WEB-888 as REFERENCE signal generator

The WEB-888 with its original web-based image on SD card allows you to generate a GPS-based signal in addition to an amazing web receiver.

Click here for details from the WEB-888 manufacturer: rx-888.com

You can also buy a ready-made SD cards.

WEB-888 contains SMA connector described by EXT-CLK. This connector can serve as input and output of the reference frequency. An interesting feature is the generation of a signal that is superimposed on the GPS signal. This allows it to serve as a reference source for external devices.

The settings are made in the WEB-888 administration page. You can get there via a web browser by typing the IP address of WEB-888 and adding /admin.

See the Config page for the EXT-CLK SMA options. The first is External Reference clock (Y/N) - this is the reference input from another 10MHz source. The second option is output - signal generation with the option to hang on to the GPS signal. In this case, write the frequency in Hz and set the GPS correction.

Note: in order to use the internal GPS receiver, you must connect an external GPS antenna and position it appropriately facing the open sky.

Here is an example of 10MHz signal generation. The signal is suspended on the GPS and the output level is around -14dBm.

The disadvantage can be the low level of the generated signal - devices with REF IN usually require a higher level. Another and bigger problem is the spectral purity of the signal. The output has no filter and so contains a large amount of harmonics. Therefore, using this output requires a good LPF or BPF filter and a buffer amplifier.

Very Important

Please note two important things:

1. Be careful not to overload the SDR and ADC inputs with a strong signal, such as your own transmitter. This can destroy the ADC and degrade the SDR. A new 16-bit ADC costs almost as much as a full SDR.

We recommended and RF limit as protection. Several can be found directly in our offer. Others are already part of our more complex devices. 

2. SDR cooling The box does include a fan, but when using the SDR 24/7 or as a stand-alone skimmer, the CPU and converter get hot. Poor cooling leads to their destruction or reduced lifetime!

Therefore, please ensure sufficient cooling and check the fan regularly to prevent it from cooling due to dust.

⚠ There is no warranty for damaged ADC and fan!