Dumb Yagi/Gamma Question

[radiogaga]

I have acquired a 6m Yagi from a friend on behalf of a SK. It appears to be a Moonraker 3 Element.

Setup as it had been when taken down (can see from marks on the Ali) and I cannot get the SWR to anything near acceptable. 1:4

The fixing bolts were missing and whilst there is no issue with the reflector or director the Driven Element is causing me some confusion. The element fixing bolt and Gamma Match Bolt (currently a screw in my picture) both mean that those parts are electrically connected to the boom? Should they be?

I know this will be a daft question but when you've had 18 years of vertical end feds.........

[wa10]

The element and box both electrically connect to the boom,

I can see the gamma insulator passing through the box which looks correct but can't see what's going on at the other side where the coax connects,

Make sure the box & coax braid are electrically connected to the boom and the inboard end of the gamma rod is isolated and only connected to the coax inner, antenna should measure open circuit with a multimeter on the coax connector.

good luck.

[radiogaga]

Cheers, the other side is simply an SO-239 with the 213 connected. It does show open circuit. I'll keep going with it... Why did I sell my analyser

[radiogaga]

Is adjustment of the Gamma match by the sorting bar or extending the gamma bar, both are possible.

[wa10]

Both the gamma shorting strap position and the gamma capacitor/ rod setting are important.

[radiogaga]

Maybe by luck then it's 1:1 at 52.990 - Down at 50.150 it's up to about 3:1

[Farty]

Is the big driven element isolated from the support beam? Can't tell from the pic if the optimally through the insulator of his through the whole lot.

[prettypolly]

move the end elements of the middle element in 1 inch at a time soon see its an trick i use that defo works

[radiogaga]

move the end elements of the middle element in 1 inch at a time soon see its an trick i use that defo works

Is that extending the middle element In a conventional dipole fashion?

When you get 5 mins with the PSU write up I'd be very grateful too. I have three here to do now

[prettypolly]

yup dipole fashion no harm in trying

[Samalex]

its needing the gamma match slider adjusted or your element sizes are too small/wrong

try moonraker see if they have a manual or check here for approx size

http://www.dxzone.com/cgi-bin/dir/jump2.cgi?ID=20269

check boom size first