Bird Technologies 20-70-26 User Manual

YOU'RE HEARD, LOUD AND CLEAR.

Instruction Manual

®

Series-Notch

6 5/8” and 10” Diameter

Manual Part Number

Cavity Filters

7-9146

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 7-9146

Copyright © 1996 TX RX Systems, Inc.

First Printing: July 1996

Version Number Version Date

1 07/25/96

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.

GENERAL DESCRIPTION

The Series-Notch® cavity filter passes a relatively
wide band of frequencies (

passband

) while
simultaneously rejecting a very narrow band of
frequencies (

notch frequency

). Minimum
separation between passband and notch frequency
is 50 KHz. The notch depth is variable from 15 to
25 dB. A variety of models are available that cover
the range of frequencies from 30 to 960 MHz. 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 diameter
difference between the two determines the filters
selectivity and it's maximum power dissipation. The
10" diameter filters have a slightly higher selectivity
(more attenuation at the notch frequency)
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

There are three adjustable parameters found in a
Series-Notch filter including the passband

frequency, the notch frequency, and notch
depth. Each of these parameters is labeled on the

response curve shown in figure 1.
Two types of Series-Notch filters are available,

lowpass and highpass. Lowpass filters permit a
very narrow separation between the notch and the
low frequency portion of the passband. Likewise,
highpass filters will permit a very narrow separation
between the notch and the high frequency
passband. The lowpass filter, unlike the highpass
filter, can be tuned for a symmetrical response.
The difference between the two types of filters is
determined by the loop plate assembly used. The
cavity itself remains identical for both types. The
part number is stamped on the loop.

dBm

20

10

0

-10

-20

-30

-40

-50

-60

1

MHZ/DIV

50 dB ATT

Notch Frequency

98.00
MHZ

Passband

GEN 0 dBM

Notch Depth

300

KHZ/RES

10 MSEC

Figure 1:
Spectrum Analyzer / Tracking Generator display of
the Series-Notch filter tuned lowpass. Response
curve above is for model # 20-29-01 ( 88 - 108 MHz).

dB

40

30

20

10

0

-10

-20

-30

-40

1

MHZ/DIV

50 dB ATT

98.00
MHZ

Passband

GEN 0 dBM

Notch Frequency

300

KHZ/RES

10 MSEC

Figure 2:
Return loss response curve for the "lowpass"
Series-Notch filter shown in figure 1. Response curve
above is for model # 20-29-01 ( 88 - 108 MHz).

low frequency passband and the high frequency. A
symmetrical response can only be obtained with
relatively large separations between pass and
notch frequencies. Figure 4 shows the resulting
return loss curve.

Figure 1 shows the response curve of a lowpass
filter while figure 2 shows the same filter's return
loss curve. A symmetrical response can be seen
in figure 3 where the notch is centered between the

TX RX Systems Inc. Manual 7-9146-1 07/25/96 Page 1

All of the physical components of the filter are
labeled in figure 5, with the adjustable parts shown
in emboldened italics. Coarse and fine tuning rods
are used to adjust the notch (resonant) frequency.