LP7E (Lowpass Eliminator): Graph, Table and Order Info
Example: LP7E-ch.70 / 75
- LP7E-ch.70/75 passes frequencies from 5 to 504 MHz (ch.70), and removes frequencies from Fs (ch.75) and above for reuse.
- Passband loss: <1 dB
- Cut-off loss( Fc, ch.70): < 4 dB
- Stopband: > 55dB from 529 to 760 MHz
- Transition: 5% frequency separation between Fc and Fs (i.e., 504/529 = .95 - approx)
| Mkr | Freq (MHz) | Attn (dB) | Channel |
| 1 | 460.000 | -0.905 | Passband |
| 2 Fc | 503.750 | -3.75 | 70 snd |
| 3 Fs | 529.250 | -57.46 | 75 pix |
| 4 | 40.750 | -0.075 | Passband |
Pix = Picture, Snd = Sound
Table: Example LP7E model
| Model # | Passband * (MHz) | Cut Off (Fc) Loss | Stopband (MHz) * | Transition (number of chs, freq. separation) |
| LP7 E-42/50 | 0 to 42 | < 2.0 dB | 50 to 1000 | 8 MHz |
| LP7 E-ch.4/5 | 0 to 72 (ch.4) | < 4.5 dB | 77-750 | 5 MHz |
| LP7 E-ch.13/25 | 0 to 216 | < 3.5 dB | 228-750 | 2 chs, 12 MHz |
| LP7 E-ch.36/39 | 0 to 300 | < 3.5 dB | 312-750 | 2 chs, 12 MHz |
| LP7 E-ch.44/48 | 0 to 348 | < 3.5 dB | 366-750 | 3 chs, 18 MHz |
| LP7 E-ch.56/60 | 0 to 420 | < 4.0 dB | 438-750 | 3 chs, 18 MHz |
| LP7 E-ch.60/65 | 0 to 444 | < 4.0 dB | 468-750 | 4 chs, 24 MHz |
| LP7 E-ch.70/75 | 0 to 504 | < 4.0 dB | 528-1000 | 5 chs, 28 MHz |
| LP7 E-ch.80/85 | 0 to 564 | < 4.0 dB | 588-1000 | 5 chs, 28 MHz |
| LP7 E-ch.94/105 | 0 to 650 | < 4.0 dB | 680-1000 | 6 chs, 30 MHz |
| LP7 E-ch.116/122 | 0 to 750 | < 4.0 dB | 784-1000 | 6 chs, 30 MHz |
| LP7 E-870/950 | 0 to 870 | < 3.0 dB | 950-2200 | click here for Graph |
* Passband insertion loss <1 dB (except at cutoff knee), Stopband > 55dB typical.
Order Info:
Order as: LP7E-ch.(Fc/Fs): see calculating transition example below*
Specify: Fc (cut off channel/frequency) and/or Fs (stopband channel/frequency)
Example: LP7E-ch.70/75 or LP7E-504/529
Calculating Transition for example Highpass (HP7E-ch.80/86)
Example 1: Lowpass must pass to Fc (504 MHz = ch.70), where
does 55dB roll off (Fs) begin?*
From Fig.1: Fs = Fc x 1.05 (5% transition)
Given Fc = 504 MHz (ch.70), then, Fs = 504 x 1.05 = 529 MHz (ch.75).
*click Freq. Chart for channel frequencies
Example 2:Lowpass stopband required at Fs (529 MHz = ch.75),
where is passband cut off (Fc)?*
From Fig.1: Fc = Fs x .95 (5% transition)
Given Fs = 529 MHz (ch.75), then, Fc = 529 x .95 = 504 MHz (ch.70).
*click Freq. Chart for channel frequencies