(Scott Dorsey) writes:

Back in the seventies, the general RF level was a lot lower. Remember
back when you could actually turn on an AM radio and get decent reception?

At least in the US, the proliferation of cheap consumer electronics has
really resulted in incredible amounts of hash on the VHF bands and below.

Hell, I remember when those 40 MHz VHF-LO radio mikes worked great! I
could not imagine using one of those in the RF horror of any metropolitan
area today.

Nice story: at the university were used some cheap radio microphones,
that used the same frequency band of some (illegal here) cordless
phones near the 50 MHz band. Sometimes in the midst of a caclulus
theorem explanation instead of the teacher's voice we started hearing
some phone call, making the classroom start laughing.

(Scott Dorsey) writes:

Back in the seventies, the general RF level was a lot lower. Remember
back when you could actually turn on an AM radio and get decent reception?

At least in the US, the proliferation of cheap consumer electronics has
really resulted in incredible amounts of hash on the VHF bands and below.

Hell, I remember when those 40 MHz VHF-LO radio mikes worked great! I
could not imagine using one of those in the RF horror of any metropolitan
area today.

Nice story: at the university were used some cheap radio microphones,
that used the same frequency band of some (illegal here) cordless
phones near the 50 MHz band. Sometimes in the midst of a caclulus
theorem explanation instead of the teacher's voice we started hearing
some phone call, making the classroom start laughing.

Are you ok with one more big variable in your set up? With anything
wireless you should really have a backup. ie if you need one then
you'd better have two, etc.. Even the most expensive digital wireless
systems have bad days, due to the huge imbalance in transmitter power
between your wireless and the DTV, digital paging , wireless medical
gear and numerous other businesses (legal and not) using the same
spectrum. In the city it is really a jungle out there now for
wireless. If you go UHF, then yes get diversity.
Try to keep your receiver antenna in clear view and above the height
of the transmitter antenna. Keep both away from large metal objects
and other devices that emit RF (practically everything that you would
be using). Try the system out before the audience comes, and keep the
receiver someplace where you can see its RF indicators so you can see
if you are getting into trouble. And have a backup plan (cable)
ready.

Philip Perkins

Are you ok with one more big variable in your set up? With anything
wireless you should really have a backup. ie if you need one then
you'd better have two, etc.. Even the most expensive digital wireless
systems have bad days, due to the huge imbalance in transmitter power
between your wireless and the DTV, digital paging , wireless medical
gear and numerous other businesses (legal and not) using the same
spectrum. In the city it is really a jungle out there now for
wireless. If you go UHF, then yes get diversity.
Try to keep your receiver antenna in clear view and above the height
of the transmitter antenna. Keep both away from large metal objects
and other devices that emit RF (practically everything that you would
be using). Try the system out before the audience comes, and keep the
receiver someplace where you can see its RF indicators so you can see
if you are getting into trouble. And have a backup plan (cable)
ready.

Philip Perkins

In article ,
Philip Perkins wrote:
Even the most expensive digital wireless systems have bad days, due to
the huge imbalance in transmitter power between your wireless and the
DTV, digital paging , wireless medical gear and numerous other
businesses (legal and not) using the same spectrum.

In the UK, if it's operating on a legal frequency, and a good make, none
of the above should cause you any problems within the normal range of the
device. Of course as with any RF (and other) equipment a very strong rogue
RF field can cause trouble, but not the above under normal circumstances.

I use UHF radio mics on location in London, and have rarely if ever
experienced interference - assuming again it's kept within range. But even
if out of range they usually simply mute.

BTW, I'm referring to analogue systems. I've not had the 'pleasure' of
using digital yet.

--
*Work is for people who don't know how to fish.

Dave Plowman London SW 12
RIP Acorn

In article ,
Philip Perkins wrote:
Even the most expensive digital wireless systems have bad days, due to
the huge imbalance in transmitter power between your wireless and the
DTV, digital paging , wireless medical gear and numerous other
businesses (legal and not) using the same spectrum.

In the UK, if it's operating on a legal frequency, and a good make, none
of the above should cause you any problems within the normal range of the
device. Of course as with any RF (and other) equipment a very strong rogue
RF field can cause trouble, but not the above under normal circumstances.

I use UHF radio mics on location in London, and have rarely if ever
experienced interference - assuming again it's kept within range. But even
if out of range they usually simply mute.

BTW, I'm referring to analogue systems. I've not had the 'pleasure' of
using digital yet.

--
*Work is for people who don't know how to fish.

Dave Plowman London SW 12
RIP Acorn

On 16 Oct 2003 10:01:36 -0400, (Scott Dorsey) wrote:

Hell, I remember when those 40 MHz VHF-LO radio mikes worked great! I
could not imagine using one of those in the RF horror of any metropolitan
area today.


I keep thinking I'll have to upgrade my old Shure radio mic, then it
keeps working near to perfectly 99% of the time. I'm gigging in the
London UK area, which is about as metropolitan as it gets :-)

The only place it has real problems is on Thames pleasureboat gigs.
Some combination of dirty generated AC power, ship radio frequencies
and/or constantly changing location often get the better of it.

On 16 Oct 2003 10:01:36 -0400, (Scott Dorsey) wrote:

Hell, I remember when those 40 MHz VHF-LO radio mikes worked great! I
could not imagine using one of those in the RF horror of any metropolitan
area today.


I keep thinking I'll have to upgrade my old Shure radio mic, then it
keeps working near to perfectly 99% of the time. I'm gigging in the
London UK area, which is about as metropolitan as it gets :-)

The only place it has real problems is on Thames pleasureboat gigs.
Some combination of dirty generated AC power, ship radio frequencies
and/or constantly changing location often get the better of it.

Thank You all for your input.

I have bought the Samson non-diversity AX1-AR1.

Used it for the first time last night at a gig. And it was great, no
problems with it at all. I even had the received placed above my monitor
speaker.

Got a range of at least 40 meters before it started 'fading' and had no
problems walking into other rooms. I suffered no bounce at all from the so
called 'Drop-out' problem

So I can only say that diversity seems only worth getting if you run at the
maximun range. I tried everything to get a drop-out but simply couldn't,
while working within the spec'd range.

Cheers Mark

Thank You all for your input.

I have bought the Samson non-diversity AX1-AR1.

Used it for the first time last night at a gig. And it was great, no
problems with it at all. I even had the received placed above my monitor
speaker.

Got a range of at least 40 meters before it started 'fading' and had no
problems walking into other rooms. I suffered no bounce at all from the so
called 'Drop-out' problem

So I can only say that diversity seems only worth getting if you run at the
maximun range. I tried everything to get a drop-out but simply couldn't,
while working within the spec'd range.

Cheers Mark