georgew
02-23-2004, 11:44 AM
I have a couple of 1 watt teletronics amps I only use for "tests". When I put them on an orioco card they work about as well as a senao card without an amp, they are louder, but with such a high noise floor that seems to undo part of the advantage...
For the fist time I put one on a senao card. Something I would never do, except on a whim.
BAM! No noise increase whatsoever, but a massive increase in sensitivity, Output signal seems identical to not having the amp at all, the far end didn't see any change in signal. But on the receiving end, the receive amp was low in noise (-98db) and had 30db(!!) of improvement on the signal. And this is in a box with another AP radio, so there should be some local noise in the box. Obviously a 12db receive amp should not provide 30db of amplification, so the numbers have got to be off somehow... but the unit acts like the numbers are real.
I totally did not expect the results. It's a smartamp, so the output gain is probably turned down or off because I'm blasting the input with too strong a signal. With the output amp turned down, the unit does not seem to add any noise.
I theorize that the noise floor of an amp might be influenced by noise in the can from the output amp that has not fully powered down, and if you could power that amp down by not turning it on in the first place, you end up with a substantal increase in sensitivity, and you don't get the usual increase in the noise floor.
I have had people tell me that smartamps work good for them, and I always assumed they were full of it, based on my own experience and the experience of others here.
For the fist time I put one on a senao card. Something I would never do, except on a whim.
BAM! No noise increase whatsoever, but a massive increase in sensitivity, Output signal seems identical to not having the amp at all, the far end didn't see any change in signal. But on the receiving end, the receive amp was low in noise (-98db) and had 30db(!!) of improvement on the signal. And this is in a box with another AP radio, so there should be some local noise in the box. Obviously a 12db receive amp should not provide 30db of amplification, so the numbers have got to be off somehow... but the unit acts like the numbers are real.
I totally did not expect the results. It's a smartamp, so the output gain is probably turned down or off because I'm blasting the input with too strong a signal. With the output amp turned down, the unit does not seem to add any noise.
I theorize that the noise floor of an amp might be influenced by noise in the can from the output amp that has not fully powered down, and if you could power that amp down by not turning it on in the first place, you end up with a substantal increase in sensitivity, and you don't get the usual increase in the noise floor.
I have had people tell me that smartamps work good for them, and I always assumed they were full of it, based on my own experience and the experience of others here.