kc0rey...help with SWR

[fastSVT]

I just got a Cobra 29 and am trying to get my SWR set. The meter on the radio shows it to be approximately 1.4 on channels 1 & 40. However, my antenna light kinda comes and goes. Seems like it comes on more frequently when I'm next to a building. Is this normal?

Now I know you and others don't like the built in meters, and I'm going to buy one from Radioshack. But before I do, I would like to know just how much "open space" I need for the tuning. I drive a wrecker in a rural area, and the best location I can come up with is a church parking lot with the corner of the building being about 70 feet away off at an angle. Will this be okay for the tuning?

By the way, the readings I got were with no adjustments

Cobra 29 LTD Classic
RadioShack 5ft magnet mount antenna mounted center of the cab roof (stock coax?)

[drfuller18]

Originally Posted by fastSVT

I just got a Cobra 29 and am trying to get my SWR set. The meter on the radio shows it to be approximately 1.4 on channels 1 & 40. However, my antenna light kinda comes and goes. Seems like it comes on more frequently when I'm next to a building. Is this normal?

Now I know you and others don't like the built in meters, and I'm going to buy one from Radioshack. But before I do, I would like to know just how much "open space" I need for the tuning. I drive a wrecker in a rural area, and the best location I can come up with is a church parking lot with the corner of the building being about 70 feet away off at an angle. Will this be okay for the tuning?

By the way, the readings I got were with no adjustments

Cobra 29 LTD Classic
RadioShack 5ft magnet mount antenna mounted center of the cab roof (stock coax?)

Im not Corey, but ill try to touch base on this.. The meters in the radios arent real accurate..You need a SWR test meter. or an antenna Analyzer..My favorite ,cost alot and not worth you purchaseing for your little job.. But an inline SWR meter is..See what they cost, You might get it done cheaper than a meter..What kind of antenna is it?? And when you test, it a good rule of thumb to get your antenna in as open of area as possible..Make sure your grounds are good. And if its a whip type antenna that you adjust by slideing the whip up and down..the longer the whip outwards will generally find you somewhere closer to 1, the further in the whip goes inward the coil load, the closer the area will move to 40..You have to find where 19 for example will be by adjusting the whip.. Maybe this helps a little.

[fastSVT]

I actually just found an inline meter my attic. Guess I'll hook it up and see what's going on. So does the parking lot I described seem like it will give me enough open space?

I honestly don't know what type of antenna it is. All I know is it's magnetic and on my roof. haha

How do I know if it's a whip type? I know it has an allen-head screw that can be adjusted.

[drfuller18]

Originally Posted by fastSVT

I actually just found an inline meter my attic. Guess I'll hook it up and see what's going on. So does the parking lot I described seem like it will give me enough open space?

I honestly don't know what type of antenna it is. All I know is it's magnetic and on my roof. haha

How do I know if it's a whip type? I know it has an allen-head screw that can be adjusted.

Well it should be space enough, make sure its sticks good to your top.. and yes its a whip..and you adjust it by loosening up that screw and adjusting it..If you find that it will not set where you like at let say 19..tighten the whip at the top and check, then tighten it at the bottom and check..This should tell you if your target freq. is in the middle..Dont be suprised though that it doesnt set flatline...Some antennas just will not do it..Here in the ham world we do the best we can to make the antenna as resonant as possible and then use a antenna tuner to trim the rest out But for what your doing its just as well to get it the best you can transmiter direct to antenna.. If you find that it stays high, but .....Na you said it was 1.4 your target area is there...You just need to play a little with it... Good luck