Briggie is quite right in an ideal situation to leave the SWR meter in circuit. However in a mobile situation it is less practical to do this, best way is to check the SWR from time to time if it is not practical to leave SWR meter connected.
There will be losses of the RF Energy but if the connections to the plugs are correct this should be pretty low.
Yes 4watts is quite a low power but as the saying goes "it aint what you've got it's how you use it". This is so true with radio, more power does not always mean you'll get further. The better your antenna, co-ax (aerial wire) and connections the more of your power will be released from the antenna.
As said modern radios are more tolerant of higher SWR's and will either lower the power output or shutdown to save the radio.
SWR stands for Standing Wave Ratio, it is the radio waves that come out of your radio, they go through the co-ax and to the antenna. If they do not fit the antenna they get reflected back down the co-ax to the radio where they can cause damage. Of course the more power you have the more the likelyhood of damage. Imagine the antenna to be a hole at the end of the co-ax, this hole can be adjusted or made larger or smaller. So the radio waves produced by your radio are one size, if the hole is not the correct size the radio waves can't get out and bounce back down the co-ax to the radio.
People who already have knowledge of this will be cringing at my explanation but I'm trying to explain it in very simple terms.
PL259 this is the commercial name of the screw on plug that is used to connect the co-ax to the radio or antenna connections. When fitted to the co-ax a PL259 should be nice and tight with good electrical connections. Over time the co-ax moves and eventually the electrical connection breaks down. This is likely to happen to the patch lead and eventually the aerial cable too, more so in a mobile situation. A Patch Lead is the short cable between the radio and SWR Meter.
So over time the SWR will change, usually by the cable connection being degraded or the antenna becoming degraded. Even placing the magnetic mount of the antenna in a different place. Weather will effect it too, wet or dry. Placing objects near the antenna or even the co-ax will change the SWR.
So to sum up you don't need more power just an efficient antenna system. Look after the antenna system and check the SWR from time to time.
Sorry for rambling on but all being well you will have an understanding of what it is all about.
, heres hoping its ok .
