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delay equalization
frequency spacing
delay equalization

Most RF Repeaters are available with Delay Equalization available as an option. Delay Equalization corrects for the normal parabolic group delay shape in the RF channel that is generated by the channel or branching filters. The choice to add delay equalization depends on the type of microwave signal that is being repeated and whether there are multiple RF Repeaters in tandem. Delay Equalizers add cost and so are sold at added price. Delay Equalizers also add loss to the repeater, possibly reducing the system fade margin and reliability.

The time when Delay Equalizers are required is when the normal unequalized delay is great enough to cause unacceptable errors in digital systems or intermodulation distortion in analog FM systems. In digital systems, the peak-to-peak delay over the major modulation lobe should be less than 1/3 of the symbol rate. The following charts are useful in determining the need for equalization.

Determine if Delay Equalizers are required.

The charts below show the differences between an UnEqualized Channel and an Equalized Channel. Note that two equalizer sections are used to create a more uniform, that is , flatter channel Group Delay response.
Chart 1, 2, Channel Delay
Chart 1, 2, Channel Delay

Repeater Models, Bandwidth and Traffic Examples with Delay Equalization Recommendation

Table 4, RF-1500E, 16 MHz RF Bandwidth, no equalizers available, always unequalized.
Traffic Modulation Equalizers, 1 Repeater Max
Tandem Repeaters
6.5 Mb/s, 4xDS1,
3.5 MHz 		4 FSK, 16QAM, QPR3, 9QPRS No 3
13 Mb/s, 8xDS1,
3.5 MHz 		16QAM, 64QAM, QPR7, 49QPRS No 3
2 Mb/s, 1xE1 QPSK, OQPSK, 4QAM, 4PSK, FSK, MSK No 3
8 Mb/s, 4xE1, 1xE2 QPSK, OQPSK, 4QAM, 4PSK No 3

Table 5, RF-2000E, 20 MHz RF Bandwidth
Traffic Modulation Equalizers, 1 Repeater Equalize at n
Tandem Repeaters
6.5 Mb/s, 4xDS1,
3.5 MHz 		4FSK, 16QAM, QPR3, 9QPRS No 3
13 Mb/s, 8xDS1,
3.5 MHz 		16QAM, 64QAM, QPR7, 49QPRS, 32TCM No 3
26 Mb/s, 16xDS1,
5 MHz 		64QAM, 128TCM No 2
45 Mb/s, 1xDS3,
10 MHz 		QPR9, 81QPRS, 64QAM, 64TCM No 2
2 Mb/s, 1xE1 QPSK, OQPSK, 4QAM, 4PSK, FSK, MSK No 3
8 Mb/s, 4xE1, 1xE2 QPSK, OQPSK, 4QAM, 4PSK No 3
8 Mb/s, 4xE1, 1xE2 FSK, MSK No 2
34 Mb/s, 1xE3,
14 MHz 		16QAM, 16TCM, 32TCM No 2
34 Mb/s, 1xE3,
28 MHz 		QPSK, OQPSK, 4QAM, 4QPSK, FSK, MSK N/A,
Use RF-2000EW 		N/A,
Use RF-2000EW
< 300 FDM Channels,
< 5 MHz 		FM analog No 2
480 FDM Channels,
10 MHz 		FM analog Yes
Prefer RF-2000EW 		1
600 FDM Channels,
10 MHz 		FM analog Yes
Prefer RF-2000EW 		1
TV, Color FM analog Yes 1

Table 6, RF-2000EW, 30 MHz RF Bandwidth, always equalized.
Traffic Modulation Equalizers, 1 Repeater Equalize at n
Tandem Repeaters
45 Mb/s, 1xDS3,
10 MHz 		QPR9, 81QPRS, 64QAM, 64TCM Yes 1
34 Mb/s, 1xE3,
28 MHz 		QPSK, OQPSK, 4QAM, 4PSK, FSK, MSK Yes 1
34 Mb/s, 1xE3,
14 MHz 		16QAM, 16TCM, 32TCM Yes 1
480 FDM Channels,
10 MHz 		FM analog Yes 1
600 FDM Channels,
10 MHz 		FM analog Yes 1
960 FDM Channels
14 MHz 		FM analog Yes 1
1200 FDM Channels
28 MHz 		FM analog Yes 1
TV, Color FM analog Yes 1

Table 7, RF-2500E, 20 MHz RF Bandwidth, no equalizers available, always unequalized.
Traffic Modulation Equalizers, 1 Repeater Max
Tandem Repeaters
< 13 Mb/s, 8xDS1,
3.5 MHz 		16QAM, 64QAM, QPR7, 49QPRS No 3
< 8 Mb/s, 4xE1, 1xE2 QPSK, OQPSK, 4QAM, 4PSK No 3
34 Mb/s, 1xE3,
14 MHz 		16QAM, 16TCM, 32TCM No 2
< 300 FDM Channels,
< 5 MHz 		FM analog No 2

Table 8, RF-4000, 40 MHz RF Bandwidth
Traffic Modulation Equalizers, 1 Repeater Equalize at n
Tandem Repeaters
< 13 Mb/s, 8xDS1,
< 3.5 MHz 		16QAM, 64QAM, QPR7, 49QPRS No 4
45 Mb/s, 1xDS3,
10 MHz 		QPR9, 81QPRS, 64QAM No 4
45 Mb/s, 1xDS3,
20 MHz 		16QAM, 16TCM, 32TCM No 3
90 Mb/s, 2xDS3,
20 MHz 		64QAM, 64TCM No 2
135 Mb/s, 3xDS3,
20 MHz 		256TCM No 2
34 Mb/s, 1xE3,
14 MHz 		16QAM, 16TCM, 32TCM No 3
34 Mb/s, 1xE3,
28 MHz 		QPSK, OQPSK, 4QAM, 4PSK, FSK, MSK No 2
140 Mb/s, 4xE3,
40 MHz 		16QAM, 16TCM, 32TCM Yes 1
155 Mb/s, OC-3
40 MHz 		64QAM, 128TCM Yes 1
600 FDM Channels,
10 MHz 		FM analog No 2
960 FDM Channels,
20 MHz 		FM analog Yes 1
1260 FDM Channels,
20 MHz 		FM analog Yes 1
1500 FDM Channels,
20 MHz 		FM analog Yes 1
1800 FDM Channels,
40 MHz 		FM analog Yes 1
TV, Color FM analog Yes 1

Table 9, RF-4000N, 28 MHz RF Bandwidth, no equalizers available, always unequalized
Traffic Modulation Equalizers, 1 Repeater Max
Tandem Repeaters
< 13 Mb/s, 8xDS1,
< 3.5 MHz 		16QAM, 64QAM, QPR7, 49QPRS No 4
45 Mb/s, 1xDS3,
10 MHz 		QPR9, 81QPRS, 64QAM No 2
45 Mb/s, 1xDS3,
20 MHz 		16QAM, 16TCM, 32TCM No 2
90 Mb/s, 2xDS3,
20 MHz 		64QAM, 32TCM No 1
34 Mb/s, 1xE3,
14 MHz 		16QAM, 16TCM, 32TCM No 2
34 Mb/s, 1xE3,
28 MHz 		QPSK, OQPSK, 4QAM, 4PSK, FSK, MSK No 1
600 FDM Channels,
10 MHz 		FM analog No 2
960 FDM Channels,
20 MHz 		FM analog Yes 1

Table 10, RF-4500, 40 MHz RF Bandwidth
Traffic Modulation Equalizers, 1 Repeater Equalize at n
Tandem Repeaters
34 Mb/s, 1xE3,
14 MHz 		16QAM, 16TCM, 32TCM No 3
34 Mb/s, 1xE3,
28 MHz 		QPSK, OQPSK, 4QAM, 4PSK, FSK, MSK No 2
140 Mb/s, 4xE3,
40 MHz 		16QAM, 16TCM, 32TCM Yes 1
155 Mb/s, OC-3
40 MHz 		64QAM, 128TCM Yes 1
600 FDM Channels,
10 MHz 		FM analog No 2
960 FDM Channels,
20 MHz 		FM analog Yes 1
1260 FDM Channels,
20 MHz 		FM analog Yes 1
1800 FDM Channels,
40 MHz 		FM analog Yes 1
TV, Color FM analog Yes 1

Table 11, RF-6000E, 30 MHz RF Bandwidth
Traffic Modulation Equalizers, 1 Repeater Equalize at n
Tandem Repeaters
< 13 Mb/s, 8xDS1,
3.5 MHz 		16QAM, 64QAM, QPR7, 49QPRS No 4
26 Mb/s, 16xDS1
5 MHz 		225QPRS, QPR15 No 4
45 Mb/s, 1xDS3,
10 MHz 		QPR9, 81QPRS, 64QAM, 64TCM No 3
90 Mb/s, 2xDS3,
29.58 - 30 MHz 		16QAM, 16TCM, 32TCM Yes 1
135 Mb/s, 3xDS3,
29.58 - 30 MHz 		64QAM, 128TCM Yes 1
140 Mb/s, 4xE3
30 MHz 		64QAM, 128TCM Yes 1
155 Mb/s, OC-3
29.58 - 30 MHz 		128TCM Yes 1
< 300 FDM Channels,
< 5 MHz 		FM analog No 3
< 600 FDM Channels,
10 MHz 		FM analog No 2
1800 FDM Channels
29.58 - 30 MHz 		FM analog Yes 1
TV, Color FM analog Yes 1

Table 12, RF-6000EL, 28 MHz RF Bandwidth, no equalizers available, always equalized
Traffic Modulation Equalizers, 1 Repeater Max
Tandem Repeaters
< 13 Mb/s, 8xDS1,
3.5 MHz 		16QAM, 64QAM, QPR7, 49QPRS No 1
26 Mb/s, 16xDS1,
5 MHz 		64QAM, 128TCM No 1
26 Mb/s, 16xDS1,
10 MHz 		64QAM, 32TCM No 1
45 Mb/s, 1xDS3,
10 MHz 		64QAM, 32TCM, QPR9, 81QPRS No 1
< 300 FDM Channels,
< 5 MHz 		FM analog No 1
< 600 FDM Channels,
10 MHz 		FM analog No 1

Table 13, RF-6000EW, 40 MHz RF Bandwidth, always equalized.
Traffic Modulation Equalizers, 1 Repeater Equalize at n
Tandem Repeaters
135 Mb/s, 3xDS3,
40 MHz 		16QAM, 32TCM Yes 1
135 Mb/s, 3xDS3,
40 MHz 		64QAM, 128TCM Yes 1
140 Mb/s, 4xE3
40 MHz 		16QAM, 32TCM Yes 1
140 Mb/s, 4xE3
40 MHz 		64QAM, 128TCM Yes 1
155 Mb/s, OC-3
40 MHz 		64QAM, 128TCM Yes 1
1800 FDM Channels
40 MHz 		FM analog Yes 1
2400 FDM Channels
40 MHz 		FM analog Yes 1
TV, Color FM analog Yes 1

Table 14, RF-7000EL, RF-8000EL, 28 MHz RF Bandwidth, no equalizers available, always equalized.
Traffic Modulation Equalizers, 1 Repeater Max
Tandem Repeaters
< 13 Mb/s, 8xDS1,
3.5 MHz 		16QAM, 64QAM, QPR7, 49QPRS No 1
26 Mb/s, 16xDS1,
5 MHz 		64QAM, 128TCM No 1
26 Mb/s, 16xDS1,
10 MHz 		64QAM, 32TCM No 1
45 Mb/s, 1xDS3,
10 MHz 		QPR9, 81QPRS, 64QAM, 64TCM No 1
2 Mb/s, 1xE1 QPSK, OQPSK, 4QAM, 4PSK, FSK, MSK No 1
8 Mb/s, 4xE1, 1xE2 QPSK, OQPSK, 4QAM, 4PSK, FSK, MSK No 1
34 Mb/s, 1xE3,
28 MHz 		QPSK, OQPSK, 4QAM, 4PSK, FSK, MSK No 1
34 Mb/s, 1xE3,
14 MHz 		16QAM, 16TCM, 32TCM No 1
< 300 FDM Channels,
< 5 MHz 		FM analog No 1
< 600 FDM Channels,
10 MHz 		FM analog No 1

Table 15, RF-7000E, RF-8000E, 30 MHz RF Bandwidth
Traffic Modulation Equalizers, 1 Repeater Equalize at n
Tandem Repeaters
< 13 Mb/s, 8xDS1,
3.5 MHz 		16QAM, 64QAM, QPR7, 49QPRS No 4
45 Mb/s, 1xDS3,
10 MHz 		QPR9, 81QPRS, 64QAM, 64TCM No 3
90 Mb/s, 2xDS3,
30 MHz 		16QAM, 32TCM Yes 1
135 Mb/s, 3xDS3,
30 MHz 		64QAM, 128TCM Yes 1
2 Mb/s, 1xE1 QPSK, OQPSK, 4QAM, 4PSK, FSK, MSK No 3
8 Mb/s, 4xE1, 1xE2 QPSK, OQPSK, 4QAM, 4PSK, FSK, MSK No 3
34 Mb/s, 1xE3,
28 MHz 		QPSK, OQPSK, 4QAM, 4PSK, FSK, MSK No 2
34 Mb/s, 1xE3,
14 MHz 		16QAM, 16TCM, 32TCM No 2
140 Mb/s, 4xE3
30 MHz 		64QAM, 128TCM Yes 1
155 Mb/s, OC-3
30 MHz 		128TCM Yes 1
< 300 FDM Channels,
< 5 MHz 		FM analog No 3
< 600 FDM Channels,
10 MHz 		FM analog No 2
1800 FDM Channels
30 MHz 		FM analog Yes 1
TV, Color FM analog Yes 1

Table 16, RF-6000E-04, -44, RF-8000E-04, 2 Amplifier 1+1, low cost.
Traffic Modulation Equalizers, 1 Repeater Max
Tandem Repeaters
2 Mb/s, 1xE1 QPSK, OQPSK, 4QAM, 4PSK, FSK, MSK No 4
8 Mb/s, 4xE1, 1xE2 QPSK, OQPSK, 4QAM, 4PSK, FSK, MSK No 4
34 Mb/s, 1xE3,
28 MHz