DX-440 part question

[midwestsw]

I have owned this radio for some time and it has always been a stable, reliable performer. However, it
no longer operated on battery power. I opened it up and decided to try bending the three battery contacts
from the battery compartment inward toward the contact area on the board. Also, cleaned the contact
points on the board. That brought the radio back to life and worked as it should. When I went to button
up the radio I discovered a small rectangular black foam block with adhesive residue on one side, laying
on the workbench. I cannot figure out where it belongs inside the radio. ( I did remove the battery contact
board from chasis for inspection). Has anyone else had theirs apart and can tell me where it should
be placed ?

I appreciate it
midwestsw

 

[mmckenna]

I've had mine apart, but I don't remember where that was. Look for adhesive reside on the inside of the back case.

 

[com501]

Battery holder cover. Mine turned to slime a few years back and I replaced it.

 

[midwestsw]

Thanks for the quick replies. Foam is still present on my battery cover, the block in question is about an inch long by one quarter, I did look for residue inside, but can't see any. I just want to make sure it is not a crucial insulator,
Obviously the factory placed it for a reason...

 

[mmckenna]

I just went out and popped the back off mine. Unless I lost mine too, I don't see anything like that.
I didn't pull the circuit boards out, so maybe it's under there somewhere.
As Com501 said, the only one I did see was on the battery door. About an inch square and 3/16's thick.

 

[midwestsw]

thanks mmckenna,
I appreciate You doing that.

 

[mmckenna]

Glad I could help.

There are some interesting and easy mods for those radios (Radio Shack DX-440/Sangean 803).

There's an "anti-chuffing' mod that reduces/gets rid of the annoying "chuff" noise when you change frequencies. Makes it a bit easier to listen when searching across the bands.

There's also an easy mod where you can use the BFO pitch as a fine tune.

While not high dollar receivers, they're pretty good for the price. I bought a DX-440 when RS was selling them new. Used it quite a bit when camping, often for AM broadcast DX and long wave beacons.
In a moment of poor judgement, I sold it at a hamfest for about $40 bucks. Kicked myself later for that.

A few years back a co-worker had a "spare" Sangean 803 and gave it to me. I cleaned it up, did the mods and still use it to this day.

 

[Boombox]

You can always hard wire the battery contacts to the board. I did that with my DX-440.

The foam part was present in numerous radios and was intended to keep batteries from jostling inside the battery compartment.

It is probably unnecessary, or -- if your batteries jostle in the compartment -- could easily be replaced by plastic shims cut from a large bottle top or other piece of flat plastic. Cut some square shims, place them over the batteries before closing the compartment.

I have one radio (a Sangean PR-D5) that needs shims because the batteries jostle and make noise from time to time (not all batteries are made to the same exact size specifications, and some battery compartments are a hair oversized for this reason).

Good luck with your DX 440. I use mine from time to time on MW and SW. On MW it is mediocre by itself (small loopstick) but with an external loop it works great. On SW it sound terrific through headphones, and the narrow filter helps whenever the ham bands are crowded.

I wired back to back diodes to protect my DX 440 when I had an 100 ft outdoor antenna (two diodes, reversed from each other, wired between the antenna terminal inside the radio, and the negative battery terminal -- there are external diode protectors that can also be used to protect your radio from static discharges when using an outdoor antenna).

I just use a 25-30 ft indoor antenna now with my DX440 (and other radios) and still get good results -- although propagation recently has been a bit spotty.

 

[midwestsw]

Thanks guys. I knew this was the place for answers, really appreciate the replies. Here in Iowa, with
the temps being what they've been, have been spending some time with the radios and taking care
of some problems with them. I purchased my 440 in the late 80's I believe and it's been a favorite.
Along with my Yaesu FRG-8800, often somewhat maligned, it has always performed well, and in
my opinion a very attractive radio. With a 100 ft. longwire, it really makes a difference. I really miss
the days when there were so many SW broadcasters on the air. Too bad technology has impacted
our hobby the way it has. Then again, this forum and the web has provided us with information
and the ability to purchase equipment that is not readily available in alot of areas. Guess I'm
just an old guy that misses the nostalgia of days gone by. Thanks again for the help.

 

[Boombox]

^^^^^^I hear you on the nostalgia bit. I even miss things as late as 2002-2003, when I could tune in the 31 meter band and hear India behind Asia, and plenty of Russian domestics were still on the air in the early morning here on 41 and 49 meters, audible here in the PNW. Then Germany was still running its domestic SW service on 49 meters -- I heard that once, playing 80's music -- on an 80's radio (my DX-440). The winter of 2002-2003 I rediscovered SWLing, and it was a good season. Of course, my 100 ft. wire helped. It later blew down in a storm. :-(

Today it's different, of course. Less stations, and propagation is whimsical. But if you listen at the best times for your location there is still a lot to be heard when propagation is working. You just have to appreciate the sounds of different languages. I know a little bit of Spanish, and a few words in Portuguese. I don't know any other on-air languages but can ID certain ones from the sounds.

Although there is less to hear today, what is out there often has cool music and the languages make listening a challenge.

Then again, there are always the ham bands. If you know even a little bit of morse code you can catch call letters and IDs, and SSB is easy to tune on the 440.

PS, don't forget that the DX-440 works well on the AM band. The narrow filter can really help with IDing stations next to a strong local or strong regional. If you don't have great MW reception on the DX-440 in your location a small external loop will really kick it into high gear. Just set the antenna to INT and set the external loop to the right side of the radio or on top of it, above the dial (where the coil is on the loopstick). If you have a larger loop, just sitting it anywhere near the radio will boost signals. I have a plastic milk crate loop and it works well.

 

[mmckenna]

^^^^^^I hear you on the nostalgia bit. I even miss things as late as 2002-2003, when I could tune in the 31 meter band and hear India behind Asia, and plenty of Russian domestics were still on the air in the early morning here on 41 and 49 meters, audible here in the PNW. Then Germany was still running its domestic SW service on 49 meters -- I heard that once, playing 80's music -- on an 80's radio (my DX-440).

Back in high school (1980's) I remember hanging out with a friend in his garage. He had a 1969 Chevy Nova that he was always tinkering with. Anyway, he had a Radio Shack SW radio in the garage with an alligator clip to the garage door track for the antenna. Back then there was a station out of Utah called KUSW. Their jingle was something about "Superpower, KUSW!). They played a lot of good music and their signal was strong. They didn't last too long, but it was good while it lasted. Those were some good times. I think it was that experience that really got me into radio.

 

[Boombox]

Back in high school (1980's) I remember hanging out with a friend in his garage. He had a 1969 Chevy Nova that he was always tinkering with. Anyway, he had a Radio Shack SW radio in the garage with an alligator clip to the garage door track for the antenna. Back then there was a station out of Utah called KUSW. Their jingle was something about "Superpower, KUSW!). They played a lot of good music and their signal was strong. They didn't last too long, but it was good while it lasted. Those were some good times. I think it was that experience that really got me into radio.

I have similar memories of hearing Radio Moscow 24/7. Some of their programming actually was quite good. I would wash the car and have my multibander out on the front porch, with Vladimir Posner or Joe Adamov's voice blasting away over the driveway. When Radio Moscow became the Voice of Russia, they still were interesting, and the domestic Russian outlets from Magadan and Petropavlovsk ("Mayak") -- some of which broadcast in the lower meter bands -- began to play Western pop music along with the usual Russian classical and other music.

Then it all began to disappear.

 

[midwestsw]

Wow Mmckenna,
I remember Superpower KUSW...! But hadn't thought about it for years, probably since the last time I
listened to them. I believe I received a QSL card from them, and maybe a bumpersticker. Also HCJB
Quito, Ecquador. I was 13 or 14 years old and fascinated to be hearing something so exotic so far away over the radio. That radio was my fathers Hallicrafters S53 A that he had purchased new. He was one of
our greatest generation members, a Navy radioman in WW2. He has since passed, but he gave me that radio a few years before. It now holds an honorable place on a shelf at my bedside, and gets turned
on every night tuned to WHO-1040 in Des Moines, IA. Sometimes I tune across the SW bands as well,
not hearing a whole lot. But that lighted dial is a comfort and a reminder of good 'ol days gone by.

 

[mmckenna]

HCJB, yes, that came in really well here even with a crappy radio and a random length wire about 8 feet off the ground.

As a teen, it was interesting listening to the world news from a different point of view than the USA. Pre-interent days. Back when there when the only way to get news was the newspaper, a few magazines, network TV or AM radio. Usually all owned by large US corporations.

 

[midwestsw]

I feel kinda sorry for the younger generation coming up...I wouldn't trade my shortwave radio days
as a kid for the technology they have today. Can't imagine there would be too many interested
playing with radios. They don't have a clue how much enjoyment and memories we have thanks
to our earlier days.

 

[aggie72]

The battery line goes through the dc jack. If you plug a dc adapter in the jack then you will bypass the battery. I suggest you try plugging any plug that will fit (power off) into the DC jack and exercise the internal switch. Also squirt some Deoxit if you can to clean the contacts and see if that works.

 

[Boombox]

^^^^^^Another solution to keep the battery contacts secured to the PCB is to add some solder to the contact pad.

Either way, on some DX-440's the battery contact still can be a little flakey at times: mine would make scratch noises when squeezed (while holding the radio, turning it to null MW stations, etc.) from slight movements over the contacts.

That's why I hard wired mine. But one of my mottos is also "if it ain't broke, don't fix it."

 

[graywoulf]

A question about your back to back diode mod

I wired back to back diodes to protect my DX 440 when I had an 100 ft outdoor antenna (two diodes, reversed from each other, wired between the antenna terminal inside the radio, and the negative battery terminal -- there are external diode protectors that can also be used to protect your radio from static discharges when using an outdoor antenna). I just use a 25-30 ft indoor antenna now with my DX440 (and other radios) and still get good results -- although propagation recently has been a bit spotty.

Greetings! I found your post while searching for information about the back to back diode modification for RS shortwave receivers. I just bought an RS DX-390 radio and I would like to add an external antenna for it but I want to be careful about static electricity this winter being that we have carpeted floors. Could you please give me some more information on how you did yours? I want to leave out the potentiometer that I have seen in some of the diagrams I have found if possible. I have also looked for any type of add on ready made external device that will protect my radio but I don't really know what to look for by name so I have not had any luck there. Any help that you care to provide will be greatly appreciated.

 

[ka3jjz]

This little project has been well received - if you are looking for a quick and dirty way to reduce static charges and put an external gain control on your radio, this is one way to do it...

https://forums.radioreference.com/receive-antennas-below-30mhz/295299-great-first-timer-project.html

Be sure to read the entire thread...Mike

 

[graywoulf]

Thank you for the information. Am I correct in that four of either diode is needed for that circuit?