HFU HF Underground
Technical Topics => Equipment => Topic started by: ThaDood on August 14, 2020, 1834 UTC
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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.
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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. :)
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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.
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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.
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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.
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Nice review 👍
I had one, I miss it.
If I recall the LW performance wasn't that bad.
(My PL660 is full of birdies)
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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 :)
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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.
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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.
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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
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Yeah, starting a Support Group would be a great idea.
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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.
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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.
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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. :(
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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.
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The DX440/803A doesn't have protection diodes built in, but if you are reasonably good with a solder gun or soldering iron, protection diodes can be wired in using hookup wire and a couple back to back diodes -- or even rigged at the external antenna itself.
MW performance is fairly good but on mine it's much improved by adding an external MW loop.
The "carrier noise" could be the PLL whine, which often will go off if you strike in the 'lock' button, for some reason. On my radio, I never heard it much through headphones. DX the SWBC bands was a dream when there were still signals on the air, the DX-440 has really good audio through headphones.
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My 803A is going bad to worse now. The high pitched whining noise got worse than yesterday, and now when pressed LW, it refuses going to LW, but revert back to MW with very loud high pitched winning noise. :(
It was working perfect, but maybe it doesn't like the MLA30 active loop? When plugged in with the MLA30, the audio was getting rough, and and powering on, it kept making whoosh noise, and then high pitched whine appeared with the strong signals. Now when pressed the LW, it goes to MW? I am glad that I am having the other radios, so at least my RXing the regular programs is not affected.
Tried with the LOCK button, but nothing changes. I thought initially it didn't like the 9V wall wart, but it was not the case.
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I left the 803A unplugged for a few hours, and powered on again. The LW is now back, it goes to LW OK. But the high pitched squeal on the reception is still there. Maybe some of the parts inside have gone bad? such as caps or resistors? That 9V wall wart works fine with the other radios.
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Well, if you do go inside, the most common problem that I've run into with several of these radios is that ribbon cable that half-ass plugs into an IC socket. Every time, (Due to dissimilar metals.), those pins and contacts are found corroded. If you find that, the quick fix is to clean all that out with 91% isopropanol, let dry completely, plug-in that ribbon cable, and see if that worked. However, that corrosion will happen again. On several radios, including my own, I've hard soldered those ribbon cable pins to the contacts of that IC strip. Mine still works +25 years later.
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Thanks for the great advice Dood. Much appreciated.
Yep, I will open it up and try to sort it, but not immediately.
There are lots of other tasks for me to do now and time is just not allowing for working on the radios these days, and I have other radios including the newly acquired TECSUN S2000, and PL-680, PL-660, D-808 ... so I have a plenty of radios to fall back on fortunately.
But I am scunnered to face this problem from the 803A which looks like new, and worked like new even a few week ago. In fact, I now recall when I got this 803a , and inspected the battery compartment, I had seen a dried out battery leak, I cleaned it up, and it became spotless. I have not taken it as any serious problem as it looked spotless again. Not sure if the pcb had been affected by the leak too. Anyhow a project for the coming winter. :)
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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.
Thanks 👍
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My new to me 440 should be here tomorrow :)
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So FedEx has seem to lost my 440 :(
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Oh, wow... I was a freight inspector for about 2 years, and over 95% of complaints came due to FedEx. I just finally had a package of stove hood filters get here, after a 4 week delay. Fortunately, that was USPS. If you catch FedEx delivering it, inspect that outside of the package immediately. And, if you see damage, REFUSE that package, and stick it back with FedEx. The driver will do what they can to try and not make that happen, but it is your right to do so. What sucks is that you have a single driver, with a huge area, with terrible time restraints. If stuff gets damaged, TFB. Like most down-sized corporations, they pretty much operate and exist to satisfy investors, and not you.
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Oh, wow... I was a freight inspector for about 2 years, and over 95% of complaints came due to FedEx. I just finally had a package of stove hood filters get here, after a 4 week delay. Fortunately, that was USPS. If you catch FedEx delivering it, inspect that outside of the package immediately. And, if you see damage, REFUSE that package, and stick it back with FedEx. The driver will do what they can to try and not make that happen, but it is your right to do so. What sucks is that you have a single driver, with a huge area, with terrible time restraints. If stuff gets damaged, TFB. Like most down-sized corporations, they pretty much operate and exist to satisfy investors, and not you.
Good points
It now says it was delivered.
Not to me!
My neighbours all deny getting a package.
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I left the 803A unplugged for a few hours, and powered on again. The LW is now back, it goes to LW OK. But the high pitched squeal on the reception is still there. Maybe some of the parts inside have gone bad? such as caps or resistors? That 9V wall wart works fine with the other radios.
I don't know about your radio, but DX440s and 803As had high pitched whine when new.
Your radio probably needed a reset. Sometimes microprocessors on SW portables wig out. My DX375 did that once, years ago.
The 440 is an old model, but the parts shouldn't have gone bad necessarily. I have older transistors that still work well.
It sounds like your radio may have some issues, or maybe just wasn't powered up for a few years. Mine acted funky when I first powered it up after several years' hiatus.
I'd use batteries instead of a wall wart, to be on the safe side. I have two 9 volt wall warts that when I measured them, they put out 11 volts. The 440 is light on batteries... they last a while.
Good luck.
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Thanks BB for your advice and info.
No there is no reset button with my 803A. And I left it without power or batteries for days. I powered it on tonight, and it sounded a lot better.
But when I tried FM, the received FM station was very strong - end stop signal. The whining problem returned. It is a very loud carrier with the incoming signal. It was happening with AM signals as well. But like before when the signal is weak, the whining carrier disappears.
So, I could set it to monitor a DX freq. on 4 Mhz tropical band.
Not sure what is causing it. BFO for the CW and SSB sounds distorted too. There is definitely some problem with this 803A.
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The Dx440 and Sangean versions, they were so popular when the Gulf War was on, and news listeners wanted alternative information and those radios weren't on the shelves for a while.
I have heard of people having problems with the SONY 2010, and I'm not sure if its' a JFET that goes, or an IGFET, insulated gate, that goes. I've just heard about it from various hams, that it might be near by their transmitter, or connected to a longwire, and transmit, and it can damage the front end.
It's not always blown either, it can be partly damaged and make noise or be intermittent on-off reception, as the Fet can fail as a short or open.
Realistic/Sangean, good lower end portables, glad that Radio Jay covered it. Did you know there was a version with a cassette recorder too?
KBear
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Uh-huh... The Sangean ATS-818ACS , https://www.universal-radio.com/catalog/portable/1069.html I knew several friends that had that. And, you are right about it being the DX-440 / ATS-803A with a cassette recorder. Pretty much did everything that my Sangean portable does, plus folks could record a 40M pirate off-air to boot. You don't seem to see those around anymore. And, at a time when cassettes are now starting to make a somewhat come-back now. (Yeah, go figure.)
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I have a DX-392 radio with the cassette player. The cassette player of my DX-392 doesn't work (maybe needing a new belt), but the radio works great.
It is a good old radio. I logged many interesting DX signal with the DX-392.
I like the big freq. display, big control knobs and tuning dial of the DX-392. The reception is also good = it seems giving more intelligibility under difficult conditions caused by weak signal, fading, QRM and QRN.
This vid is about the DX-392 exactly same one I have.
https://www.youtube.com/watch?v=MY7Eg75h4f4
https://www.youtube.com/watch?v=95VW7VJhnbw
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The tuning knob on my DX-390 is much smoother than the one on my 440.
The 390's like butter, there might be something wrong with my 440, it feels like there is sand in there.
It works great though ;)
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The tuning knob on my DX-390 is much smoother than the one on my 440.
The 390's like butter, there might be something wrong with my 440, it feels like there is sand in there.
It works great though ;)
Nope. Different design. The DX-390 uses a potentiometer. The DX-440's tuning knob is an older design, and uses actual rotating contacts. That's why they feel different.