Re: rewinding a PL-380 antenna


sdwillingham
 

Hi Rick,

--- In ultralightdx@..., Rick Robinson <w4dst@...> wrote:
As stated in a list
post from Silicon Labs engineer Scott Willingham, the dBuV readings
on the LCD are for the output of the Si4734s internal LNA, not the
ferrite bar antenna output. The readings do however show the
improvement of rewound antennas versus stock antennas. The Si4734 is
a very impressive piece of technology to be able to do all that it
does in tuning an antenna, DSP functions aside.
The comment about the dBuV reading is incorrect. The RSSI readings are referred to the pins of the chip, which are the inputs to the LNA. In the Tecsun radios operating in the MW band, this is also the voltage across the loopstick. In SW bands, the Tecsun ULRs use a preamp/LNA on the circuit board between the whip antenna and the Si4734. In that case, the RSSI readings reflect the signal at the output of Tecsun's external LNA.

Thanks for the complements about the Si4734. While Tecsun and others emphasize the chip's DSP features in marketing, the Si4734's performance is also enabled by considerable analog Kung Fu.

-Scott-

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