R8600 R 8600 Purpose Attenuation ?

[BOBRR]

Hi,

Have an R 8600.

Have been trying to receive Navtex on 518 KHz. No luck ever, from any station, at any time. Even when local transmitter is supposedly transmitting. Am about 50 miles from.

Have read that these low freqs are purposely attenuated in radios to reduce noise on broadcast bands.

No idea if it is on the R8600. Is it ?
If so, any way of bypassing
this attenuation ?

What would be the best filter settings, and any and all other settings to increase the probability of 518 KHz reception ?

Thanks,
Bob

W

 

[arg0s]

Have been trying to receive Navtex on 518 KHz. No luck ever, from any station, at any time. Even when local transmitter is supposedly transmitting. Am about 50 miles from.

What antenna are you using? A (active) loop would be the best option at this frequency.

Have read that these low freqs are purposely attenuated in radios to reduce noise on broadcast bands.

No idea if it is on the R8600. Is it ?
If so, any way of bypassing
this attenuation ?

The IC-R8600 has switchable attenuators but none are fixed. No need to bypass anything.

What would be the best filter settings, and any and all other settings to increase the probability of 518 KHz reception ?

IFBW > frequency shift (170Hz) + symbol rate (100Baud). A BW of 300...350Hz would be fine. Some software decoders need a larger BW (e.g. 500Hz) for scanning and locking onto the signal.

 

[merlin]

If you know the station, you can look up the times they broadcast.
Also, the same broadcast can be found on a number of ITU channels.
With about 30 navtext channels in my Barrett, it is usualy quiet, but different times of day/night,
a couple will slam in good.
1600.00 Khz is strong right now @ 0657 UTC. (northwest US)