KB7YOU Ham Radio Operations Manual   Location: Grid Square: DM41aa   DD MM SS.ss: 41d 01m 29.9s N 111d 55m 41.0s W D MM.mm: 41d 01.499m  N 111d 55.683m W D.ddd: 41.02398 Degrees North 111.92805 Degrees West

 

 

[Back to Radio Page] [Rocklizard Home Page]

 

Chris Levin, KB7YOU

 

To operate with AFSK, you put your transmitter in the SSB mode instead of FSK mode, and you put an audio signal into the microphone input (some transceivers have a rear connector for data input).  When you transmit, MMTTY causes your sound card to put out a pair of audio tones which cause your transmitter to send the required RF output.  Sounds simple, right?  Here's the tricky part:  The tones are two sine waves - nothing fancy - but the frequency and amplitude of the tones is critical. 

 

Let's say you want to transmit on 14080 kHz, as in the previous example.  Remember, your MARK signal has to be on 14080 kHz.  How do you get there with AFSK?  Here's how.  With your transmitter in the LSB mode (Lower Side Band), whatever frequency goes into the microphone input will be subtracted from what your dial says and be transmitted on that frequency.  For example if your dial says 14080 kHz. and you put in a 1000 Hz. audio tone, your transmitter will put out an RF signal at 14079 kHz., exactly 1000 Hz. lower than your dial.  So in this case, if the 1000 Hz. represented your MARK signal, you would have to set your transmitter to 14081 on the dial, and your MARK signal would be transmitted on 14080, just as you wanted.  Ok so far? Now, what about SPACE?  Remember, you want your SPACE signal to be transmitted 170 Hz. lower, on 14079.83 kHz.  What audio tone will give you 14079.83?  Simple - 14081 minus 14079.83, or 1170 Hz.  So the MARK audio frequency is 1000 Hz. and SPACE is 1170 Hz.

 

3.1        Radio Setup

• Mode: LSB
• Power: 80% Maximum. Radio gets a bit “wide” at full power when using AFSK modes.
• AGC: OFF
• Speech Compressor: OFF

• ALC/Audio Input: Peak the audio input so that ALC is in the 6-8 range.

 

20 meter RTTY is most popular. RTTY is in the 14.080 to 14.099 range. On 80 meters, tune to 3.607 MHz.

 

4.1        Radio Setup

• Mode: USB
• Power: 40 Watts works well. I have done contacts at <10 watts. Don’t exceed 80% Maximum. Radio gets a bit “wide” at full power when using AFSK modes.
• AGC: OFF
• Speech Compressor: OFF

• ALC/Audio Input: Peak the audio input so that ALC is in the 7-8 range.

 

4.2        Common PSK-31 Frequencies

• NOTE: All frequencies assume USB. Remember, PSK-31 convention is to always use USB.
• 3.580
• 7.070
• 14.070 ** Most popular
• 21.070
• 50.290
• 144.150

 

 

Common packet frequencies:

• Common range: 145.010-145.090
• 144.39 – APRS

145.010 – Used for forwarding.

 

FSK441 is a very fast digital mode for meteor scatter. JT44 is a slow digital mode for EME and troposcatter.

 

6.1        Radio Setup

Unlike other digital modes, FSK441 and JT44 like to be driven “hot”. They are designed not to cause unnecessary splatter when configured this way. Following are the basic setup parameters:

• Mode: USB
• Power: 50% to MAX. NOTE that this is a 100% duty cycle transmission for 30 seconds at a time so lower powers should be used to avoid straining the radio.
• AGC: On or Off – See the manual. I think it should be on unless it distorts incoming transmissions.
• Preamp: ON.
• Speech Compressor: ON
• ALC/Audio Input: Peak the audio input so that ALC is in the 8-9 range.

 

2 Meter calling frequency: 144.140.

6 Meter calling frequency: 50.270.

 

These tables were copied from the ARRL Operations Manual and “The Considerate Operators Frequency Guide” from QST. Note: I have not included automatically controlled data stations in these ranges.

 

 

7.1        Digital Communications Frequencies for each band

Band	Frequency Range
10 meters	28.070-28.120
12 meters	24.920-24.925
15 meters	21.070-21.090
17 meters	18.100-18.105
20 meters	14.065-14.095 (Most active digital band)
30 meters	10.120-10.140
40 meters	7.080-7.100
80 meters	3.580-3.620
160 meters	1.800-1.810

 

7.2        Other Digital Frequencies

 

Band	Frequency Range	Description
10 meters	28.190-28.225	Beacons.
	28.200	IBP/NCDXF Beacons
	28.680	SSTV
12 meters	24.930	IBP/NCDXF Beacons
15 meters	21.150	IBP/NCDXF Beacons
17 meters	18.110	IBP/NCDXF Beacons
20 meters	14.110	IBP/NCDXF Beacons
	14.230	SSTV
40 meters	7.040	RTTY DX
	7.171	SSTV
80 meters	3.590	RTTY DX
	3.845	SSTV
160 meters	1.843-2.000	SSTV, SSB and other wideband modes.
	1.999-2.000	Beacons

 

 

NOTE: 2004-01-03 – I’m hearing lots of RTTY activity on 40m in the 7.050-7.060 range. Contest weekend? Contesters tend to be VERY rude about band plans.

 

 
 

 

 

 

 

 

 

 

9.1        Fists Calling Frequencies

FISTS members can be found on or near any frequency ending in .x58 (.058, .158, .258, etc). Here are recommended calling frequencies by band. REMEMBER, these are recommended CALLING frequencies and QSO's should be moved to another frequency.

2m    144.058 MHz 6m    50.058  MHz 10m   *28.058 MHz 12m   24.918  MHz 15m   *21.058 MHz 17m   18.085  MHz 20m   *14.058 MHz 30m   10.118  MHz 40m   *7.028  MHz All IARU Regions 40m   7.058   MHz IARU Region 2 80m   *3.558  MHz 160m  *1.808  MHz

Note 1:  The calling frequencies for 10m, 15m, 20m, 40m - All IARU regions, 80m, and 160m, are only 2 kHz. below QRP calling frequencies (7.030 MHz is the QRP calling frequency in Europe). Please only QSY *down* from these frequencies.

U.S. Novice sub-bands
10m     28.158 MHz
15m     21.158 MHz
40m       7.118 MHz
80m       3.708 MHz

Note 2:  Please use the Novice sub-band calling frequencies as much as possible.  It will benefit Novices, and also provide support for retaining the spectrum.

 

9.2        Weekly Nets

Sunday Century Award Net 1500 EST/2000 UTC  & 1500 EDT/1900 UTC 14.058 MHz	Sunday Slow Speed Chat 1700 UTC 21.158 MHz
Tuesday Slow Traffic Net 2100 EST/0200 UTC & 2100 EDT/0100 UTC 3.682 MHz	Thursday Slow Traffic Net 2100 EST/0200 UTC & 2100 EDT/0100 UTC 3.682 MHz
Saturday QSO Groups 2000 UTC 14.058 MHz 2300 UTC 7.058 MHz

 

NOTE: Daylight Savings Time (DT) runs from 0200 local time the first Sunday in April through 0200 local time the last Sunday in October.