Motorola multiplexer vs tri-band antenna

[Anderegg]

Putting together a new news vehicle, and I need to decide between keeping our existing Larsen NMO150/450/758 with Stridesberg 8 port active multicupler, or "upgrading" to a Motorola EQ000103A01 VHF/UHF/700/800 antenna multicoupler, with three band specific antennas, running into the same multicoupler. I am wondering if the loss associated with multiplexing would be similar to the loss associated with a tri-band antenna. I am not sure if anyone here has any experience with the Motorola EQ000103A01. I have one I picked up for $70 used, and put some BNC adapters on it (has QAM connectors) for testing, but I know all these adapters are also causing some losses, so not sure I can reliably determine through signal testing what the actual signal degredation may be.

If we go multiplexer, would be running a 380MHz 1/2 wave UHF, a 155MHz 1/4 wave VHF, and 5/8 wave 3db 7/800 antenna array. The Larsen tri-band has extremely good 7/800 performance, loosing only a couple of RSSI points to a dedicated 5/8 wave 7/800 antenna. On Military 380 MHz UHF, the tri-band sucks, and on VHF it is not exactly amazing either.

Paul

 

[prcguy]

The losses in a triplexer are small, usually well under .5dB on any band and probably .25dB on VHF and below. My opinion is the ability to use or swap around higher gain antennas for each band will greatly overcome the slight loss in the triplexer. The Larsen Tri-Band has no gain over a 1/4 wave on VHF and very little if any on the other bands.

The question then becomes do you need the extra antenna gain? Are you finding weak reception on any band with the Larsen Tri-band? If so individual antennas can improve the signal some if they are coming in from a distance but if your snuggled up against a mountain with the transmitters on top and getting poor reception due to the signals not reaching the base of the mountain, the gain antennas might be worse in that case. But you can always swap out for a low gain antenna if you know you need it in advance.

Many other companies make good triplexers, I have some from Sti-Co, Austin Antenna and a few others that work well.

 

[Anderegg]

Dealing with more distance than terrain. If I can break even with signal loss going to multiplex with 7/800, then I am pretty sure the VHF and UHF dedicated antennas would make those bands actually usably receivable. Oh yeah, this is for RX only.

Paul