Identification Question
 

I was looking for a graphic of the US Ham Bands that included the ARRL
band plan to replace the out of date posters in the club's shack. I
went to looking around and found a few neat looking PDF files but I
couldn't find a poster that has both the Part 97.301 and the ARRL band
plan in graphical form.

I couldn't find what I wanted, so in true ham radio style I started to
develop one of my own. While I was digging though part 97.301 and the
ITU band plans I came up with an unanswered question. In Part 97.301,
only 60 Meters is specified to be USB. The rest of the bands can
legally be used with either USB or LSB when using SSB phone. I figured
that the ARRL's band plan would specify USB or LSB for the band, but
they don't, at least in the tables I found.

I understand that there is a convention born of convenience when SSB
was just getting started. Apparently it was easier to build multi-
band rigs for SSB that did upper and lower side band on various bands
when this all got started but most of us don't build our rigs today.

Where can I find out what the convention here is for 160, 80, 40, 20,
17, 15, 12, 10, 6, 2 (and up) SSB phone operation?

Thanks!

-= bob =-

Identification Question
 

"KC4UAI" wrote in message
...
I was looking for a graphic of the US Ham Bands that included the ARRL
band plan to replace the out of date posters in the club's shack. I
went to looking around and found a few neat looking PDF files but I
couldn't find a poster that has both the Part 97.301 and the ARRL band
plan in graphical form.

I couldn't find what I wanted, so in true ham radio style I started to
develop one of my own. While I was digging though part 97.301 and the
ITU band plans I came up with an unanswered question. In Part 97.301,
only 60 Meters is specified to be USB. The rest of the bands can
legally be used with either USB or LSB when using SSB phone. I figured
that the ARRL's band plan would specify USB or LSB for the band, but
they don't, at least in the tables I found.

I understand that there is a convention born of convenience when SSB
was just getting started. Apparently it was easier to build multi-
band rigs for SSB that did upper and lower side band on various bands
when this all got started but most of us don't build our rigs today.

Where can I find out what the convention here is for 160, 80, 40, 20,
17, 15, 12, 10, 6, 2 (and up) SSB phone operation?

Thanks!

-= bob =-


Extracted from the fcc question pool -- see google for "usb lsb convention"
get a pdf file "Technician Study Sheet"

sez

Radio Modes

The simplest radio signal is just a single frequency. By turning that radio
wave on and off, it's possible to send morse code (CW). Amplitude
Modulation is the simplest voice modulation scheme but it's not very
efficient because it has two identical (redundant) sidebands with the voice
information and the radio carrier that doesn't contain any information.
Amateur radios often use Single Sideband (SSB) transmissions that are
spectrally (space) and power efficient by removing one of the AM sidebands
and the carrier before transmission. This leaves either the upper or lower
sideband (USB/LSB). Convention dictates that lower sideband (LSB) signals
are used below 10MHz and upper sideband (USB) is used above 10MHz.



60M as you pointed out is USB



Lamont

Identification Question
 

In article ,
KC4UAI wrote:
I understand that there is a convention born of convenience when SSB
was just getting started. Apparently it was easier to build multi-
band rigs for SSB that did upper and lower side band on various bands
when this all got started but most of us don't build our rigs today.

The story I heard is that this started because Collins radios had an IF
of 9MHz and only needed one set of (expensive) sideband filters to have
LSB below 9 and USB above. Mixing to get the final output: F1+F2 gives
same sideband you start with, F1-F2 inverts.

That's what I was told.

Identification Question
 

On Dec 13, 8:27�pm, (Mark Kramer) wrote:
In article
om,

The story I heard is that this started because Collins radios had
an IF of 9 MHz and only needed one set of (expensive) sideband
filters to have
LSB below 9 and USB above. Mixing to get the final output:
F1+F2 gives
same sideband you start with, F1-F2 inverts.

That's what I was told.

You were told wrong. That mixing scheme does not invert the
sideband.

This amateur radio urban legend has been around a while, but that's
the first time I heard it attributed to Collins.

Here's what really happened:

A few hams were using SSB in the 1930s. W6DEI, Ray Moore, was
on the ham bands with SSB in 1934 or earlier, and the use of SSB
is promoted in "200 Meters And Down", first published in 1936. But
it wasn't until after WW2 (late 1940s) that SSB began to become
really popular with hams.

The HF ham bands in those days were just 80, 40, 20, 11 and 10 meters.
US hams didn't get 15 meters until 1953 or 54, and didn't
get 30, 17 and 12 meters until after 1979. 160 had been a popular
band before WW2 but it was reallocated to LORAN during the war
and we got it back a little at a time over many years, with all sorts
of restrictions, until LORAN was finally phased out.

40 meters had no 'phone segment until 1953/54, either. 11 and 10
were great as long as there were sunspots.

So the two most popular 'phone bands were 20 and 75, which were
much narrower then than today. For some reason, the 75 meter SSB folks
chose LSB, while the 20 meter gang went for USB. Most rigs of the time
could do either sideband on either band, but the convention took hold
early on and never changed. When US hams got 15 meters, it seemed
natural for 15 to be USB, and when 40 got a 'phone band, it was
equally natural for 40 to be LSB. It had nothing
to do with Collins or 9 MHz IFs.

Now about the mixing scheme:

None of the early Collins ham rigs had a 9 MHz IF. Collins made
mechanical filters, which were only practical up to about 500 kHz
or so, and sideband choice with them was a simple matter of
switching a BFO crystal.

Some early SSB transmitters did indeed generate SSB at 9 MHz, and then
heterodyned it to 75 or 20 by mixing with a VFO in the
5 MHz range. But that mixing scheme *does not* invert the
sideband! If you take a 9 MHz SSB signal and mix it with a 5 MHz
VFO signal, you'll get the same sideband out of the mixer as you
put in, regardless of whether you add for 20 or subtract for 75.
The VFO will tune backwards on 75, but the sideband will not
invert. Those early rigs all had USB/LSB switches in order
to match the convention.

The only way to get sideband inversion by mixing is if the local
oscillator frequency is higher than both the input and output signal
frequencies. The 9 MHz-IF story isn't just an urban legend - it
flat out doesn't work.

It *is* true that if you generate SSB in the 5 MHz region and mix it
with a ~9 MHz VFO, you'll get the desired sideband inversion. Some
1960s SSB rigs used that scheme - but they were long after the
convention was in place. And the urban legend doesn't mention
those rigs.

If you want to see the math on how all this works, I can post it.

73 de Jim, N2EY

Identification Question
 

Identification Question
 

On Dec 14, 6:43�am, Bill Horne wrote
:

ISTR that early Swan transceivers offered only USB
for 20, 15, and 10,
and only LSB for 80 and 40.

You are correct, sir! But they were not the only ones to do
that - National and some others did too. The early Heath
monobanders had no sideband switch, for example.

Swans used IFs in the 5 MHz range.

They say the memory is the second thing to
go, but perhaps that was where this convention got started.

The problem is that by the time Swan showed up in the early 1960s,
the standard was already in place. And later Swans let you use
either sideband.

The 9 MHz IF/ 5 MHz VFO system was popular in the 1950s. The
Central Electronics 10A, 10B and 20A exciters all used it, as did
the popular W2EWL SSB rig featured in the article
"Cheap and Easy SSB". You'd think those popular rigs would have
caused the standard to be that the same sideband would be used
on both 20 and 75, because they don't invert the sideband. Swan
would then have been bucking an established trend. Yet the opposite
is true. I suspect that Swan chose their heterodyne scheme to
save a little money by not needing a second BFO xtal nor a switch.

BTW, given a choice between LSB and USB, the
military's preference is
for Upper sideband, since using USB makes it easy to talk another
station on to a net frequency: if his voice sounds high, then so is his
frequency.

IMHO, there's also the simplicity. If everyone is on USB, regardless
of band, you don't have to think about which one to use, or even
provide a choice.

73 de Jim, N2EY

Identification Question
 

In article ,
wrote:
On Dec 13, 8:27�pm, (Mark Kramer) wrote:
and we got it back a little at a time over many years, with all sorts
of restrictions, until LORAN was finally phased out.

LORAN is still active, at least according to the Coast Guard.

Identification Question
 

(Mark Kramer) wrote:

LORAN is still active, at least according to the Coast Guard.


LORAN "C" still exists* but LORAN "A" has been eliminated. It was
LORAN A that used part of what we call the 160 meter band.



* But just barely exists, at that. Take a look at a marine electronics
catalog. The only LORAN-related product that I was able to find by
searching an on-line catalog was a replacement antenna that was made by
Shakespeare. You would think that the flat panel multifunction displays
(depth, RADAR, fish finder, moving map, etc.) would have LORAN as an
option, to back up GPS, but it appears to me that they do not.

--
Klystron

Identification Question
 

On Thu, 13 Dec 2007 20:27:37 EST, (Mark Kramer)
wrote:

The story I heard is that this started because Collins radios had an IF
of 9MHz and only needed one set of (expensive) sideband filters to have
LSB below 9 and USB above. Mixing to get the final output: F1+F2 gives
same sideband you start with, F1-F2 inverts.

That's what I was told.

The real story is that it was the Central Electronics (CV ??) exciter
that had that scheme.
--

73 de K2ASP - Phil Kane

From a Clearing in the Silicon Forest
Beaverton (Washington County) Oregon

e-mail: k2asp [at] arrl [dot] net

Identification Question
 

On Fri, 14 Dec 2007 06:43:35 EST, Bill Horne
wrote:

BTW, given a choice between LSB and USB, the military's preference is
for Upper sideband, since using USB makes it easy to talk another
station on to a net frequency: if his voice sounds high, then so is his
frequency.

USB was the commercial standard for the 50 years or so that I've been
in that business. Even with ISB (Independent SideBand) where each
sideband has different information, the "lower" sideband(s) are not
inverted relative to the "upper" sideband(s).
--

73 de K2ASP - Phil Kane

From a Clearing in the Silicon Forest
Beaverton (Washington County) Oregon

e-mail: k2asp [at] arrl [dot] net