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SSB in DX-398
I have a Radio Shack DX-398 that I bought in '97 or '98. Whenever I try to
listen to anything in either usb or lsb, it sounds sort of like the chipmunks. The pitch just sounds wrong and unintelligable. I don't have a lot of experience with swl, so I don't know if this is normal or not. I would expect normal AM broadcasts to be distorted, but signals that I'm sure are ssb also sound bad. (This problem comes to mind now because I was attempting to pick up the pirate broadcast on 6925 mentioned on this newsgroup just a few minutes ago, which I'm pretty sure is usb. I can pick it up. I even recognized the old David Crosby song they were playing. But it's still un- intelligable.) |
You should be able to tune it in.
I have used my DX398 and have had no trouble. Try tuning slowly above and below. I am receiving the 6.925 pirate (now Underground radio) in USB, so tune below it. Terry |
I don't quite know what you mean by "tune below it," but I wonder if
there's something wrong with my radio. It's always sounded like this in SSB. BTW, I'm in Fort Wayne, IN. Know where they're transmitting from? |
I just dug out my DX398 and hooked it to my
VHF diskcone and have tuned the 6.925 signal. You will have to push the "step" button to change the tuning step. I can get the signal tuned very clearly. Terry |
Well, I've got it tuned. I can recognize the music, but it's far from
clear. A few minutes ago there was a man's voice speaking that was pretty clear, though. Probably the best results I've gotten from ssb. Generally speaking, should usb be less understandable than regular am? |
In article ,
"Scott A." wrote: I have a Radio Shack DX-398 that I bought in '97 or '98. Whenever I try to listen to anything in either usb or lsb, it sounds sort of like the chipmunks. The pitch just sounds wrong and unintelligable. I don't have a lot of experience with swl, so I don't know if this is normal or not. I would expect normal AM broadcasts to be distorted, but signals that I'm sure are ssb also sound bad. (This problem comes to mind now because I was attempting to pick up the pirate broadcast on 6925 mentioned on this newsgroup just a few minutes ago, which I'm pretty sure is usb. I can pick it up. I even recognized the old David Crosby song they were playing. But it's still un- intelligable.) The DX-380 does not have a BFO or SSB ability so you won't be able to make this type of transmission understandable. -- Telamon Ventura, California |
Thanks, but mine is a DX398.
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I suspect it will take some time to "master"
the art of SSB. On most receives SSB will never be as clear as AM, but it should be close enough so that you can listen to and enjoy music. Try hunting arround 14 MHz and listen to the hams. I am in, just south, of LExingtonKY, and the current pirate, Underground Radio is giving a ~S8 On the DX398 I had no reading, but I was using my scanner antenna. I plan on bringing my antennas out to a patch panel so I can rapidly change from one radio to another. I had such a panel, but I am rewiring my radio desk, so it will have to wait awhile. I am going to drop him an email and see what happens. Terry |
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DX398 not DX380.
Terry |
You're right. Seems my radio is working fine. I've moved my radio and
hooked up the not-so-great amplified sw antenna I bought at RS about the same time as the radio. It sounds just fine now. Noisy, but very clear. Just got done listening to a little story about an acid flashback. I even sent them an email at the address they broadcast. btw, I'm planning on building a "broomstick" antenna. I know it's not the best thing, but it's cheap, easy, and portable. I'm thinking it will bring broadcasts like this in much better. I can probably even use it with the amplified antenna. |
Thanks for the link. I actually have my original manual. Read it just a
couple nights ago. I was actually suspecting that the radio wasn't working right, but this is easily the best sounding ssb broadcast I've heard using this radio. I'm convinced now it works find. Thanks again. |
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ER, you might want to take a look at the DX398 again.
I have mine in front of me and it certainly does have SSB mode, support for both LSB and USB. I modified mine to defeat the tuning muting, but even with that, I just barrowed my wife's stock DX398 and I can tune it just fine. I prefer the lack of mute,. On the lower right front there is a button labled am/mode. This toggles/steps the radio through AMLSBUSBAM. Again, please recheck your "facts". Terry |
In article ,
"Scott A." wrote: Thanks for the link. I actually have my original manual. Read it just a couple nights ago. I was actually suspecting that the radio wasn't working right, but this is easily the best sounding ssb broadcast I've heard using this radio. I'm convinced now it works find. I still have my DX-398. It is my first portable SW radio. Portable defined as you can easily hold it in one hand. Unfortunately it does not have SSB mode or a BFO so you can pick up a SSB transmission but not demodulate them properly. It is a great sounding radio for AM transmissions, which is almost all of the SW program broadcasters. Very few programs are in SSB. This leave out most of the Hams broadcasting in SSB but some still broadcast in AM. Most of the military and utility stuff is SSB. -- Telamon Ventura, California |
Check out:
http://support.radioshack.com/produc...20-228&Reuse=N This should take you to the page at Tandy's web with a direct link to a PDF of the owner's manual. Terry |
I believe you're mistaken. The DX-398 does have true usb and lsb. Press
the AM mode button to cycle through them. |
In article _3BId.16732$ru.5265@fed1read07,
"Caveat Lector" wrote: The DX-398 Manual is on line at URL: f Since it is in pdf I can't copy it and don't care to type it, but the procedure is quite clear for LSB and USB tuning --- see page 25 of the manual Sorry about my previous posts. I pulled the radio out and did not see a BFO or SSB switch on it and I don't recall ever using it for SSB. When I get some new AA batteries for it I'll have to try the hidden SSB modes. Didn't think I'd learn a new thing about a radio I have owned and not used for years. -- Telamon Ventura, California |
Used select text in Acrobat Reader to copy text from a pdf file...
When you have located an SSB station, press AM MODE to receive the transmission. Repeatedly press AM MODE to switch between USB or LSB transmissions (try LSB for frequencies below 10 MHz or USB for frequencies above 10 MHz). 4. Set STEP to SLOW then readjust MANUAL TUNING for maximum intelligibility. Gary K4GPB "Scott A." wrote in message ... I have a Radio Shack DX-398 that I bought in '97 or '98. Whenever I try to listen to anything in either usb or lsb, it sounds sort of like the chipmunks. The pitch just sounds wrong and unintelligable. I don't have a lot of experience with swl, so I don't know if this is normal or not. I would expect normal AM broadcasts to be distorted, but signals that I'm sure are ssb also sound bad. (This problem comes to mind now because I was attempting to pick up the pirate broadcast on 6925 mentioned on this newsgroup just a few minutes ago, which I'm pretty sure is usb. I can pick it up. I even recognized the old David Crosby song they were playing. But it's still un- intelligable.) |
That's normal for the DX-398/ATS-909.
"Scott A." wrote in message ... I have a Radio Shack DX-398 that I bought in '97 or '98. Whenever I try to listen to anything in either usb or lsb, it sounds sort of like the chipmunks. The pitch just sounds wrong and unintelligable. I don't have a lot of experience with swl, so I don't know if this is normal or not. I would expect normal AM broadcasts to be distorted, but signals that I'm sure are ssb also sound bad. (This problem comes to mind now because I was attempting to pick up the pirate broadcast on 6925 mentioned on this newsgroup just a few minutes ago, which I'm pretty sure is usb. I can pick it up. I even recognized the old David Crosby song they were playing. But it's still un- intelligable.) |
Plaaying around with the DX398 I have found
that a "strong" singal is much better then a weak one. I just ran 100' of wire and laid it on the newly fallen snow. Wtih no matching tranformer. (as an aside, antennas work much better if errected in bad weather, in fact the worst the weather the better the performance!). By winding the wire in and out, I have it on a military spool, I found that the DX398 is much happier with a strong signal. I don't have access to equipment to measure the exact signal required, and I don't think the ARRL lab comparison of the DX398 with other portables adressed that issue. And yes my wife is convinced that I am insane. But she willingly helps me with thes odd experiments. At some point I am going to have to errect an antenna "just for her". I am just glad she hasn't grabed one of my R2000s! (My original R2000 is showing it's age, I took it on one too many picnics and I hope to restore it in the near future. The tuning has gotten very touchy and I tend to use it for a dedicated WWV receiver at the moment.) Terry |
"Scott A." wrote in message ... You're right. Seems my radio is working fine. I've moved my radio and hooked up the not-so-great amplified sw antenna I bought at RS about the same time as the radio. It sounds just fine now. Noisy, but very clear. Try turning the RF Gain/ Attenuator down until it sounds like you want it. Makes a lot of difference. Just got done listening to a little story about an acid flashback. I even sent them an email at the address they broadcast. btw, I'm planning on building a "broomstick" antenna. I know it's not the best thing, but it's cheap, easy, and portable. I'm thinking it will bring broadcasts like this in much better. I can probably even use it with the amplified antenna. |
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In article ,
"Scott A." wrote: I believe you're mistaken. The DX-398 does have true usb and lsb. Press the AM mode button to cycle through them. I screwed up on the model numbers my radio is a 380. -- Telamon Ventura, California |
Gosh am I red faced -- been complaining about PDF for months (years) --
didn't know about the text tool for copying text. Guess it is a case of "When all else fails. Read the ^*^%%* Manual !!! Thanks for the tip Now where is that file I wanted to plagiarize (;-) -- Caveat Lector "Gary Brown" wrote in message . com... Used select text in Acrobat Reader to copy text from a pdf file... When you have located an SSB station, press AM MODE to receive the transmission. Repeatedly press AM MODE to switch between USB or LSB transmissions (try LSB for frequencies below 10 MHz or USB for frequencies above 10 MHz). 4. Set STEP to SLOW then readjust MANUAL TUNING for maximum intelligibility. Gary K4GPB "Scott A." wrote in message ... I have a Radio Shack DX-398 that I bought in '97 or '98. Whenever I try to listen to anything in either usb or lsb, it sounds sort of like the chipmunks. The pitch just sounds wrong and unintelligable. I don't have a lot of experience with swl, so I don't know if this is normal or not. I would expect normal AM broadcasts to be distorted, but signals that I'm sure are ssb also sound bad. (This problem comes to mind now because I was attempting to pick up the pirate broadcast on 6925 mentioned on this newsgroup just a few minutes ago, which I'm pretty sure is usb. I can pick it up. I even recognized the old David Crosby song they were playing. But it's still un- intelligable.) |
Caveat Lector wrote:
Now where is that file I wanted to plagiarize (;-) I believe the correct term is 'archive' mike |
It is not just a case of flipping a switch. I haven't had a 398 in several
years but the basics are, switch to sideband mode, set the tuning for lowest posible tuning steps (40 hz in this radio) and use the tuning knob to tune it in. If you can't get it tuned, you are in the wrong sideband. Switch to the other and do it again. Likely, in this part of the spectrum, those pirates are on lower sideband. "Scott A." wrote in message ... I don't quite know what you mean by "tune below it," but I wonder if there's something wrong with my radio. It's always sounded like this in SSB. BTW, I'm in Fort Wayne, IN. Know where they're transmitting from? |
Check again. The 398 is fully ssb capable.
"Telamon" wrote in message ... In article .com, wrote: You should be able to tune it in. I have used my DX398 and have had no trouble. Try tuning slowly above and below. I am receiving the 6.925 pirate (now Underground radio) in USB, so tune below it. He is not complaining about picking the signal up but making it understandable. You can't do this with DX-398. No SSB mode or BFO means no SSB detection. -- Telamon Ventura, California |
In article ,
"CW" wrote: Check again. The 398 is fully ssb capable. "Telamon" wrote in message .. . In article .com, wrote: You should be able to tune it in. I have used my DX398 and have had no trouble. Try tuning slowly above and below. I am receiving the 6.925 pirate (now Underground radio) in USB, so tune below it. He is not complaining about picking the signal up but making it understandable. You can't do this with DX-398. No SSB mode or BFO means no SSB detection. I did check again. I mixed up the model number. The 398 does have SSB and the 380 I own does not. I read the post and then looked at my radio and then commented on mine without noting the original post had a different number. Dumb. It was a bad model number day for me as I did a similar thing in another post yesterday. -- Telamon Ventura, California |
SA,
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starman wrote in :
Due to the nature (physics) of how SSB works it's difficult to make the audio sound like the original. One problem is the original pitch range is missing from an SSB signal and there's no way to know exactly what it was. For example, I have heard Art Bell, the AM radio talk show host, operating on the ham' bands in SSB. It sounds like Art but it's not the same as hearing him on an AM broadcast station. It does help if there is musical content to an SSB signal which can act as a reference for adjusting the pitch correctly. Since SSB is mostly used for voice only, it doesn't really matter if the pitch is not exactly like the original. Thanks for the info. I was, after some practice, able to get the station to sound pretty good. It's kinda weird how you can change the pitch of the voice or music by changing the tuning. All this time I was convinced that the ssb on my radio didn't work right, especially since it's one of the selling points for this model. Guess I'm still a little wet behind the ears. |
The thing that is missing in SSB is the carrier -- it was suppressed. And
unlike AM only one side band is transmitted -- either the upper sideband (USB) or the lower sideband (LSB). Only one sideband is needed to transmit intelligence. Thus Single SideBand Suppressed carrier is the whole name for SSB transmissions. At the receiver side you reinsert a carrier (BFO) which then allows demodulation. As you tune the receiver, the BFO is inserted at different points until it sound natural. A little practice and you can tune right in on it. Hams do it all the time. SSB modulation is nicely illustrated at URL: http://www.williamson-labs.com/480_ssb.htm It explains the big advantages of using SSB along with pictorials -- Caveat Lector "Scott A." wrote in message ... starman wrote in : Due to the nature (physics) of how SSB works it's difficult to make the audio sound like the original. One problem is the original pitch range is missing from an SSB signal and there's no way to know exactly what it was. For example, I have heard Art Bell, the AM radio talk show host, operating on the ham' bands in SSB. It sounds like Art but it's not the same as hearing him on an AM broadcast station. It does help if there is musical content to an SSB signal which can act as a reference for adjusting the pitch correctly. Since SSB is mostly used for voice only, it doesn't really matter if the pitch is not exactly like the original. Thanks for the info. I was, after some practice, able to get the station to sound pretty good. It's kinda weird how you can change the pitch of the voice or music by changing the tuning. All this time I was convinced that the ssb on my radio didn't work right, especially since it's one of the selling points for this model. Guess I'm still a little wet behind the ears. |
Nothing weird about it. Just like any other radio signal, you have to tune
the radio correctly. "Scott A." wrote in message ... It's kinda weird how you can change the pitch of the voice or music by changing the tuning. |
"CW" ) writes: Nothing weird about it. Just like any other radio signal, you have to tune the radio correctly. But when people don't understand SSB, of course it's "weird". Tune a regular AM signal, and the carrier ensures that it is always tuned properly. The only thing the tuning does is move the signal into the passband of the IF filter. Mistune it, and you get reduced amplitude, and altered frequency response. With an SSB signal, mistuning likewise moves the signal out of the passband. But it also has to be tuned properly in relationship to the "reinserted carrier", ie the BFO, and if that isn't right, then you will be translating the modulation to the wrong place in the audio spectrum. Voice can be ambiguous, since you often won't know how someone sounds (because you don't know their voice), so mistuning can merely make someone sound squeaky, or even sound right even if not exactly as the person sounds in real life. Music is absolute tones, and if you don't tuen that right, not only will you not hear the proper notes, but the relationship of the notes to each other is off. You know what a given note sounds like, and not much mistuning messes things up. Michael "Scott A." wrote in message ... It's kinda weird how you can change the pitch of the voice or music by changing the tuning. |
"Scott A." wrote:
Thanks for the info. I was, after some practice, able to get the station to sound pretty good. It's kinda weird how you can change the pitch of the voice or music by changing the tuning. All this time I was convinced that the ssb on my radio didn't work right, especially since it's one of the selling points for this model. Guess I'm still a little wet behind the ears. I imagine other newbies might also come to the conclusion that their radio was defective when trying to listen to SSB transmissions, so your post could be quite helpful. ----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 100,000 Newsgroups ---= East/West-Coast Server Farms - Total Privacy via Encryption =--- |
He is not complaining about picking the signal up but making it
understandable. You can't do this with DX-398. No SSB mode or BFO means no SSB detection. My 398 does it just fine. (????) jt |
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