Re: Recommended HD Antenna? (another question)

proc (darrenproctor@xxxxxxxxx) wrote in alt.tv.tech.hdtv:
> I took the diplexers off at both ends (satellite dish on the roof) and
> inside (before it went into the receiver) and ran the OTA antenna
> directly to the receiver with a separate coax. Worked great. I
> mentioned in another thread that my antenna manufacturer mentioned that
> diplexers rob the antenna up to 30% of its pulling power, per diplexer.

I think this is either a mis-statement, or a misunderstanding of the way
the numbers work, although there are some really crappy diplexers out
there.

The raw signal strength dropped by less than 1dB for me with diplexers in
the line. Technically, this is a loss of close to 30%, because every 3dB
is a doubling of signal, but it's not an absolute loss. In other words,
if the raw signal strength was 30dBm, a loss of 8dBm would be a raw loss
of around 30% of the total signal.

--
Jeff Rife | "I'm worse than Hitler?!?"
|
| "Not worse...just less warm and cuddly."
|
| -- Jay Sherman and Duke Phillips, "The Critic"
.

Relevant Pages

  • Re: Recommended HD Antenna? (another question)
    ... I mentioned in another thread that my antenna manufacturer mentioned that diplexers rob the antenna up to 30% of its pulling power, ... Technically, this is a loss of close to 30%, because every 3dB ... if the raw signal strength was 30dBm, a loss of 8dBm would be a raw loss ...
    (alt.tv.tech.hdtv)
  • Re: Recommended HD Antenna? (another question)
    ... inside and ran the OTA antenna ... directly to the receiver with a separate coax. ... diplexers rob the antenna up to 30% of its pulling power, ...
    (alt.tv.tech.hdtv)
  • Re: OTA antenna advice
    ... I disconnected the diplexers and ran the antenna (into ... Winegard Sensar II is pulling most of my locals in and up ... trainer" thing where they train the DirecTV installation supervisors ... He said multiswitches can rob 30-75% from the antenna. ...
    (alt.tv.tech.hdtv)