Re: VHF radio mic problems

On Fri, 28 Mar 2008 17:04:34 -0000, John Legon <john@[EMAIL PROTECTED]
>  
wrote:

> Duncan Wood <bodgedntp@[EMAIL PROTECTED]
> wrote in article
> <op.t8p445c0pmo3dt@[EMAIL PROTECTED]
>:
>> On Fri, 28 Mar 2008 08:58:39 -0000, John Legon
<john@[EMAIL PROTECTED]
>
>> wrote:
>>> The easiest short-term solution will be to bring in our own radio mics
>>> and put the receivers on the stage where they can be plugged into the
>>> stage circuits.  In the long run I will try to pursuade the management
>>> to move their receiver aerials out of the control room.  At the moment
>>> it isn't possible to correctly align the aerials on one side of the
>>> receivers because a monitor speaker gets in the way.  Crazy but true.
>>
>> Set that one almost straight up & th eother at 90 deg to it. Given it  
>> was
>> almost certainly wired after it was installed then the receivers will  
>> just
>> have their cabling trapped by the next device down in the rack, if you
>> pull that forwards at the same time you should be able to get to them, 

>> the
>> power leads are about a 1m long if they're running on the wall warts
and
>> if there's aerials on the front they're not using an aerial
distribution
>> amp.
>
> Thanks for the tips about aerial alignment, etc.  I've been led to
> believe that something like a Vee shape formed by the two aerials on
> each receiver was optimal, but can imagine that it might not be...
>
> The trouble is, the radio mics always work perfectly during setup, but
> then the audience comes in and seem to soak up some of the signal.
> It then becomes a bit marginal, but if your 90 degree arrangement of
> aerials solves the problem then that would be great.
>
> It occurs to me that it might be possible to "tune" the aerials using
> the A/B tuner LEDs as a guide.  I.e. with a transmitter pack somewhere
> on the stage and the tuner A LED lit, adjust aerial B until the signal
> is strong enough to make the receiver switch to tuner B.  Then do the
> same with aerial A until tuner A gets the stronger signal, and so on.
>
> But I suspect that moving the transmitter to a different position would
> give different results, owing to a complex multipath scenario with many
> signal reflections.


Yes

> Hence getting the aerials as close as possible to
> the stage seems the best solution, if it can be done...
>


Always wins.