Review of Radio Shack Accurian 12-1686 HD receiver by Bob Foxworth - in 4 parts
begin part 2 of 4 The rear of the receiver has a 5 VDC barrel jack, a 1/8 inch mini phono jack for Aux In, two pushclips (marked + and Gnd) for the two AM loop wire pigtail leads, and a Fe. F connector for the FM antenna the user chooses. There is no internal antenna provided. The pushclips are like those found on cabineted loudspeakers. The front of the receiver has the following functions: Power (push on/off), LCD display panel with blue backlit characters, rotary volume knob which also supports pushing in for mode (2 AM, 2 FM and Aux in). The 2 AM or FM ranges support hearing two pretuned stations on each band. The volume adjust is detent step rotary tuning, and a bar graph lights up when the volume knob is being changed. The Aux In is a good match for the earphone jack of a hand held digital recorder and provides good sound for one of these devices. Front panel push buttons also include "preset/store", channel-, channel+, tuning-, tuning+, DSP, and Clock. The preset saves your favorite frequencies but again do not survive a removal of the power cord from the wall. Channel mode selects previously preset stations and tuning mode selects any frequency by stepping up or down (10 kHz steps) or can be held in to go to search mode. DSP has five settings, "jazz" "pop" "classic" "rock" and "none" which apparently just adjust the eq and rolloff for different types of music. I believe their usefulness is marginal and to me is somewhat cosmetic as it does not affect the RF environment. The clock displays date and time (12-hour) in an all numeric format on the LCD panel. When AC power is disconnected, the clock does not store the time, and does not reset from any HD data stream, but must be re-keyed each time the AC plug is connected. The clock shows if no "artist" data is being sent. The radio will, however, store the last AM or FM frequency chosen, if the power is removed and reapplied. As the intention is to have the user operate the set with the panel power pushbutton ( a relay click is heard) this should not be an issue. A mini-phono headset jack is provided on the front panel, which mutes the speakers, and provides an easy way to get audio recordings from the set. I did not, as of now, attempt using the remote, as it would not add to the electronic behavior of the radio. Radio reception. Testing was done in northwest Tampa. With no AM antenna connected, my locals on 620, 820 and 970 are heard weakly, say s-3 to s-4, and 570 at threshold level. Maybe 10 - 15 dB boost can be had by holding the finger next to the clips and inductively coupling. Using the loop gives good level on these local AM signals but a faint background noise in analog mode is heard. Rotating the loop creates maybe 20 to 25 dB of nulling when the loop is "upright". Laying the loop "flat" reduces pickup substantially. The manual vaguely refers to repositioning the antenna if the signal is weak, but has no explanation of proper loop positioning. Many "open" (daytime) AM channels showed varying types of slight to substantial complex noise, which defies simple description, but serves to partially mask weak AM signals. Test frequencies such as 590 or 640 (Habana, Cuba), WRZN 720 or WWBF 1130 were heard with substantial degradation in s/n ratio compared to reception with test analog receivers. The type of noise would vary by frequency, being birdies, rumbling or grinding. The test for sensitivity on these weak signals showed many were uncopiable or at marginal audible copy, when they could be copied with little difficulty on sets such as the dx398 "barefoot", due apparently to the reduced antenna gain and the higher noise floor. There is a very long AGC attack time and when the freq is step-tuned, the new frequency is muted for over a second and slowly rises in volume. Listening to frequencies where several signals are present, with pronounced beating, yields a pumping, chuffing irregular sound that makes hearing the audio difficult. Tests were done using a R-S 15-1853 loop. This is the circular tuned loop that was sold a few years ago. It was possible to get a boost in signal when this loop was near-field coupled to the Accurian's loop, but the tuning was not sharp or distinct, and had to be adjusted carefully and slowly, as if the front end of the Accurian was almost "fighting back", an effect I have never seen before and find hard to describe. I have not yet attempted to completely substitute a different loop in place of the stock one. There were some AM frequencies that were relatively noisefree and once, I had a hearable copy on Jamaica-720 a little after sunset. The summary for AM is that (1) I don't think this receiver is acceptable for DXing non-HD stations in analog mode and (2) does not have the sensitivity to get a usable signal from a HD station outside of its local coverage area. It gives a mostly acceptable quality for local, strong non-HD AM signals. I did notice the artifacting on AM HD signals such as with the Limbaugh and other talk shows. I'd rate it as slightly annoying for any extended time. I foresee a marketing issue where a set buyer may believe that every AM signal will be received in the enhanced mode that HD offers, when in fact the great majority of AM signals may actually sound worse, due to operating non-HD and from the noise issues I experienced. end part 2 of 4 _______________________________________________ IRCA mailing list [email protected] http://montreal.kotalampi.com/mailman/listinfo/irca Opinions expressed in messages on this mailing list are those of the original contributors and do not necessarily reflect the opinion of the IRCA, its editors, publishing staff, or officers For more information: http://www.ircaonline.org To Post a message: [email protected]
