Akai AT-93 Tuner
As I began to examine the features of the attractively styled AT-93 AM/FM tuner from Akai, my first reaction was one of moderate resentment. I resent equipment that tries to think for me instead of letting me do things myself. The Akai AT-93 is one of those tuners that decides which of its two antenna inputs provides the best signal, whether it should be in wide or narrow i.f. mode, whether to employ one of its two levels of stereo blend circuitry to reduce noise for weak-signal stereo, and whether to activate its high-cut filter to further reduce noise or other interference. Upon closer examination, and a brief reading of the owner's manual, my resentment quickly turned to admiration. Akai had the good sense to allow a user to defeat those decisions by simply touching any one of several manual-override buttons. Here, at last, was a tuner that offered the best of both worlds: Optimum automatic operating modes for those who simply want to sit back and listen to the best FM reception available, even during rapid DX-ing, and manual selection of all modes for inveterate experimenters and button-pushers.
The Akai tuner has a pair of antenna inputs, each of which can be connected to a separate antenna. For example, you could have two outdoor antennas facing in different directions. The AT-93 employs a comparator circuit that samples the incoming signals and routes the stronger signal to the tuner circuitry when the station is first tuned in.
As mentioned, the microprocessor-equipped AT-93 judges signal quality to determine the best setting for i.f. bandwidth, stereo blend (two levels plus mono), and high-frequency cut. These settings (or your own overriding ones) can be stored in any one of the tuner's 20 memory presets. There's an unusual feature associated with these, presets: The Akai has a sequential station-call function for automatic selection of up to three different stations. The desired stations are memorized and then recalled when the tuner is turned on via a timer. This function is extremely useful for absentee recording. If you set the external timer to switch on and off as many as three times, the unit will be tuned to preset 20 the first time, preset 19 the second, and preset 18 the third. In addition to the sequential station-call tuning just described, there are several other ways to tune the AT-93: You can manually select presets, auto-scan through the presets, auto-scan to the next station up or down, or tune up or down in 0.1-MHz increments.
As for the AT-93's circuitry, it employs a dual-gate MOS-FET in the r.f. stage and a phase-locked-loop, quartz-synthesized tuning system. Separate power-supply circuits are used for the digital and audio sections.
Control Layout
At the left end of the slim, black front panel is the power on/off button. Operating-mode buttons for antenna selection, i.f. bandwidth, blend selection, and high-cut filtering come next. An "FM Auto" button selects automatic or manual FM-reception mode, while touching any of the other four operating buttons restores manual control of the previously automated function. The display area at the upper right of the panel shows tuning information as well as the various modes currently in effect. Pressing a "Preset Scan" button at the far right initiates scanning; pressing the same button a second time locks in the chosen station. Additional buttons along the lower left edge of the panel select muting, band, and the scanning mode. Next come the up and down manual tuning switches and 10 preset buttons. No "shift" key is needed to make these handle the 20 preset station frequencies; pushing any button twice switches it from the first decade (1 to 10) to the second (11 to 20). Above the preset buttons, appropriate green or red LEDs illuminate to show which decade has been chosen. A "Memory" button at the lower right corner completes the front-panel layout.
The rear panel is equipped with two 75-ohm coaxial antenna connectors, spring-loaded terminals for hooking up the separately supplied AM loop antenna, and a pair of audio output jacks. The 75-ohm coaxial receptacles are not quite the standard F-type used in the U.S. for video and other r.f. applications, but fortunately Akai provides the necessary adaptor so you can connect a standard coaxial transmission line.
Use and Listening Tests
I started auditioning the Akai AT-93 with the unit set to its automatic tuning mode-the one in which the tuner's own microcomputer decides which antenna, i.f. setting, blend mode, and high-frequency cut to use for each received signal. The two antennas employed were my outdoor multielement antenna and an amplified indoor antenna. For each of the 53 usable signals I was able to pick up, I deliberately reset all of the parameters that the tuner had decided to use, one by one, to see if I could improve on the AT-93's choices. Of the 53 signals received, the tuner switched to mono on five of them because of weak signal strength. I decided that I could tolerate two of those five signals in stereo after all. In every other respect and for every other signal received, I could not outsmart or second-guess this tuner! It always chose the optimum operating parameters. Although this may have wounded my ego a bit, it sure speaks well for the way the built-in microcomputer decides to program this amazing unit.
Setting up my 20 presets was easy-a lot easier than on some tuners and receivers I've tested. I also tried out the absentee recording capability. While the AT-93 was in my listening room, I had to be away for two days. On both days, two different stations were broadcasting programs I wanted to record. I only had a one-event timer, so I got someone in the lab to manually turn on the tuner for the second event. Sure enough, the second preset frequency appeared, just as promised. As an FM tuner fan from way back, I was truly astonished by the performance this Akai component delivered-especially since its price is about half that of several tuners I recently tested and listened to that didn't perform as well. If you are looking for the right FM tuner for your system and care about good FM reception, I can recommend the Akai AT-93 without any qualifications or reservations.
