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Current Operating Frequency and Mode

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What happens where on 630-meters? A few more comments about where to place your signal depending on mode

– Posted in: 630 Meter Instructional Topics, 630 Meters

There have been a lot of questions about what mode goes where on 630-meters.  As there is an active community already in place on the band these standards are already established for many modes but for someone just coming on the band, that information may be difficult to find so I hope to handle some of that right now.

Under part-5 experimental rules the band has consisted of digital modes and CW.  Wide band modes have really not seen much activity but since the FCC has allowed them, it was thought best to locate those modes in an area where there is not much activity with the current active  community of operators.  Note that this graphic also generally harmonizes with other parts of the world, including Europe, Asia, and Oceania.  Having said that, here is what it looks like:

Courtesy W1FR


CW is pretty explanatory and just about all CW activity occurs below 475 kHz (carrier frequency).  Also most CW occurs on the opposite passband used for other low bands (40/80/160m).  That means that when in CW mode, you want to be listening to the USB passband.  Some operators may need to select CW-REV or CW-NOR, depending on their receiver.  My Yaesu FT-1000 uses CW-USB and CW-LSB to describe each receive passband.  When in doubt, check the opposite CW passband but all specified frequencies are carrier frequency.  In theory this should be a moot point with the signal heard in the same position regardless of which CW passband is used but in practice they are often very different, perhaps due to a lack of stability of an oscillator or exciter while doing a mix-down.

Why did we choose the USB CW passband?  To harmonize with the sound card modes that use USB.  There was no reason for everyone to bump into one another or try to figure out how to avoid overlap using various modes in such a narrow band.

For now, we have settled into 474.2 kHz as the CW calling frequency (carrier frequency), listening with the “reverse”  passband setting, as described above.

Here are additional breakdowns including popular digital modes:

WSPR:  474.2 kHz USB dial frequency, audio between 1400 – 1600 Hz

JT9:  474.2 kHz dial frequency, audio between 1000 – 1350 Hz (can spill into FT8 area as necessary)

FT8:  474.2 kHz dial frequency, audio between 800 – 1000 Hz (can spill into JT9 area as needed)

JT65:  Yet to be formalized but if high digital activity at 474.2 kHz dial frequency between 800 and 1350 Hz, move up to 475 kHz dial frequency + 1000 – 2000 Hz audio.  Probably best to announce your activity somewhere.  Most guys are using JT9.

Wide band modes are probably any mode wider than 200 Hz but there is nothing written in stone.  USE GOOD JUDGEMENT and when in doubt, ask!

SSTV:  This is a wide band mode and should be found somewhere above 476 kHz.

SSB: 476 kHz and up.  Some have used 479 kHz LSB which seems to work.  Don’t forget you need a linear amplifier!  Switch-mode amps won’t cut it.

RTTY:  probably best above 476 kHz somewhere.

SSTV and SSB are new territory but the plan is in place to keep wide band modes away from narrow band modes, many of which are used to complete two-way QSO’s

Note that A2 modulated CW is illegal below 50.1 MHz so NDB transmitter users keep this in mind.  WSPR is a far better beaconing method and you will receive many more reports than an unattended CW beacon.

Did I miss anything?  If you need to know about where a mode should go, send me an email on the contact page or my gmail address.

Good luck!