FAQ

¿Which receiver suits me the best?

After knowing the most important features of a receiver, you will be able to make the best choice. These characteristics are: sensitivity, dynamic range and signal processing.

1. Sensitivity

It is the receiver’s faculty to obtain the reception of the minimum signal input. In the telemetry receivers it is defined as “Minimum Detectable Signal” (MDL) and it is expressed in dBm or microvolts (µ)

The sensitivity varies between the next ranges:

- From 130 dBm to - 150 dBm

- 130 dBm => 0’071 µV and -150 dBm => 0’007 µV Over 50 ohms.

As they are negative numbers, the bigger the quantity in dBm, the higher the sensitivity. At VHF, we can reach a little higher sensitivity than at the UHF band.

 -130 dBm is the minimum sensitivity used in small and very easy-to-use receivers. When we use a receiver with a -140 dBm sensitivity it is as we had a three times more powerful emitter. With a sensitivity of -140 dBm, it is like the emitter used with the -130 dBm had 20 times more power. When the used emitter is consuming the maximum energy from its batteries, what happens to the most powerful falconry and pigeon breeding transmitters, it’s essential to get a power 10 or 20 times higher since batteries cannot offer more energy. The only solution is to gain a better range by increasing the sensitivity of the receiver or by processing the signal.

Sensitivities list:

-140 dBm: 10 times more sensitive than -130 dBm (equivalent to multiplying the transmitter power by 10).

-143 dBm: 20 times more sensitive than -130 dBm (equivalent to multiplying the transmitter power by 20).

-146 dBm: 40 times more sensitive than -130 dBm (equivalent to multiplying the transmitter power by 40).

-149 dBm 80 times more sensitive than -130 dBm (equivalent to multiplying the transmitter power by 80).

2. Dynamic range

It is defined as the receiver’s ability to pick up a signal input with the widest relationship with the Minimum Detectable Signal, until a maximum signal without reaching saturation. This relationship is measured in dB. A good receiver must have a dynamic range of, at least, 100 dB. When this value is not high enough, the receiver becomes saturated and, when it is placed near to the emitter, it receives signals from all directions or in a very wide angle. When the animal is hidden between weeds or bushes, we will need a very high precision.

This defect is typical from many old receivers that, in some cases, use an additional attenuator -activated by a switch- which lightly improves this behavior. A modern receiver must be capable to receive powerful emissions of a range of distance from 50 km to a few centimeters without reaching saturation and with no need of an additional attenuator for short distances.

The Gain/Volume control must let us make a multi-turn fine adjustment so we could get a better pointer adjustment, with neither saturation nor signal loss with a minimum turn of the control (as it happens with the 310-degrees conventional controls).

A low sensitivity receiver, like -130 dBm, is more likely to be placed near an emitter without reaching saturation since it does not amplify the signal so much as others do. However, it gets a lower distance range.

3. Signal processing

It permits to introduce one or various improvements on the signal reception as well as on its reproduction, improving even the receiver’s sensitivity or the signal’s quality. We have backed the last improvement; with our PT-3 system, we get clean, strong and long signals even though the emitter is a long distance away from the receiver. We also achieve an extraordinary precision improvement, as the reception angle decreases, which only causes a very few centimeters errors.