Lectrosonics UMCWB - Manual (Page 8)

UMCWB
LECTROSONICS, INC. 8
While the wide bandwidth of the multi-coupler is very
convenient, it also requires that the antennas used
with it also have a bandwidth wide enough to cover the
range of the receivers that are installed. If the entire
bandwidth from block 21 through block 29 is to be used,
the best antenna would be one of the ALP Series log
periodic models.
ALP620 Log-periodic antenna
The ALP Series antennas are ideal for use with wide-
band multicouplers, offering a directional coverage pat-
tern and a gain of 4.5 dBd. Three different models are
available to suit your specific needs.
Whip antennas can only be used if the frequency block
of the antennas is the same as the installed receivers,
or one block higher or lower. For example, block 24, 25
and 26 receivers can be used with block 25 antennas.
Whip antennas can be used as long as the frequency band
matches the receivers installed in the multi-coupler.
If a circular pattern is needed, the SNA600 dipole
model is an excellent choice, however, it is limited to
a 100 MHz bandwidth (about 4 blocks). It is tuned to
match the frequencies of the installed receivers by
adjusting the length of the elements according to the
scale on the body of the antenna. It is supplied with
a mounting strap, hardware and a rotatable mounting
block, and folds for storage.
Antenna Types and Bandwidth
The SNA600 dipole antenna folds for storage
To achieve wideband, circular coverage, two SNA600
antennas tuned to different frequency ranges can be
used with an external combiner, however, loss could
occur depending upon how they are positioned and how
much overlap exists in their tuning ranges.
To reduce the interaction between two SNA600 anten-
nas, mount them in a vertical orientation, about a half
wavelength apart, so they will be in each other’s null.
In theory, there will be some noise generated by mix-
ing the signal from the “out of band” antenna with the
intended one, but it is likely to be inconsequential in
actual use.
High freq tuning range
Low freq tuning range
2-way
combiner
Output to
multicoupler