Re: [Discuss-gnuradio] Question Regarding GMSK2 examples

[Eric Blossom]

On Tue, May 02, 2006 at 12:01:47AM -0400, Elaine Garbarine wrote:
> That makes sense to me.  Is there anyway to access the payload even if the
> data is not decoded correctly?  I know this seems like a useless concept but
> it's something we would like to do.

Yes, the payload (with errors) is passed even if ok is False.

> Also, a quasi-related question, the README file included in the GMSK2
> directory makes a note that the boards must be at least 3m apart in order
> for the rx to work properly.  Why is it necessary to place the boards at
> least 3m apart?

It's so that the transmitter doesn't drive the receiver's front end
into a seriously non-linear zone.  The Flex 400 Tx section will put
out about 100 mW, which is enough to cause intermodulation distortion
(IMD) on most receivers if they're close by.  For demos using amateur
handhelds as receivers, we've replaced the transmit antenna on the
Flex 400 (oops, that's the daughterboard formerly known as the Flex
400) with a 50 ohm load to avoid the problem.

Bottom line, it's the non-ideal analog stuff ;)

Eric