| QRF provides both one-way and two-way amplifiers for wall-mounted
MDU/Hotel/Motel applications. The one-way models are not upgradeable to two-way
service and are limited in their applications in this time of high-speed internet modems
and VOD applications to the consumer residence. |
| Most of our two-way models are available in 5 to 40 MHz return
models. Older 550 MHz versions were commonly offered with 5 to 30 MHz return paths.
SIZE equates to heat sinking capability in any line of
amplifiers. The QDAX
family is the largest and offers the widest range of models and features. QDE is the low-cost push-pull model for 550
MHz customers. QDEJ, sometimes known as
the "junior" is a single-hybrid platform for specialized push-pull RF
applications, when a low-cost drop amplifier isn't enough. All
our indoor wall-mounted amplifiers use a class 2, external power transformer to meet
UL/CSA requirements. |
| The larger size of QDAX amplifiers
allows the use of power-doubled and dual power-doubled output hybrid arrays. QDAX 550 MHz amplifiers used traditional mechanical gain pots for
interstage slope and gain controls, while later-model 750/870 MHz QDAX models used pin-diode circuitry to provide slope and gain functions
between the input hybrid and the output hybrid(s). The dual output hybrid models are
known as "quadra-power" since they have TWO
power-doubled hybrids wired in parallel at the output stage for higher output capability
or lower distortions. ALL QDAX amplifiers come standard with a 5/8" entry
fitting for pin-type connections to hardline coaxial cables. A VSF-59 adapter is
provided and factory installed for type "F" cable connections or may be removed
for hardline connections. |
| The QDAXF models offered maximum gain
and slope by reducing the interstage losses. In this line, the slope and gain
controls were replaced with a pad and equalizer. This allowed very high RF slope levels on the order of 12 to 14 dB across the range
from 50 to 750/870 MHz. This provides the performance needed in the most stringent
system designs. It also provides good RF linearity beyond the capabilities of the
original slope and gain control models above. |
| And for those of you "who want to have
your cake and eat it too", there is the QDAXS, which combines the features of
a fixed-interstage EQ with pin-diode slope and gain controls. With this model,
maximum slope with good RF linearity are available in a "fine tuning" slope and
gain model. This is also the first line of QDAX amplifiers designed to accept the NEW Gallium Arsenide (GaAs) power-doubled hybrids. |
| As mentioned above, the smaller QDE amplifiers are limited to
service for 550 MHz and below and are available in 5-30 MHz/50-550 MHz two-way
models. Two way versions are limited to low-current return amplifiers. One-way
models are also available. One unique model, called QDES
is used for high-gain applications in return path circuits. There is even a model
that offers a single gain stage, which is a power-doubled hybrid. |
| LAST and LEAST in size is the QDEJ. This little guy offers high
performance when compared to drop amplifiers. Since we build them here in the USA,
they can be customized in both 1-way and 2-way models. This is basically a push-pull
hybrid in a box. The "forward side" of the amplifier accepts an input pad
and EQ. The return path provides passive or active FLAT gain in the two-way
models. Two-way may be 5-30 MHz or 5-40 MHz. Gains vary with hybrid
choices. The ONE-WAY models make great rugged test amplifiers for use after a
bandpass filter and before a spectrum analyzer for proof testing. |