Bird Technologies 21-87A-11-xx-T User Manual

YOU'RE HEARD, LOUD AND CLEAR.

8625 Industrial Parkway, Angola, NY 14006 Tel: [phone] Fax: [phone] [e-mail] www.bird-technologies.com

Installation and Operation Manual for

T-Pass® Transmit Multicouplers

73-90-11 Series

Manual Part Number

7-9100

Warranty

This warranty applies for five years from shipping date.

TX RX Systems Inc. warrants its products to be free from defect in material and workmanship at the time of shipment.

Our obligation under warranty is limited to replacement or repair, at our option, of any such products that shall have
been defective at the time of manufacture. TX RX Systems Inc. reserves the right to replace with merchandise of
equal performance although not identical in every way to that originally sold. TX RX Systems Inc. is not liable for dam-
age caused by lightning or other natural disasters. No product will be accepted for repair or replacement without our
prior written approval. The purchaser must prepay all shipping charges on returned products. TX RX Systems Inc.
shall in no event be liable for consequential damages, installation costs or expense of any nature resulting from the
purchase or use of products, whether or not they are used in accordance with instructions. This warranty is in lieu of all
other warranties, either expressed or implied, including any implied warranty or merchantability of fitness. No repre­sentative is authorized to assume for TX RX Systems Inc. any other liability or warranty than set forth above in con­nection with our products or services.

TERMS AND CONDITIONS OF SALE

PRICES AND TERMS:

Prices are FOB seller’s plant in Angola, NY domestic packaging only, and are subject to change without notice. Fed­eral, State and local sales or excise taxes are not included in prices. When Net 30 terms are applicable, payment is
due within 30 days of invoice date. All orders are subject to a $100.00 net minimum.

QUOTATIONS:

Only written quotations are valid.

ACCEPTANCE OF ORDERS:

Acceptance of orders is valid only when so acknowledged in writing by the seller.

SHIPPING:

Unless otherwise agreed at the time the order is placed, seller reserves the right to make partial shipments for which
payment shall be made in accordance with seller’s stated terms. Shipments are made with transportation charges col­lect unless otherwise specified by the buyer. Seller’s best judgement will be used in routing, except that buyer’s routing
is used where practicable. The seller is not responsible for selection of most economical or timeliest routing.

CLAIMS:

All claims for damage or loss in transit must be made promptly by the buyer against the carrier. All claims for shortages
must be made within 30 days after date of shipment of material from the seller’s plant.

SPECIFICATION CHANGES OR MODIFICATIONS:

All designs and specifications of seller’s products are subject to change without notice provided the changes or modifi­cations do not affect performance.

RETURN MATERIAL:

Product or material may be returned for credit only after written authorization from the seller, as to which seller shall
have sole discretion. In the event of such authorization, credit given shall not exceed 80 percent of the original pur­chase. In no case will Seller authorize return of material more than 90 days after shipment from Seller’s plant. Credit
for returned material is issued by the Seller only to the original purchaser.

ORDER CANCELLATION OR ALTERATION:

Cancellation or alteration of acknowledged orders by the buyer will be accepted only on terms that protect the seller
against loss.

NON WARRANTY REPAIRS AND RETURN WORK:

Consult seller’s plant for pricing. Buyer must prepay all transportation charges to seller’s plant. Standard shipping pol­icy set forth above shall apply with respect to return shipment from TX RX Systems Inc. to buyer.

DISCLAIMER

Product part numbering in photographs and drawings is accurate at time of printing. Part number labels on TX RX
products supersede part numbers given within this manual. Information is subject to change without notice.

Bird Technologies Group TX RX Systems Inc.

Symbols Commonly Used

WARNING

ESD Electrostatic Discharge

Hot Surface

Electrical Shock Hazard

Important Information

CAUTION or ATTENTION

High Voltage

Heavy Lifting

Bird Technologies Group TX RX Systems Inc.

NOTE

Manual Part Number 7-9100

Copyright © 2011 TX RX Systems, Inc.

First Printing: March 1993

Version Number Version Date

1 03/05/93

2 05/10/93

3 01/24/94

4 07/08/96

5 10/17/11

Changes to this Manual

We have made every effort to ensure this manual is accurate. If you discover any
errors, or if you have suggestions for improving this manual, please send your
comments to our Angola, New York facility to the attention of the Technical Publications
Department. This manual may be periodically updated. When inquiring about updates to
this manual refer to the manual part number and revision number on the revision page
following the front cover.

Contact Information

Sales Support at 716-217-3113

Customer Service at 716-217-3144

Technical Publications at 716-549-4700 extension 5019

Bird Technologies Group TX RX Systems Inc.

Table of Contents

General Description ........................................................................................... 1

T-Pass Selectivity vs. Cavity Loss....................................................................... 4

Unpacking ............................................................................................................ 4

Installation Overview........................................................................................... 4

Assembly.............................................................................................................. 4

Peg Rack Assembly ............................................................................................ 6

Cavity / Isolator Mounting .................................................................................... 6

Installation ........................................................................................................... 7

Intermodulation Considerations........................................................................... 8

Multicoupler Checkout ......................................................................................... 9

Required Equipment .......................................................................................... 9

Procedure .......................................................................................................... 9

Measurement Accuracy ..................................................................................... 9

Multicoupler Tuning .......................................................................................... 11

Tuning Specifics ................................................................................................ 11

Fine Cavity Tuning............................................................................................. 12

Procedure .......................................................................................................... 12

Coarse Cavity Tuning ........................................................................................ 13

Procedure .......................................................................................................... 13

Retuning System to all new Frequencies .......................................................... 14

Multicoupler Expansion .................................................................................... 14

Typical Expansion Channel Installation ............................................................. 14

Peg Rack Procedure ....................................................................................... 14

Relay Rack Procedure..................................................................................... 15

Setting Cavity Insertion Loss ........................................................................... 15

Cavity Loss Setting Procedure 1 ..................................................................... 17

Required Test Equipment .................................................................................. 17

Procedure for T-Pass Loop ............................................................................... 17

Procedure for BandPass Loop .......................................................................... 19

Cavity Loss Setting Procedure 2 ..................................................................... 20

Required Test Equipment .................................................................................. 20

Procedure for T-Pass Loop ............................................................................... 20

Procedure for BandPass Loop .......................................................................... 21

Maintenance ....................................................................................................... 23

Isolators.............................................................................................................. 23

Table of Contents Manual 7-9100-5 10/17/11

Figures and Tables

Figure 1: Interconnect diagram of typical system ................................................ 1

Figure 2: Typical transmitter noise suppression ................................................... 3

Figure 3: Front view of 21 channel multicoupler ................................................... 5

Figure 4: Mounting rack detail .............................................................................. 6

Figure 5: Typical combiner installation ................................................................. 7

Figure 6: Measuring T-Pass channel performance .............................................. 8

Figure 7: T-Pass cavity fine tuning ..................................................................... 11

Figure 8: T-Pass cavity tuning controls .............................................................. 12

Figure 9: Coarse tuning a T-Pass cavity ............................................................ 13

Figure 10: Expansion channel installation .......................................................... 15

Figure 11: Top view of T-Pass cavity ................................................................. 16

Figure 12: Setting loop adjustment reference..................................................... 17

Figure 13: Setting T-Pass loop using step attenuators....................................... 18

Figure 14: Setting BandPass loop using step attenuators.................................. 19

Figure 15: Setting T-Pass loop insertion loss ..................................................... 21

Figure 16: Setting Bandpass loop insertion loss ................................................ 22

Table 1: Specifications .......................................................................................... 2

Table 2: Typical T-Pass channel insertion loss..................................................... 3

Table 3: Test data sheet ..................................................................................... 10

Table 4: Cavity insertion loss reference loop settings......................................... 16

APPENDIX A

800 MHz Isolators (Compact Style)

General Description .......................................................................................... 24

Installation.......................................................................................................... 25

Verifying Isolator Functionality........................................................................ 25

Recommended Test Equipment ...................................................................... 25

Measuring Reverse Isolation (S12) ................................................................... 25

Measuring Insertion Loss (S21)......................................................................... 25

Figure A1: Verifying Reverse Isolation ...............................................................26

Figure A2: Verifying Insertion Loss .................................................................... 26

Figure A3: Typical Reverse Isolation Waveform ................................................ 27

Figure A4: Typical Insertion Loss Waveform...................................................... 27

Table 1: Specifications ........................................................................................ 24

Table of Contents Manual 7-9100-5 10/17/11

GENERAL DESCRIPTION

S

TX5

TX4

TX3

TX2

TX1

Transmitter Combiner (T-Pass)

Figure 1: Interconnect diagram of a typical Trans-

mit T-Pass Combiner. Typical five channel system
shown as an example.

The 73-90-11-NN Series T-Pass Transmit Combin­ers are designed to connect up to 21 transmitters
to a common antenna. They use three-port band­pass filters (called T-Pass cavities) and ferrite iso­lators to provide low channel insertion loss, high
isolation between transmitters, high antenna-to­transmitter isolation, high intermodulation suppres­sion, and excellent transmitter noise suppression.
T-Pass transmit combiners are broadband and
easily adaptable to the most difficult duplex system
design requirements.

An interconnect diagram of a typical transmit com­biner is s h own in Figure 1. The T-Pass filter
passes one narrow band of frequencies and atten­uates all others with increasing attenuation above
and below the pass frequency. The T-Pass filter
has a “dual-port” output loop plate which allows the
filter to be easily connected to other T-Pass filters.
Connections between the filters are made with a
“thru-line” cable that behaves like a low loss 50
Ohm transmission line. The thru-line cables are
individually optimized to their own channel fre­quency. No compromises are necessary to accom­modate other channel frequencies. Each channel
can therefore be anywhere in a very broad fre­quency range.

An isolator is added at the input to each T-pass
channel to increase channel isolation. The ferrite
isolators will isolate the transmitter from unwanted
signals that enter the system via the antenna. The
transmitter sees an excellent impedance match on
its output, because the isolator absorbs reflected
power that would otherwise enter the transmitters
output stage. This improves the stability, spectral
purity and long-term reliability of the transmitter.

The TX combiners can be expanded one channel
at a time with factory-tuned, easy-to-install expan­sion channel assemblies. Expansion is usually
accomplished without modifications to the existing
system, and usually amounts to nothing more than
placing a new channel assembly, or several, on top
of the existing system. New channel frequencies
can be above, below, or between existing channel
frequencies.

The number of channels in the combiner is indi­cated by the last two digits of the model number in
place of the NN designation. All of the information
for both installation and expansion is included in
this manual. The combiner is easy to install and

TX RX Systems Inc. Manual 7-9100-5 10/17/11 Page 1

Specifications (Note 1) 73-90-11-2C-nn 73-90-11-2D-nn

Frequency Range (Note 2) 806 - 960 MHz

Cavity Type and Diameter 3/4-wave 6.625” (168 mm)

Max Continuous TX Power @ Tx-Tx Separation

150 Watts @ 450 KHz

125 watts @ 250 KHz

Isolator Load Power (Continuous) (Note 3) 5W / 60W 5W / 100W

Minimum TX-TX Separation @ Cavity Loss

450 KHz @ -1.25 dB
250 KHz @ -1.80 dB

Channel Insertion Loss See Table 2.

Typical TX-TX Isolation @ Minimum Separation -80 dB

Typical Antenna-TX Isolation -70 dB

Typical TX Noise Suppression See Figure 2.

Nominal Input Impedance, Ohms 50

Maximum Input Return Loss (VSWR) -20 dB (1.22:1)

Temperature Range -30° to +60° C

Connectors, Input and Antenna N(F)

Mechanical Mounting Peg Rack™ included with system

Mounting Options (Notes 4 and 5)

-MC: 14” H x 19” W rack-mount adaptor plates

-LR: System supplied without Peg-Rack

Maximum Number of Channels Per Rack 15

Dimensions (Note 6)

65.25” H x 24” W x 20.7” D
(1659 x 610 x 526 mm)

Weight, lb. (Kg)

Basic single-channel system:

Expansion channel assembly:

31 (14.0)

12 (5.4)

32 (14.5)

13 (5.9)

Notes:

1.-nn in model number represents number of channels.

2.Consult factory on T-Pass multicouplers for frequencies below 806 MHz or above 960 MHz.

3.Models available with 5W/25W loads. Same specifications as 60W and 100W models, except load power.

4. -MC option reduces maximum number of channels to 12 per pack.

5. -LR systems are tuned and tested on customer frequencies, then disassembled for shipping.

6. rack depth with cavity tuning rods at maximum frequency. Rod travel is approximately 2.2” (56 mm).

Table 1: Specifications.

TX RX Systems Inc. Manual 7-9100-5 10/17/11 Page 2

Tx-to-TX Separation Cavity Loss (dB)

Channel Loss (dB) vs. Number of Channels

2 3 4 5 8 10 12

1 MHz

-1.25

-2.1 -2.3 -2.4 -2.5 -2.8 -3.0 -3.3

500 KHz -2.3 -2.8 -3.0 -3.2 -3.6 -3.9 -4.1

450 KHz -2.4 -2.9 -3.2 -3.4 -3.9 -4.1 -4.3

250 KHz -1.80 -3.1 -3.8 -4.1 -4.4 -4.9 -5.2 -5.5

Table 2: Typical T-Pass Channel Insertion Loss.

Note regarding Table 2: The typical channel losses specified here are for equally spaced channels

only. Channel loss may be higher or lower in multicouplers where separation varies from one channel to
another. Contact TX RX Systems for T-Pass channel loss specifications based on your actual system
frequency plan.

0

-5

Attenuation (dB)

-10

-15

-20

-30

-25

-35

-40

-45

-50

-55

0.01 0.1 1 10

Offset from Fo (MHz)

100

73-90-11-Series Systems

6.625" Diameter 3/4-Wave, Fo = 860 MHz

IL = -1.25 dB
IL = -1.80 dB

Figure 2: Typical Transmitter Noise Suppression.

TX RX Systems Inc. Manual 7-9100-5 10/17/11 Page 3

has been factory tuned in most cases so that no
adjustments are necessary. The specifications for
the 73-90-11-NN family of T-Pass combiners are
listed in Table 1 and the typical T-Pass channel
insertion loss is shown in Table 2. The response
curve shown in Figure 2 shows the typical trans­mitt e r noise suppression. N oise suppression
depends on the cavity’s loss setting.

T-Pass Selectivity vs. Cavity Loss

As in the case of bandpass cavity filters, T-Pass fil­ter selectivity depends on the coefficient of cou­pling of the cavity loops at re sona nce. Tighter
coupling decreases inser tion loss and selectivity
while loose coupling increases them.

Although 800 - 1000 MHz T-Pass cavity loops can
be set to approximately -0.8 to -3.0 dB insertion
loss at resonance, TX RX Systems Inc. uses two
standard cavity loss settings, -1.25 and -1.80 dB,
that produce adequate selectivity for the majority of
multicoupler applications in this range. The curves
shown in figure 2 represent the lower selectivity
side of the response curve of a typical 6.625 -inch
diameter, 3/4 -wave 860 MHz T-Pass cavity filter.

Br i dging loss in a progressive thr u line T-Pass
structure varies in the same general manner as
bridging loss in a parallel junction bandpass struc­ture; it decreases as cavity selectivity increases.
An optimal cavity loss setting exists that minimizes
channel loss under a specified frequency plan and
number of channels. See Tech-Aid No. 92002 (lit.
NO. D3001D93) for a complete set of selectivity
and bridging loss curves for T-Pass cavities from
66 to 960 MHz.

parts are accounted for. Any shortages should be
reported to TX RX Systems or its authorized repre­sentative.

It is important to visually inspect the system com­ponents for any shipping damage as soon as pos­si ble after ta king deliver y. It is the customers
responsibility to file any necessary damage claims
with the carrier.

The transmit combiner is a very rugged device and
is well packaged for damage-free shipping to any
place in the world. However, a high impact during
shipping can have a detrimental affect. A damaged
shipping container is a sure sign of rough handling.
The most easily damaged parts of the combiner
are the tuning rods. These rods are marked where
they exit from the locking nut with a dab of red var­nish or other color/type of paint. If this seal appears
to be broken it may indicate that the system has
been detuned in transit.

INSTALLATION OVERVIEW

Installation of a TX RX transmitter multicoupler
con s ists o f som e or all of the follow i n g ste p s
depending on how completely the unit was assem­bled at the factory:

1) Determine the exact mounting location for the
multicoupler.

2) Assemble the mounting rack.

3) Install the cavities with isolators then install the
T-Pass Thruline cables and accessories into
the rack.

UNPACKING

Most T-Pass transmitter multicouplers are shipped

4) Connect the transmitters and antenna(s) to the
appropriate connectors of the multicoupler.

fully assembled in a cardboard crate. The cavities
are usually mounted in a suitably sized Peg-Rack
which is a patented design of TX RX Systems, Inc.
Other types of mounting may be supplied for cus-

5) Verify proper operation of each channel by
measuring power output for each individual
channel.

tom tailored systems as specified at the time of
order. In order to reduce shipping costs, some mul­ticouplers are shipped partially assembled. In this
case, customer assembly of the mounting rack and

An unassembled multicoupler will usually be bro­ken down into the following general parts groups:

ASSEMBLY

installation of the cavity channels may be required.

1) Peg rack assembly.

Accessories or other products ordered with the
multicoupler will usually be found either already

2) T-Pass cavities with mounting clamps.

mounted in the rack or packaged separately as cir­cumstances dictate. It is important to check the
packing slip against the contents to make sure all

TX RX Systems Inc. Manual 7-9100-5 10/17/11 Page 4

3) Isolator & loads on mounting brackets with
mounting clamps.

L2

L3

L5

L7

L9

L11

L13

L15

L17

L19

L21

L4

L6

L8

L10

L12

L14

L16

L18

L20

TX 1

TX 2

TX 3

TX 6

TX 7

TX 10

TX 11

TX 14

TX 15

TX 18

TX 19

TX 4

TX 5

TX 8

TX 9

TX 12

TX 13

TX 16

TX 17

TX 20

TX 21

21 Cavity Peg-Rack
Model 93-00-10

Figure 3: Front view of 21 channel multicoupler showing cavity and cable layout. Mul-

ticouplers with fewer channels follow the same cavity stacking and cable pattern from

the bottom up.

Isolator mounting clamp
connecto r positi one d on
bo ttom of c avity for th is
channel only.

Isolator mount i n g cla m p
connec tor access hole on
bottom for this bracket. Hole
is on top for all other isola­tors.

Tra nsm i t te r s c o nne c t t o
type N connector on isola­tor.

Channel Number

First cavity has built-in short
circuit.

Antenna connects here

TX RX Systems Inc. Manual 7-9100-5 10/17/11 Page 5