Marine AIS Equipment for NOAA WX DX

[N1LF]

Posted this on the WX & Utility Forum, but am cross-posting it here since it is equipment related. Hopefully the moderators will forgive me. I think the information is important to the community.

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AIS is a shipboard broadcast system that acts like a transponder, operating in the VHF maritime band, that is capable of handling well over 4,500 reports per minute and updates as often as every two seconds. It uses Self-Organizing Time Division Multiple Access (SOTDMA) technology to meet this high broadcast rate and ensure reliable ship-to-ship operation.

AIS operates principally on two dedicated frequencies or VHF channels: AIS 1: Works on 161.975 MHz- Channel 87B (Simplex, for the ship to ship) AIS 2: 162.025 MHz- Channel 88B (Duplex for the ship to shore)

The development of AIS has resulted in an increased demand for equipment to allow reception of these signals at 162 Mhz, including large Yagi antennas, low-noise preamplifiers, etc. DXers interested in monitoring the NOAA Weather Band can take advantage of these tools.

For example, antennas designed for AIS reception work great on NOAA Weather Radio. Here are some:

A 10-Element Yagi for just over $200:
https://antennas-amplifiers.com/prod...a-pa162-10-5a/

InnoVAntennas has a bullet-proof LFA low-noise AIS antenna for around $160
https://www.innovantennas.com/en/sho...as%20shop.html

Arrow Antennas makes a 3-element Portable Yagi for AIS
https://store.shinemicro.com/mm5/mer...e=ANT-0003-162

Also available are preamplifiers and bandpass filters that can really help boost weak DX on the WX band:

https://store.uputronics.com/index.p...&product_id=93

This one boasts a noise figure of only 1.5 dB
https://antennas-amplifiers.com/prod...ndpass-filter/

I'm interested in hearing from other WX band DXers who are using AIS antennas, preamps, filters and the results that you're having. Please also post other gear that you find in this thread.

[n2mh]

The uptronics preamp works real good for me. I use it to feed a CATV 4-way splitter which then goes to 4 different receivers. The 20 dB gain more than makes up for the ~6 dB loss in the splitter. I have the splitter feeding an rtl-sdr dongle, an old Icom IC-2800 mobile, an old Motorola Motrac vhf receive strip (which has an interesting history) and an old Midland 2-way vhf radio. Compared to the real FM radios, the rtl-sdr dongle is pretty deaf. The uptronics preamp is a pretty good hearing aid for it.

I verified that the gain is indeed in the 20 dB ballpark. And, the .75 dB noise figure sets the noise figure for all the receivers.

Note that the preamp is available from airspy us. If you are in the States, you don't have to order it from the UK.

73, Mark, N2MH