The millionth time this question has been asked.

Here goes.

I’m just coming back to CB and I’m installing a CRT MILLENNIUM into my Disco 3 as space is a real pain in this car. I have a steel full length roof rack that my sirio performer 3000 is bolted to and I have an SWR of 2.5 on 1 2.7 on 20 and 3 on 40 on UK 40. Now if I switch to ce 40 I have an SWR or 1.2 on 1 and 1.5 on 40.

What am I doing wrong?? When I had thIs antenna on my manky defender earlier this year (with a different rig) my SWR was always around 1.2 to 1.5

I do apologise for asking the question that must drive you bonkers but I genuinely thought I’d done ok fitting the antenna.

Thank you guys.

Myke.

Sorry, the antenna is a sirio performer PL P-800

Slacken the grub screw and Extend/Reduce the whip by 2mm a time before calibrating and checking SWR

Tiny adjustments each time. If the SWR goes higher after extending the whip the do the opposite, a tiny bit at a time until the the SWR on ch19 is as low as possible

That antenna is factory tunes at CE/Midband. Your not doing anything wrong. Just adjust whip length until its low on the main channel you use. Make sure the connection between the mount and the rack is clean and tight and should be fine.

Firetrap wrote:

That antenna is factory tunes at CE/Midband. Your not doing anything wrong. Just adjust whip length until its low on the main channel you use. Make sure the connection between the mount and the rack is clean and tight and should be fine.

Thank you.

As I get older I run out of patience to do stuff for myself 🤬🤬

The roof rack is steel and 8ft x 4ft so it should be a good ground plain ?

Shall I do a continuity check from roof rack to the body of the car?

As above, the antenna is too long which is why it's got a low SWR on Ch1 EU but higher on UK40. Part of the reason it's now too long is because you've a better RF ground than you had on your Defender.

Forget trying to get 1:1 on all the channels, the antenna doesn't have the bandwidth. As long as you can get 1.6-1.8:1 or less from EU Ch1 to UK Ch40 which it should be capable of doing then you're good to go. If you shorten it as much as you can and it's still not low enough you may need to consider cutting the whip, just do a small bit at a time.

Higher the frequency, shorter the whip.
Lower the frequency , longer the whip.

Paul.

Thank you all everyone.

I’ve spent the past hour trimming and I now have an SWR of 1.1 : 1 on 40 (UK) and 1.05 : 1 on channel 01.
I’ve never had it that good.

Should be viable on the mids as well

On CE 01 it’s 1.7 and on 40 it’s 1.4 so I’m bloody chuffed.