TNF200 Tuneable Notch Instruction Sheet

1.0 Introduction

The TNF200 series of notch filters are designed to provide a deep notch and to pass a wide range of frequencies. This makes them useful for harmonic measurements when used in conjunction with a network analyzer. Notch frequencies are available from 0.5 Mhz to 1.3 GHz.

2.0 Description

The TNF200 is contained in a small nickel plated brass case. There is a single adjustment which controls the notch frequency. These filters are capable of passing DC as well as AC up to the specified MUF, maximum useable frequency.

3.0 Bench Tests

Before installing the unit it is advisable to run performance tests to verify that the TNF200 is operating properly. Also, units that are suspect can be verified by these performance tests.

A network analyzer is required to run performance tests on the filter. Connect the output (generator portion) to one port on the filter. Connect the input (receiver portion) to the other port. The ports are symmetrical so it doesn't matter which port is connected to which device.

NOTE: To determine where the notch is first set the network analyzer to cover from the lowest to highest possible notch frequency. These frequencies are listed on the label of the filter.

Set a marker on the analyzer to the highest notch frequency of the filter.

Set the trimmer to minimum capacity (slug CCW at top). Turn adjustment CW until the notch is centered on the marker.

Set the network analyzer to sweep from the notch frequency to the maximum useable frequency. There should be no other notches within the sweep that are greater than 0.5 dB below 1.0 GHz or 1.0 dB from 1.0 GHz to the MUF.

3.0 Bench Tests-continued

Set a marker for the lower notch frequency of the TNF200. Adjust the notch to the lower frequency.

Again set the sweep to cover to the MUF and check for parasitic notches as above.

This completes the performance tests, if the TNF200 passes all of these it is an acceptable unit.

4.0 Operation

If the TNF200 is being connected in a system where the effects of the notch are observable, the TNF200 can be tuned after installation. If the effects are not observable, the TNF200 must be tuned to the desired notch frequency before installation.

Tuning
1. Connect a signal generator that will generate the desired frequency to one of the ports of the TNF200.
2. Connect a power meter, spectrum analyzer or network analyzer to the other port.
3. Adjust the signal generator to the the frequency to be notched.
4. Adjust the trimmer for minimum power indication; this will be the center of the notch.

Connect the TNF200 in series between the source and the load devices. Insure that the impedance of the system is relatively close to 50 ohms. If there is any doubt it is advisable to measure the TNF200 performance in circuit.

Continued on next page.

4.0 Operation-continued

5.0 Maintenance

The TNF200 is designed to be maintenance free, however the following precautions will assist in preventing corrosion or mechanical damage:
If the unit is in damp or corrosive atmospheres store the filter in a closed plastic bag, with desiccant, when not in use.
Keep protective covers on connectors when the filter is not in use to prevent entry of foriegn materials or damage from foriegn objects.
The filter may be cleaned using any of the commercially available solvents. The nickel plate and stainless hardware will resist damage from all but the most corrosive of chemicals.

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5.0 Maintenance-continued

NOTE: some filters are supplied with connectors having a silver plate. Extra caution shuld be taken to insure that no damage occurs to the silver plating.

The trimmer capacitors are supplied with a conductive lubrication to improve the smoothness. Care should be taken not to allow solvents or other liquids to enter the trimmer as these may dilute the lubrication.

6.0 Specifications

Please see the attached product data sheet for a complete list of specifications for the TNF200.

website: eagle-1st.com

email: sales@eagle-1st.com

Phone: 928 204-2597

PO Box 4300

fax: 928 204-2568

Sedona, AZ 86340

24 Sep 2005 css-a ΥΤΦ-8