Quote from: Cherry on December 11, 2018, 08:32:21 PMThis article was written by the US tester.
A review of the new Retevis RT51- an inexpensive Poc Alternative

The  RT51 PoC Handheld radio is a Push-to-Talk (PTT) communications tool, uses existing AT&T and T-Mobile cellular for voice signal propagation. Retevis presents it as an inexpensive communications device and platform that allows for group and one-on-one PTT communications over great distances. The radio is listed for sale on the website for only $129.00 which is very inexpensive compared to existing similar radios on the market. You can see the listing and purchase here: https://www.retevis.com/rt51-poc-hier-handset-radio
Requirements to put the radio to work are:

1. a SIM card for at least 500MB data for each radio;
2. The software to program your radio and programming cable.
3. the admin account to manage groups and users;
4. the dispatch platform for managing all your business communications.
PoC stands for PTT over Cellular. There are a plethora of these devices and platforms showing up in the marketplace these days. They all require access to the internet, a data plan with a cell phone company and a communications server to connect to that provides the connectivity for the subscribed to services.

Interesting feedback.

I agree with what you said about the total dependence on the mobile network; it's both its strength and its limitation. In real-world situations, especially in somewhat isolated areas, it can quickly become critical if the coverage drops, even briefly.

On the other hand, the integrated GPS and the decent sensitivity of the cellular module remain real advantages for group tracking. I tested a similar system while traveling with an eSIM on an older dedicated smartphone, and it can be quite useful when properly configured, with a good, stable data plan.

For field use, the most reassuring aspect is clearly the low power consumption and the simplicity of using through-hole components, which really facilitates maintenance outside the workshop. The fact that the Arduino manages the functions also makes the settings more flexible, but it means you have to think about backing up the firmware in case of failure or reset.

I finally found a FT-818ND specific resource.
This page includes a MARS/CAP TX-RX modification for the FT-818ND :

https://www.mods.dk/index.php?ModelId=1274&ModelRec=ft-818&RadioId=1-yaesu

According to the article, the modification is done through SMD jumpers/diodes on the main board, and the exact procedure may depend on the regional version of the radio.

Be careful though: some FT-817 information partially applies to the 818, but not all board layouts are identical. A backup of current settings and a full reset after the mod are usually recommended.

Hi.
Thanks for the links. They help me a lot.

Hi!
It's great to see a forum that's still active thanks to the contributions of regular members.