Quote:
Originally Posted by be236
Yes, you're correct.. when I said signal of -5 dBm, I mean that's the NM value I get here in Tvfool when it shows channels for my specific location.
So back to my actual problem that I started for this thread.
The channels I want show up to -16 dB NM value. Then I need to find an antenna that is spec-ed/claimed to be +16 dB gain or higher , right so that I can get above the 0 dB threshold to get a signal lock?
That Lava antenna claims +30 dB gain (but not sure if they meant that is for the pre-amp gain and not the antenna gain itself).
The DB8 antenna I see in various sites show a gain of +16 dB, which would get me to this 0 dB threshold... but looks like I need more gain to get signal... would I have to string 2 DB8s together or something like that (would look unslightly)...
|
If the prediction is 100% accurate, and if there is never any fading, and if there is no interference, and if you have a perfect receiver, then reception of a signal with a NM of -16 dB would require an antenna that has 16 dB of gain on the channel of interest plus the additional gain needed to overcome the noise figure of any amplifier used. That equates to antenna gain of 19 dB in theory (assuming a preamp NF of 3 dB).
In the real world, a 10 dB 'fade' margin is cutting it quite close. Engineering for a margin of 15 dB is not overkill by any means (IMO). So I'm suggesting an antenna with 29 to 34 dB of forward gain. (I know of no such antenna on the consumer or commercial market.)
Reception of a signal arriving at a NM of -16 dB is going to be impossible in some cases, unreliable in others. In a few cases, you'll get lucky and find that the prediction was off in some way.
It may be more practical to find a friend in Bellingham or Lynden who would allow you to operate a HTPC or Slingbox remotely.