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Reviews For: Radio Shack DX-400

Category: Receivers: General Coverage

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Review Summary For : Radio Shack DX-400
Reviews: 13MSRP: 249.95
Description:
AM/FM/SW/LW portable communications receiver (1985-1996)
Product is in production
More Info: http://
# last 180 days Avg. Rating last 180 days Total reviews Avg. overall rating
00133.9
KG7M Rating: 2022-02-16
Overall Great, But Not Good for Bandscanning Time Owned: 0 to 3 months.
I recall when the DX-400 came out in 1984. It was Radio Shack's Top of the Line in 1984. For 1983 the only General Coverage Receiver they had was the (crummy) DX-100. It roughly matched the look of their Navajo Base CB. Their last decent SW Receiver had been the DX-302, its last year being 1982. So the DX-400 was a return to a decent set. BTW, it's also a Uniden CR-2021.
I recently picked one up on eBay from a very nice Seller. He correctly stated that the radio had nearly no volume, a burned out S-Meter Dial Lamp, and very dim Digital Readout Lamps. The radio arrived in excellent shape. I attached it to my outdoor antenna, about 70 feet of random wire running from my 3rd floor unit to an oak tree - up above 70 feet. It runs into an SCG-230 and then into a MFJ-989C Tuner. The Tuner is a Godsend in Portland due to overload from local AM and FM Broadcasters. Well, the Audio is WAY low. I can use it by plugging a set of Amplified Computer Speakers into the Headphone Jack. I had hoped that the Audio Issue was just an output jack issue that could be fixed with deoxit. Nope, it appears to be defective electrolytic caps in the output of the Audio IC. As far as the Dial Lamps, they are a series of Surface Mount LEDs. So, in theory they should outlast me. So I'm looking at a possible defective resistor in the driver circuit. What's a bummer is that there's no Service Manual Available. Only a Owner's Manual with an unreadable Schematic. Fortunately I did find a Schematic in the form of FOUR very hi-res images. I was able to "stitch" them together.
I (respectfully) disagree with the Reviewer that states that the DX-400 is a powerhouse AM BCB DX Machine. I also own an RF2200, GE SuperRadios in a couple configs, Crane's CC Radio EP, and even Drake's TR7 and SPR4. My experience with the DX-400 is that it's not a good DX performer on the BCB because you cannot disconnect the AM Loopstick when using an External Antenna. My DX-390 and DX-398 run circles around it as they both contain a circuit to disconnect the AM Loopstick. Granted, the DX-400's Antenna Trim is great. On SSB and CW the DX-400 is a very solid performer. I can receive both USB, and LSB Signals without having to touch the Fine Tune Control at all. It is a bear for Bandscanning though with either a weird 3 kHz Step, or a 1 kHz Step. Still, for what it represented when it came out, and its performance today, I rate it 5 Stars. Soon I will open it up to repair the low audio and fix the Dial LEDs issues. Lastly, in 2022 they are overpriced on the used market.
KF4WDZ Rating: 2010-12-31
MW DX champ Time Owned: more than 12 months.
With an inductively coupled loop (I use a Grundig AM200/Kaito AN200) this one actually outperforms my Panasonic RF-2200, Sony ICF-2010, Superadio 1,2, and 3, and CC Radio + in sensitivity and selectivity on MW/AM. Sure a loop can improve just about any radio, but I have yet to see any portable beat this combination. Even without the loop it out shines the CC Radio +. It's the ability to tweak the antenna trim control that makes this one such a hot performer.

That being said it's a bit of a pain to tune as it has no tuning knob, however it will jump in 10KC steps if you hold down the center "fast" button (I have been known to slide a toothpick next to the button to hold it down).

The FM section is a bit above average. No FM stereo, though.

But, yea I know...it's a SW radio, right?
It does alright with a longwire and doesn't seem to overload, though I do wish it had an RF gain control instead of the three step attenuator. The attenuator is effective though. SSB reception is quite good and a breeze with the huge BFO knob. You may find yourself wishing for a sharper filter, but for it's class it's quite acceptable and on par.
With just the (REALLY long) whip I'd say it's about average for it's class even when compared to today's portables....or about the same as a DX-440 or Sangeian ATS-909, but better than the 818 if that helps at all.

It's sound quality is pleasant (nice mellow and full for it's size), and it has a tone control. I know that may not seem like that big of a deal, but any kind of real tone control is getting rather hard to come by in this day and age. Even back then the well thought of 2010 didn't even have this feature.

The good news is that they can often be found for a very low price for what they are as for some reason they don't seem to be very popular or well known ...making them an outstanding bargain. I don't think you can do any better for the money, for sure.

If you're into MW/AM DX I highly recommend picking one up.
KC9KTI Rating: 2009-10-17
A great receiver! Time Owned: more than 12 months.
I bought one of these new back in the 80s. Remember when Radio Shack sold radios? I scraped my money together and got one of these new and spent many hours pulling in broadcasts, ship to shore, coast guard and amateur radio stations. I remember receiving many a cordless phone back then too. I still have this receiver in my shack as a back up and I will never get rid of it. If youfind one at a swap meet, get it!
DXTUNER Rating: 2008-12-13
Portables should have stayed just like this one Time Owned: 0 to 3 months.
These early-1980s SW receivers, you can't beat 'em with a stick. I've owned, at one time or another, various Yaesu, Icom, Kenwood & Palstar desktop receivers as well as numerous portables mainly from the Kaito & Sangean lines. I recently purchased this DX-400 for $75 on Ebay, so that I'd have a low-priced temporary radio until I afford my next high-end desktop receiver. While my main thing is monitoring distant sideband utility stations, I figured I'd be happy if I could at least get some shortwave stations on this well-used DX-400. Just to fill a void.

What did I get? Well let's put it this way: I'm in absolutely NO rush to buy my next high-end HF receiver!

As far as reception & sound quality goes, I put this old DX-400 in the same class as the Kenwood R-1000. You heard that right. And for sideband utility monitoring I actually prefer this large, well-built portable over the Palstar R30C! (The R30C could never stay on frequency; I continuously had to re-tune & chase the signal all over the place). This DX-400 has superb sideband reception, easily beating the RedsunRP2100/Katio KA2100 w sideband adapter. The Kaito KA 1103? No competition! As I said, the DX-400 performs every bit as well as the classic Kenwood R-1000 desktop.

They don't make radios like this anymore -- although they should. The "antenna trim" (i.e., antenna tuner feature)is a MAJOR plus. It allows me to peak AM signals, and also un-peak sideband transmissions so that all the noise is removed. This radio even has a fantastic analog S-meter.

Do not hesitate buying the DX-400 is you find one in good working condition. Its a real classic as far as I'm concerned. Portables have de-volved since this vintage.

N0SYA Rating: 2007-11-09
Good monitor rig. Time Owned: more than 12 months.
Some observations on the dx400:
Dual conversion pll synthesised rx, AM/FM/BFO modes, 100KHz to 30MHz LF/MF/HF coverage, 45MHz and 455KHz ifs, two if bandwidths, one seems to be 4KHz, the other 8KHz or more. 6 memories for FM and AM each, includes memories for scan edges. Has numerical keypad for direct frequency input. Also has slew conrols to alter frequency. This is the biggest drawback, no tuning knob. Has "Antenna Tuning" control (varicap diode I assume) to better match antenna load to RF amp and/or mixer, effective in most instances with the vertical whip or external antennas.

Seems to be fairly stable once warmed up, use with a wall wart or other dc source to preclude damage from internal heating and drifting with the ac power. This seems to be a common malady with the series, the caps dry out or leak. Dc power may prolong the life of the rig.

The bfo resolution is far too coarse, needs an internal mod to increase it. A larger knob helps in adjusting the as-is bfo. May be easily modified for other IF bandwidths as it uses a common MuRata 455KHz filter. Second glaring drawback is reception on both sides of zero-beat. Might also be suited for a synchronous detector mod if one can be had cheaply enough. FM rx audio is very nice but not stereo. This nice FM audio might mean the rig is amenable to efforts to clean up the wooly AM/BFO audio. An external speaker of better quality helps.

Overall, easy to use for monitoring single channels such as SWBC listening or MFBC, tedious for any bfo demodulation rx. Recommended if can be found inexpensively.
VA3UDX Rating: 2007-09-27
Good RV/cottage/backup radio Time Owned: more than 12 months.
I'd like to start off by saying that the DX-400 is well-deserving of a rating of 3.5, but 4 would be a bit too generous. The DX-400 was my first SW radio with a BFO - and a big BFO knob at that! (this is a good thing) The BFO opens up your listening world to various utility stations, amateur radio as well as coast guard and military stations. Although the sensitivity of the DX-400 is average by today's standards, it was a very good radio when it first came out in the early 80's.

I'd like to point out that the DX-400 is remarkably similar to the Sony ICF-2001; but a far cry from the legendary Sony ICF-2001D / ICF-2010.

I'll point out some of the pro's and con's of the DX-400:

Cons:
a) No VFO. A VFO is a must if you are a band-scanner or you like to search for DX.
b) Tuning Step - 1 OR 3 kHz. That's right - there's no 5 kHz step on this radio. I find the 3 kHz step rather obscure, although it does come in handy at times when searching for utility stations.
c) Only 6 memories. (the upper and lower band limits can also be used as memories - so a total of 8 memories is possible)
d) Small display. (however this also means it's simple and uncluttered)

Pros:
a) Direct entry keypad. Really handy if you have a broadcast schedule.
b) Operates on 12-volts. I can use the same mobile adapter that powers my scanner.
c) Large BFO knob. Makes for easy tuning of SSB signals.
d) 3-position RF Gain Selector (Local/Normal/DX) antenna attenuator and tone control. I much prefer a tone knob to a switch. These three features work well together to help clean up a signal.
d) Analog signal meter. It's just a preference...

Today, I use several other radios that are more convenient to use than the DX-400. However, the DX-400 is a good starter radio and makes a suitable backup - especially if you have an international broadcast schedule. (schedules are readily available over the internet)

Overall - a good radio, but I'd suggest the Sangean 803A/DX-440 or the Sangean 818/DX-390 instead. (or the cassette variety)
NU0C Rating: 2007-08-04
Think outside the box Time Owned: more than 12 months.
I missed the boat when the Uniden 2021s were selling out cheap in the early 80's. But then I noticed that the DX-400 looked to be the same radio, with a REAL S-meter to boot. So I bought one on sale, and have never regretted it. I later acquired a 2021 from a non-ham who didn't want to pay the $25 I charged him to fix it (the same service manual can be used for both radios, and yes I have one).

Aside from being a decent portable/camping radio, both versions made a handy addition to my radio test bench (and the computer workbench in the sub-30 MHz days). I've used them to sniff oscillators for activity, monitor transmitted signals, set carrier null, and as a frequency meter (zero-beat to WWV and you can make some very accurate frequency measurements). In fact, with a "sniffer" cable connected to the external antenna terminals, you can probe any circuit that operates below 30 MHz without tapping into the circuit! The FM band, although not stereo, sounds decent as well, and the range can be extended below 88 MHz by altering the state of a pin on the CPU. IIRC, the bandwidth switch actually switched in a narrower ceramic filter, rather than reducing audio bandwidth as another writer supposed. It's been a while since I cracked the service manual, so I can't say for sure.

The radio does have a few "warts", already adequately covered by other writers. I will say, try not to drop it! Although fairly well constructed, a shot to the power switch can crack the circuit board that it is mounted on; also, the AC power socket is susceptible to cracking, and this is a critical point as there is a leaf switch for AC/DC switching built in to the socket. Don't ask me how I know these things....

Bottom line, it's a nice little radio that would make a good addition to any shack, office, workshop, ... ? Given a choice, I would prefer the DX-400 over the Uniden 2021 for the S-Meter; the LEDs on the 2021 have very limited resolution.
W3DBB Rating: 2006-12-10
good performer Time Owned: more than 12 months.
I have two of these. I bought one new in '84 for $300 and bought a used one at the Harrisburg (PA) hamfest in '99 for $40.

Both are super receivers. The Realistic DX-400 (and the nearly identical Uniden CR-2021) were hot performing portables in their day. Portable communications receivers didn't progress too much beyond the DX-400. The Sony ICF-2010 was a slightly better receiver than the DX-400 because the Sony had a synchronous detector that really worked. The ICF-2010 is now discontinued.

The DX-400 is remarkably free from overload, even with a large outdoor antenna. The built-in antenna tuner and step attenuator make this possible.

The two bandwidths work on AM and SSB/CW signals and were well chosen for most shortwave broadcast and amateur radio listening. Selectable upper and lower sideband would have been nice but were not included. The narrowest bandwidth is too broad for use as a CW filter but perhaps an audio filter such as an Autek QF-1 could be interfaced with this receiver for CW reception. I have never tried this. The receiver is quite stable, with a slow drift (less than 1 kHz total) for the first hour. After that, rock stable!

The DX-400 uses an internal AC transformer and detachable suicide-cord in lieu of the wall-warts commonly used today. The only caveat is the internal transformer runs a little warm so when not using the receiver pull the plug at the wall outlet.

The DX-400 is solidly constructed for a plastic-cased receiver. The audio from the built-in speaker isn't high fidelity, but it isn't objectionable as distortion has been kept to a minimum. Phase noise from the PLL is noticeable, but again, the designers of this receiver did a good job of keeping it to a minimum.

As an added bonus this receiver also tunes FM broadcast, and again, immunity from overload is the rule even using an antenna with some gain.

The only difference between the Realistic DX-400 and the Uniden CR-2021 was the Realistic used a true analog S meter and the Uniden used a row of LEDs.

If you find one cheap in good condition, grab it!

JOEANALSSANDRINI Rating: 2006-12-10
Early Digital Portable Time Owned: more than 12 months.
This was my first digitally-tuned shortwave radio and I must say that immediately upon using it, I was somewhat disappointed. Why? The radio can tune (AM) in 1 kHz, 3 kHz, 10 kHz, or 30 kHz steps - no 5 kHz step! This makes manual bandscanning very cumbersome. In addition, when tuning in 1 kHz steps (the only practical tuning step for SW), the "chugging" is very obtrusive. Its automatic scanning on my sample stops 1 kHz high.

However, once a station is properly tuned, the radio performs fairly well. It is a TRIPLE-conversion radio (still the only triple-conversion SW portable ever made, I believe) but its image rejection is not what one would expect from such a circuit. Its two bandwidths are audio bandwidths, not IF bandwidths, I believe. For SSB, the radio performs poorly. Its sensitivity leaves a great deal to be desired. And, of course, no synchronous detection circuitry. (This was a fairly early digital radio design.)

In short, I found my old Lafayette HE-10 to be the superior overall receiver, even though it was already 22 years old when I bought the RS model.

Yet, for program listening, it is a not-bad performer and is very well-built. It is generally very easy to operate, even by someone with little SW experience. As batteries have slightly "swelled" in size since the 1980s, it is difficult to remove spent batteries from the well-hidden cavity. But the radio does have an inboard power supply and works well on AC. It uses screw terminals for antenna connectors; these are better than the usual portable antenna sockets.

If available at a fair price (and the radio is in good condition), it is an "okay" receiver which could serve well for listening to the more powerful stations "in the clear."

TECHDUDE Rating: 2005-12-23
awesome portable Time Owned: 6 to 12 months.
I bought one on Ebay 11mos ago. For a partable I am very impressed, I think it performs better than any other portable I own which are Sangean ATS909 & ATS803. It's almost as good as my Kenwood r-1000. The only negitive is no rotary tuning knob. If anyone knows how to add one email me direct motoxx386@bellsouth.net Also if anyone has a service manual I am looking for a copy.

73's