bedea â Rosenberger - Bedea Berkenhoff & Drebes GmbH

More documents

Recommendations

Info

New developments and accessories for the CoMeT test set-up bedea – Rosenberger CoMeT- newsletter - 01/2003 - S. 2 There are different improvements, complements and accessories to the CoMeT test set-up about which we want to inform you more detailed. Due to the modular construction, the different components or complements may be assembled without any restriction. 1 Stretching device When measuring the screening attenuation in the tube, the cable under test shall be centred in the middle of the tube to avoid changes of the characteristic impedance in the second system. This may be achieved by maintain the measurement with vertical mounted tube but with incumber handling With the stretching device, one can keep the sample centred in the horizontal mounted tube. Care should be taken not to apply to high stretching forces to the screen of the sample because this will change its characteristics. The stretching device is equipped with a torque wrench which allows to control the stretching force. Figure 2 – Stretching device for the CoMeT test set-up Supply schedule: Stretching device, 1 set of contact slices, 2,2 to 9,8 mm, torque wrench An investigation of the influence of stretching forces to the test results of screening measurements may be ordered from bedea. 2 Extension set for 10mm to 15mm diameter Measuring the screening attenuation and the transfer impedance up to 15mm diameter over screen with the CoMeT 40/2 (standard application up to 9,8mm over screen). The additional reflection due to the enlarged case shall be taken into account when evaluating the test results. An investigation of the influence of additional reflections to the test results of screening measurements may be ordered from bedea. Supply schedule: Enlarged contact case, contact slices from 9,8mm to 14,8 mm. bedea Berkenhoff&Drebes GmbH, Postfach 1140, D-35607 Asslar, Germany, bmund@bedea.com
edea – Rosenberger CoMeT- newsletter - 01/2003 - S. 3 3 Complement set "high screening" When measuring screening attenuation of > 85 dB, special care shall be taken to contact the screen of the sample under test in the connecting case. If the contact slices don't fit close to the screen under test or if a open slot remains in the connecting case, wrong test results may be obtained. The complement set "high screening" consists of a separated case which presses the contact slices close to the screen when screwing it together. Due to the smaller gradation of the contact slices the fitting to the screen is improved. Measurements with the complement set "high screening" with a semi rigid cable sample resulted in ≥ 135 dB screening attenuation up to 1 GHz and ≥ 125 dB up to 3 GHz. sheath contact slice inner conductor thread braidt screening case contacting resistor and braid load resistance Figure 3 – Contact case of the Complement set "high screening" Supply schedule: 1 set contact slices with intermediate sizes of 2,55mm to9,55 mm, separated contact case with pressing device, brass, golden and VA-steel. 4 Additional contact cases To measure the screening attenuation of connectors and cable assemblies, the connecting case was modified that one can connect the assembly or the connector direct to the contact case. The mating part of the connector under test can be mounted direct to the contact case and matched with its characteristic impedance. Figure 4 shows an example wit a F-connector. For the measuring of cables with connectors respectively of cable assemblies different cases with drillings for different connector systems are available, e.g. F-connector, (CATV, 75 Ohm) N- 50-system, BNC etc. Furthermore, a contact case with feeding hole for other connector systems or threads is available. With the same principle also IEC- and BNC-connectors may be applied. The different contact cases may be used also with the new "Tube in Tube" system. bedea Berkenhoff&Drebes GmbH, Postfach 1140, D-35607 Asslar, Germany, bmund@bedea.com
Page 1: edea - Rosenberger CoMeT - newslett
Page 5 and 6: edea - Rosenberger CoMeT- newslette
Page 7: edea - Rosenberger CoMeT- newslette

bedea â Rosenberger - Bedea Berkenhoff & Drebes GmbH

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?

bedea â Rosenberger - Bedea Berkenhoff & Drebes GmbH