On 8/12/11 4:23 PM, Andrzej Kobus wrote:
On Aug 12, 2:01 pm, Darryl wrote:
On 8/12/11 6:46 AM, Andy wrote:

On Aug 10, 6:26 pm, Darryl wrote:

The need in the USA for a permanently attached FLARM antenna was the
FCC's requirement not something FLARM wanted to do.

How did you arrive at that conclusion?
The documentation on file at FCC clearly indicates that the reason the
antenna is locked into position is that the connector type is not FCC
approved. It is my conclusion that FLARM chose this compromise to
avoid the delay of changing to an approved connector.

To be clear (maybe to other readers) it is not an "FCC approved
connector" in that sense like they are using some cheap connector now
and need a technically better one, they require a connector that
prevents the user swapping the antenna for another non-approved one
(i.e. one different than the device passes FCC tests with). Its CFR 47
Sec. 15.203 - that rule exists because of the concern about users
substituting higher gain antennas and exceeding the radiated power and
other specs within the IMS band (in this case). The whole
fixed/removable antenna comes up in other FCC approved/unregulated
consumer devices e.g. with consumer FRS vs. licensed GMRS radios. In
most consumer (e.g. non-licensed user) devices this usually results in
the antenna or cable being permanently attached to the device. Some of
the FCC enforcement/interpretation of this stuff gets a bit head-scratching.

Darryl

So how is this going to work with a brick version, will there be an
external antenna or will the brick come with fixed internal or fixed
external antenna that limits our ability to put the brick where we
have space?

I don't think FLARM has got into specifics on this.

The Flarm transmitter antennas that the FCC really care about are not
"internal" on any FLARM unit (they have to point vertical, are too
large, and need to be clear of the components inside the box. They are
external--typically mounted on the case and outside the USA today there
are options for using a coax cable for remote mounting that antenna.

FLARM know what people have asked for/need here and I expect them to
have something that is remote installable. Small companies may not be
able to justify paying the setup/tooling costs for a custom RF connector
and matching antenna assembly. With different packaging of the brick
itself one option _may_ be a permanently fixed but "serviceable" antenna
coax connection. The sort of thing that comes "permanently" attached to
the unit but can be replaced/swapped for a longer one etc. by a
qualified installer able to open the box--and using standard connectors
inside the box.

Like I said, some of the FCC interpretation of this stuff can be a bit
head-scratching. So who knows exactly what Flarm will do, I have no
idea. I will worry about the exact details on how to instal my brick
once I see the final product announced/approved.

There are should be no issue with GPS receiver antennas or the 1090ES
receiver antenna, and the logical thing there is just have them be
external and removable using standard connectors (MCX, SMA, ...)

Looking forward to getting my brick...

Darryl