Author Topic: Antenna  (Read 5602 times)

microflying

Antenna
« on: June 12, 2016, 06:57:50 pm »
Just fitting my recently delivered ADS B package. Can you explain the two antennae. I presume the small one connected to the USB dongle receives signals from other devices. What does the large antenna do? Has anyone fitted to a Sportcruiser yet? just wondered where the best position is for the antenna.
I would like to obtain another antenna so as i can easily transfer the unit between aircraft and leave respective antennae attached can i obtain one?
Would also like a smaller Power cable. Is it described as USB to mini USB? There are several different types of these smaller plugs.

Paul_Sengupta

Re: Antenna
« Reply #1 on: June 12, 2016, 07:09:02 pm »
The antenna connected via a cable, with one with the small mag mount at the bottom, is for receiving transponders, Mode S with or without ADS-B, and is connected into the DVB-T (small black square) dongle. The other antenna with the 90 degree bend and the SMA screw on plug is for the P3i, which is the inter-PilotAware communications antenna, for transmitting and receiving the unit's position to/from other PilotAware units. Do not switch on the unit without this antenna connected or it could damage it.

The power cable is micro USB, and you really want one with 20 AWG power conductors in it.

« Last Edit: June 12, 2016, 07:11:28 pm by Paul_Sengupta »

exfirepro

Re: Antenna
« Reply #2 on: June 12, 2016, 09:31:48 pm »
Hi micro,

Suggest you have a read at this if you haven't already done so.

http://www.pilotaware.com/app/download/9862867/160513+Antenna+location..pdf

Antenna type and position has a significant effect on how well you transmit and receive signals, especially in metal bodied aircraft. In the sport cruiser assuming you don't want to go through a 'mod', I might be tempted to try fitting the PAW unit in the parcel area behind you, with the  short ADSB antenna and either a tuned low profile dipole (or the supplied pilot aware end fed dipole - the long one - on an extension cable) as vertically as possible to the sides of the canopy behind you and the passenger. They could probably be fixed using suckers and should still work forward reasonably well.

Worth a try - unless anyone else has any better ideas.

If you want to shorten your cable, I woulld try  juicEbitz 'Ooh-la-la' 0.5m USB to Micro USB cable (e-bay) same make as supplied by pilotawarehardware, though they seem to have revised their power cable specification to 24awg (previously quoted as 20awg) but are claiming it is more effective than the old one.

Regards

Peter

Regards

Peter

JCurtis

Re: Antenna
« Reply #3 on: June 12, 2016, 09:57:17 pm »
..though they seem to have revised their power cable specification to 24awg (previously quoted as 20awg) but are claiming it is more effective than the old one.

Not sure physics agrees with that statement. 
Rough calc for the losses in just the cable work out as;

1m, 20AWG, 5v @ 1 Amp has a loss of ~1.34%
0.5m, 24AWG, 5v @ 1 Amp has a loss of ~1.68%

Probably work OK though if the connectors on the end are the same as the 1m cable, the losses caused by the connectors can be really bad in the cheap cables.
Designer and maker of charge4.harkwood.co.uk, smart universal USB chargers designed for aviation.  USB Type-A and USB-C power without the RF interference. Approved for EASA installs under CS-STAN too.

JCurtis

Re: Antenna
« Reply #4 on: June 12, 2016, 10:05:27 pm »
Well it seems their TipTop 0.5m cable is 20AWG on the power lines.

https://www.juicebitz.co.uk/index.php?route=product/product&path=60&product_id=67
Designer and maker of charge4.harkwood.co.uk, smart universal USB chargers designed for aviation.  USB Type-A and USB-C power without the RF interference. Approved for EASA installs under CS-STAN too.

exfirepro

Re: Antenna
« Reply #5 on: June 12, 2016, 10:19:57 pm »
Thanks Jeremy,

I was a bit confused as to how they were claiming an improvement. 20awg is good - especially at half the length!

Not really 'here' BTW. Sitting in a hotel room in Oban, ready to catch the ferry out to the Western Isles first thing tomorrow. Wanted to fly but her indoors needs too much luggage  :-* :'(

Peter