I'm certainly not avionics expert, but unless something has recently changed at
Garmin, your radio shop is, ugh, pulling your leg.  My 430W does not have an
external antennae, and it was installed by a well known shop in north Texas.
Also, I remember reading the requirements from Garmin, ie, a specific antennae
coax, certain location on the panel, etc, but nothing about external antennaes.

That being said, I expect that you will get better reception with external
antennaes.

On the subject of GNS430s, there is a new software release. The shop doing my
x-ponder cert installed version 3.1.  No charge to me, Garmin pays the shop 1
hour labor for every upgrade they do.
Matt McManus
LNC2 360

Quoting Berni <bbreen@cableone.net>:

> I just had an existing 430 converted to WAAS and added another new 430W to
> my stack.  According to the radio shop the antennas MUST be installed
> externally and in a certain configuration (not next to one another).
> According to the shop Garmin mandates that their authorized shops install
> them this way or not at all.
>
>
>
>  Berni
>
>
>
>   _____
>
> From: Lancair Mailing List [mailto:lml@lancaironline.net] On Behalf Of Colyn
> Case at earthlink
> Sent: Wednesday, July 02, 2008 11:42 AM
> To: lml@lancaironline.net
> Subject: [LML] WAAS antennas
>
>
>
> Has anyone else noticed any issues with their WAAS GPS installation?
>
>
>
> I just convereted a 530 and 430 to 530W and 430W.    My GPS antennas are on
> a tray just under the glass section in front of the vertical stab on my IVP.
> Since I got Waas I get "No GPS navigation - user other nav" message.  It
> happens on the ground, it happens whether near buildings or not, it happens
> to both navs but at different times.   It lasts from 30-45 seconds
> typically.
>
>
>
> One theory that has been put forth is that the WAAS units look further down
> the horizon (or need to to get a big enough constellation) and that I may
> have some blockage at those low angles.   So far I haven't seen this happen
> in the air.
>
>
>
> I also converted my cessna 530 to 530W.    I haven't noticed any issues.
> The antenna is OUTDOORS in that installation.
>
>
>
> Colyn
>
>
>
>