Alinco DJ-S41T Reviewed

©1997,2000, 2003 Bill Ricker, N1VUX, BOSTON
(Excerpts of © Alinco for review purposes.)

§ Impressions § Documentation § Technical § Accessories § Rumors and Ideas § Summary [sm radio]


I am again enjoying playing with the vest-pocket HT I bought recently (in between playing with the new TNC). This is a small radio. Not only will it fit in a shirt pocket, it will fit in a vest pocket or sport-jacket outside brest pocket.

I haven't found many repeaters that can hear me over Boston's loud background noise if I'm any distance away, but I can hit the fine NETARC machine from several miles out, so I think the radio is fine. I worked a guy in Hampton Beach NH via NETARC the first night. I have yet to figure out how practical it's going to be for joining the fox-hunt chat on 440 mobile (may need a passive-re-radiator on the window like cellphone users have for 800MHz -- no, I don't want a new dual-band mobile!).

This web page is so big because I think this radio is hamstrung by its user manual, so I've done a longer one than it came with.

Update: Note that this page was authored in 1997 when the DJ-S41T was new,
the S11 was only a rumor, and the newer C1/C4/C5 weren't even idle speculation.
I have switched to using the DJ-C5 myself.
My DJ-S41 survived several falls,
but eventually lost an argument with a brick sidewalk. My DJ-S11 lost its antenna,
and the threaded insert for the belt-clip screw pulled out of one of them,
which I gather has happened to others,
but at the going price of $77-$88, still well worth having as a spare.
Other Year2000 updates right-adjusted like this.

2003: My C5 needs a new antenna *sigh*,
and I now have a pair of like-new DJ-S41T's,
which I picked up at a flea for $80 the pair,
with boxes (he was asking $60@, 2/$100, but it was late.)


Vendor Supplied

I've managed to figure out the DJ-S41T with precious little help from the "Manual" (although most of what I figured was there, hidden). What a stupid little "manual", it's all of one sheet, with some space wasted with cyrillic and japanese translations of the half-complete quick reference chart. But it fits in the vest pocket with the radio :-) The Alinco homepage has a good set of specifications as well as a nice prospective press release and first convention splash.

Update: I've heard rumors that more recent purchases
have included a better manual.

The Interactive Diagram
image cred: Alinco Home Page

[picture of radio]

My Documentation

Most controls are labelled "Button/Another". "Button" is what it does normally and "Another" (or F-Another) is what it does with F pressed. The Modes described under each key are cross-referenced further down.

Volume (On/Off)
Normal single-use volume control with associated power switch, seemingly nothing fancy. Except... if a button is depressed while turning it on, some mode changes. And AutoPowerOff can turn it off without touching the volume. but can you turn it back on without turning it off for real?
Call switches from VFO or Memory to Memory-C, the calling channel. You can tell which you're in since the Calling channel when in use from Call shows as C in the memory channel number, rather tha c.
F-Bell sets the alarm which will indicate if something came in. I think it's supposed to beep, but maybe only if it gets the 1750Hz tone.
On-Call toggles between which of a 1750 tone or a rising "alert" sweep tone will be sent as as an outgoing call when PTT+UP or PTT+DOWN is hit while transmitting.
Tapping Scan initiates up-scanning (same as holding Up). If in VFO, it will scan the whole band (including outside the FM bandplan). If in Memory, it will scan all 21 memories including C. While scanning, tapping some buttons are ignored, others just stop the scan.
F-Shift enters Offset Programming (or Shift) modefor the current VFO or Memory channel. Up/Down will let you modify the default 5MHz shift should you need to, but that's unlikely. Tapping F-Shift in Shift mode will toggle three-ways between simplex with no shift indicator in the LCD, tx-up showing [+], and tx-down showing [-].
Note that if done on a memory channel, it will NOT be saved unless them memory channel is re-written from itself before you change off the channel. This may be a feature, it lets you test a change without committing to it.
On-Scan is not documented as doing anything.
Other Shift-related combinations: PTT-Scan/Shift is low power toggle, and Moni-Scan/Shift is reverse (input) monitor.
Tapping Lamp turns the light on for however long it feels like.
F-APO engers auto-power-off mode, which sets (up/down to set, PTT to save) the number of seconds of non-receive that will elapse before it shuts down.
On-LAMP will toggle whether the light stays turned on until you tap it off again or goes out on its own.
Down decrements the frequency by the current increment (step), see under "Up".
F-Tone enters CTCSS Tone Selection mode. Up/Down change the tone; while in tone-select mode, F-Tone toggles tone on or off, [T] appears on the LCD when on. PTT to exit.
Held, Down will initiate a scan, like SCAN only downard.
Modes: In most modes, Up and Down select whatever parameter PTT will save.
PTT+DOWN: Pressing up or down while transmitting with PTT will SEND either a 1750Hz tone or a rising sweep tone (depending on the mode setting) as a call.
On-DOWN turns the "stand-by beep" or courtesy tone off.
The up button increments the frequency by the current increment, which is set by F-Step's mode, in which Up/Down adjust the step; 25kHz, 50k, 100k as 10, 150k (as 15), 200k (as 20). Note that the displayed step sizes are not intuitive. Traditionally, 25>20 but "20" is the biggest step and "25" is the smallest.
Held, Up will initiate an upward scan, same as SCAN, except taking longer.
Modes: In most modes, Up and Down select whatever parameter PTT will save. Tapped during Scan, will stop it on current freq (VFO or memory).
PTT+UP: Pressing up or down while transmitting with PTT will SEND either a 1750 tone or a rising sweep tone as a call.
On-UP turns the "stand-by beep" or courtesy tone On. The unit will can send courtesy tones, possibly useful when simplex or if the repeater doesn't but you want to. Probably rude when on a repeater that has courtesy tones already, as it makes you sound like a linked repeater system.
Toggles between using the single VFO and the 21 Memory channels.
F-MW starts memory-write mode from the current VFO setting or the current memory slot; use the Up/down buttons to pick which memory to write to (Memory number blinks), and finish with unshifted V/M/MW. Use F-MW while in MW-mode to erase the memory channel selected (blinking). (I guess you could use a PTT to cancel MW mode.) Writing from a memory slot to itself is how you save temporary changes (eg adjustments to shift or tone) which would otherwise be reset to their old values if you changed channels and came back.
On-V/M toggles the unit into/out-of the mode used on the non-programmable business band model: fixed channellized by channel number, you only see the channel numbers. Not terribly useful for hams, who ought to know their frequency...
Push To Talk. Does what you expect most of the time, push it and you talk. It will display the xmit frequency if it's legal, or OFF if it's offset out of band.
PTT exits many of the modes.
PTT enables SHIFT to toggle LOW power (50mW or +17dBm)/regular (340mW / +24dBm).
There is no documented F-PTT or On-PTT function.
Monitor bypasses the squelch, so you can hear anything down in the noise.
This is used for the mandator listen-before-talk as specified in Part-97 and ARRL good operating practices.
It's in a very handy location for its intended use, even thought at 350mW, who'm I gonna win a double with? I guess with a IC-4AT a few miles further out.
(Since the TONE doesn't do tone decode, this is just bypassing the pre-set carrier/ signal squelch.)
Tapping Shift while hodling MONItor will switch you to listening to the transmit side of the repeater (or back), the "reverse" monitor, when transmit shift is in use.
The Function button, while pushed, enables the non-bolded versions of the keys.
F introduces many of the modes, modifying other keys.
Tapped quickly by itself, F enables changing the MHz with Up/Down, which it denotes by blinking the digit in question: 448.1750. Tap a second time, it moves to the 100KHz: 448.1750 and a third time to exit the mode, but it will time out quickly to normal (only mode that does?). This is not usable in MEMORY mode, only in VFO. It is also usable in SHIFT to change MHz, in case you need to go from 5MHz offset to 1 or 10MHz in your local bandplan. I haven't tried it in TONE, maybe it would let you do tones quicker? I doubt it.
Talk here.
Listen here.
LCD display, has memory channel #, frequency is displayed like 449.9250. The .25/.50/.75 are stacked as literal items on the LCD, not formed from segments, so the .75 looks like a superscript and the .25 like a subscript and the .50 like a whithered arm, but it actually reads better than this sounds, since they're nice crisp numbers, and it gives a feel of how high it moved.
Has indicators [+] [-] for active offset, [T] for Tone active, [LOW] for low-power setting, [APO] for AutoPowerOff active, a Bell for Alarm set (blinking if triggered).
There is no BNC or SMA connector to attach a gain antenna to. It comes with a fold-down rubber duckie that might be >0dBi if you're lucky. I'm wondering if a passive-re-radiator on/out the window (such as are sold for use with 300mW pocket cellphones, but re-engineered twice the size) would help when using it in a car that isn't mounting a "real" 440 rig.


Modes are described under the key that initiates them. Some modes are transient programming modes, usually exited by PTT. Some Modes are global settings toggled on and off. Many modessome keys uses in modes are cross referenced.) Just about each F-button combo either enters programming mode or toggles a global mode. Turning the unit On with most any button depressed also affects some mode; some toggle, some others are paired with another button for set/reset so that you can know what state you'll be in without knowing where you are.

The programming modes initiated by the F-of-key are:

The global settings / modes and their keys are:

Explanations, Elaborations, Warnings

Things which weren't obvious after reading the original instructions once, and probably bear repeating even after my above expansion/cross-referencing.

  1. Faster QSY'ing is tap F, then up/down the blinking MHz digit, tap F, up/down blinking 100kHz. This is addition; it carries. (On the sheet, but I found it on the radio first.)
  2. I could not figure how to get it into 50mW "low power" mode. (Nor can I figure why I'd want to, except when at the MIT flea.) Alinco replied (email): While pressing the PTT, press the SCAN/SHIFT key to toggle between hi and low power.
  3. If I understand correctly, the only pages (calls) this unit will respond to are if the other unit sends 1750Hz. (Alinco didn't correct me, so I guess I'm right.)
  4. I find no distinction between the scan mode started by holding UP and by pressing scan, except how long you push it; neither will STOP once it finds something. (ditto)
  5. This unit has CTCSS/Tone/PL Encode but not Tone Decode (ditto), and no option to install same.
  6. If you set the wrong split (or Offest, using F-Shift: [+] or [-]) the LCD will show [OFF] instead of the xmit frequency when you push PTT to transmit.
  7. Setting the desired Tone or Shift value isn't enough, you have to activate it. While in TONE programming mode (F-Tone), hit (F-Tone) again to turn on [T] indicator to send the PL tone you've chosen. In Offset programming (split, shift) set mode (F-Shift), hit Shift to toggle [+], [-], none.
  8. Repeater offsets start at 5MHz, conforming to expectations. To program a deviant split, enter Shift programming mode with F-Shift and then tap-f, Up/Down to change the MHz of split and tap-f again for 100kHz and either timeout or then tap-f yet again to use the normal up/down to tweak it finer if it's really peculiar. They say this can do +-15.99Mc shift, but I don't think NFM is going to excite an ATV repeater? (I'll never do this, everybody's +-5Mc here, except of course the cross-banders :-).


Reading the Schematic

The schematic is printed on the back of the single sheet manual. If you can't read the fine print on the schematic, you probably don't want to mess with surface mount anyway, but I want to know how it works.

From the size, I had assumed it was all custom ICs on a one board, LCD and buttons on another, but no, it's a real radio minaturized. The idea that there are three board in there plus the keyboard and LCD, all with multiple transistors, is really odd, when you consider that most of the volume of the unit is batteries (3xAA), with the LCD/buttons/speaker consuming much of the the rest!

The schematic indicates a surprising number of discrete transistors and other components. At 350mW it's using paralleled finals: three 2SC3356's provide the drive. The CPU+AF board sports 4 ICs (not including two power regulators numbered as ICs), one of which has a 4.00MHz xtal for its clock. The RF board has a PLL and an NFM discriminator chip, but otherwise the transmit amp/multiplier chain, the receive down-converter chain, and the VCO daughter board are all discrete transitors and parts (surely surface mount!). The RF board has three filter sections right at the antenna for both spur suppression on xmit and interference rejection on receive, and further filters in the IF.

Is the second IF really 450kHz [as documented] rather than 455kHz like everything else since Collins? (I guess it doesn't matter since there's no room to go adding a Collins filter : - ). I suppose one might add an IF tap; I had supposed the low IF probably wouldn't leave the main chip, but it actually is routed through an off-chip filter, so if one really wanted to grab the 450kHz IF to add SSB detection or something, it'd only be a question of having room enough. (Why would you? I dunno. I may do that mod to my cheap junk scanner, though.)

In Use

I was expecting more intermod rejection on a unit that isn't cursed with extended receive. I realize there really isn't room for a set of helicals, even for 440, but since I do not buy anything (except used scaners cheap at a flea market) that has "extended receive" expressly to avoid intermod and image problems, I was a little dissappointed to have 'scan' fetch up on some perfect doubles between commercial and public service UHF users. But not bad either, compared to say my cheap wide-open scanner on the same frequencies, though, it's reasonably intermod resistant.

350mW (25dBm) doesn't seem to be enough to kerchunk repeaters with high squelch settings or in desensed environments like city-center. I was expecting a bit more range; I think some of our downtown repeaters must have desense problems or have their squelch too high. (With all those megawatt pagers downtown I can't imagine why : - ) Since I get into one linked system from several miles away on the back side of the hill, I don't think it's me and the DJ-S41T. (I may need to borrow a unit with CTCSS Decode/ display to verify/correct published PL's for some of 'em too.)


HRO didn't have ANY accessories for it. Not yet knowing how long the Alkaline AA's will last, nor how long I'll have to change 'em and keep memories, I didn't know whether I'd be needing the charger stand or not, but they couldn't do the "do you want fries with that" thing. I expect HRO will have it soon.

With a 5.5V connector on top, I figured a dashboard adapter would be smart. I'll have to 'brew one with a 7805 or whatever....

Alinco replied to my comment: "There is a mobile DC to DC adapter (12v to 5.5v) available. The drop in charger and nicads are not available yet. The batteries should last you at least a few weeks under normal use."

Update: Drop in charger was never released;
rumor is that they couldn't get it reliable at a price proportional to the radio.

(Indeed, my first set of Alkaline Batteries did last several weeks on mostly receive.)

I've seen passive-re-radiators for folks using pocket cellphones (also 300mW devices) in cars without installation kits; they clipped to the car window. I'm thinking such a device would be useful for those of us with only 2m mobiles so we could use the 440 pocket in the car. (yes, I could buy a 440mobile, but that's not the point.)

Update: I've got serious doubts about this idea now.

Rumors and Ideas

The guy at HRO says rumor is Alinco is doing a 2m version. Sounds good. I like my RS HTX-202, but it is bulky. My wife and daughter know they can choose either of the DJ-S41T or it's 2m twin when available when they get their licenses (when for dauther, if for wife).

Alinco replies: "There may be a 2mtr version on the market soon. Stay tuned for that. "

A dual-bander at 300mW would be an ever better urban YL/XYL HT.

Somebody will introduce a 220M+1.2G dual which'll be very popular with the coded classes fleeing the no-code-bands and folks who go to Dayton (where 440 and 2m are desensed completely, so I hear). (I understand the reason we don't see this yet is that the US is one of very few countries with a 220 allocation.)

Alinco closed with: "We appreciate your comments and are working to improve areas that need improving."


I'm not ecstatic yet, but I'm not yet convinced I made a mistake either. I expect it'll be fun wandering at the MIT flea at least, and I can check into the AMSAT net on NETARC once a week.