Applications

Notch filters are useful in situations where a selected frequency must be attenuated while passing all others. Notch filters are commonly used to:
1. Increase dynamic range of spectrum analyzers.
2. Remove interfering signals in high gain amplifying systems.
3. Remove harmonics from signal sources or low power transmitters.
4. Prevent receiver overload in co-located repeater installations.
5. Identify or eliminate off-band interference at lower cost than cavity type filters.
6. Direct connection to communications transceivers for the purpose of suppressing out of band signals that are causing overload.

Application Notes

The use of notch filters to enhance spectrum analyzer measurements is discussed in the application note:
"Spectrum Analyzer measurements"
This note is available for down loading from this website in PDF format.

Description

The TNF200 is designed using carefully chosen parts in the tuned circuit to insure that there are no unwanted disturbances in the pass band. The guarenteed pass band is then specified; this is known as the MUF.
The TNF200s have a wide, deep notch which makes them unsuitable for use on in-band signals, or signals that are close to the notched frequency. The main advantage of the TNF200 is the extremely wide useable frequency.

Description-continued

The table on the next page lists the MUF for each filter in the TNF200 family. The TNF207, TNF208, TNF210 and the new TNF212 all use a diplexer system to pass the upper frequencies. By routing the notch filter thru the low pass filter section any parasitic notches from the tuned circuit are suppressed.
Due to the High "Q"; circuitry, the notch depth is typically 25 dB or greater. The notch width of the VHF models, as measured at the 15 dB attenuation points, is wide enough to suppress a modulated TV signal.
Because insertion loss is minimal, typically <0.5 dB, a TNF200 may be inserted for each unwanted signal, But when two unwanted frequencies are close together, one TNF200, tuned between the two frequencies, will suppress both signals. Another benefit of the high Q is a power handling capability of 25 watts of RF power.
The TNF200 is contained in a heavy-duty nickel plated brass enclosure providing excellent shielding. Stainless steel hardware and nickel plating prevent corrosion from dissimilar metal action. You can expect the unit to withstand many years of normal abuses of heavy use.

Quality

To insure that high quality is maintained each unit is thoroughly inspected both mechanically and electrically. All units are aged and then retested to insure superior stability over the lifetime of the instruments.

Availability

These units are normally stock items: 1 week delivery. Special orders or large quantities usually require 2-4 weeks.

Specifications

Please refer to next page for detailed specifications.

SPECIFICATIONS

Electrical

Impedance:

50 ohm ± 5%

Power Rating:

10 Watt at notch
25 Watts in pass band

Insertion Loss:

<0.5 dB below 1.0 GHz
<1.0 dB below 2.0 GHz

Note: Insertion loss applies only to the maximum usable frequency of the filter

Bandwidth(3dB):

See Table

Environmental

Temperature:

+0 to +70C operational
-55 to +125 storage

Humidity:

10-80% RH, non-cond

Shock:

Drop from 1"

Vibration:

100 G any Axis

Waterproof:

No

Mechanical

Case Size:

Weight:

<12.0 Oz

Construction:

Can is of brass .025"; nickel plated. Connectors are stainless steel or brass. All hardware is stainless steel.

SPECIFICATIONS-cont

Options

Connectors

"BF"

BNC female Standard

"MF"

SMA female

"NF"

N female Standard

"NM"

N male

Test:

Test data can be provided on pass band and stop band, return loss, and group delay.

TD

Test Data Plots

COC

Certificate of Conformance

Ordering Information

Select the frequency range desired from the table below. The correct part number of the filter will be in the left hand column. Add the correct suffix for the type of connectors desired from Options above. Call the factory or authorized representative to place order.

Click on drawing for enlarged view