PowerFlarms at Avenal Contest

On Thursday, May 24, 2012 10:17:13 AM UTC-6, Bart wrote:
On May 23, 10:47*pm, bumper wrote:
There are a few reasons that one PF equipped aircraft might "alert" while the other conflicting aircraft doesn't.

In a perfect world it should be a two way street. However, the installation or placement of an antenna for transmitting is more critical than that for a recieve antenna. If glider #1's PF antenna is installed less optimally than glider #2's PF antenna, it may well be that #1 gets the alert while #2 does not. As #1's poor antenna install may receive marginally well, but wastes transmit power due to a high SWR or a null due to blocking structure.


Oh. PF uses one antenna to transmit and another to receive?

Bart

PF uses FLARM port A to transmit and receive. It uses FLARM port B to receive only. There is a third port for the transponder/ADS-B receive function. And the brick adds a fourth connector for remote GPS antenna.





On Thursday, May 24, 2012 10:17:13 AM UTC-6, Bart wrote:
On May 23, 10:47*pm, bumper wrote:
There are a few reasons that one PF equipped aircraft might "alert" while the other conflicting aircraft doesn't.

In a perfect world it should be a two way street. However, the installation or placement of an antenna for transmitting is more critical than that for a recieve antenna. If glider #1's PF antenna is installed less optimally than glider #2's PF antenna, it may well be that #1 gets the alert while #2 does not. As #1's poor antenna install may receive marginally well, but wastes transmit power due to a high SWR or a null due to blocking structure.


Oh. PF uses one antenna to transmit and another to receive?

Bart

Here's the excerpt from the manual:
"BRICK has two separate FLARM radio transceivers: FLARM A is used to receive and transmit and must always be connected to an antenna; FLARM B is only used to receive, an optional antenna may be used for better reception performance."

Its the same for both portable and brick versions. Although the portable only has the FLARM A connector with reverse polarity (via a staked on connector adapter".

With the 2 antenna setup in use there could easily be regions where you have receive coverage but not transmit coverage.

-Dave