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bmaggin1
01-26-2015, 08:11 PM
I have an iMax 2000 mounted on PVC 20' in the air.. It is secured against the eve of the house and the base of the antenna is 4' above the roof line. I am using RG-8/U (78'). My problem is that I can't get the SWR down below 1.5 on all channels. Using modified SR-655HPC Stryker radio.

Anyone got any ideas about what I can do to get the SWR lower. Maybe ground the antenna or put on the ground plane kit??

Thanks in advance - 73 to all

JesseJamesDallas
01-26-2015, 10:37 PM
Mount it on a metal pole.............You can use chain link fence top rail...

mjd420nova
01-26-2015, 11:12 PM
Best approach would be to provide a ground wire from the bottom of the antenna on the top of the pole to a stake in the ground. Be aware that the length of this ground wire can be manipulated to make appear that the antenna is different heights above the the real ground.

bmaggin1
01-27-2015, 01:00 PM
Thanks to all that replied will purchase metal pole and put it on that.. or upgrade to SPT-500..

Thanks again,,

hotrod
01-27-2015, 05:30 PM
yes get a metal pole . then buy a 9ft. ground rod and #10 bare wire .after antenna is up and ground rod
is in ground drill a small hole in mast and install ground wire there. this method grounds the pole itself
put the ground rod near/beside the mast and only use enoungh wire to make the 2 connections. stay away
from muliples of 9 feet on the ground wire

bmaggin1
02-01-2015, 05:16 PM
Well installed metal pole 20' and mounted antenna on it. SWR stayed the same and even got worse on channel 40 (1.6).. tried tuning the rings with no effect. I can turn rings all the way up or all the way down and the SWR doesn't change at all. If you are wondering I am using a MFJ-259C to measure the SWR.. Do you think I need to put a ground plane on the antenna??

mjd420nova
02-02-2015, 09:26 AM
If the SWR on 40 is higher than on 1, the vertical mast is too long. You do need to have some sort of ground plane, short stubs or up to 8 feet, again, they will affect the SWR too so start with small changes.

JesseJamesDallas
02-02-2015, 05:35 PM
1.5 - 1.6 SWR I wouldn't worry too much about it...Some antenna's that's as good as they will tune, and nothing wrong with a 1.5...anything under 2.0 and your good to go anyway.

hotrod
02-02-2015, 06:12 PM
if using a mfj 259 then ya should know to use other methods of tuning tune impedence /R and reactance X
so it reads R=50 [this should be if using 50 ohm coax] and X =o or as low as can get it. thrive to keep R=50

BOOTY MONSTER
02-08-2015, 02:20 AM
....... tried tuning the rings with no effect. I can turn rings all the way up or all the way down and the SWR doesn't change at all. .......

ls this a new antenna ? if so get it replaced .
if it's old/used or been stored away ..... check the bottom for pin holes and make sure they are open . they are to prevent condensation in the match coils .

bmaggin1
02-08-2015, 06:54 PM
ls this a new antenna ? if so get it replaced .
if it's old/used or been stored away ..... check the bottom for pin holes and make sure they are open . they are to prevent condensation in the match coils .

No this is a new antenna.. tried different cable (RG-213 [100'], and even raised the antenna 5' above peak of house.. SWR remains the same.

Have tried calling the manufacture and the only thing that I get is an answering machine with no call back..

bmaggin1
02-27-2015, 09:32 PM
Even thou the holes were open, must of had condensation in the match coils. It hasn't rained and temperature has been in the mid 70's .. SWR is now at 1.1 and R=50 using RG-213 (106')..

Thanks to all that gave me suggestions on this problem.. See you all on the flip side and 73..