CF7W: Wide Bandpass Filters (Models & Graph)
Example Graph: CF7W-300/456 Wide bandpass
- Designed to pass chs 36 to 62, and reject chs 33 and 66 and beyond
- Passband loss: < 2 dB (except < 3 dB at band edges - Mkr 1 & 2)
- Stopband: >40 dB min (Mkr 3 & 4)
- Selectivity: Pass/stop frequency transition is 5% (14 MHz on lower side, 20 MHz on upper sid
| Mkr | Freq (MHz) | Attn (dB) | Channel |
| 1 Fc1 | 300.000 | -2.556 | 36 |
| 2 Fc2 | 456.000 | -2.723 | 62 |
| 3 Fs1 | 286.000 | -49.079 | 33 |
| 4 Fs2 | 476.000 | -47.546 | 66 |
| 5 | 378.000 | -1.355 | 50 |
Example Graph 2: CF7W-VHF/UHF Double Wide bandpass
- Designed to pass both VHF and UHF bands and provide 25 dB out of band rejection - use as pre-selector for Off-Air TV system amplifiers
- Low Passband loss: < 1 dB (except < 1.5 at 806 MHz)
- Good Return Loss >16 dB
| Mkr | Freq (MHz) | Attn (dB) | Channel |
| 1 | 174.000 | -0.882 | 7 |
| 2 | 216.000 | -0.890 | 13 |
| 3 | 470.000 | -0.841 | 14 |
| 4 | 806.000 | -1.625 | 69 |
Table: Example CF7W models
| Model Numbers CF7W-Fc1 / Fc2 | Passband Fc1 - Fc2 (MHz) | Passband Channels (CATV) | Stopband Lower (MHz) >40 dB loss | Stopband Upper (MHz) >40 dB loss |
| CF7W - 7/47.5 | 7 to 47.5 | T7 to T13 | 0 to 5 | 52 - 750 |
| CF7W - 54/88 | 54 to 88 | 2 - 6 | 0 - 50 | 94 - 750 |
| CF7W - 88/108 | 88 to 108 | FM Band | 0 - 80 | 120 - 860 |
| CF7W - 120/174 | 120 to 174 | 14 - 22 | 0 - 107 | 186 - 860 |
| CF7W - 174/216 | 174 to 216 | 7 - 13 | 0 - 164 | 228 - 860 |
| CF7W - 216/300 | 216 to 300 | 23 - 36 | 0 - 206 | 316 - 860 |
| CF7W - 300/456 | 300 - 456 | 37 - 62 | 0 - 286 | 476 - 860 |
| CF7W - 450/560 | 450 - 560 | 63 - 80 | 0 - 430 | 586 - 1000 |
| CF7W - 470/812 | 470 - 812 | 14 - 69 UHF | 0 - 445 | 850 - 1000 |
| CF7W - 550/750 | 550 - 750 | 80 - 116 | 0 - 526 | 780 - 1000 |
Model CF7W - Specifications and Order Info
Order as: CF7W ( Fc1/Fc2 ) *
Specify Fc1 and Fc2 ( refer to graph above )
Fc1 = Lower 3dB cut-off ( in
MHz )
Fc2 = Upper 3dB cut-off ( in MHz )
Fc1 & FC2 can be specified as channel
numbers
General Specifications
Passband loss & flatness ...... . 2 dB .5 dB
Return loss ...............................14 dB typical
Attenuation level .................... - 40 dB min std
Bandwidth ............................. 0-750 MHz std
Housing .............. Indoor and outdoor available
Connectors & Impedance: ..... F-type, 75 ohms *
* 75 ohms BNC, 50 ohms BNC and N also available
Note: Standard Transition (Fc1 to Fs1, 40 dB roll off, is approx 5% )
Example : CF7W-300/ 456 (see graph) ...
•
lower stopband at 40 dB roll off
is at 286 MHz (300 x .95 = 286);
• upper stopband at 40 dB roll off is at 476 MHz (456 x 1.05 = 476)