# Detached antenna and connecting wire length

Since my this particular question didn't get any answer, I thought of asking a more focused question, along a path which seems a bit more feasible after few tests.

Is it possible to install the antenna of the 433MHz ASK/OOK TX module, some distance away from the module itself ? All my present tests use the antenna wire directly attached to the module, and of course, they work fine. However, if I add a length of wire to increase the distance of antenna, the whole wire, I believe, would behave like an antenna - right ? And that would detune the antenna ? Any solutions to the problem where TX module and antenna need to be spaced out ?

Edit

Based on the comment (PeterJ's) and answer (pjc50's) so far, here's what I understood as the possible solution.

• What kind of antenna are you using? If it has a 50 ohm impedance the usual way would be to use coax. – PeterJ May 4 '13 at 8:04
• @PeterJ, thanks for taking time to look at the question. The antenna, in my experiment has the absolute poor-man's solution, i.e. a quarter-wave monopole, i.e. about 16cm length of AWG26 straight wire. – bdutta74 May 4 '13 at 9:14
• As per pjc50's answer and comment below 50 ohms is the impedance of the cable so you won't want the series resistor, but at the transmitter end you'll want to tie the shield of the coax to ground. – PeterJ May 4 '13 at 11:14

• @icarus74 the characteristic impedance of the coax will be in the datasheet. Usually there's something printed on the cable that you can put into Google. It likely starts with "RG-". Most video cable is $75\Omega$, which may be "close enough". You will get a higher SWR, which may or may not be acceptable to your TX module. – Phil Frost May 4 '13 at 13:49