (technical information); WWW:wolfe.net/~kiwa.
New Products From MFJ Enterprises
I received a press release about the MFJ-118 JUMBO LCD clock. It displays a single time zone in either 24 or 12 hour format. The clock digits are 1.25 inches high for easy visibility. The year, month, day and day of the week (in either English, Spanish, German or French) are also displayed. It runs on a single AAA battery and sells for $29.95. The overall case size is 5 1/2 x 2 3/4 x 3/4 inches. The press release doesn’t mention backlighting.
The 1988 MFJ catalog lists several new goodies. The one that caught my eye is the MFJ-1048 passive preselector to provide an extra measure of front-end selectivity over the range of 1.6 to 33 mHz. It has a RF sensing switch allowing it to be used with transceivers. It sells for $119.95. The $99.95 MFJ-1046 is for receive-only applications. I also spotted the MFJ-762 step attenuator. It provides up to 81 dB of attenuation in one dB steps. It is designed to work with 50 ohm loads, uses BNC connectors (SO-239 adaptors are supplied) and sells for $69.95. MFJ Enterprises can be reached at 300 Industrial Park Rd., Starkville, MS 39759; (800) 647-1800; www.mfjenterprises.com.
JPS SPEC-12 Spectrum Analyzer Software
This $75 program/interface combo turns a PC into an audio spectrum analyzer when used with the JPS NIR-12 noise reduction/filter. It graphically displays the action of the NIR-12. It can also be used to set up the bandpass filter for data modes. JPS Communications, P.O. Box 97757, Raleigh, NC 27624-7757; (919) 790-1048 (Tech line), (800) 533-3819 (Orders); www.jps.com.
New Receiver Kit From Ten-Tec
The model 1254 receiver kit has been announced in a recent Ten-Tec ad. It is a dual-conversion superheterodyne design with a digital display and 15 memories. It requires 13.8 volts DC for operation and an AC power supply is included. It measures 2.25 x 6.5 x 6.5 inches (HxWxD) and sells for $195. The building time is listed at 25 hours, so it’s probably not a kit for beginners. Call (423) 453-7172 for a catalog or (800) 833-7373 to order. The mailing address is T-Kit, TEN-TEC, Inc., 1185 Dolly Parton Pkwy., Sevierville, TN 37862. The Website is www.tentec.com.