HFU HF Underground
General Category => General Radio Discussion => Topic started by: jordan on February 09, 2014, 2120 UTC
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On shortwave, I understand that pirates use both AM and SSB for their transmissions. But why would they use SSB? It is terrible for music, even with a receiver capable of decoding the signal. They would also be limiting their audience, because although many people have shortwave receivers, they can only tune into AM transmissions due to the lack of a BFO. So for those two reasons alone, you would think most pirates would use AM.
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I can think of two reasons for SSB use.
1. It [the signal] travels farther, using less energy. A 50 watt AM transmission will not be as well heard as a 50 watt PEP watt SSB transmission.
2. The newer solid state HAM equipment is designed for SSB transmission use, if they do have an AM option, it is usually of lower power. Many of the pirates on AM
are using rebuilt AM transmitters from the 1950-1960s.
Anyway, there are others on this board that can add to this I'm sure!
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Some SSB rigs can actually sound really good. Some Kenwoods and Yaesus in particular. Icom, not so good. Also if you have a really nice receiver on the other end, where you can open up the filters, it can really sound great sometimes.
AM has more heart and soul though.
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Some SSB rigs can actually sound really good. Some Kenwoods and Yaesus in particular. Icom, not so good. Also if you have a really nice receiver on the other end, where you can open up the filters, it can really sound great sometimes.
AM has more heart and soul though.
The better SSB receivers still wouldn't sound as good as AM would, especially for a music broadcast. The fidelity on AM is low enough as it is. So if I were ever to do such a broadcast (which I currently have no equipment for), I would still use AM. The intent would be to get as many potential listeners as possible.
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The better SSB receivers still wouldn't sound as good as AM would, especially for a music broadcast. The fidelity on AM is low enough as it is. So if I were ever to do such a broadcast (which I currently have no equipment for), I would still use AM. The intent would be to get as many potential listeners as possible.
Part of getting more listeners is having a stronger signal. As much as I like the sound of AM, watt for watt, SSB gets out much better.
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aww hell ::)
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I've wanted to try vestegial sideband like TV and Canadian time station CHU uses. Basically it's AM with the lower sideband chopped. It's compatible with AM radio and many SWL's like myself, listen to a propagated AM signal in SSB (exalted carrier) anyway.
Peace!
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Other than being perhaps a little "tinny" on the audio, I think the ICOM R-75 does a fine job decoding music in SSB-- sounds almost like AM to me, as long as you can tune the correct frequency. You certainly don't get the "scrambled" sound of the older receivers. The only thing is the frequency range sounds a little like the old AM transistor radios, but that is improved some by using a larger external speaker. If I wasn't looking at the radio, it would be hard for me to tell the difference in most cases, and that's saying something.
My DX-394, which I'm stuck using at present, is just about unusable for SSB stations. I forgot how bad it was after having the R-75 for a few years...
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Other than being perhaps a little "tinny" on the audio, I think the ICOM R-75 does a fine job decoding music in SSB-- sounds almost like AM to me, as long as you can tune the correct frequency.
Yes, I agree completely. The key is being exactly on frequency. Most modern ham rigs are pretty good about this, but theres a few pirates I can immediately identify as soon as they sign on, just by how far off frequency they are. I won't name names :-)
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The big thing is to be heard...
That being said... I am locked in to using the SB mode to hear most of anything BUT... the product detector in the rigs I use tend to discriminate against AM... sad but true. At time I wish I had my R-390A, SX-28A or SX62A but at this location it would only hear NOISE!
If and only if (IFF) I were to do the pirate thing I would do the DSB reduced carrier thing... Most modern receivers (good ones that is) have a bandwidth of <=5KHZ... not Hi-Fi by any means really.
Fidelity wise the best a person could ask for is 5KHZ... and that can easily be done with DSB or SSB. The biggest problem would be phase distortion... but that is another problem to add to the pile...
In 'pure' AM the best detector I have used in the past is the 'infinite impedance detector'... try finding a rig with that... The biggest problem with that is NO AGC! But the audio quality is just plain incredible! It beats anything I have seen in any radio from the past to even the 'so called high tech' gismos of today.
An R390A or a SX28A that has been modified with this type of detector will beat anything a ++ kilo-buck modern rig can buy today IMHO... it is what it is....
Why use DSB? Why not? Most modern receivers can't deal with low distortion AM anyway... 5Khz IS NOT HiFi in any meaning of the word... Not even close... Heck 5Khz is less than half of what a normal human ear can hear.... Even at my advanced age I can still hear >>14KHZ...
If a receiver can hold tolerance at any frequency without adding serious phase distortion... then SSB or DSB is more than adequate... I prefer DSB but that's just me :-)
73 Vince KA1IIC
Have a great day and a better tomorrow!!! :-)