I have the GNC 300XL and GNC 250XL installed in my aircraft. Both are exactly the same in operation except the 300 allows access to the non precession approaches, STARs and SIDs on the database.

The 250XL is VFR only unit and as a VFR install, both units would cost the same to install. If you were to install the 300XL as IFR you would also need a CDI and an annunciator:

http://www.aircraftspruce.com/catalog/a … s300xl.php

You may want to consider installing a factory overhauled 300XL ($2595)as you can purchase one of these units cheaper than a new 250XL ($2795). That will give you an option to upgrade the installation later to IFR.

http://avionicsgps.com/avionics_gps.php … amilyNum=5

I have found the units to be excellent and have them integrated with the GMA 340 and autopilot system.

Operation is straight forward and simple but does vary slightly to the operation of the 400/500 series.

Manuals for the 250XL can be found at:

http://www.garmin.com/products/manual.j … 0-00122-00

or the 300XL at:

http://www.garmin.com/products/manual.j … 0-00161-00

At one stage I did have a problem with one of the units. I sent it to Garmin and they fixed it FOC. No problems since.

I subscribe to the Jeppesen update service and download the updates using their datawriter. I had problems with the original datawriter and now have their Datawriter II which works a treat. Jepp have now brought out a USB version.

http://www.jeppesen.com/

I hope all this helps,

Troy

I love my 250 xl.  Have had it for years.  No problems but makes a lazy navigator out of you.  Update is $60 if you subscribe to the service with Jepp.  One time charge of $130? (update included) if you by their software.

Steve,

If you are installing the 300XL as IFR I think you still need the annunciator to display what mode the unit is in. This function is built into the 400/500 series and they do not need an annunciator if the unit is mounted within the pilots scan. Check with your installer.

Troy

Does anyone know how to adjust the squelch threshold? 

I am having trouble with distant transmissions constantly interferring with my peaceful flights.  I would like to squelch them down so that I don't have to hear them.

The radio has a 'Squelch' button, but his only turns squelch on or off, there is no way to set the threshold manually.

Please reply to my email address, as I probably won't be able to find this site again.

Thanks,

Ron

I am looking for my first airplane a 182. I have been looking for a 182P which is in my price range. I would appreciate anyone's thoughts on specific issues and squawks both in 182s and the P model specifically. We are looking for a low time engine with and IFR GPS, everything else is negotiable.
Anyone know a good pre buy mechanic in south Florida?