Maco Antennas M103C Assembly Instructions Manual - page 8

 THESE DIMENSONS ARE APPROXIMATE.

 THEINSTRUCTIONS ON 

 THE

S.W.R TO DETERMINE EXACT 

 THERE

ARE2 

TOR ADJUSTMENT, 2. SLIDER POSITION.

DO NOT MOVE BOTH AT THE SAME TIME. MOVE

THE CAPACITOR FIRST, THEN, IF NECESSARY MOVE

THE SLIDER, AND GO BACK TO THE CAPACITOR.

S21, 

 x 

 SCREWS

LK. WSHRS   SQ.

NUTS

S21, 

 N12

 x 

 SCREWS

LK. WSHRS   SQ.

  2 4   N U T \

  S T A R - e

WASHER

GAMMA STRAPS

(SLIDER)

 COAX.

CABLE

(CUSTOMER

FURNISHED)

 PLASTIC SHOULDER

WASHER

 FLATWASHER

 GO1 P GAMMA MATCH

GAMMA MATCH MOUNTING

Mount the gamma match (GO 

 to the driven element, using the gamma straps 

 and

attaching hardware as shown. Attach your 52 ohm coaxial cable to the connector (S42) and dress along boom

and down the mast. The gamma is shown pointing down   this is to let water out.

ADJUSTING THE STANDING WAVE RATIO 

Refer to Figure 4. The dimensions given are approximate and should be used as a starting point.*

The gamma match has 2 adjustments. First is the capacitor adjust and second is the slider adjust. Connect

a SWR bridge coax between your transmitter and the antenna and check the SWR. If adjustment is required,

loosen the clamp on the gamma match and the screws holding the slider (gamma straps 

 Next move

the capacitor adjustment first one direction, then the otheruntil 

 is obtained. If SWR

is not yet satisfactory, move the slider out 2” away from the boom. If the reading has gone up move the slider

back to the original position and then 2” towards the boom. Now readjust the capacitor for minimum SWR.

You shouldnow be able to determine which direction to move the slider. Repeat the above procedure moving

the slider in smaller increments until a satisfactory SWR is obtained. Tighten all hardware. Disconnect the

SWR bridge and reconnect your coaxial cable.

7