External antena instalation

[CarlosAbreu]

Hi List

Due to house move I installed my external amplified Wimo antena in the roof, however I don't need 5m of from a total of my 20m ecoflex 10" cable. I have rolled it with care, I think there's no problem with a loss of signal however I would like to hear from you about this.

May I keep this or I must unroll the cable, please advise.

In the old local I picked more flight because was higher and near LPPT (with visual contact), now as I'm in a lower place and more distant the flight tracking is less but I still keep around near 30 flights in peak hours.

Brgds
CA

[neroon79]

Hello Carlos,

As long as you keep the diameter of the cable roll-up big enough there shall be no significant increase of signal loss caused by the roll-up.

Problems will occur as soon as the actual bending radius is below the minimum bending radius (usually 5 to 10 times of cable diameter). In that case the cable can be damaged in terms of its geometry between inner and outer conductor resulting in a change of its wave impedance and an increase of its attenuation. Both reduces signal quality and strength and therefore reception range and airframe count.

For 10mm cable diameter the minimum bending radius (for 90° turn) would be 50mm to 100mm. The minimum roll-up diameter (360° turn ) is higher than the 90° bending diameter an shall be at least 300mm. From own experience I would advice a minimum roll-up diameter of about 500mm (20'')  to be ensure cable health.

Ingo

[CarlosAbreu]

Hi Ingo

Thank you very much for your detailled explanation.

I checked the minimum 360º cable turn and it's 200mm, so tomorrow with daylight I'm going to unroll the cable and keep it stretched behind furniture, it seems to be the best option.

After that I compare data received and keep you informed.

Have a nice Sunday.

Brgds
CA

[CarlosAbreu]

Hello Ingo

Cable changes were made early mornming. I unroll all excessive cable and just rool 360º 2m with a 400mm diameter. Due to furniture layot I could't extend it more and it was impossible to roll up until 500mm. However I roll it with carefull and without any pressure, it seems good to me.

During test, data receiveid is the same range in peak hours however it seems there is a little improvement in other short periods but as today is Sunday and June is the begining of vacation period I could check some unusuall charter flights specially from LPPT and LPPR, I'm not sure about this data received so I'll check in the following days in order to get a conclusive reply.

One more time thanks for your advise.

Brgds
CA