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YOU'RE HEARD, LOUD AND CLEAR.
Instruction Manual
Vari-Notch
6 5/8” and 10” Diameter
Manual Part Number
®
Cavity Filter
7-9144
8625 Industrial Parkway, Angola, NY 14006 Tel: 716-549-4700 Fax: 716-549-4772 sales@birdrf.com www.bird-technologies.com
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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.
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Manual Part Number 7-9144
Copyright © 1996 TX RX Systems, Inc.
First Printing: July 1996
Version Number Version Date
1 07/22/96
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.
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dBm
10
200
KHZ/DIV
98.00
MHZ
300
KHZ/RES
-10
-20
-30
-40
-50
-60
-70
0
40 dB ATT
INSERTION LOSS
REJECTION
NOTCH
GEN 0 dBM
Figure 1: Spectrum Analyzer / Tracking Generator display of the highpass Vari-Notch filter.
Response curve shown for model # 15-29-01 (88 - 108 MHz)
GENERAL DESCRIPTION
The Vari-Notch® cavity filter is designed to pass a
relatively narrow band of frequencies
(passband)
while simultaneously rejecting a wide band of frequencies
(rejection notch).
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 a slightly higher selectivity
compared to the 6-5/8" models. Additionally, the
10" filters can safely dissipate up to 40 Watts of RF
Power, while the 6-5/8" filters can dissipate up to
30 Watts. Maximum input power for the 6" and 10"
diameter filter's is listed in table 1.
Insertion loss 6" diameter
power rating
10" diameter
power rating
0.3 dB 449 Watts 599 Watts
0.6 dB 230 Watts 308 Watts
Table 1: Input power ratings
PASSBAND
10 MSEC
Two types of Vari-Notch filters are available, lowpass and highpass. Lowpass filters have the passband below the notch frequency while highpass
filters have the passband above the notch.
The difference between the two types at VHF frequencies is determined by the inductive element
used in the construction of the loop plate assembly.
At UHF frequencies the same loop plate is used for
both low and highpass. The cavity itself remains
identical for both types. Figure 1 shows the re-
sponse curve of a highpass filter.
There are three adjustable parameters in a Vari-
Notch filter including the passband frequency, the
rejection notch frequency, and insertion loss.
Each of these parameters is labeled on the response curve shown 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 passband while a variable
capacitor is used to adjust the rejection notch. The
insertion loss is adjusted by rotating the loop plate
assembly.
TX RX Systems Inc. Manual 7-9144-1 07/22/96 Page 1