In my "Shack" (implies higher quality than what I actually have) there is an unused Cat 5 jack that used to be for AT&T Uverse high speed internet feed. Outside there is enough cable that I could use to feed a dipole antenna. So rather than make a new hole in the wall and buying coax feedline I wondered if I could use this Cat 5 cable for low power HF (30MHz max) QRP work. Having the extra pairs in the cable could be handy for power and control of remote amplifiers, antenna tuners or such.
Belkin specs for Cat 5e:
Electrical Characteristics
Impedance: 100+15 Ohms
Mutual Capacitance, Max. nf/1000 ft.: 17.1
DC Resistance, Max. Ohms/1000 ft.: 28.6
DC Resistance Unbalance of a pair: 5% Max.
Capacitance Unbalance (Pair to Ground): 330pf/100m Max.
Propagation Delay Skew: 25 nS/100M
Normal Velocity of Propagation: Plenum FEP insulated 69%,
Non-Plenum insulated 66%
MHz IMPEDANCE ATTN. NEXT ACR ELFEXT PSNEXT PSACR PSELFEXT R.L.
1 100+15 2 68.3 66.3 68.8 66.3 64.3 66.8 22
4 100+15 4.1 59.3 55.2 56.7 57.3 53.2 54.7 25
8 100+15 5.8 54.8 49 50.7 52.8 47 48.7 26.5
10 100+15 6.5 53.3 46.8 48.8 51.3 44.8 46.8 27
16 100+15 8.2 50.3 42.1 44.7 48.3 40.1 42.7 27
20 100+15 9.3 48.8 39.5 42.8 46.8 37.5 40.8 27
25 100+15 10.4 47.3 36.9 40.8 45.3 34.9 38.8 26.3
31.25 100+15 11.7 45.9 34.2 38.9 43.9 32.2 36.9 25.6
62.5 100+15 17 41.4 24.4 32.8 39.4 22.4 30.8 23.5
100 100+15 22 38.3 16.3 28.8 36.3 14.3 26.8 22.1
I'm not sure I understand transmission lines and antennas yet but it looks to me like with impedance matching at each end this ought to work.
Am I way off in my thinking?
thanks...
earl...