Ever wonder why 40 meters is LSB and above 40 meters is USB

[htperry]

WHY THINGS ARE THE WAY THEY ARE....Ever wonder why 40 meters is LSB and above 40 meters is USB?

We can blame Central Electronics ... In September 1952 they came out with the CE-10A a multiphase exciter with 9 Mhz phasing circuitry The 9 Mhz SSB signal was then heterodyned by mixing with a 5 Mhz crystal or suitable external VFO to the desirable frequency , 9 Mhz minus 5 Mhz gave us 80 meter LSB, 9 Mhz plus 5Mhz produce 20 meter USB. A commonly used 5 Mhz VFO was the military BC-458 transmitter with a reduced power output obtained by reducing plate voltage to 75 VDC. In that, the standard was established by Central Electronics, subsequent manufacturers followed suit with their designs. ...

For a complete history of the Central Electronics product line CHECK ...http://www.ce-multiphase.com/history.html

 

[WZ4I]

All except 60M, which is USB.

 

[Jeepsnguns]

I always wanted to know that but didn't take the time to research or ask. Thank you.

 

[htperry]

All except 60M, which is USB.

The 60m secondary allocation for ham radio didn't exist in 1962.

 

[WZ4I]

It did not. However it does now...

 

[noway2]

I had wondered why that was the case. So it was a technical coincidence....

 

[georgel]

I love learning about the history of why things are the way they are. So much convention is because, "it how it's ways been done" or like in this example, because it's what we had and it just sticks. Ah, tradition.

Along a similar vein but totally unrelated to radio is the video series How the States Got Their Shapes. Fascinating if sometimes querky history.

Yeah, the 60m allocation was contemporary enough to not be bound by convention. But, arguably the whole band is atypical and un-conventional.

Another prime example is that commercial aircraft, up until very recently, and I don't actually know if this ever changed, still had landing gear levers that had little wheel on them for visual confirmation. Many digital readouts were designed to mimic the look and feel of analog readouts. I got to "test fly" some real world training simulators a few years back and was very surprised. [IMG2=JSON]{"data-align":"none","data-size":"full","src":"https:\/\/s.yimg.com\/lo\/api\/res\/1.2\/fF7nOb55aif9nXTb29HtKQ--\/YXBwaWQ9eWlzZWFyY2g7Zmk9Zml0O2dlPTAwNjYwMDtncz0wMEEzMDA7aD00MDA7dz01MzM-\/http:\/\/www.infobarrel.com\/media\/image\/32549.jpg.cf.jpg"}[/IMG2]

 

[WZ4I]

I love learning about the history of why things are the way they are. So much convention is because, "it how it's ways been done" or like in this example, because it's what we had and it just sticks. Ah, tradition.

Along a similar vein but totally unrelated to radio is the video series How the States Got Their Shapes. Fascinating if sometimes querky history.

Yeah, the 60m allocation was contemporary enough to not be bound by convention. But, arguably the whole band is atypical and un-conventional.

Another prime example is that commercial aircraft, up until very recently, and I don't actually know if this ever changed, still had landing gear levers that had little wheel on them for visual confirmation. Many digital readouts were designed to mimic the look and feel of analog readouts. I got to "test fly" some real world training simulators a few years back and was very surprised. [IMG2=JSON]{"data-align":"none","data-size":"full","src":"https:\/\/s.yimg.com\/lo\/api\/res\/1.2\/fF7nOb55aif9nXTb29HtKQ--\/YXBwaWQ9eWlzZWFyY2g7Zmk9Zml0O2dlPTAwNjYwMDtncz0wMEEzMDA7aD00MDA7dz01MzM-\/http:\/\/www.infobarrel.com\/media\/image\/32549.jpg.cf.jpg"}[/IMG2]

If you love learning history, a trip to Newington, CT is a must. I have been several times, and each time I learn something new....

 

[WZ4I]

 

[georgel]

I've only been to CT a couple of times in my life and that was on business. If I happen up that way again, sometime, I'll be sure to stop by.

 

[WZ4I]

I've been very fortunate, and have been several times. If you get a chance to go, plan on spending at least 4 or 5 hrs there. They will take you on a tour of HQ, where you can see first-hand the testing labs, QSL Bureau, etc. The W1AW Memorial Station is open to all licensed amateurs to operate. The QSL card above was sent to a friend of mine in Taylorsville that I worked on 40M when there in back in 2006.

Watch the video... > http://www.arrl.org/w1aw

 

[htperry]

It did not. However it does now...

This post was not a band plan. It was about "how did the bands 40m and below come to be commonly LSB in 1952".

While 60M exists now, other band allocations have been made since 1962 and will be made from this point forward. The explanation of how LSB came to be in common use in 1952 will still be the same.

 

[WZ4I]

This post was not a band plan. It was about "how did the bands 40m and below come to be commonly LSB in 1952".

While 60M exists now, other band allocations have been made since 1962 and will be made from this point forward. The explanation of how LSB came to be in common use in 1952 will still be the same.

I'm very familiar with the history of amateur radio.

 

[htperry]

sigh

 

[JohnFreeman]

CE's scheme was (and is) brilliant.... I have a 20A with the matching VFO (which as you say , is a packaged ARC5) transmitter on the air and it really works well. Nulling the carrier with a magic eye tube indicator is really effective and fun). I drive a Globe/WRL LA1 linear with it for about 150W PEP out and I get excellent reports. It's a handfull of knobs as you can imagine, but that's part of the fun.

While I use it mostly on the Vintage SSB net, it's always fun to move around 20M and not mention the rig until the other stations mentions theirs, or comments on the good audio.

Thanks for the reminder of the excellent engineering that went into the VFO mixing scheme. Its a lasting testament to the task of engineers, which is almost always to do the most with the least.

 

[noway2]

Keep in mind that was back in the day before they could say, ah, well, we'll just fix it in the software.

 

[htperry]

Keep in mind that was back in the day before they could say, ah, well, we'll just fix it in the software.

The gentleman's custom of LSB for 40M-below came out of how early SSB hardware functioned. On the original bands, there's no regulatory requirement that you use LSB on 40m-below. It's an honored custom that aids in keeping traffic straight. You'll be more successful in the hobby if you are compatible with the most operators, which on 40M-below will be to generally operate LSB.

You will still hear operators using USB, DSB and AM on any of the bands that aren't required by regulation to a particular operation; i.e. when at band edges, you may use LSB/USB to keep from overrunning the edges (only one example). I think the least likely you will hear is Double Side Band, but it's not unheard of. BTW, there's a difference between regulatory requirements and ARRL guidelines. It's an important distinction.

JohnFreeman What transmitter do you have that is DSB? I'm sure with your vintage collection, you have an old B&W with side band generator or something similar. This could lead to another thread about the reluctance of operators to adopt side band operation at all. It was like the vinyl records vs CD days.

 

[WZ4I]

You will still hear operators using USB, DSB and AM on any of the bands that aren't required by regulation to a particular operation; i.e. when at band edges, you may use LSB/USB to keep from overrunning the edges (only one example). I think the least likely you will hear is Double Side Band, but it's not unheard of. BTW, there's a difference between regulatory requirements and ARRL guidelines. It's an important distinction.

K4OKA (Big Al) was notorious for running DSB, with a Henry 8K. That was until Riley Hollingsworth with the company of local LE knocked on his door..

 

[JohnFreeman]

I do have a B&W with SB generator (and a B&W5100 back in there somewhere too), but I think it's a filter type generator, not DSB (at least after the filter).
I don't think I have any DSB rigs other than perhaps a WRL transmitter ... the 40/80 small rig might be DSB.

Now... AM, I have a lot of those!