double sideband?

[TICKDOG]

Anybody ever heard of double sideband? I think my dad had one back in the '70s

[Night Crawler]

I ran Double Sideband and Single sideband back in the early 70's with one of these and a Heathkit Apache Transmitter. [Please login or register to view this link]

[TICKDOG]

that might be it, hard to remember. sposta be in the barn in AL If I find it maybe someone in the forum can use it?

[Grizs50]

Double Sideband is also known by it's much more common name, AM, that is double sideband with a carrier. ANd also FM.

Hope that hopes.

[Night Crawler]

Double Sideband is also known by it's much more common name, AM, that is double sideband with a carrier.

There is also Double Sideband Suppressed Carrier. Where the Upper and Lower Sideband are being transmitted at the same time without a carrier.
It's not the same as Amplitude Modulation it requires that a carrier be injected to demodulate the signal usually using a BFO where you are able to tune either the Upper or Lower Sideband.

[Foxhunter]

He's right. I think in most instances when DSB is mentioned or cited, it is referring to the surpressed carrier version rather than AM (which is double sideband-ed).

Night Crawler I didn't know with DSB the demodulation process worked using an injected carrier and BFO. Learning something new every day.

What kind of radio there is it Tickdog ? Did you ever find it ? I collect radios 'ya know !

[Night Crawler]

Night Crawler I didn't know with DSB the demodulation process worked using an injected carrier and BFO.

Not both the BFO [Beat Frequency Oscillator] is adding the carrier you need to receive the information on either the upper or lower sideband [On the Receive End] that has been removed by the balanced modulator when transmitting SSB or DSB.
Most to near all modern receivers today use a carrier oscillator instead.
If you look at the SB-10 link above that was a early form of SSB generation that used a Phasing type method [Not a Balanced Modulator] which you could transmit USB, LSB or DSB with or without a carrier if a carrier was used it would result in a low level type of Amplitude Modulation.
From what I remember it was a real pain in the butt to tune

[treetall]

oh man just regular ssb confuses me. and now yall are talking about double ssb. let me get up out of here

[Slowdraw]

Think of AM as having 3 components: Carrier (dead key) and upper and lower sidebands. There is more explanation possible but I don't want to get too technical.

The early sideband radios only suppressed the carrier allowing the station that is receiving it's signal to tune to either the upper or lower sideband. It was cheaper in the early days to build a transmitter like that. Crystal filters were very expensive and a necessary part of a "single" sideband radio. A good example of one of these DSB (double side band) radios is a Tram Titan II, but there were others.

Transmitting both sidebands is a waste of 50% of your transmitters power (obviously) so as soon as technology got better, the radios that used DSB disappeared.

[De_Wildfire]

Is double sideband the same as the ESSB mode on some radios today?

['Doc]

"Is double sideband the same as the ESSB mode on some radios today?"
No, it isn't. One is talking about how a signal is presented, both upper and lower sidebands. ESSB is related to audio bandwidth, meaning the transmitted signal is wider because a wider range of audio is being transmitted, it's still just one sideband.
- 'Doc

You also won't find that 'ESSB' on any commercially sold radio. You can only get it by modifying a transmitter. It doesn't meet standard FCC standards.

[TheCBDoctor]

Hi,

In the early days of CB channel 23 was reserved for both regular CB voice and special use on a secondary basis for remote control in both the automotive and medical fields. That special use allowed a double sideband suppressed carrier with a peak power of 25 watts.

When the band was expanded to 40 channels the use of channel 23 for double sideband was eliminated. That is why there is 20 KHz between channel 23 and channel 22 on the older 23 channel radios. The FCC just mandated that channel 24 and 25 be placed in between channel 22 and 23. The order in frequency is actually channels 22, 24, 25, 23 and then 26.

Double sideband suppressed carrier is still used for certain applications, but not in the CB band. With the introduction of FM and digital technologies, it will soon be a thing of the past. By the way, if you are running 2 watts dead-key and have a peak power of 35 watts, then you are running double sideband suppressed carrier. The carrier is not eliminated but reduced to a point that at a some point in the distance an AM receiver will not pick up the carrier and you will sound raspy or off frequency because, although the carrier is a waste of power, it is needed for an AM receiver to properly receive such a signal.

Respectfully,

[De_Wildfire]

"Is double sideband the same as the ESSB mode on some radios today?"
No, it isn't. One is talking about how a signal is presented, both upper and lower sidebands. ESSB is related to audio bandwidth, meaning the transmitted signal is wider because a wider range of audio is being transmitted, it's still just one sideband.
- 'Doc

You also won't find that 'ESSB' on any commercially sold radio. You can only get it by modifying a transmitter. It doesn't meet standard FCC standards.

Elecraft is a commercially sold software like Yaesu, Kenwood, Icom, and Tentec and there is a ESSB option in the menu which is a simple on/off function. To modify a radio like this you have to download the software. When I opened up this radio for the emergency communication services to go out of band, the manufacturer needed proof of all sign and then they sent me a link to click on. When the radio does updates I have no control of it. It does a lot of clicking on and off and I have to wait until it's finished.

[Slowdraw]

I hope to get an Elecraft K3 someday. QRP and CW are some of my interests. A K2 would make me happy though, and I'd get to put it together! Yay!