[NLRS] SKM52 GPS module possibly suitable for GPSDO system

[Doug Reed]

<http://www.hanssummers.com/ultimategps2.html>

If you have any interest in building a GPS disciplined oscillator for
your home test equipment or for a microwave source, you might want to
investigate the SKM52 GPS module to use as the core GPS receiver for
your system. One of the key requirements for a GPSDO system is that
the GPS module must have high accuracy in the 1PPS output. Most cheap
GPS modules are in the 1us (one microsecond) range for the 1PPS output
accuracy. The SKM52 is spec'ed at 10ns RMS error (100x better!) which
gets it up into the range usually occupied by more expensive GPS
timing receivers.

If you wanted to build an APRS box, just about any GPS module will
work since all we need is location within 100's of feet. For that
purpose, any of the available sub-$25 GPS modules will work.

If you have any need for a GPS module, this is one to consider. I also
like the U3 HF beacon kit that Hans Summers has created. It also
sounds like it might be possible to use the U3 beacon kit to drive a
VHF-UHF transmitter in place of the crystal oscillator and generate a
very accurate CW beacon signal. The cost of a U3 beacon kit and a
SKM52 GPS is under $60 and results in a GPS disciplined beacon TX that
could be used to drive just about any old mobile radio RF deck to
build a VHF-UHF beacon TX. Details of the U3 beacon kit are also on
the Hanssummer.com web site. Note that you would probably not be able
to use a FM TX strip with WSPR mode since the WSPR waveform requires a
linear amplifier for minimum bandwidth. But for CW, QRSS, FSK, or
Hellschreiber, it should work.

Both modules are available from QRP-Labs and are linked from the web
site above. It saves on overseas postage and may allow faster shipping
if there is stock on hand.

73, Doug Reed, N0NAS.