Review: Alinco DJ-X1 Scanner Copyright (C) 1993 by Michael Schuster Last revision: 14 Sep 93 (schuster@panix.com) INTRODUCTION Back when the ICOM R-1 wideband pocket scanner had just been released (except in North America) there was talk that another manufacturer of amateur radio equipment, Alinco, was readying a similar model for sale. That scanner, based upon the design of the DJ-F1T 2-meter handheld, came to be known as the DJ-X1. Sized just slightly larger than the ICOM R1 in every dimension, and having similar capabilities, it attracted my interest after years of putting up with the R1's deficiencies: - poor filtering - lack of front-end AGC, causing severe overload problems - images and poor ultimate rejection due to mixing of spurs from the noisy synthesizer (fixed by the Raycom filter upgrade) - poor battery life using the internal 300 mAH battery pack - poor performance on HF The DJ-X1 has not been marketed by Alinco USA. Given the present regulatory climate in this country, it is unlikely that such a continuous-coverage receiver would ever be sold here. The only way to get one is to import it from another country (Japan or UK). After selling my R1 I ordered a DJ-X1, based upon a favorable review in ShortWave Magazine (UK) and positive comments from several DJ-X1 owners on the Usenet. Since most North American scanner enthusiasts are unfamiliar with this model, I was asked to write this review to fill that knowledge gap. The DJ-X1 is a very strange bird, as the following description will show. PRICE Since the DJ-X1 is not sold in the US, there is no reference point for selling price. At the time of this writing, British dealers usually charge between 280 and 330 pounds sterling ($420 - $495) which, not surprisingly, is basically the same price as the ICOM IC-R1. FIRST, AN APOLOGY This review is going to be sketchy in some areas (specifications, battery life, and actual measurements of sensitivity, selectivity, etc) as it is based upon only a short period of use. I will be as complete as I can in my assessment of this device without venturing into the area of speculation. SPECIFICATIONS Frequency coverage: 2-905 MHz guaranteed (tunes 100 KHz - 1300 MHz) Modulation modes: AM/FM narrow/FM wide Channel steps: 5, 9, 10, 12.5, 20, 25, 30, 50, and 100 KHz Current draw: MAX: 300 mA BATT SAVER: 24 mA Receiving system: AM/FMn: triple conversion FMw: double conversion EXTERNAL APPEARANCE AND CONTROLS Just as the ICOM R-1 resembles the "SAT" series of handheld ham rigs, so the Alinco DJ-X1 resembles the DJ-F1T and DJ-F4. While tiny, it has the solid feel that ham equipment has, and which [sadly] most consumer scanners lack. The case is heavy-gauge plastic and metal, the knobs feel sturdy, and the keypad legends are printed on the case where they will not wear off from friction. On top there is a standard BNC antenna connector, ganged volume/squelch controls, and a click-stop VFO knob. On the right side are phones/line-out and DC-in connectors; each with a permanently attached protective rubber flap. The power connector is a standard mini coax and nominal 9VDC, center positive. On the left is a large rubber pad having three indented buttons. These are "additional function" keys which are used in conjunction with the keypad. These F-keys are located exactly where the push-to-talk switch would be on a ham rig, giving the visual impression that this is, in fact, an HT rather than a scanner. I suppose that in certain situations this could be a plus. The width and height are just a touch larger than the ICOM R-1. Rather than having an internal battery pack, the DJ-X1 has a slide-on pack which clips to the back, and has the same height and width as the scanner itself. The battery is attached to the back of the scanner via a spring-loaded metal catch. This can be locked to prevent accidental release. The supplied 700 mAH pack is hefty, and makes the DJ-X1 a full third fatter than the R-1. The DJ-X1 used to be shipped with a clip-on battery case which came empty (you filled it with nicads yourself). Perhaps in order to improve sales, current models ship with a sealed battery pack that is not user-modifiable. The belt clip screws onto the battery pack, since when attached it actually forms the rear surface of the scanner. There is also a loop for a (supplied) carry strap as with the R-1. Note that while there is a DC-in socket on the scanner itself, power connected there will NOT charge the attached battery. You have to use the external charging stand to do that. ACCESSORIES Other accessories supplied are a charging stand (with integral wall transformer according to country of sale), belt clip, carry strap, and two rubberized antennas. The antenna described as "low band" seems to be peaked for low-band VHF, high-band VHF, and to some extent 220. The "high band" duckie performs best on UHF and 800. There is considerable overlap, however, and Alinco seems to have recognized that no single rubberized antenna can hope to adequately cover the wide receive range of this radio. Neither antenna is adequate for shortwave. During my testing of this model I almost exclusively used the GRE all-band rubber antenna that I bought for use with the Yupiteru MVT-7100. On the bands that each Alinco antenna seems to be peaked for, they perform similarly to, or very slightly better than, the GRE antenna. Alinco sells a $20 vinyl case for the DJ-F1T which also fits the DJ-X1. It has clear vinyl overlays for the display and keypad, and cutouts for other controls and attachments. Its method of closure, which must be able to accommodate the different size battery packs that might be attached, is unique: the back consists of two mating surfaces of Velcro-style material that can maintain whatever size that might be necessary to make the case fit snugly with the scanner as currently configured. It works. Also, the fill-your-own battery case that used to be standard equipment with this scanner, is still available as an accessory for the DJ-F1T and DJ-F4 scanners from Alinco USA. DISPLAY The tiny speaker is front-mounted near the top of the scanner. The speaker grille is flanked on either side by a column of push buttons (2 on the left side and 4 on the right). Below the speaker is the tiny LCD display. The contents of the LCD panel gives the first hint at how odd this scanner really is. First, the numerals are tiny, and of different sizes. The hundreds digit is smaller than the other two, and there is no direct readout of increments below 5 KHz. Instead, truly minuscule LCD segments bearing the legends "50", "25", and "75" are activated when needed. So 476.3875 would be displayed as little 4, plus large 76.38, followed by an activated "75" bar. To the left of the hundreds digit are two smaller digits which indicate the memory channel number. Frequencies about 1000 MHZ are indicated by the illumination of an "over 1000" bar, not by a "1" digit on the LCD. There are indicators for numerous scanner modes and functions, which are equally tiny as well as cryptic. For instance, narrow FM mode is indicated by a symbol which looks like a boat anchor. AM modulation is indicated by the letter "A", and wide FM mode by the illumination of both the boat anchor and "A" symbols. The scan/search speed is indicated by the number of segments in a tiny pie chart. One segment means 10 cps, two means 15, and three mean 20. A small "V" or "M" (actually \/ and /\/\) indicates whether one is in VFO or memory mode. Tiny additional LCD segments (bars, triangles, numerals) are added to indicate which memory bank is active. Also, there are one or two-letter indicators for battery saver and duty cycle, and for other functions that are not worth cataloging here. Curiously, although there is a defeatable "beep" which sounds when you press any of the buttons, its on/off state is not indicated anywhere on the display. The fact that the scanner is scanning or searching is indicated only by the fact that the decimal point of the frequency display is blinking. There is also a horizontal signal strength meter like that on the Yupiteru or ICOM handhelds. I did not evaluate its accuracy or linearity. The LCD display is sidelit, and like the Yupiteru MVT-7100 the main keypad below it is translucent so that it is illuminated when the dial light is active. The dial light has two modes: a standard "push and it stays on for a few seconds" mode, and a novel "automatic" mode. In the latter situation the dial light goes on whenever you manipulate the controls. This is a great idea, and I wish the other manufacturers would do something like this! KEYPAD The main keypad has tiny buttons but they are well-spaced and not recessed as on the ICOM, so that they are easy to find and press without error. The "ENTER" button is not in a logical place, and its label is not highlighted in any way as to make it easy to find. Most of the buttons on the keypad, and on the columns of buttons aside the speaker, have dual functions. The main function is printed in white above the button, and the secondary function printed below in blue. To activate the second function you simultaneously depress the first "function" key on the left side of the scanner. There is no indication on the LCD that you have activated any of the "F" keys. Each of the three "F" keys may be used in conjunction with the VFO knob to rapidly increment one of the three MHz digits. But there is no indication on the LCD as to which one you are about to change, until you actually see it happen while turning the VFO knob. OPERATIONAL FEATURES The scanner has the standard set of functions one would expect from this type of product: scanning stored memory channels, limit search, priority channel, manual entry, and moving data between the VFO and memory channels. There are 100 memories which are arranged into three groups: two "scanning memory" banks of 40 channels each, and one "search storage" bank. The two 40-channel scan banks cannot be linked. Any number of the 40 channels in each (referred to as the main and sub bank) may be individually locked out. The other 20 channels are used in an unusual way. The first 10 (L0, U0, L1, U1, etc) store the limits and modulation of the five available search banks. They do not store the channel increment you have selected; more on that later. The other 10 channels are filled automatically during a frequency search. This function is essentially useless, as the DJ-X1 lacks the "zero-matic" or "center-track" tuning found on Uniden or GRE scanners. So search may stop well short of the actual frequency of a signal found during search, and each break of the squelch fills another of the 10 scratchpad memories. When these memories fill, they are re-written, and there is no provision to prevent duplication of entries. There is no provision for locking out individual frequencies (such as those where birdies or uninteresting signals exist) from being received during a frequency search. The manual does not state whether memory channels are volatile (i.e. if they will eventually get cleared some time after the batteries die or are disconnected). In my use of the scanner it seems that the memory channels, operational settings, and current mode are probably stored in an EEPROM and therefore do not disappear when the batteries run down. This is a plus over the IC-R1 which uses a secondary lithium cell to back up the memories for a few days after the main battery is exhausted. Entering frequencies on the DJ-X1 is done in a most unusual way. It is not difficult, but it takes some getting used to. Basically you cannot directly key any value smaller than 10 KHz. You must enter a frequency nearby, and then use the VFO knob to increment to the actual frequency. Best shown by example: to enter 151.505 MHz, for instance, you would select a channel increment of 5 KHz (see below) and then key in the following: 1 5 1 . 5 ENTER and the display would indicate 151.50; from there you would click the VFO knob upwards one notch so that the little "50" bar is illuminated. Voila ... 151.505 MHz. The DJ-X1 has a full range of channel increments from 5 to 100 KHz. Selection of increment is pretty straightforward: press the "step" button and the currently active increment is displayed. Click the VFO knob up or down until the one you want is displayed, and then press the memory/VFO button to go back info VFO mode. The LCD then displays the tuned frequency (which may have changed in order to conform to the new step you have selected). This much like the MVT-7100. Initially it seemed that manual selection of step (increment) size is ignored when the scanner searches between frequency limits. The scanner insisted upon choosing a step size based upon defaults that are stored in ROM, and which almost always seem to be 5 KHz. So if you choose to search for police signals between 470.6375 and 471.6625 MHz, for example, you will be able to enter these frequencies accurately into an Ln/Un memory pair. But when you activate the limit search (called programmed scan) between those two frequencies, the scanner searches in 5 KHz increments, not 12.5 as would be assumed given these frequency limits. As a result, it searches in between the actual assigned channels. It turns out there is a way around this. Buried in the manual is a small note that FUNCTION-0 on the keypad toggles the state of the auto mode (and increment) select function. Not only is the zero key unlabelled as to the presence of this additional function, but the LCD display does not give any indication as to the status of autoselect mode. But using FUNCT-0 to turn off autoselect (the default ... you guessed it ... is "on") allows you to limit search using the channel spacing you have first selected using the keypad and VFO knob. You must also change the modulation mode if necessary. Granted you must select the increment manually every time you use a different pair of search limits, but the actual number of keystrokes compared to, say, the AR-1000, is still much less and the steps are easy to master. There are two ways of doing a frequency search without upper and lower limits (i.e. pick a frequency, modulation, step size, and direction and just keep going). In these functions the scanner will use the step size you have chosen regardless of the status of the automode function. SHORTWAVE PERFORMANCE First, let me dispense with the issue of medium and shortwave reception. No "continuous coverage" scanner will perform like a dedicated shortwave radio costing even half its price. The DJ-X1 is no exception. However, it does have adequate sensitivity to receive more powerful international shortwave broadcasters when attached to a reasonable telescopic whip antenna. It will even receive powerhouse signals using the GRE rubber duckie, which puts its sensitivity in the class between the AOR AR-1000 and Yupiteru MVT-7100. Filtering in AM mode is very broad, and many signals suffer from gross bleed-over of signals in adjacent channels. The product specifications are guaranteed only down to 2 MHz, and my limited testing bore that out. There are two reasons for that conclusion: first, sensitivity drops off dramatically below 5 MHz or so. Second, the lower you go, the more the set is plagued by powerful internally-generated birdies. So, the DJ-X1 will be useful for casual shortwave listening; nothing more. "SCANNER BAND" PERFORMANCE Sensitivity/selectivity on the other bands is adequate; much better than the ICOM R-1 but not in the same class as the GRE PRO-43 or Yupiteru MVT-7100. In Manhattan I found that, like many scanners, the UHF band was filled with intermod from paging transmitters. Again, this was somewhat better than the R1, but using the Alinco can be challenging under these conditions. At home in tue suburbs, it was much better behaved, but I did find snippets of signals where they didn't belong in various bands and out- of-band segments. As indicated before, the DJ-X1 will scan/search at 10, 15, or 20 increments/second. The manual warns that weak signals can be missed at either of the two faster speeds. I found this to be true, but noted also that it seemed to occasionally miss strong signals as well. This, however, may be related to the next problem I had with the scanner - "stuttering" while scanning memory channels. After programming about 20 local frequencies into the main scan bank, I put it into memory scan mode and listened. The scanner seemed to be "stuttering" - that is, it kept getting tripped up on several of the programmed frequencies even when no transmission was present on those channels (as verified by an MVT-7100 programmed with the same frequencies). Since there is an obligatory 2-second delay after squelch is broken, this frequent interruption greatly reduces the effective scan speed. Raising the squelch threshold made it stutter less, so I began to think the Alinco was stopping on false signals like the R1. But the phenomenon was quite different, and not consistent. Stepping manually through the memory channels I found that the squelch would sometimes open for a fraction of a second when moving from a channel having a frequency in the VHF-hi range, to a channel having a frequency in another band. For instance, if CH#0 had 151.925 and CH#1 had 450.800, moving from CH#0 to CH#1 would sometimes cause a noise burst, while moving from CH#1 to CH#0 would not. I thought at first that the VFO was generating noise bursts when stepping through adjacent channels required it to make big jumps in tuned frequency. But the intermittent nature of this phenomenon led me to eventually abandon that theory. Listening to the memory channels having VHF-hi frequencies with the squelch open, I occasionally heard faint interference in the background, sounding something like the video carrier of broadcast TV. My working theory is that this subtle intermod interference is intermittently breaking squelch on VHF-hi, and interrupting smooth memory search in the process. AUDIO The R1 showed that passable audio was possible even when using a tiny speaker. Audio on the DJ-X1 is not as good as on the ICOM. While the speaker is the same size, it provides sound which is more restricted in frequency range and somewhat more distorted. It is equally poor through headphones connected to the jack on the side of the radio. This is really not too objectionable when listening to the bark of a police dispatcher, for instance, but further limits the useability of the scanner for broadcast listening (shortwave or local programming). SUMMING UP I began by introducing the Alinco DJ-X1 as an "odd bird". I hope that my rather verbose description of its configuration and operational characteristics have made that statement clearer. The search for the perfect pocket scanner, sadly, still continues. Any wideband scanner, particularly one with continuous coverage, is an expression of the art of compromise. Any ultraminiature scanner is also built with design compromises. So ultraminiature wideband continuous-coverage scanners like the Alinco DJ-X1 and ICOM IC-R1 are doubly compromised in their design. I think that overall the DJ-X1 is a more useful receiver than the IC-R1, especially since filter upgrades for the R1 are no longer available. Certain aspects of its operation (stuttering during scanning past some frequencies, and arcane displays and operational logic, for instance) detract from its better RF performance. If size is your overriding consideration, I suggest that you compare both receivers carefully before deciding.