Results 1 to 2 of 2
Thread: Confused with swr tuning
- 02.19.2010 #1
- Member Since
- Feb 2010
- Celveland, Ohio
- Thanked: 0 Times
Confused with swr tuning
Alright so I got a hold of a buddy who has a workman swr meter, like the one I just ordered for myself, and went about tuning my radio and antenna since the antenna warning light would come on every time I keyed up and talked on every station.
I understand how to actually tune it but what I'm confused about is it says to tune on 1,40, and 20. Well which one do I choose because they all read different from each other. I don't know how to really put it so I will just say what i did.
Ok so I set my cobra to channel 1 and then set the swr meter needle to the "set" mark, then I fliped down the switch on the meter that will tell you your swr. I then changed the channel to 40 and the needle went more then it did on 1. So I trimmed the antenna down after a few more trys to bring 40 lower and I ended up with about 1.4 on 1 and 1.7 on 40 and I don't remeber what 20 was.
So is that the correct way if checking and tuning? Do you set the meter to the set mark and then read your swr for 1 then switch over to 40 and try and match the two as close as possible with lowest rating, and if it's higher on 40 then on 1 you need to lower the whip? When I heard use channel 20 that confused me.
Sorry I'm kinda all over the place, I'm still learing.
- 02.19.2010 #2
- Member Since
- Aug 2009
- Seminole Florida
- Thanked: 471 Times
A match of 1.7 to 1 is FINE ........ not great but ok ...
OK tuneing .....
IF your match is LETS SAY ..... 1.7:1 on ch 40 and 1.2:1 on ch 1 .....
This shows your antenna is set to the low end of CB ( CH-1 ) so you need to bring the antenna frequency UP and you need to make the antenna slightly SHORTER ......
Same would go if it was 1.2:1 on 40 and 1.7:1 on ch-1 you would need to SHORTEN the wip length.
99.999% of radios are ok even at a 2:1 match but you start to lose signal that high ....
VSWR ( SWR ) this is what losses look like ....
1.0:1 loss = 0 percent 100% of power goes out the antenna
1.5:1 loss = 4 percent 96% of power goes out the antenna
2.0:1 loss = 10 percent 90% of power goes out the antenna
3.0:1 loss = 25 percent 75% of power goes out the antenna
NOW remember what does not go out comes BACK and your final has to handle it ......
This is a simple overview I hope it help you .