manufacturing a diverse range of interference filters for M.A.T.V., TV and Communications applications
Introduction:
Jenlex Filters manufacture a wide range of Filters, Combiners, Splitters,
Amplifiers, Down Converters and Outlets for M.A.T.V., C.A.T.V., TV and Communications
applications.
Our equipment range for
M.A.T.V., C.A.T.V. and TV applications are 75 Ohm Impedance and are fitted
with F type connectors and are manufactured in Aluminium housings for Out
door / Indoor applications, although a range of other housings are available
for special purpose applications.
Filters manufactured for
communications applications are of 50 Ohm impedance and are manufactured
with BNC connectors as standard, but a range of other connectors are available
to meet specific requirements. All filters are available in Aluminium, Stainless
Steel or plated Copper enclosures, depending on requirements.
50 / 75 Ohm Notch Filter:
This filter is a masthead mount weather resistant filter housed in an Aluminium
outdoor enclosure. This filter is built to reduce interference to TV on
the VHF and UHF Bands or Communications equipment. Each filter is built
with BNC and F connectors to allow ease of connection and have water resistant
boots and cable fillings.
The most common use of
this type of filter is the reduction of FM or Pocket Pager interference
to TV and Communications filters. Usually the FM filter is broad band tuned
to cover 88 to 108 Mhz, but may be tuned to a nominated FM station.
The notch filter can be
tailor made to notch out any frequency from 500Khz to 990Mhz and can be
made broad enough to notch out a single frequency to a TV station.
This unit is useful for
installations where a combination of Digital and Analogue signals are being
used on a common house, MATV, CATV installation and can be connected in
series to improve signal reception.
This filter is a low loss,
high attenuation, narrow band width filter factory tuned to your nominated
centre frequency.
Typical Figures:
· Insertion Loss: 0.75dB.
· Attenuation @ centre frequency: >40dB.
· Band Width: Generally 1.5Mhz @ 3dB points.
75 Ohm Braid Breaker Hi-Pass Filter:
This unit is meant for in-door use and uses Belling & Lea connectors
for ease of installation and eliminates the need for special installation
tools. A mast mount version of this filter is also available on request.
The Hi-pass Filter is excellent
for reduction of interference from 27 Mhz CB, 1.5, 3.5, 7, 14 & 28 Mhz
Amateur Radio interference.
Typical Figures:
· -35dB @ 27 Mhz.
· -40dB @ 14 Mhz and rising to -80dB on the Broadcast Band.
75 Ohm Braid Breaker:
Is a self contained isolation unit with Male and Female Belling & Lea
connectors for ease of installation.
The Braid Breaker is ideal
for use where isolation is required between the TV / Radio Receiver(s) and
external antenna. This unit isolates both the antenna outer cable braid
and the centre cable conductor from the TV / VCR / Radio but still allows
the signal to pass through.
50/75 Ohm Tunable Notch Filter:
This filter is tunable over the VHF bands I & III. The Band I Notch
Filter is tunable from Channel 0 to Channel 4 and the Band III Notch Filter
is tunable from Channel 7 to Channel 11. These filters are useful when you
need to reduce a VHF channel that is higher in level than the other channels
at either the input of an amplified system or as part of an existing passive
system.
We may set each notch filter to your required channel, or you can tune the
filter with the aid of an insulated screw driver and, if possible, a Field
Strength Meter, you can tune the filter on site to the channel you wish
to reduce in level. Each filter comes in a metal housing with a Male &
Female Belling & lea connector for ease of installation and an average
-20dB attenuation for the tuned channel within the operating band of the
filter.
50 / 75 Ohm Band Pass Filter: this filter is built in an Aluminium weather resistant housing with BNC / F connectors and are meant for use in an indoor / outdoor situation. For TV installations these filters are generally installed just below the TV Antenna before a Masthead Amplifier, but it also may be used in an indoor situation for an amplified system, particularly where a combination of Digital and Analogue systems are present, particularly Channels 9 and 10. Usually a Band Pass Filter is required for either channel where interference is present. Each Band Pass Filter is made to your required Channel or Frequency.
75 Ohm Diplexer:
The diplexer can be used to mix a single channel from one antenna and a
number of channels from a second antenna to a single down lead, each diplexer
is custom made to your requirements.
We also offer a multi-input
diplexer that will allow up to seven (7) separate channel inputs and a single
output.
· This unit has a zero to 20dB attenuator for each input to allow
adjustment of signal levels.
· A low gain amplifier may be included on one or more of the inputs
where a signal level is to low on one or more of the inputs to allow equal
levels at the output.
TV UHF-VHF Single Channel
Down Converter:
Each unit is custom built to your requirements. This unit allows conversion
from any nominated UHF channel down to a selected and unused VHF channel.
This unit is handy to use where a building or house is wired for VHF only
and there are new UHF channels are available but it is not economic to rewire
or upgrade the splitters and directional couplers for the system. Each unit
needs a minimum input signal level of 500 microVolts to a maximum of 1.5
milliVolts signal level input for 1 milliVolt output for a solid picture
to TV.
50 Ohm Band Reject Cavity Resonator:
this 50 Ohm, low cost, tunable Band Reject cavity resonator is primarily
used to assist with the reduction of Pager interference to Packet Radio
on 147.600 Mhz. For maximum suppression of Pager interference in a strong
signal strength area, a -100 dB and a 400 Khz notch could be required which
would need three(3) to four(4) cavities. Although this example is for Pager
interference, we can custom manufacture cavities to your requirements and
nominated centre frequency. Each cavity can be tuned between 250 Khz to
500 Khz either side of the nominated centre frequency and have a choice
of BNC or N type connectors.
50 Ohm Band Pass Cavity Resonator: This 50 Ohm Tunable Cavity Band Pass Filter is primarily used for the Amateur Band, but works equally well on other communications frequencies and suites a range of commercial applications. Band width is better than 400 Khz at the 3 dB points either side of the nominated centre frequency with a typical insertion loss of 0.5 dB. The main uses for this type of filter is reduction of spurious unwanted signals from a transmitter and receivers suffering from adjacent channel interference.
50 Ohm 400 to 450 Mhz Cavity Notch Filter: A tunable filter available in either Notch or Band Pass filters to operate over the 400 Mhz to 450 Mhz range.
Typical Band Pass Figures:
· Insertion loss typically 0.5 dB at nominated centre frequency.
· Band width better than 4 Mhz @ 3 dB points.
Typical Notch Filter Figures:
· Insertion loss typically 0.5 dB either side of 3dB points of nominated
centre frequency.
· Notch attenuation >-32 dB at nominated centre frequency.
50 Ohm Helical Notch Filter: The 50 Ohm Helical Notch Filter is manufactured as a low power handling notch filter for areas where space is at a premium. There are four models of this filter, with corresponding degrees of notch and insertion loss and their specifications are as follows:
Model HNF1: This is a two stage Notch Filter
comprising 2" round resonators with its associated co-axial wiring
harness. The attenuation
of this unit at its centre frequency is better than -40 dB, with an insertion
loss of 1.7 dB at the nominated working frequency either side of the notch.
Model HNF2: Is a four stage resonator, comprising
four 1" square resonators whose response can be tunes to a narrow band
width, or stagger tune to cover a broader coverage at a lesser attenuation
level.
· Attenuation at narrow
band width is typically -80 dB.
· Narrow band width is typically 400 Khz @ -3 dB points.
· Attenuation at broad band width is typically -25 dB.
· Broad band width is typically 1.5 Mhz @ 3 dB points.
· Insertion loss is typically -2dB outside notch, within nominated
working frequency.
Model HNF3: Is a three stage resonator, comprising
three 1" square resonators whose response can be set to narrow or broad.
· Attenuation at narrow
band width is typically -55 dB.
· Narrow band width is typically 500 Khz @ -3 dB points.
· Attenuation at broad band width is typically -22 dB.
· Broad band width is typically 1.5 Mhz @ 3 dB points.
· Insertion loss is typically -2dB outside the notch area and within
the specified working frequencies.
Model HNF4: Is a two stage resonator, comprising two 1" square resonators whose response is set to narrow band.
· Narrow band attenuation
is typically -30 dB.
· Narrow band width is typically 500 Khz @ -3dB points.
· Insertion loss is typically -2dB outside notch area, within nominated
working frequencies.
This unit is adaptable to most commercial and amateur radio uses and are
most effective over the medium VHF (100 Mhz) to low UHF (350 Mhz). Most
units are available in natural Brass and Copper construction for economic
pricing, through to Silver plater units for long term installations.
The Helical Resonator Notch Filter is capable of handling 1 Watt through
50 Watts of transmit power and are available with BNC connectors as standard,
but other connectors are available on request. Other connectors styles available
are PL259(UHF), N type.
50 Ohm Interdigital Band Pass Filter: The interdigital Band Pass Filter is a compact unit with sharp cut-off on the start and finish -3dB points and offers low insertion loss in a five section filter. Interdigital filters are most effective over the Microwave frequencies 1.0 Ghz through 5.0 Ghz
Single Outlet Loop Wall Plates:Is a standard single outlet wall plate offered in a range of resistive attenuation outputs and are best used in an amplified system to give even level outputs in a shop or show room display situation.
The stock values available are: -32dB, -26dB, -20dB, -16dB, -12dB & -12dB(T). The -12db(T) unit has a 75 Ohm terminating unit built into it and is recommended as the final plate used on a cable run to provide stability and reduce the appearance of ghosting on a line that is not fully populated with TV sets as a load. As a suggested layout, we recommend the plates be used from highest to lowest attenuation plates where the highest attenuation plate is closest to the amplifier and the lowest attenuation plate furthest away from the amplifier. We will gladly provide a free plan for your layout, showing plate values, suggested cable distances and splitter and amplifier values.
Triple Outlet Loop Wall Plates:These wall plates have the same characteristics and appearance as the single wall plate but with a triple outlet and are most useful where high density TV/VCR/DVD displays are used. These plates will reduce wiring time by twothirds as only one plate has to be wired and only one hole cut into the shop wall, instead of three wall plates. Triple wall plates are available in the same attenuation range as single wall plates. We also provide a free plan layout service for the use of the triple wall plates as for the single wall plates.
3KV Isolated Wall Plates:This
is a conventional Belling & Lea wall plate with 3KV isolation that is
primarily meant for use in flats or units and shops where high voltage is
isolation is called for as part of a distribution system or new installation
or upgrade. Each wall plate
is fitted with an F connector on the rear for ease of cable connection and
maintain cabling integrity. Units are available with rear cable connection
as right angle connection or flush connection.
3KV In-line Isolation Units: This unit gives 3KV isolation to both centre conductor and braid in a slim line unit that is fitted with F connectors for entry and exit so that it can be used with existing installations that require high voltage isolation upgrade without the cost of retrofitting new wall plates throughout the building. This unit can be placed in-wall cavities, roof space or behind existing wall plates or any convenient hiding place.
Amplified Eight-way Splitter: This unit is a self contained eight-way splitter in a metal housing with its own amplifier and power supply. These units are a useful unit for shop displays where a single outlet is only available in the middle of a shop or out in a common display area in a shopping centre and eight or more TV / VCR / DVD's are to be displayed and maintain signal and picture quality.
-20dB DC Isolated Screw-in Test Probe: This is a 75 Ohm test point used for testing street exit points for Cable TV and is manufactured under License to Telstra for supply to Foxtel, but may be supplied to other customers by prior arrangement. This unit is a bright nickel plated unit with threaded end to attach to the street splitter outlet and a BNC connector that is attenuated by 20dB for connection to selected test equipment.
0dB DC Isolated screw-in Test Probe: This unit is identical to the -20db unit with the main difference being that there is only DC Isolation to the BNC connector so that a direct measurement can be made from the cable street splitter exit point.
65 Mhz Low Pass Filter:
This is a small pocket sized filter with Male and Female BNC connectors
for ease of connection to test equipment and are primarily meant for checking
reverse channel conditions and checking for cable faults. These units are
manufactured expressly for Telstra for the Foxtel cable TV system, but may
be supplied to other customers by prior arrangement with Telstra and Foxtel.
Jenlex Filters
122 Wanda Street, Mulgrave VIC 3170, Australia
Tel.(03) 9548-2594
http://www.vicnet.net.au/~jenlex