Bird Technologies 11-70 User Manual

YOU'RE HEARD, LOUD AND CLEAR.

Instruction Manual
Bandpass Cavity Filters
6 5/8” and 10” Diameter

Manual Part Number

7-9145

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

Warranty

This warranty applies for one year 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.

Manual Part Number 7-9145

Copyright © 1996 TX RX Systems, Inc.

First Printing: August 1996

Version Number Version Date

1 08/05/96

Symbols Commonly Used

WARNING

CAUTION or ATTENTION

High Voltage

Use Safety Glasses

ESD Elecrostatic Discharge

Hot Surface

Electrical Shock Hazard

NOTE

Important Information

Bird Technologies Group TX RX Systems Inc.

dBm

10

1

MHZ/DIV

98.00
MHZ

300

KHZ/RES

0

-10

-20

-30

-40

-50

-60

-70

INSERTION LOSS

40 dB ATT

PASS FREQUENCY

GEN 0 dBM

10 MSEC

Figure 1: Spectrum Analyzer / Tracking Generator display of the Bandpass filter.
Response curve shown for model # 11-29-01 (88 - 108 MHz)

GENERAL DESCRIPTION

The Bandpass cavity filter passes one narrow band
of frequencies (

passband

) and attenuates all
others with increasing attenuation above and below
the pass frequency. Bandpass filters have
adjustable selectivity characteristics which allows a
trade off between insertion loss and selectivity, with
a higher loss giving greater selectivity. Maximum
power handling is determined by the insertion loss
setting. A variety of models are available that cover
the range of frequencies from 30 to 960 MHz. The
portion of the frequency range that each model will
tune across is determined by the cavity's physical

length.
Either 6-5/8" or 10" diameter resonator shells may

be used to construct the filters. The difference
between the two sizes determines the filters
selectivity and it's maximum power dissipation. The
10" diameter filters have slightly higher selectivity

compared to the 6-5/8" models and can safely
dissipate up to 40 Watts of RF Power. The 6-5/8"
filters can dissipate up to 30 Watts. Maximum input
power for the 6" and 10" diameter filters is listed in
table 1. When a filter is operated above 1.0 dB loss
in transmitter applications, we recommend
inserting a ferrite isolator between a transmitter
and the Bandpass filter because the VSWR may
exceed 1.5 : 1.

Insertion loss 6" diameter

Power Rating

10" diameter

Power Rating

0.5 dB 275 Watts 368 Watts

1.0 dB 146 Watts 194 Watts

3.0 dB 60 Watts 80 Watts

Table 1: Input power ratings.

There are two adjustable parameters found in a
bandpass filter including the pass frequency and
the insertion loss. Each of these parameters is

TX RX Systems Inc. Manual 7-9145-1 08/05/96 Page 1

Cavity Resonator

Coarse Tuning Rod

Coarse Tuning Lock

10-32 Cap Screw

Calibration Index

Calibration Mark

Input/Output Port

Loop Plate

Assembly

Schematic

Symbol

Loop Plate

Assembly

Input/Output Port

Calibration Mark

Calibration Index

Fine Tuning Rod

Loop Plate

Hold Down Screws

Figure 2: The Bandpass filter.

labeled in figure 1. All of the physical components
of the filter are labeled in figure 2, with the
adjustable parts shown in emboldened italics.
Coarse and fine tuning rods are used to adjust the
pass (resonant) frequency. The insertion loss is
changed by rotating the two loop plate assemblies.

TUNING

Required Equipment

The following equipment or its equivalent is
recommended in order to properly perform the
tuning adjustments for the Bandpass filter.

1. IFR A-7550 Spectrum Analyzer with optional

Tracking Generator installed.

2. Double shielded coaxial cable test leads

(RG142 B/U or RG223/U).

3. 5/32" hex wrench.

4. Connector - female union (UG29-N or

UG914-BNC)

5. Connector - tee (UG-107 B/U).

Fine Tuning Lock

Knurled Thumb Nut

General Tuning Procedure

Tuning of the filter requires adjustment of the

frequency.

monitoring the output of a tracking generator after
it passes through the filter. Adjustment of the
insertion loss is optional on units that are preset by
the factory, which is most often the case. To insure
proper tuning of the Bandpass filter, all
adjustments should be performed in the following
order;

1. Preset loops to an index value of 10 if not fac­tory set.

2. Tune the pass frequency.

3. Set the insertion loss if other than 1.0 dB loss is
desired.

4. Fine tune the pass frequency

Cavity Tuning Procedure

1. Setup the analyzer / generator for the desired
frequency and bandwidth (center of display) and
also a vertical scale of 2 dB/div.

The pass frequency is adjusted by

pass

TX RX Systems Inc. Manual 7-9145-1 08/05/96 Page 2