Twisted Pair Requirements

Cable - The Twisted Sender will operate in a single pair or multi-pair cable of unshielded twisted pair (UTP) wire, stranded or solid. Individual pairs MUST BE unshielded, however an overall cable shield is acceptable with cables of 16 pairs or more. Other video signals, data and control signals or power supply voltages on other cable pairs will not cause interference if the individual pairs are twisted together.  If the Twisted Sender must be used with a multi-conductor (unpaired) cable, wires that are run adjacent in the cable should be used in order to achieve maximum common mode rejection.

Wire Gage - Wire between 20 and 26 gage is recommended in order to achieve optimum transmission distances. Refer to the Wire Reference Chart below. Twisted Senders will operate over a wide range of wire gages, with some possible sacrifice in transmission distance and or common mode rejection capability, depending upon the gage and specifications. Check with NIT for technical assistance at (847) 718-0600.

Wire Pairs - The copper pair must be isolated , having NO voltage, NO Loading Coils and NO capacitive lightning arrestors or devices connected to the pair. Any capacitive devices connected to the transmission pair will have the effect of swamping the high end video frequencies and limiting transmission distance.

Loop Resistance - Making an accurate determination of the length of the transmission pair is extremely important. Most installation problems with Twisted Sender systems are due to inaccuracies in determining the cable length. Total length can be measured with a simple ohmmeter by testing the loop resistance (total resistance of both wires measured at one end with the opposite end shorted). After measuring the Loop Resistance, refer to the Wire Reference Chart to determine the twisted pair length.

WIRE GAGE/LOOP RESISTANCE  REFERENCE CHART  

                     FEET

GAGE	1000	2000	3000	4000	5000	6000	7000	9000	11000
20	20 ohms	40 ohms	60 ohms	80 ohms	100 ohms	120 ohms	140 ohms	180 ohms	220 ohms
22	32	64	96	128	160	192	224	288	352
24	51	102	153	204	255	306	357	459	561
26	82	164	246	328	410	492	574	738	902

TS1000, TS1500 and TS2000 Resolution Chart - Horizontal Lines

Feet	1000	2000	3000	4000	5000	6000	7000	8000	9000	10000	11000
TS1000	625	550	475	400	325	275
TS1500	625	550	475	400	325	275
TS2000	675	625	575	500	425	350	300	250	200	175	150