Sangean ATS-909/Radio Shack DX-398 FAQ: Technical Information

Dave Moisan, N1KGH
Updated November 5th, 2003


How well does it perform compared to...

...The DX-390 (ATS-818)?

NOTE: All these observations are anecdotal and may exaggerate some differences and ignore others.

Personal listening time with each radio in YOUR listening conditions is your best determination.

There is an excellent review of small shortwave radios, including the ATS-909, in the August 1997 issue of QST.

The consensus on seems to be that the 390 is not a particularly sensitive radio. I evaluated the 390 for a friend of mine and was not impressed.

...The Grundig Yacht Boy 400?

The Yacht Boy is said to have better sound, but performance is similiar. It, like the Sony 7600 discussed in the next question, is a physically smaller radio so if size is a factor, that is something to consider.

...The Sony 7600?

The 7600 does have synchronous detection, but lacks some amenities on the 909, such as a signal strength meter. This FAQ author almost got a 7600 when Nobody Beats the Wiz closed their Massachusetts stores. (Alas, it was gone the next time I went there with money...)

...The Sony 2010?

Reviews are mixed on One camp proclaims the 2010 as superior, mostly due to its synchronous detector that the 909 lacks. The other, notably led by Art Bell of fringe-talkshow fame, pushes the 909.

...The GE Superadio?

Mediumwave performance of the '909 is decent, typical of most SW portables. However, like most portables, it can't compare to the Superadio, unaided, due to its much smaller mediumwave loopstick.

When the 909 is coupled with an external mediumwave antenna such as the Select-A-Tenna, its performance is very close to the Superadio. I give the Superadio a slight edge, since at my location in Salem, Massachusetts, during the daytime, my Superadio II can barely pick up the 720 kHz CHTN, in Charlottetown, P.E.I. (some 600 miles away over water!); my DX-398 cannot do it without the external loop antenna I have (essentially a homemade Select-A-Tenna).

I'm not much of an FM listener, but I do prefer the 909's digital display to the horribly inaccurate analog dial on my Superadio.

Is the ATS-909 Y2K compliant?

The 909 has two clocks for both a home time zone and a "world" time zone. There is no date function, therefore the radio is Y2K compliant by default.

How do I hook up an external antenna to it?

The radio accepts a 1/8" stereo headphone jack for its external antenna. It's wired a little differently than you think.

A 1/8" stereo plug has tip, ring, and sleeve connections

The tip goes to the antenna terminal and the sleeve goes to ground, just as you would expect in this unbalanced antenna input. Shortwave signals are routed from the external antenna jack when a connector is plugged in.

The ring--the terminal in the middle of the plug--has a special purpose. When you ground it, medium wave signals are also routed from the external jack instead of the radio's internal loopstick. This is why some people have reported poor MW reception when they use regular 1/8" mono patch cables to connect their antennas.

But for medium wave DXers, this is an opportunity to connect their favorite antennas to the radio; the lack of a good MW antenna connection has made some otherwise good radios less than desirable.

If you prefer to use the internal loopstick for MW, simply leave the ring of the plug unconnected.

Ingo Truppel has another approach:

An important note to the MW/LW - external antenna. It is not useful to connect the ring terminal of the antenna plug to ground. Instead of that it should be connected also to the antenna terminal and parallel via a 1 kOhm resistor or an inductance (some mH) to ground - that way you get more sensitivity for MW/LW (look at the scheme for that). I use an self made active antenna (150kHz-30MHz tuned) with an output transformer which grounds the antenna for DC. So I only connect the ring of the antenna plug to the antenna terminal.

[I haven't tried this. The antenna I use is also DC grounded, so Ingo's idea should work for me...DM]

How do I disable the internal MW antenna?

Using a 1/8" stereo connector, ground the ring terminal to the sleeve. Or else use a 1/8" mono connector. The FAQ author much prefers the former method as this can be controlled by a SPST switch to disable and reenable the internal antenna, thus saving the antenna jack inside the radio from wear.

Does the 909 have birdies (spurious signals)?

Yes. The 909 has two strong birdies at 27.022 MHz and 27.472 MHz, and several others at 17.865 and 18.165 MHz.

Are the station memories really permanent like the manual says?

No. The station memories can be changed.

The new frequency should now be stored in memory.

How does the priority button work?

The priority function is not well explained in the manual, and it behaves differently depending on what band is involved. On MW, LW and FM, the priority button has its own memory location, so you can store a station to it like any other memory.

On SW, though, the priority button calls up an already existing station memory; it does not store a station itself, but only the reference to a station in the memory pages.

To set a priority station in MW, LW or FM bands:

Tune to the station you want. Hit the M key. Hit the PRIORITY key (that key that looks like a "1" and an arrow.) That's it. When you next hit the PRIORITY key, the station you stored will come up.

To set a priority station in the SW band:

First, the station you want to hear must already be stored. Find a empty page (usually page 29) or overwrite a memory location and store your station there. Then hit M and PRIORITY. As long as the station is stored in "regular" memory, the PRIORITY key will call it up.

How do I use the timers?

Rocky,, offers this explaination:

First of all, timers 1 and 2 will turn off the radio after one hour and timer 3 will allow the radio to play until you turn it off.

Turn the radio on and tune to the station that you want the radio to come on to. You can use any frequency and mode on SW or any AM, FM or LW station. Let's say I want to wake up to KNX-1070 at 5:20am.

Now press the MEMO button and the word "MEMO" will flash on the display. Press the TIMER 1 button and the radio will beep. Press TIMER 1 again and the word "timer" will flash on the display. Use the AM MODE button to select radio (you should see the musical notes on the display).

Now use the numbers on the keypad to enter the turn on time. For my example I pushed 5, 2 and 0. Be sure to use 24-hour time. Now press ENTER and "TIMER 1" will show on the display. To check the status of the timer at any time just press the TIMER 1 button and you will see the time and frequency that the radio will turn on to. Press TIMER 1 to go back to regular radio operation. To delete the timer just press the TIMER 1 and CLEAR. To turn the timer back on again just press TIMER 1 button and the "enter" button.

The timers also have a "snooze" function. When my timer 1 comes on at 5:20am and I want to get a little more sleep, just press TIMER 1 button when the radio comes on and it will turn off and turn on again in about 5 minutes. Timers 2 and 3 also have the "snooze" feature.

How do I connect a tape recorder?

Recommended Recorders

According to Radio Shack's help line, there are three tape recorders that work with this radio:

Remote-cable Problems

Chad Vizino:

To control a tape recorder using the radio built-in timer feature and its REC STANDBY jack, it is necessary, for most recorders, to reverse the polarity of the patch cable used to connect the radio REC STANDBY jack to the remote mic (REM) jack of the recorder.

With a patch cord attached to the REC STANDBY jack and measuring the voltage from the other end of the patch cord, the tip of the submini plug is positive and the lower segment is negative.

However, to make a cord that works with my cassette recorder, I had to reverse the polarity, making the tip negative and the lower segment positive.

I bought (and subsequently returned) a GE brand cassette recorder ($20) from K-Mart just to cross check recorders since all other testing was done with Radio Shack models. It had the same problem (needed the reversed polarity cable.)

My record output is distorted!

Chad Vizino:

Another somewhat related piece of information on connecting a recorder has to do with the REC LINE OUTPUT jack. The DX-398 manual states and I confirmed (but would be worth putting in the FAQ under the question suggested below) that connecting the REC LINE OUTPUT jack to the MIC input jack of a recorder will result in a distorted recording. The recorder must have a line-in jack--the Radio Shack models do haves an AUX input jack. I could find no other commonly available recorder with such an input.

I also tried an attenuating patch cord into the MIC jack of the GE recorder mentioned above since it did not have a line-in jack. I had no success with this procedure--the recording was very muted and had lots of hiss. However, the Radio Shack recorder with the AUX input works fine.

[On the other hand, computer sound cards usually have line inputs. These work great, provided that one doesn't have RFI coupled through the cable.]

See also the IF clipping mod.

What RDS information does the radio display?

For those unfamiliar with RDS--Radio Data System--it is a subcarrier sent with FM signals that contains a data stream. This data stream can consist of an ID, a clock signal, traffic advisories and other information. RDS is in wide use in Europe, but less so in North Americal.

According to a Sangean service rep, "whatever information a radio station is broadcasting through RDS the 398/909 can receive."

North American broadcasters (are there Canadian RDS stations?) usually only send an ID and clock info. (By the way, the clock data is NOT guaranteed to be accurate, unlike the similar service that PBS stations send to VCR's.)

Any European listeners who can give a definite answer are most welcome to write.

What's the best AC adapter to use with the radio?

RS now recommends the #273-1758M, a 6V 300mA adapter. This seems much better than the multivoltage adapter they once recommended.

The FAQ author was sold a different adapter when he got his radio, the #273-1454D, a 6V, 150 mA adapter. As the radio draws 300 mA, the adapter is technically undersized. But this adapter has worked for nearly two years without any trouble.

Bill Bowen writes:

The best adaptor for the 398 (and also the 390/392) that us commonly available is the Radio Shack 273-1663. This adaptor is 3/6V switchable, it IS regulated, and puts out 700 MA. When connected to my DX-398 and the radio set for normal listening volume, the ripple is less than 25 MV.
I've used one of these on my DX-390 for 4 years and just got another one for the 398. The adaptor costs $19.99 + tax.

My radio locked up! How do I fix it?

On the bottom edge of the radio, to the right of the keypad, there is a small panel with a hole marked "RESET"; insert a paperclip into the hole and release. The clock display should reappear--you might need to reset it--and you should be able to turn on the radio.

My radio locked up and reloaded completely different memories!

First, some background: Sangean has two versions of the 909. One version for the US (and Canada?) and another version everywhere else. All 909's have a mask ROM that is programmed with the radio's firmware, and a set of station memories for listeners in Europe and Asia.

European and Asian consumers get this model. US-bound radios undergo one more step before they're shipped: The radio is programmed with a selection of frequencies for listeners in the US, selected by the famous DXer Glenn Hauser.

Unfortunately, under certain conditions, the radio locks up in a mode where it expects to be programmed at the factory, and since no programming is forthcoming, it resets the memories to the original defaults stored in ROM.

According to one Sangean representative, this is a very common tech support issue with the radio, for which a few radios are actually returned for reprogramming.

Barring development of a third-party 909 reprogrammer, you'll have to either reenter your favorite frequencies manually or send it back to Sangean.

More information on the 909's memory system is available.

(The FAQ author has had his radio lock up on him no less than three times! But the radio still has all the memory presets it was purchased with. So it goes.)

What stations are already programmed into the 909?

There are two different versions of the 909 with different presets depending on whether it's an American model or a European/Asian model. Here are the respective lists:

My radio won't turn on!

My radio won't turn off!

My radio's locked on a single station!

This is a scary problem with a simple solution: Check the keypad for any stuck buttons. The radio doesn't support any kind of n-key rollover such as you find on computer keyboards, so if any key is stuck, the keyboard won't respond. It's very annoying when the priority key is stuck so that you can't turn the radio off or change the station!

People who use their own stand to hold the radio may have this problem if the stand makes contact with the keypad, as it likely will if you're using one of those collector's plate stands with the protrusions on the front.

If none of these remedies works, see the next question.

I checked the keypad, and my radio still doesn't respond!"

Some users have noted that after the radio has been stored for a long time with batteries installed, the radio will lock up and the reset button will not work. Removing the batteries doesn't help, since the radio is still powered by a memory capacitor that takes a long time to discharge by design.

In that case, remove all batteries from the radio and let it sit for at least a few hours, perhaps as long as six days (as reported by one user on the DX398 list at Yahoo! Groups.)

According to Sangean, this is a known issue. Radios powered on AC have not exhibited this problem. (My radio is AC powered and I note that it has locked up on power-on approximately once every month or so, though I have always been able to reset the radio so far.)

In any case, you shouldn't need to take a hammer to it, though I sympathize, having owned radios that malfunctioned at full volume!

The AGC's slow!

The AGC on the Sangean is slow. This is especially noticeable when you turn on the radio or switch to MW, LW or SW from FM. Ingo Truppel has a fix for this in the mods section of the FAQ.

How do I adjust the LSB/USB offset?"

You should only need to adjust the BFO if it is noticeably out of adjustment.

The BFO can be adjusted as follows: The radio should be at normal room temperature, not in the sun nor out in the cold. Let it sit there for about 30 minutes.

[Illustration of BFO adjustment location in ATS-909 receiver]
  1. Tune to WWV, CHU, or an equivalent frequency standard. If none is available at your location, a local MW station will do.
  2. Remove the plastic LCD cover with a thin metal or plastic object.
  3. There are two adjustment pots under the display, they may be gray or orange. The pot to adjust is TC301, on the right side.
  4. Switch from LSB to AM to USB and compare the beat note. If you don't notice a difference in the beat notes, don't bother changing it.
  5. If the beat note is low on LSB, turn the pot slightly clockwise.
  6. If the beat note is high on LSB, turn the pot slightly counterclockwise.
  7. Repeat step #4 until the beat notes sound the same.

Note that TC302 adjusts the clock. If you find your SSB unchanged and your clock very fast (or slow), you adjusted the wrong pot!

This is at best only a rough adjustment. You'll need a frequency counter and the service manual if you want to do it right.

I live in Saudi Arabia. My radio doesn't have SSB capability. Can I add it?

It would be a challenge. Not only are there parts missing, such as the BFO and detector, but it's likely the microprocessor would need to be changed out. It's possible, in theory, to change out the processor and collect all the other pieces, but it would cost you. Sangean's not very likely to send a kit of parts for this.

What are the A and B inputs on the bottom of the radio?

They are for reprogramming the radio's memory at the factory. The A and B inputs are an interface known as I2C, Philip's standard for inter-IC communication (hence the name). Think of it as a miniature LAN for embedded microprocessors, memory and support chips (which the Sangean certainly has!)

The 909's factory interface and memory system has a page all its own.

Where can I get a service manual?

Radio Shack has a manual available. The part number is #11965753 and you can get it from RS National Parts at 800-241-8742 and it costs $17.69 +tax and S&H. If you're not in the US, try emailing Tandy Support, or write

National Parts
900 Terminal Road
Fort Worth, TX 76106
Attn: Hazel Pointer
Voice: (817) 624 - 1196 [Canadians can call 1-800-223-8344]
fax: (817) 740 - 0834

Where can I get replacement parts?

Radio Shack has some parts available. See the DX-398 Detailed Parts List online at Radio Shack. the display window I broke?

Radio Shack doesn't have a part number for this. Sangean's part number is #3058601. C. Crane will sell you a replacement for $10.

A note on the LCD window: If you need to remove it for cleaning--it seems to easily get dust underneath it--use a thin screwdriver or metal nail file and pry it from the top, working around the edges until it pops free. Do it gently, lest you crack the LCD itself!

...or the flipstand?

There is a rite of passage for ATS-909 owners: They break the flipstand at the bottom of the radio. Your FAQ author has passed by that measure and is now without the original stand!

Universal Radio sells lucite radio stands. Or you can simply get a decorative easel (for the Mr. Spock commemmorative plates the Franklin Mint sells, for example) from K-Mart, Wal-Mart or the like. Cost is under $5. (The easel, should be 8" long when extended--too short, and the radio will fall over. Not that this happened to me...)

I now have a better stand, a white wire plate stand from A.C. Moore that holds the radio up unconditionally, with a little bending. Any crafts or housewares store will have one.

Sangean America has replacement stands, which they will reportedly send out at no charge. So has Radio Shack--;their part number is RSU# 12090718, though they will charge for those.

To fit the new stand into place--or to fit a stand that's popped off--run the stand under warm water to soften the plastic. Then carefully bend the stand until the studs on both sides pop into the matching holes on the back of the radio. Let the stand cool off, and you're ready to go again. (Thanks to James Marshall for this tip.)

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Last updated on November 5th, 2003