Shure Dual Channel Receiver Question

[KBToys82]

I'm looking at purchasing 2 wireless handheld microphones that don't necessarily have to be rack-mounted, as I will be using them for my school's events where I don't want to use the current sound system already in-place because of lack of mobility.

I noticed that it would be substantially cheaper to purchase the 2 channel receiver along with 2 microphones, rather than buying 2 transmitter/receiver combos. The cause of my concern is the internal antenna with the dual channel receiver. Now the main events I will be using the system for is indoor graduation ceremonies located in our gym, and the outdoor ceremony on our football field. In both cases, the receiver would be located less than 100ft from the microphone, but I was just wondering what everyone else thought.

Thanks!
Kyle

 

[RonHebbard]

I'm looking at purchasing 2 wireless handheld microphones that don't necessarily have to be rack-mounted, as I will be using them for my school's events where I don't want to use the current sound system already in-place because of lack of mobility.

I noticed that it would be substantially cheaper to purchase the 2 channel receiver along with 2 microphones, rather than buying 2 transmitter/receiver combos. The cause of my concern is the internal antenna with the dual channel receiver. Now the main events I will be using the system for is indoor graduation ceremonies located in our gym, and the outdoor ceremony on our football field. In both cases, the receiver would be located less than 100ft from the microphone, but I was just wondering what everyone else thought.

Thanks!
Kyle

If I'm understanding you correctly, you're weighing RF signal loss in air against the losses in cables AND connectors.
I think I'm voting for air and short cables with as few connectors as possible. Let's page @FMEng for his thoughts on this.
Tooleoo!
Ron Hebbard.

 

[MNicolai]

Sounds like you're talking about BLX. My concern would be where the receiver lives. If it's near the stage, not a big a deal either way. If it's at the back of the room, you now have to do some silly things to get the receiver a few feet over the heads of the crowd so it has line-of-sight to the stage.

Whereas with other receivers if you find yourself with a crowd of several hundred people between the receiver and the stage, you can cable a few feet over to a pair of antennas on mic stands to get up above the crowd and maintain line of sight.

 

[KBToys82]

Both scenarios, there would be no audience between the receiver and transmitter. Both cases would have the audience behind the receiver.

 

[FMEng]

Typically, we like to have both spacial and polarity diversity, by skewing the polarity of the two antennas 90 degrees. The internal antennas in the dual BLX have spacial diversity, but not polarity diversity. That could make it slightly more prone to dropouts. Near, the stage, I wouldn't worry about the difference, but I consider 100 feet a fairly long distance. At long distances, you want every advantage you can get.

The whip antennas are more efficient in the direction away the front of the receiver, when mounted on the back, because the top of the receiver acts as a ground plane. Naturally, that's completely the opposite of how they are usually oriented toward an operator at FOH. I was doing an outdoor event with an old VHF system, and was having terrible dropouts. I turned the receivers around to face the stage, and elevated them an extra couple of feet by stacking a couple of tote boxes, and the dropouts quit. The model with internal antennas prevents any kind of flexibility for using gain antennas or elevating them away from the receivers.