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View Full Version : Help with olms reading with Wilson 1000 ant.



redwagon
07-24-2014, 08:36 PM
In checking my coax cable I was getting a reading of a short circuit. Taking apart the system and retesting for olms reading would need to be and open circuit. My reading was showing a closed circuit. The reading from just the antenna by its self showed a closed circuit. (reading of 0). I have two of the 1000's with a little age on them. Any help would be a plus.

222DBFL
07-25-2014, 11:35 PM
Don't measure with antenna on, take the whip and base load off and the measure from the so-239 connector. Outside to outside should ohm out and inside to inside should ohm out, there should be no reading between outer and center pin. Hope this helps. The Wilson's I have had some issue with water intrusion and the swr Would rise as it got wet. Just my experience. The old Wilson's were built much better than the new ones. Have you tried switching out the coax. I switched from rg8x to lmr240 and it makes a difference. Better shielding with good coax. May not make a difference but I am a firm believer in quality coax. The junk they put out these days isn't shielded very well. I also switched to sirio antenna and mag mount and am a happy camper. Just some food for thought. God bless

redwagon
07-28-2014, 03:24 PM
Thanks 4 the help

856
07-28-2014, 05:18 PM
Mag or hard mount. A mag mount will sometimes give funky readings.

856
07-28-2014, 05:23 PM
Don't measure with antenna on, take the whip and base load off and the measure from the so-239 connector. Outside to outside should ohm out and inside to inside should ohm out, there should be no reading between outer and center pin. Hope this helps. The Wilson's I have had some issue with water intrusion and the swr Would rise as it got wet. Just my experience. The old Wilson's were built much better than the new ones. Have you tried switching out the coax. I switched from rg8x to lmr240 and it makes a difference. Better shielding with good coax. May not make a difference but I am a firm believer in quality coax. The junk they put out these days isn't shielded very well. I also switched to sirio antenna and mag mount and am a happy camper. Just some food for thought. God bless
Where did you order your cable? 1500 watt cable at about 1/4" is nice.

BOOTY MONSTER
07-29-2014, 01:17 AM
what are you using to measure the impedance of your antenna ?
btw .... antennas work off ac , not dc . a short is not necessarily a short on a antenna

222DBFL
07-29-2014, 05:58 AM
Times microwave lmr240. I work as a cell site tech so I run across coax of different sizes all the time. If I had to purchase like said it would be from times microwave and it would either be lmr240 or lmr400. I have changed all my coax on all my mag mounts to lmr240, and all coax jumpers are either lmr400 or lmr400uf, the UF type is more flexible. The lmr240
IMO makes a difference over rg8x, not so much In the numbers area but in the shielding and type of foam used between outer and center conductor. I am a firm believer in a proper antenna system and have spent a lot of time getting my mag mounted sirio turbo 5000 to work how I want it to. I am able to talk to my friends base at over 60 miles from Daytona through Orlando, not an easy trip. I have taken a lot of time and money to get what I wanted without being able to drill. And yes a fm mount can give some funny readings, I take mine off the vehicle and bring it to a wood bench and without the antenna attached I can measure using an ohm meter (volt meter set to ohms), whether or not I have a short or not, this is with a pl145 mag mount, I do this when I change the coax to lmr240. Will try to post some photos of one of my new mag mounts that has had the coax replaced with lmr240, will do later on as I am headed to work now.

BOOTY MONSTER
07-29-2014, 01:44 PM
FWIU .... a "ohm meter (volt meter set to ohms) " can't measure antenna impedance because it does not transmit a set frequency for the antenna to resonate to . a antenna is not like a speaker or electronic component that has a fixed value .. it's impedance will change with the frequency it's radiating at . the multi-meter can tell you if it has a open or closed circuit .... but either can be perfectly fine depending on the design of the antenna and as long as the antenna isn't damaged .

some base loaded mobile antennas will show as a closed circuit (DC grounded) antenna because thy use hairpin or capacitors in the tuning section ... the K40 is one but i don't know if the sirio is or not . with base antennas using a gamma to tune will show a open circuit , using a tapped loop (maco 58 for example) or tapped coil will show a closed circuit . the penetrator 500 hairpin will also show as a closed circuit .

here's a short little article that discusses the difference some but not in a lot of detail because it's focus is on earth grounding

http://www.iceradioproducts.com/80.html

you need a antenna analyzer to measure the impedance of the antenna .

http://www.eham.net/reviews/products/31

222DBFL
07-29-2014, 02:34 PM
Thanks booty monster, I know the k40 will show as you said it has a cap or resistor in the base load. I use my meter to check for open or closed circuit, at Least on my pl145 sirio mag moth I can. I use my Anritsu if I really need to measure my antenna system properly. One of these http://img.tapatalk.com/d/14/07/30/8ahegebu.jpg
Perks of the job!!