pro2004, 31.1000 MHz FM and 31.8000 MHz FM seem to be two of the more commonly heard low band fisheries radio frequencies for myself too.
This is a French signalling system for turning on and off street lighting and other things. I hear them a lot via Sp-E.
I think the three freqs are 31.325, 31.6875, 31.975. A French friend informed of this.
They can't be very high powered.
If you can hear these also check 35.0 - 36.2 in 12.5 khz steps NFM for Autoroute traffic out of France which can be data or voice.
These are incredibly busy.
31.3250 MHz 31.325 FM seems to come in every time I can hear Europe on 11m/10m and VHF low, at least the lower parts of VHF low band. Often it comes in with the POCSAG paging signals all over 26 MHz but also 29.750 MHz, 29.800 MHz, 29.850 MHz, 29.900 MHz and 29.950 MHz. The UK hospital paging systems use 26 MHz, 27 MHz, 31 MHz and 49 MHz. The 31 MHz frequencies are 31.725 MHz 31.750 MHz and 31.775 MHz.
Next time I hear the data signals on 31.325 MHz / 31.975 MHz I’ll also check 31.6875 MHz.
35.000 MHz - 36.200 MHz (12.5 kHz steps) is a good one too. I know that another active data band is the 40 MHz Italian paging band:
40.0125 MHz
40.0375 MHz
40.0625 MHz
40.0875 MHz
and the 43 MHz “VHF CB” band (Italy). 43.3000
MHz to 43.5875 MHz 12.5 kHz steps. Lots of data link signals on those frequencies as well as FM voice. Apparently the 43 MHz equipment is widely used outside of Italy and it can easily be modified to cover 42.3000 MHz - 45.0875 MHz (in 12.5 kHz steps) with increased power instead of the usual 43.3 MHz - 43.5875 MHz band.
The 26-28 MHz band is
full of paging and data link or telemetry signals when the band is open.
26.150 MHz to 26.950 MHz (50 kHz steps) with notable frequencies being 26.700, 26.750, 26.900 and 26.950 MHz. 26.700 MHz and 26.750 MHz will usually have multiple signals on them at once, and in some countries a specific system will be offset +/- 5 kHz so 26.695 MHz, 26.700 MHz, 26.705 MHz and 26.745 MHz, 26.750 MHz, 26.755 MHz.
26.950 MHz is home to paging systems and data links. Lots in Europe.
26.945 MHz and 26.960 MHz are used for 2 watt data link systems.
I can also identify the use of 27.300 MHz, 27.350 MHz, 27.360 MHz, 27.450 MHz up to 27.950 MHz as POCSAG paging frequencies (somewhere in Europe) - 50 kHz steps. Offsets that I’ve personally noted in use include
27.500 MHz - offsets: 27.505 MHz 27.510 MHz and 27.5125 MHz
27.850 MHz - offsets: 27.845 MHz, 27.8475 MHz and 27.848 MHz.
27.450 MHz has a paging system on it (someplace in Northern Europe or the Nordic countries). The interesting thing about 27.4500 is that particular system transmits an unmodulated FM carrier when the pager transmitter is idle.
Of course, when the band is open, the entire 26-28 MHz band is loaded with CB chatter, AM, FM and SSB.
For Latin American and US band openings:
26.995 MHz
27.045 MHz
27.095 MHz
27.145 MHz
27.195 MHz
27.255 MHz
26.9950 and 27.1950 both have multiple data link systems on them that I hear when the band is open to Latin America. 27.195 has at least one constant MFSK data stream signal on it, and there’s another MFSK data burst system that uses 27.195 and I have logged on 26.995 as well. 27.255 is home to all sorts of data links, data bursts, telemetry and I’ve even heard POCSAG paging signals on it. Most of the time it’s FSK or MFSK bursts on 27.255 though. 27.2550 MHz is also CB Radio Channel 23 so it will often be a real mess, but even in AM mode the FSK bursts will come in. In FM mode too, but USB/LSB is where they really come screaming in. Do a Google search for “data bursts 27.255” or “data 27.255 MHz” and there’s all kinds of examples. FCC regulations permit up to 4 watt output on 26.995, 27.045, 27.095, 27.145 and 27.195 for data, remote control and telemetry - and up to 25 watt output on 27.255 for the same purposes. Bandwidth is limited to 8 kHz but there’s no restriction on the mode itself, which explains the wide variety of data digital signals heard on these frequencies.
