I got a great deal on a Realistic DX-440 the other day. Although the battery door is missing and the battery box needed some cleaning the radio works great!
The best part is it only cost $7.50 and the AC adapter was only $1.
I was particularly interested in the longwave reception and its pretty good. I've already picked up four aviation beacons around 363 kHz.
Made for Radio Shack by Sangean, the DX-440 is nearly identical to the Sangean ATS-803A. Some of the buttons are labeled differently and they removed the audio line-out recording jack. But, all I have to do to add the recording jack is remove the pop-in cover to expose the opening in the case and install a jack as the PCB is ready for it.
I found a modification for the radio to eliminate "chuffing" while tuning the radio. Apparently the audio mutes when the PLL is not locked. This causes an annoying "chuffing" sound with each 1 kHz step while tuning. Simply disconnecting the mute line eliminates the "chuffing".
Checking prices on Ebay, these two radios list anywhere from $50 to $200 so I got a deal.
I like that word "chuffling" and it perfectly describes what my RCA Superradio does when I try to tune the upper AM band on the analog dial. It "chuffles" with a thumping in and out of the woofer and I can't actually hear the radio frequencies being tuned.
The particular Super Radio I have never stays tuned at the higher AM band, and it's pure hell trying to re-tune it because of the chuffling.
Since it's not a digitally tuned radio it probably doesn't have a PLL circuit, but it sure chuffles.
MRAM let us know what you
hear on longwave. I have done listening down
there and I like it a lot.
A good friend had a Part 15 188 kHz (?) cw beacon
there years ago. That was cool.
Carl - I had a Sony ICF-2002 portable from 1982
that chuffed. It still is a great radio.
No chuffing in the shack lately.
The 2002 is at my brother's house.
Maybe we'll dig it up some day.
Bruce, CBJB, Ex. Chief Chuffer Operator
So far I've heard four NDB aviation beacons. These are all within about 10 or 15 miles of my location. They send a non-stop Morse Code ID which represents their location. My wife is a pilot and she looked them up in her book.
There is a data stream which may be loran or some type of fax. I'll have to run that through my PC and see if it fits any of the formats. It could be noise from a computer too.
I haven't heard any "broadcasts" yet (other than some intermod from local flame throwers.)
I have a PC program which works with the ultra low speed Morse used for DX, experimental stations like your friends beacon. I'll have to let that run on a known beacon frequency for a while and see if it picks out anything.
The DX-440 has a connection for an external antenna. I don't know if it is for all bands including the VLF. I'll compare the NDB signals while switching between internal and external antennas.
A big loop antenna for VLF is probably the way to go as they are less affected by electrical noise, responding to the magnetic wave.
So much to do, so little time....