Fox Receiver 2m

Sam weeks ago i found that the ARDF resources from G3ZOI was updated. URL fox description I like this design wary good. So I ordered one bored and this arrived a few days later, PCB + 2 potentiometers, 3.5 mm jack for earphone and 2 Led, soldered and aligned. Order a box from Elfa 10-431-36 Aluminium 115 x 64 x 30 mm 1550B. I won’t little different setup see picture, possible to operate attenuator and pejel with one hand. Already use a old antenna. Fox Antenna Is made after this info. Use Isolated SMA connector and can easy change antenna.

Testing on Lab bench.

 

Current 13.6 mA.

Frequency 143,6 – 145,0 MHz

 

Input            RSSI pin 7.

-100 dBm    0,98V

-90                1,16

-80                1,40

-70                1.66

-60                1,84

-50                2,0

-40                2,23

-30                2,45

-26                2,5 max.

 

MinDetectebelSignal  around -120dBm

 

To turn on led1 red it needs maximum signal -30 dBm.

I measure Led1 Vforward around 1.8V if I remember correct.

I use one Elfa 75-036-76 it turns on 1,6V with the same current. Now Led1 turns on earlier.

 

Practice at home 3 Km away strong signals excellent reception.

Red diode lightning 100 - 150m before Fox.

2015-04-24 First Competition. Bad result, but excellent receiver especial I like the pitch it helps to determine the exact direction, When Red diode on, take exact bearing and catch the fox.

 

It is my third 2m Fox receiver and the best I have.