Ferra is the portable MW radio transceiver.
It is very simple. The main point of Ferra is in the one short sentence.
Below you may read the details.

Rang: 0,8-5 MHz (custom available frequency)     
         0,9-1,1 MHz (underground band            
         1,8-2,0 MHz (ham radio band)

Output power: 1; 5 watt
Modulation: LSB (standart), USB (custom)
Radio size: 183х126х49 mm
Antenna size: 30х30х500 mm
Battery: 4,5 Ah, 11.1 V, Litium-ION
RX Sensitivity: 0,5 mKV

Features
: internal modem for sending of a short text messages (especially reliable mode), full-size kayboard, storing of 10 last received messages.
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There is no doubt there are many others different wireless stations. But we have only one question – will it work?

And Ferra works!

1. Terrestrial radio communication 
Ferra was tested in field conditions repeatedly. Our tests were in Omsk region, in Yakutia (Sakha) and in EU countries. The communication range varies depending of the features of relief, water barriers and forests.
The general test results are below:
Voice communication Ferra-Ferra is about 30-60 km. The Ferra sets are in hands of operators. Then raising the antenna increases communication range.
When to send short text messages increases communication range up to 100 km. This is important for areas where there is no cellular communication.

2. Underground radio communication
It is well known that the underground radio communication very difficult to ensure. Radio waves strongly absorbed by the rock strata therefore, the communication range is reduced. Especially if the radio waves pass through the rock strata directly, and not along the shafts or the wall of the caves.
Ferra was subjected to a series of tests in mines and caves to identify opportunities in such difficult conditions. Our radio station was tested on Urals, in Rostov region and in Kazakhstan.

The general test results:
The communication range along the shaft is about 1,5-3 km (points of communication can be located in one mountain drift and in different, in parallel or perpendicular).
The communication range through the rock strata is about 1 km in message mode and less in voice mode.
We are sure that for Ferra radio with a weight of 2 kg shown results are interesting and deserve attention.
We didn’t find analogues, so we did Ferra.
If you find similar, please contact us.

Description
The set consist of a low-power and low-frequency transmitter (5 w) and ultra small antenna that is fixed on the shoulder of the miner.

Key Features
System «Xferra» provides communication range over a kilometer through the rock strata.

The system does not require any different guides (cables, railes).

Applications
The system «Xferra» is intended for radio communication in mines, diggings and caves.

General Specifications
Our results were confirmed by tests in the anthracite mines with significant inclusion of higly wet rocks.

Lamprecht

Test protocol