Finally!!! Radio Jay Allen covers the Realistic DX-440/Sangean ATS-803A portable

[ThaDood]

I've told Ray Jay about this portable for years, and apparently I'm not the only one,    https://radiojayallen.com/realistic-dx-440-sangean-ats-803a-am-lw-sw-fm-radio/

I still use mine daily, or should I say nightly, as a bedside radio. Radio Jay did knock the selectivity on the FM portion of this portable. In the mid-1990's, I did the Bruce Elving IF TOKO filter swap, from 200kHz to 110kHz, and after that it was, and still is, an FM DX machine. Necessary today with all of those FM translators littered, (And yes, I mean littered.), all over the FM dial. My big gripes are the same as with other portables. When either the memory AA batteries, or the "D" batteries, leaked, that acid would run into the main board. I run my portable off of a transformered wallwart. No battery acid, and no RF hash from a switching power supply. Of coarse, when I loose power at the house, I have to reset the clock and the 9 Memories on it. (B.F.D...) The other pitfall is that ribbon cable that loosely plugs-in to a terminal strip are dissimiliar metals, thus corrosion always seems to happen on the pins of that cable. I've repaired several ATS-803A's / DX-440's by hard soldering those ribbon cable pins to the board. Problem solved, and mine still working +27 years later of having that done. Anyway, +30 years later, my Sangean ATS-803A still rocks on.   

[alpard]

I forgot about my ATS-803A. It has been sitting on the shelf for a few months while I was playing around with the other radios.  When I saw this thread, I took it off the shelf and powered on, and it is still working great too.

My 803A is maybe from the very last run from the factory. It looks like NEW inside out, and everything  is fine. The only problem I was having was when I connect the mains DC adaptor, it gets noisier, and the reception is not as good as when running from the batteries. It says 9V at the power point in the 803A, but somehow I felt that it doesn't like 9V DC. So, I have connected 6V DC adaptor, and it seems happier.

Due to this problem, I have been running with the D size cell batteries, which are not cheap.  I never saw my D size cell batteries leak, but I have seen in the past the battery compartment is messed with the leakage on other 803A I used to have.  They have gone, but when I saw this newish looking 803A, I had to have it, because it was going for good bargain price too.

But a very cable receiver. It is a keeper classic.

[ThaDood]

Do you want to download the Service Manual for that? Here's the link for that here,     https://elektrotanya.com/realistic_dx-440.pdf/download.html
As for your ATS-803A not liking 9VDC? Are you using a transformered AC to DC wallwart, or a lite-weight switching one? That will certainly make the difference in noise. However, if yours is a happy camper at 6VDC, sounds like you are good. One thing weird about this portable is the write-up review that it had gotten in Passport To World Band Radio. This is the only radio where under 'CONS' they've listed NONE. That was very strange, since they would usually rip into every idiosyncrasies that a radio has, no matter how minute that is. Look under the Passport To World Band Radio reviews from 1990 - 1992. 

[alpard]

Thank you for the link.

I am using a lite switching adaptor = it is actually the one made by RadioShack for their DX-392 radio.
But before that, I tried with a nameless Chinese made 9V switching DC Adaptor, which was actually outputting 9.7V DC.  And that was bad.  The 803A sounded raspy and very noisy.  In 5 - 10 minutes, I took it out, and gone back to the D size batteries.  It sounds best with the batteries, but very expensive to run it 12 hour - 15 hours a day with them.

I was thinking of getting a multi voltage output rechargeable batteries for engine jump starter. IN fact I have one in the shed, non working. I don't think it is fixable. And there is other options such as as buying a rechargeable batteries from Amazon and making up 6V, and keep recharging them.

What antenna are you using with your ATS-803A?  I am using just a random wire with ATU, and works best.

[ThaDood]

For LW, MW, and lower HF, a homebrew Windom antenna with a 4:1 W2DU current Balun. But for FM, I mostly use the telescopic built-in whip antenna. One EXT modification that I did with EXT Antennas for that radio was to make a plug with opposing 1N4148 diodes across the center and GND conductors, for decent spike protection. Where I'd gotten that idea from were the Sony ICF-2010 portable gurus that did that to protect that radio's static sensitive J-FET front-end. BTW, that is interesting that your ATS-803A doesn't seem to like +9VDC going to it. I'm not using the original wallwart for my radio, but one from a trashed cordless phone base unit that is a transformered wallwart that happened to be +9VDC, 500mA, loaded. So, that worked out fine. BTW also, you might be able to find such one yourself at any junk store, or the Salvation Army, or Good Will, stores. I'm buying up every transformered wallwart I see, most for around $1.00 each. You just never know what they might be useful for. Better than +$20.00 for a new one.

[Under30]

Nice review 👍
I had one, I miss it.

If I recall the LW performance wasn't that bad.

(My PL660 is full of birdies)

[Under30]

You guys are a bad influence LOL
I just bought one on da Bay. $125.00 free shipping, looks like new, and is tested

I bought one when they first came out, sold it when I moved

Can't wait to receive it

[chanito]

I installed an IF to soundcard converter in mine so I could use DReaM. There's a little blank plastic panel on the side that now hosts a RCA connector. Originally purchased the 440 in 1991 to listen to shortwave coverage of Desert Storm. I did the anti-chuffing mod at one point. Radio still works to this day and has seen countless hours of operation. It's kind of a beast to use portable, but I like that the layout is not tiny and cramped.


One tip to make the BFO and RF Gain knobs finger friendly is to find a piece of 1/4" aquarium tubing and cut two rings, about 2mm long. Slip those over the center post of the knob. Enjoy.

[ThaDood]

Neat chanito! The Audio MOD's that I also did on my ATS-803A include changing the resistors to that DIN socket connection, but damned if I can remember what the value of those resistors were. That fixed audio tap connector is nice, but very low level, so I changed the resistors internally to a lower value. I never did that anti-chuffing MOD, but that MOD for the 'lil knobs sounds like a nice idea for the fat fingers. Also, back in the early 1990's, I've heard of other AST-803A / DX-440 users that have monitored Gulf War COMM's from 25MHz - 30MHz with just that radio's 40 inch telescopic whip. Find a portable that has that today. Ya know what, there are still Yahoo Groups on the Sony ICF-2010 portable, but I still don't think that there's a Yahoo Group for the ATS-803A / DX-440. Hmmmmmmmmmm... Maybe we should start one, since it sounds like there's enough fanfare and info to do just that.

[N0TLD]

I love Radio Jay AND the ATS803/DX440, so seeing the new article made me happy today.    I've had my 803a for a long time, and modified it a bit (less chuffing while tuning and some audio improvement) but those mods were very slight -- even stock it is simply a great radio, plain and simple... and well deserving of its rich praises over the decades. Glad to finally see it on Jay's Mega Shoot Out lists!

Mike
N0TLD

[alpard]

Yeah, starting a Support Group would be a great idea. 

[Under30]

Does the 440 have static electricity issues that plague the Sony ICF2010?
I heard the first FET in the Sony could get blown out with a static charge very easy.

[ThaDood]

Looking at that crammed schematic in the .PDF Service Manual, that 1st Front End transistor is a PNP BJT. Thus far, no static problems with the Front End of my radio going on +30 years. So, at a gander, I'd say that Front End on the DX-440 / ATS-803A is not as static sensitive as the Sony ICF-2010's. That said, it's still pretty sensitive, compered to other portables out there, for weak signal hearing. So, if you put that portable to a longwire, 80M dipole, Windom, etc., the added protection of opposing 1N4148 diodes, or something less noisy, for spikes beyond .7V, is not a bad idea.

[alpard]

What is the symptom of the blown FET by static electricity?

My 803A seems having problem of high pitched carrier noise coming out when the received signal is very strong.  So, it is affecting on the LW and MW bands local station signals. The noise disappears when the incoming signal is weak or the signal is detuned.

It also has dull and muddy audio on BFO is on, and trying to receive the SSB on the ham bands.
Looks like something is not right here. Either the filer or BFO is degrading the incoming signals.

On SW AM signals, the high pitched tone is not present most of the times. But if the signal is very strong, then it appears there too.

PS: I took out all the batteries from the 803A, and connected the 9V wall wart, and it seems fine.  I think the problem was not to do with the 9V wall wart, but the 803A was developing some kind of problem already at the time = high pitched RF bleed on the strong incoming signals and muddy BFO now.

[ThaDood]

If your DX-440 had the Front End blown, it would be incredibly deaf, with the exception of super strong signals, like in the millivolts. As far as having a lower supply voltage affect your radio's performance, very possibly. The PLL is voltage controlled and the AGC might act weird on you, besides that initial loud PING that they'll all do for a 1/2sec when tuning into a very strong AM carrier. (Which has been one gripe that some have had about the AGC with this radio. Some folks have actually gone as far as modifying that. I have not.) If your AGC is a little wacky on strong signals, try adjusting that RF Gain knob. As far as SSB HAM's sounding muddy? Some of those ops have very low toned audio, (And some of them sound damn near broadcast quality sounding on my Kenwood rigs.), and may sound funky with a receiver with just a BFO. That, and each station maybe slightly off FREQ as well. I'm just brain storming with what I do with mine on various stations.