David Norris
2004-10-17 20:54:58 UTC
For those who are interested:
After some experiments with my own, I have found the performance compatible
to other devices (such as wireless camera receivers and a videoscanner).
The main reasons people knock the sensitivity seem to be:
Many people do not realise that being several megahertz in bandwidth, your
video signal has to be about 30db stronger to be usable. So you would not
expect the kind of range you get for NFM voice signals of the same power (a
wireless camera has a max. of 100mW);
Also, the regular aerials sold for scanning don't really operate up at
2.4GHz, so you get far superior results even using low gain
(omnidirectional) camera/802.11b wireless networking aerials (which are
SMA, so an adapter is needed). I notice that where comparing the R3 with
other equipment, many people are using the supplied aerial with the R3,
whereas the videoscanner will come with an aerial which is optimised for
the frequency range concerned - so not a fair trial.
I have also found that performance on the 13 and 23cm amateur bands seems to
be roughly identical (using ATV transmitters of 50mW output and 1/4 wave
aerials on both bands). On 13cm, using the legendary Pringles' can antenna,
as well as a dedicated 20db gain G8GML panel antenna, range was extended
considerably.
Incidentally, I have also hooked up the R3 to a Solarcon A99 aerial, which
tunes reasonably from 14 - approximately 35 MHz, covering the upper HF
amateur bands, and whereas I expected it to overload (so I would hear
everything on HF at once, as commonly happens with scanning receivers on
HF) I found that it performed surprisingly well.
My only complaint is: why didn't Icom extend the FMTV range to cover the
whole of 23cm (1240 - 1325 MHz) instead of finishing at 1300? It is still
possible to receive pictures in AM mode by off tuning by 2-3 MHz, but this
is less than ideal.
Having owned this radio for several months now, I say that whereas it's not
for everyone, it was a good investment overall for me as I'm into ATV.
Has anyone else experimented with the R3 I wonder?
DN
After some experiments with my own, I have found the performance compatible
to other devices (such as wireless camera receivers and a videoscanner).
The main reasons people knock the sensitivity seem to be:
Many people do not realise that being several megahertz in bandwidth, your
video signal has to be about 30db stronger to be usable. So you would not
expect the kind of range you get for NFM voice signals of the same power (a
wireless camera has a max. of 100mW);
Also, the regular aerials sold for scanning don't really operate up at
2.4GHz, so you get far superior results even using low gain
(omnidirectional) camera/802.11b wireless networking aerials (which are
SMA, so an adapter is needed). I notice that where comparing the R3 with
other equipment, many people are using the supplied aerial with the R3,
whereas the videoscanner will come with an aerial which is optimised for
the frequency range concerned - so not a fair trial.
I have also found that performance on the 13 and 23cm amateur bands seems to
be roughly identical (using ATV transmitters of 50mW output and 1/4 wave
aerials on both bands). On 13cm, using the legendary Pringles' can antenna,
as well as a dedicated 20db gain G8GML panel antenna, range was extended
considerably.
Incidentally, I have also hooked up the R3 to a Solarcon A99 aerial, which
tunes reasonably from 14 - approximately 35 MHz, covering the upper HF
amateur bands, and whereas I expected it to overload (so I would hear
everything on HF at once, as commonly happens with scanning receivers on
HF) I found that it performed surprisingly well.
My only complaint is: why didn't Icom extend the FMTV range to cover the
whole of 23cm (1240 - 1325 MHz) instead of finishing at 1300? It is still
possible to receive pictures in AM mode by off tuning by 2-3 MHz, but this
is less than ideal.
Having owned this radio for several months now, I say that whereas it's not
for everyone, it was a good investment overall for me as I'm into ATV.
Has anyone else experimented with the R3 I wonder?
DN