Professional use radio system

Mariner2011

Dear FlexRadio community, I am looking for your suggestions. We are considering using Flex 8400 with PowerGeniusXL for the coastal radio project with Bushcomm BBA-1kDE antennas (broadband, without ATU, as their VSWR is better than 2:1). TX and RX sites will be separated by about 10 km. The same radios will be used for receiving, with low-power antennas (also Bushcomm). The customer requested to replace the old system on Barrett 2050, and we are choosing between direct replacement to Barrett 4050 and Flex 8400. Flex takes less space in the rack, PowerGenius XL has its own Ethernet port for monitoring, and it can supply 1.5 kW of RF TX power. Besides, Flex 8400 is based on the latest technology, while Barrett 4050 is already quite old (while it is based on SDR technology as well). Last but not least, Flex 8400 + PowerGeniusXL is priced at half of Barrett 4050 with 1 kW amp. MIL or NATO certification, ALE, and extended bandwidth options are not required; only extended transmit modules to cover marine frequencies in 2,4,6,8,12 and 16 Mhz bands.

Do you have any suggestions? Is there anything we need to account for in advance?

What, in your opinion, are the pros and cons of Flex for my application?

The system might be used extensively, for 3-4 hours per day, on different frequencies for voice communication and Digital Selective Calling dispatch (with our software package).

Any suggestions would be greatly appreciated!

Best regards,

Leo

KD0RC

Hi Leo, I would suggest giving Flex Sales a call. They will be able to give you definitive answers to your questions.

Neil D Friedman N3DF

Does coastal use require some kind of type certification?

Bill AB7AA

Good question Neil. Marine frequency radios used to require a type certificate different than amateur. As far as I know, it still does.

73,

Bill, AB7AA

Mariner2011

Gents,

Thanks for your feedback. Yes, I have contacted Flex sales and received enough information, but I am still looking for suggestions from the community. We are building the coastal radio system, which does not require marine certification (GMDSS, IMO, etc). The end-user normally sets the requirements, which apply not particularly to the radios but to the system as a whole (required coverage, GMDSS operator procedures and software functions). Flex has an optional board for marine frequencies support, so this is not an issue. I am curious about the reliability of Flex transceivers in the case of extensive radio usage (3-4 hours per day or even more) on the full power of the PowerGenius XL amp.

Thanks!

Leo

KD0RC

Hi Leo, sounds like you are making good progress! 3 - 4 hours a day is not stressful at all. Many hams leave their Flex radios on 24/7. Mine is on about 14 hours a day unless I am out of town when I leave it on 24/7 so that I can operate remotely.

I can't speak to the reliability of the PGXL, but it should easily accommodate your needs as well.

Mariner2011

Gents, thanks for your feedback.

Yes, I have contacted Flex sales and received enough information, but I am still looking for suggestions from the community.

We are building the coastal radio system, which does not require marine certification (GMDSS, IMO, etc).

Flex has an optional board for marine frequencies support, so this is not an issue.

I am curious about the reliability of Flex transceivers in case of extensive usage of the radio (3-4 hours per day or even more) on the full power of PowerGenius XL amp.

Thanks!

Leo

Mike-VA3MW

@Mariner2011

I would like to seek some clarification. Are you using Amateur Frequencies or non Amateur Frequencies? Or, are you covered by something similar to a MARS license in this case?

As for the usage, 3-4 hours/day will not be an issue. However, the PGXL is only guaranteed performance is for the amateur bands only. It will work outside the amateur bands either at full power or reduced power. The reduction is power is not likely to have a noticeable change in operational performance. Meaning that the difference between 1500 watts and 1000 watts has little effect. (and, you might know that already, but I need to say it)

Mariner2011

Certainly, for coastal radio, we must use marine band 2 Mhz (MF) and 4,6,8,12,16 Mhz (HF). FlexRadio has an extended transmit module to support these freqs.

The coastal radio system is mostly used by MRCC operators to announce navigational warnings and connect ship crews to their homes (via PSTN switch). It is also used for dispatching Digital Selective Calling (DSC) messages. Of course, operators are licensed (GMDSS radio operator license) and trained to use the software. The area of operation is GMDSS A3, but normally, operators speak with ships within the country's EEZ (200 nautical miles).

We have separate transmission and reception sites 10-12 km apart. At some periods, four powerful transmitters will be operating simultaneously, which may damage the receiver's front end. Also, the RX part must be at a location with minimal ambient RF noise. Coastal radio communications are vital for ensuring the safety of sailors, as they provide essential support and coordination during emergencies, potentially saving lives at sea, and coastal radio centers must operate 24/7. Practically, the usage of HF radio may be more than 3-4 hours a day, these figures are average. They also using VHF, more actively.

Best regards,

Leo

John KB4DU

Just a question. Does this service use a channelized system or is the VFO acceptable? Many services to be channelized or type accepted.

David Decoons, wo2x

one thing I found is a post from Ranko. From 2.2 to 2.5 MHz, the amp does not pass part 97.307

Not sure if that impacts your use.

Mariner2011

Thanks for your note; regarding the 2Mhz band, we only use 2182, 2187.5 and 2174,5 Mhz, so it should not be an issue.

I believe that our system works in channelized mode, but I will double-check with engineering.

David Decoons, wo2x

But will they allow (type accept) the use of equipment capable of VFO operation and operating out of the marine band? That is what you need to check on. The Flex equipment is not certified for marine operation.

Mariner2011

In fact, FlexRadio, with an extended transmit module, operates within the marine band, so this is not an issue. The customer requires reliable transmission equipment and coastal station operator software (that's what we do) and is not concerned with type approvals. Besides, the system we build is not marine but coastal. So now I don't see any technical barriers to using Flex for my project.

Bill AB7AA

I think that you should consult with the FCC on this point. I think that you may receive a different answer then Flex's and theirs is governing.

David Decoons, wo2x

even though it will cover the frequency range, you must check with FCC regulations on what type certification is required. The Flex, even with extended TX module, is not type certified for marine band operation. Same for the amplifier.

Mariner2011

Well noted, with thanks!