Complex sentence: Those used with early wireless radio had to be more sensitive and were made with more turns of finer wire; impedance of 1000 to 2000 ohms was common, which suited both crystal sets and triode receivers.
Split into simpler sentences: Those used with early wireless radio had to be more sensitive and were made with more turns of finer wire. Impedance of 1000 to 2000 ohms was common, which suited both crystal sets and triode receivers.