Loading ...
Sorry, an error occurred while loading the content.

Re: RXTX v6.3 improved signal to noise

Expand Messages
  • vbifyz
    ... I agree with Milt. Shorting these resistors will improve SNR, but may degrade image rejection. There is a tradeoff, which is also frequency dependent. 73,
    Message 1 of 19 , Oct 15, 2012
    • 0 Attachment
      --- In softrock40@yahoogroups.com, Milt Cram <w8nue@...> wrote:
      >

      > Additional comments regarding the 10 ohm resistors--
      >
      > I'm guessing that the 10 ohm resistors are also used to swamp the
      > variations in the "on-resistance" of the switches. At low HF
      > frequencies, external noise probably dominates the S/N and the resistors
      > "stabilize" the input impedance. At higher frequencies, it would seem
      > desirable to eliminate, as much as possible, resistors in the input
      > circuitry.
      >
      > 73, Milt
      > W8NUE
      >

      I agree with Milt. Shorting these resistors will improve SNR, but may degrade image rejection. There is a tradeoff, which is also frequency dependent.

      73, Mike
    Your message has been successfully submitted and would be delivered to recipients shortly.