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|VK6JY varactor experiments|
|Written by Hans Summers|
|Tuesday, 01 September 2009 04:09|
John VK6JY sends some results from Albany, Western Australia, obtained using the circuit shown here (right). The C-meter is an AADE L/C meter and the PSU is a 15V 20A DSE 3800 (overkill? What! Never).
Comments and photos from John
Left: John's test board setup
NOTE: When the diode is in forward bias, current will start to flow and therefore the actual voltage across the LED will not be that indicated by the DMM. It could be argued that doens't actually matter much anyway, as the result of good linearity vs applied voltage is the same regardless. However it seems that Q will degrade very significantly when the diode is forward biased, though the quantitative extent of this degradation hasn't been measured.
|Last Updated on Tuesday, 01 September 2009 04:15|