Jump to content
Electronics-Lab.com Community

testing pickup


Recommended Posts

  • 1 month later...

Check with a current meter that it is drawing DC current from the power supply.  The approx number of milliamps will be given by the manufacturer.  Badly made or corroded F type connections are the most probable cause of faults.  Remember that the centre pin of the F connector plug should stick out about 2mm, proud of the surrounding threaded ring.

Use a satellite finder power meter.  If you point the LNB up at clear sky (outer space) then the noise temperature contribution from the surroundings will be negligible, so the meter reading will correspond to the noise temperature of the LNB, say 100K (K means degrees Kelvin, above the 0 K absolute zero temperature).  If you then point the LNB at your hand or towards the ground, which is at a temperature of approx 300K then the noise power reading on the meter should go up, corresponding to approx 400K (100K +300K).

Note that LNBs may fail on one polarisation or on one frequency band and that the failure mode may only occur at certain temperatures.

If you choose to try a replacement LNB in a VSAT system check the transmit reject filter and supply voltage - you don't want to be one of those people who keeps blowing up LNBs trying to find a good one !

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...