The polyacetylene HC2nH+ n = 2-7 cations were produced from a mixture of diacetylene with helium in a hot cathode-discharge source. After a mass-selective deposition, their absorption spectra were studied in 6 K neon matrixes. Besides the known (A) over tilde (2)Pi <- (X) over tilde (2)Pi system, several new transitions to higher excited 2rl electronic states of these cations have been observed. In the case of HC4H+ and HC6H+, only one new weak absorption system has been detected with the onset at 336.1 and 417.2 nm, respectively. These (C) over tilde (2)Pi <- (X) over tilde (2)Pi transitions form a series that extends to HC10H+. Two further electronic transitions are observed for HC8H+ through to HC14H+; a weaker (B) over tilde (2)Pi(u) <- (X) over tilde (2) Pi(g) and a strong (E) over tilde (2)Pi(g) <- (X) over tilde (2)Pi(g) in the UV. The integrated intensity of the UV system of the polyacetylene cations exceeds that of the (A) over tilde (2)Pi(g) transition by an order of magnitude.