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#1
11-07-2010, 12:06 PM
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Sonar DF-6X portable RDF
It's been a while since I've posted anything on VK. I haven't really been doing any TV/radio work as it cost money, and currently not having a job, I have tried to steer clear of spending money.
A few days ago, my father brought me an item. He said he found some kind of radio, but thought it was unusual and wasn't exactly sure what it was. However, he knew it was vintage and figured it was something I'd want to play with. When Dad got here with it, I knew exactly what it was... a portable radio direction finder... Sonar DF-6X. I found an RDF collector online, and according to him, this is from the 50's. He has one like it. According to this fella, this set operates on a 9 volt battery. The original 9 volt battery that came in it was quite a bit larger. After removing the rear cover, I found a bracket that held the battery. It appears that the battery was about 8 inches by 2.5 inches. The man told me the book says the original battery was designed to get roughly 4000 hours use out of it. Apparently, it was thought that the battery would outlast the radio! He told me the set will operate just fine using a single 9 volt alkaline battery. At first, I couldn't get anything out of it, but after removing the rear plug for the battery/speaker/whip antenna and then plugging it back in, the radio came to life. I sprayed all of the controls (were quite scratchy) and after that I was picking up stations on all three bands! The bands are as follows.... 200 to 420 KC (Beacon) 550 to 1600 KC (AM) 1600 to 3600 KC (Marine) Actually, I suppose this would be 1.6 to 3.6 MC shortwave. Last night, I was able to find an open carrier in three places on the Beacon band, but no broadcast. Today, I found a Morse Code signal around 350 KC... sounds like the one we use on the ship when we connect to WWL to send our weather reports. I'll have to call the 2nd Mate and inquire about that. The AM band was quite impressive... pulling in Houston, San Antonio, Dallas/Ft Worth, New Orleans, Kansas, and WSM in Nashville. I got a small handful of shortwave stations between 3.0 and 3.5 MC. I was surprised that I even pulled in the WWV time tick at 2.5 MC out of Colorado. I only have one other shortwave that I've actually been able to pick up WWV on that frequency. An interesting feature about this chassis... the transistors are all "plug in" and are able to change them out just as easy as a tube would be. That's pretty cool. It has a 4 x 6 speaker and pumps out a good bit of volume. The signal indicator on the front works great as well. There are five lytics in there, and five .05 paper caps. They seem to work fine, but being over 50 years old, I would think they'd be a bit weak. I might change them later. Since I'm not pluggin it into the house current, I'm not too concerned about blowing a paper cap for right now. But still, I'm sure that replacing them will likely freshen things up a bit. For right now, I'm going to work on cleaning the cabinet up a bit. It looks like it's been sitting on a shelf somewhere for a very long time. It's very interesting looking and still useable as a cool AM radio.
__________________
Charlie Trahan He who dies with the most toys still dies. 
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#3
11-07-2010, 02:11 PM
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Nice find! Good list of the radio beacons here:
http://www.dxinfocentre.com/ndb.htm Fun to Dx at night.  jr
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#4
11-07-2010, 03:26 PM
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Cool! Thanks for that link... I actually found a couple of those frequencies that are local to my area (had to brush up on Morse Code). I found a third frequency with a J-J-A as the identifier, but didn't find it on that list. A small mystery to crack for later!
I found a .05 that was corroded and disconnected on one side. Put in a new one and the stations came in stronger. Went ahead and changed the others, and 3 of the 5 lytics (didn't have the last two values on hand). Plays better, but there's a small rattle in the speaker, so I'll go grab a speaker out of the garage and see if it sounds better. A couple of the lytics were much higher than the label said. The two in the audio output were supposed to be 50 mfd @ 10 volts... and on my meter they read 180 mfd and the other was over 200 mfd. Putting in two new ones made the audio slightly louder.
__________________
Charlie Trahan He who dies with the most toys still dies.
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#5
11-07-2010, 03:47 PM
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This list will take a direct entry of the callsign, location or frequency:
http://www.airnav.com/navaids/ Check your code, I don't find a JJA.  jr "PPA" is Pampa Tx on 368 kHz. P = ".--." while J = ".---" easy to mistake. Last edited by jr_tech; 11-07-2010 at 04:14 PM. Reason: add PPA
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#6
11-07-2010, 05:57 PM
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Good point, but Pampa is up in the panhandle, and I doubt I would be picking that up in the middle of the day from ~800 miles away using that frequency.
 I'll go back and listen again... I'm pretty sure it was JJA. I would think it would be local as it was the strongest signal I was able to pick up. Hell... even if I don't figure it out... I'm tickled it works!  I need to get another 9 volt battery... I had pulled this one from an old remote, so it isn't really fresh. Perhaps I will end up getting some double A holders and mount where the original battery was to go... using 6 double A's should last longer than using one 9 volt square battery.
__________________
Charlie Trahan He who dies with the most toys still dies.
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#9
11-07-2010, 07:36 PM
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This site shows a bunch of different models:
http://www.angelfire.com/space/proto57/rdf.html Not that I need to collect anything else, but some are quite cool. I remember as a kid, building a Heathkit DF-1 for a friend of my parents that had a boat. It seemed at the time that it was a pretty decent radio, but I suspect that I would not think that today. jr Last edited by jr_tech; 11-07-2010 at 07:40 PM.
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#10
11-07-2010, 07:40 PM
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Yeah... this guy is the one I got my info from earlier today. He was a big help. He certainly does have a lot of them!
He's got one like mine (but accidentally labeled it as DF-6F). He thinks mine is an earlier version that the one he has since mine does not have the two toggle switches on each side.
__________________
Charlie Trahan He who dies with the most toys still dies.
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#11
11-07-2010, 07:42 PM
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Quote:
__________________
Charlie Trahan He who dies with the most toys still dies.
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#12
11-07-2010, 08:40 PM
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http://cgi.ebay.com/ws/eBayISAPI.dll...m=250322152159
(no affiliation) Looks like the same one. May of 1960.
__________________
 Do not attempt to adjust your set.
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Linear Mode
