If anyone can help be much appreciated?bought a Sirio 3 element beam t replace my Moxon for 11m.so I cut the ends t size in instructors from Sirio put it in exact same place as my Moxon which has a swr of 1.2,lowest we can get Sirio on 27.500 or any of the 27mhz band is 2.5.but go to 12m 24.900 is 1.2?something is t right?changed the coax done everything but no way will it tune on 11m.as I say my Moxon in same place works fine,also checked on 2 different analyzers and on my Lpa 100 meter.

Just another thing a few years ago I had a beam exactly same the Sirio and only 5 ft off ground and set was 1.3 across 11m band

Have you adjusted the gamma match?

Yes tried everything,even pulled the ends out so only 1 screw holding them t make beam bigger but no matter what u do it will not tune on 11m,the ends r cut t size it says it just will not tune?but it’s flat on 12m?have changed coax and plugs for new and my Moxon is still 1.3 ish on 11m.I don’t think it should sv been cut?but just going on Sirio instructions.

And Moonraker as per r not intrested?I phoned them yesterday no answer?left a message this was just after dinner sent 2 emails and nothing?I don’t want my money back just want a beam that works.

Iam disabled so had t get someone t do it for me,he knows what he’s doing is a ham himself and has had a few of these Sirio 3 elements beams but no matter what we tried it will not tune on 27 mhz but works fine on 12m 24.900.

A strange one, its suggesting its too long, it might be worth stripping it down double checking the lengths and reassembling.
It might be worth contacting sirio for advice.

you need to make it smaller, not bigger.

11m is smaller than 12m.

An old thread within the following but seeming your not alone with having swr issues on them ?

https://www.transmission1.net/viewtopic.php?t=6541

I've got the 4 ele and it gives a great low SWR on 10m.

As above, any issues it's the gamma match - horrible things, have had problems on every aerial I've had with a gamma match including the Sirio, usually the threads going on the screw and end up not making good contact, can send you on a wild goose chase trying to get the SWR down.

Like said we think it should never of been cut like Sirio said u had t do?have heard back from Moonraker who said they will contact Sirio?anyway will get t bottom of it and will let everyone know how we go on,my pal is having another go at it on Wednesday. Thanks everyone

Have you got the dimensions of, say, the driven element?

I thought they were tuned for 27MHz out of the box, I had to cut (well, move the self-tappers to reduce element size) for the 10m band in order to shift the resonant freq up to 28.5MHz.

If it's resonant on 12m it's too long and needs to be shortened.

Mine had a defective gamma match.

Did you get this sorted ive had 3 of the 3 ele and 4 ele sy beams my last sy4 wouldnt tune at all i measured the lengths and the gamma ect and still stayed sky high turned out gamma was the fault spoke to sirio themselves and they sent me gratis a complete gamma match complete put that on and hey presto swr was good 1.3 on 11m did a little tuning for 10m 1.3 to 1.4 accross most of the band good beam for 10m and even for cb users.