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Standard-Horizon GX2400GPS VHF DSC Radio

Posted: Mon Feb 17, 2020 10:26 am
by jimh
In their 2020 Marine Communications Products Catalog (available on-line) Standard-Horizon is showing a "new for 2020" VHF Marine Band Fixed-mount Digital Selective Calling radio, designated model GX2400GPS. I don't see this radio on the FCC website for approved devices, so perhaps its actual release and availability is pending in the USA. I present a brief preview of the radio, based on the catalogue information.

Fig. 1. New Standard-Horizon GX2400 VHF Marine Band DSC radio
GX2400.png (97.7 KiB) Viewed 1707 times

Most interesting to me is the qualification of the GX2400 radio for DSC compliance to ITU-R. M.493-15. This recommendation was publish in January 2019 and is the most recent revision of the recommendation. Most DSC radios being sold in the USA at present are certified to comply with prior revisions of this standard, usually the -13 revision which was published 11 years ago in 2009. At this moment, I believe that the FCC regulations still use ITU-R. M.493-13 as the standard for compliance for DSC radios to be sold in the USA. European DSC radios most likely need a more up-to-date standard for compliance. Because there is a global market for VHF Marine Band radios, and Europe is a large part of that market, it is now common for manufacturers to make radios that can comply with several standards, with the FCC in the USA and the European Union (EU) in Europe being the two biggest markets, and with different standards. I suspect that one significant difference at the moment between FCC and EU regulations is the need in Europe that the radio MUST include an integral GNSS receiver.

Standard-Horizon GX2400 Features:
  • two integrated AIS receivers monitoring both AIS channels simultaneously
  • second station capability with remote microphone
  • NMEA-0183
  • NMEA-2000
  • integral GPS 66-channel receiver
  • noise cancelling on receive and transmit
  • integrated voice scrambler with 32 or 4 code
  • fog horn
  • hailer
  • position plot display for navigation
  • although not required for Class-D DSC, this radio adds position polling and position reporting features, normal for Standard-Horizon
  • NOAA weather radio receiver with alert monitoring
  • wireless remote RAM4W or SSM-71H microphones with optional SCU-30 wireless access point

Dimensions for the front panel are 7.1-inch wide and 3.1-inch high. For flush mounting the cutout dimensions are 6.3-inch wide and 2.5-inch high. I suspect the case size has very likely been made to be compatible with prior models that flush-mounted, so that this GX2400GPS can be a drop in replacement to the existing cut-out. (More research needed to verify this.)

With the fog horn, hailer, and second station features the GX2400 is more suited for larger boats.

The GX2400GPS continues the use of soft-keys, with three keys below the display changing function as indicated by the legends above them. Four input buttons that on some prior models were below the soft-key buttons are now moved to the right of the display. This should improve the user interface by separating the four dedicated-function buttons from the three soft-key or variable function buttons.

There are separate volume, squelch, and on-off buttons and the familiar rotary dial for menu selection with a push-to-select button function integrated with the dial on the far right of the front panel. Dedicated scroll left-right buttons flank the soft-keys. The DSC DISTRESS CALL button is separated from the other controls and contained under a hinged cover on the far left.

Standard-Horizon denotes a new "Group Monitor" function, without much explanation. I presume "Group Monitor" refers to an ability to request position data from a preset list of other boats on at a defined interval, allowing a group of boats traveling together to see each other's position automatically without any operator needing to initiate a DSC call.

The more elaborate than usual voice scrambling feature should be attractive to boaters, particularly commercial fishers, who prefer to have some privacy to their VHF voice radio communication.

The Marine Band receiver is specified as an "80 dB" receiver. This most likely alludes to the receiver's ability to reject intermodulation of two strong local signals. A National Telecommunications and Information Administration (NTIA) study in 1999, "Evaluation of Marine VHF Radios: Compliance to IEC Receiver Standards", studied nine radios available. They found:

Four radios failed the co-channel rejection ratio test and only two radios passed the adjacent channel selectivity test. In most cases the radios which failed were within 3-5 dB of passing the tests. The most important IEC tests, which are related to the complaints about interference in Savannah and New Orleans, were the intermodulation rejection ratio and blocking tests. Four radios passed the intermodulation test while only one passed the blocking test.

While the available literature from Standard-Horizon fails to clarify exactly what performance is being claimed by the designation "80 dB", a reasonable inference is the strong-signal intermodulation rejection or blocking specification required in IEC 1097-7, "Global Maritime Distress and Safety System (GMDSS)-Part 7: Shipborne VHF Radiotelephone Transmitter and Receiver-Operational and Performance Requirements, Methods of Testing and Required Test Results" is being met or exceeded.

Re: Standard-Horizon GX2400GPS VHF DSC Radio

Posted: Mon Apr 27, 2020 9:36 am
by jimh
The Standard-Horizon GX2400GPS VHF Marine Band DSC radio was granted approval for sale in the USA by the Federal Communications Commission (FCC) on March 20, 2020 under FCC ID number K6630673X3D. This indicates that retail sales of this model should begin soon.

Perhaps related, I notice that WEST MARINE is having a short-term sale (ends 4/27/2020) on the GX2200 Matrix AIS GPS fixed mount radio this weekend, with the price lowed by $100 to $299 from their usual $399 price. This may be a signal that retailers want to clear out old inventory of a similar model that is about to be replaced by a new model.

In documents submitted to the FCC for verification, I notice that the laboratory doing the certification testing was

Shenzhen Huatongwei International Inspection Co,. Ltd.
1/F, Bldg 3, Honfa Hi-tech Industrial Park, Genyu Road, Dianlias, Gongming,
Shenzhen, China

Searching the FCC database of approved testing agencies, I began just by specifying the country as China. This produced hundreds of results. I found Shenzhen Huatongwei listed. The FCC reference number is CN1181. The scope of their approval for testing includes: "B3 Maritime & Aviation Radio Services equipment in 47 CFR parts 80 & 87."

The report lists the manufacturer of the device as

Vtech (Dongguan) Communications Limited
Xia Ling Bei Management Zone, Liaobu, Dongguan, Guangdong, China

The applicant for approval is listed as

Yaesu Musen Com., Ltd.
Tennozu Parkside Building 2-5-9 Higashi-Sinagawa, Shinagawa-ku,
Tokyo 140-0002 Japan

The device submitted for testing arrived on February 18, 2020. (That is one day after I published the intitial part of this article-thread, based on a catalogue downloaded from Standard Horizon.) Testing was completed and the final report indicating the device PASSED occurred on March 13, 2020. A week later the FCC granted formal approval.

I find interesting that Yaesu Musen, the parent of Standard-Horizon, is now subcontracting the building of their latest VHF Marine Band radio to a manufacturer in China. Also interesting is the use of a testing laboratory in China for certification. Although many VHF Marine Band radios have been manufactured in Japan, they were often submitted for testing to a USA-based FCC-authorized test agency for approval. Recall that at one time Standard-Horizon was a subsidiary company of Motorola. I authored a brief history of Standard-Horizon in 2017. See

Standard-Horizon: A bit of history

Re: Standard-Horizon GX2400GPS VHF DSC Radio

Posted: Thu Apr 30, 2020 9:19 am
by fno
BOE Marine has the GX2400 in black for sale but it is listed as backordered. Price is set at $449. That's considerably higher than the much talked about but never seen GX6000 radio that is now priced at $389 on the same website and is in stock.

Re: Standard-Horizon GX2400GPS VHF DSC Radio

Posted: Sat May 02, 2020 9:47 am
by jimh
GX2400GPS Rear Panel

Fig. 3. GX2400GPS rear panel.
GX2400RearPanel_.jpg (46.08 KiB) Viewed 1029 times

  • Antenna
  • NMEA-2000
  • External GNSS Receiver (if used)
  • Remote Mic (if used)
  • DC Power
  • NMEA-0183
  • External Speaker
  • PA/Hailer Speaker-mic


ASIDE to FRANK: the GX6000 radio is not the best choice for a small boat installation for several reasons:
  • GX6000 needs a separate AIS antenna; GX2400GPS does not;
  • GX6000 has eight rear panel connectors; GX2400 has only four rear-panel connectors;
  • the GX6000 radio is larger in size than the GX2400GPS.

Re: Standard-Horizon GX2400GPS VHF DSC Radio

Posted: Sat May 02, 2020 10:09 am
by fno
Thanks for the additional information, Jimh. I did not want to distract this informative thread with further conversation about the GX6000 radio. BTW, I am glad I did not run out and buy one and that is thanks to you for pointing out its unsuitability on a smaller boat for the aforementioned reasons. As I've mentioned before, if I do decide on a GX2400 before you do, I'll send it to you first for some evaluation and testing in Michigan.

Re: Standard-Horizon GX2400GPS VHF DSC Radio

Posted: Thu May 28, 2020 11:28 am
by kwik_wurk
I was looking at the specifications between the Standard-Horizon GX2400 and the GX6000, and I had settled on the 6000. Having two antenna is not an concern for my boat. The choice was because having a dedicated listening on both AIS and VHF would be helpful compared to having the device duplex the two all the time (and buying a splitter).

jimh--do you have any other opinions or suggestions.

Re: Standard-Horizon GX2400GPS VHF DSC Radio

Posted: Sat May 30, 2020 4:08 pm
by jimh
With the GX6000 and two separate antennas, one for the VHF Marine Band radio and the other for the AIS receiver, you may not be able to always receive AIS signals on the AIS receiver while the VHF Marine Band radio is transmitting because of the overloading and desensitizing of the AIS receiver from the 25-Watt transmit signal of the VHF Marine Band radio. However, if the two separate antennas were far enough separated, the AIS receiver may continue to be able to receive while the radio transmits. Some of that depends of the spectral purity of the transmitter's output. Some of that depends on the design of the AIS receiver and its ability to tolerate very strong signals on nearby frequencies. And some of it depends on how strong the AIS signals that are being sent at that moment while the transmitter is operating.

Using two antennas for the GX6000 will be better and probably cheaper than buying an active antenna switch or "splitter" to share one antenna. See another article on how to locate two antennas on a small boat for best isolation between them:

Mounting Two VHF Marine Band Antennas on a Small Boat

If you were to get the GX2400, that device will already have a built-in switching mechanism that will disconnect the AIS receiver from the shared antenna when the radio goes into transmit. You do not need to add anything to the GX2400 like an external antenna active switch or "splitter" to use it.

Re: Standard-Horizon GX2400GPS VHF DSC Radio

Posted: Thu Jun 04, 2020 12:23 am
by kwik_wurk
Unfortunately the antenna layout is awful--I already knew this. The antennas are basically 42-inches apart and abeam each other.

Part of why I was choosing to get a separate AIS antenna and separate just enough on the frequency spectrum to hopefully get out of saturation situation. I could look for another mounting position, but the hardtop has some limitations.

Re: Standard-Horizon GX2400GPS VHF DSC Radio

Posted: Sat Jun 06, 2020 9:53 am
by fno
It appears that the GX-2400B is in stock now at BOEMARINE.COM.