How do I get a better operating radio for home use? [PHOTOS INSIDE]

Discussion in 'CB Radio Forum' started by 305-Hillbilly, May 30, 2013.

  1. 305-Hillbilly

    305-Hillbilly Bobtail Member

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    May 30, 2013
    Ontario, Canada
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    I have a radio set up in my garage: a 1974/75 Cobra 132A SSB/AM CB Radio with a new Cobra HG-M75 Dynamic Power Mic and a Wilson 1000 trunk mount antenna. I've given up hope of trying to use the SSB modes for transmissions, all it comes though as it alien voices (thinking the radio may be screwy) so I just use AM and normally can pick up the truckers that roll past on the 401 E/W. Anyone out there got any tips or tricks that I could use to have a better operating radio? No power amp in this set up, just a mic, a radio and the hillbilly voice the god Lord gave me.

    also I should note I keep getting yelled at by truckers telling me I have a squeal coming up from my end. Is this a mic or radio problem?
     

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    Last edited: May 30, 2013
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  3. Turbo-T

    Turbo-T Road Train Member

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    May 31, 2009
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    First off, get that antenna away from the shop light.

    Second get it outside, upright, on top of a piece of metal all under the antenna (dead center of a car's roof top is the best), as high as you can.

    Right now in the manner you have the antenna mounted, you are sending most of the radio's RF energy back into the radio. That does 2 things....1. greatly hinders your range and 2. the finals in the radio will eventually heat up and will burn out, making the radio useless.

    As for the SSB, it's very useful. The problem is back in 1974, SSB was on channel 16.....but when the 40 channel CB's came out in 1977, the SSB channels moved (by gentlemens agreement) to channels 36-40. So in other words, SSB is pretty much useless.....on that radio....unless you can find someone on 16 (or one of the other 22 channels) that's willing to do SSB with you.

    Here's what I'd do if I were you....

    You can make what is called a "dipole". It's very easy to make. Google it, you can make your own CB antenna out of 2 pieces of wire, an old toothbrush handle, a piece of coax with a coax PL259, and some dental floss.

    Hag the dipole with the legs horizontal for skip or with the hot lead erected and the neutral lead horizontal.
     
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  4. 305-Hillbilly

    305-Hillbilly Bobtail Member

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    May 30, 2013
    Ontario, Canada
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    Unfortunately I don't have the option to erect the antenna outside, hence why it is set up in the garage. And the reason I have it mounted that way is it the only way I can get a metal contact for the antenna base. As for my range I have the antenna pointed towards the 401 (the major highway in Ontario) and east-west/north/south I cover about a 5km*sq area.
     
  5. Turbo-T

    Turbo-T Road Train Member

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    Could you do the dipole like I mentioned? Can your radio talk for 5 km? Or just hear?
     
  6. 305-Hillbilly

    305-Hillbilly Bobtail Member

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    May 30, 2013
    Ontario, Canada
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    I can try the dipole. Am I able to build it inside the garage? And yes I have about 3-5km talk radius on a clear day, I can hear for about 5-10km but I can't transmit that far. I picked up an swr meter today to help figure out my antenna.
     
  7. handlebar

    handlebar Heavy Load Member

    Hiya, Hillbilly.
    I'm looking at the pics you posted (thanks for those -- they help us muchly). As was noted by others, that antenna mounting is about as far from optimal as it might be.
    Looks like the shop light (or one of them) extends through a point more or less right under the peak of the roof. Have you got room to move the antenna to the top of one of the shop light reflectors? The antenna will be then oriented vertically, the same as 99.95% of all mobiles. By having yours sitting horizontally, you're already reducing the amount of signal to other stations to 1/10th of what would be available if it were upright. That's often referred to as the "20 dB cross-polarization loss." Antenna gain or loss also affects your ability to receive by around the same amount -- at least on paper -- but it is very noticeable, to any other station beyond very, very short range.
    If the light sorta points at the roadway you want to talk to, stick the antenna towards the end of the light that's farthest from the target area; that will maximize the amount of "ground plane" in your direction of greatest interest.

    If the shop light sorta parallels the highway, and if the antenna will fit there without touching the inside of the roof (or having to be bent to avoid it), then just center the antenna mount along the length of the light.

    By the way (cuz I dunno if you already know it) your antenna currently points towards the garage door and towards the back of the garage, as well as down into the light below it and the floor, and into the light above it and the roof, clouds, stars...so not much is pointing at the horizon, where most other stations will be. "Down" is also the direction of your power supply, mic, and the rest of the radio. Spraying RF (radio frequency signals) into susceptible parts, like those DC power lines and the microphone (especially since it's a power mic) can nearly guarantee a shriek or whistle on your transmitted signal. You won't hear it except on a second radio nearby. And cranking the gain up on your power mic instead of (or along with) the mic gain pot on the radio can increase that susceptibility to RF when you transmit.

    The antenna's signal pattern can be thought of as being kinda like a doughnut dropped over the whip. If the antenna were sitting vertically, it would still have the same shaped pattern, but now much of the energy would be pointing towards the horizon in all directions, with not as much being wasted by going up or down. It's not perfect, and that antenna has no gain compared to a reference antenna (it actually has some loss) but it does represent a usable compromise. You just have to make the most of what you've got. You mentioned that you currently had your antenna pointed at the highway; can you confirm that the highway is out the front of the garage or behind the house?

    Hope that is helpful and makes sense.
    73 from a "foot-hillbilly"

    p.s. Just saw your post from a few minutes ago. I'd start out with moving the antenna to someplace in the garage where it can be vertical, ideally over metal (which is why I suggested the top of one of the shop lights) before I start worrying about SWR. At this point, trying to adjust the antenna's whip length would be akin to trying different mufflers to improve the performance of a 6-cylinder engine that's running on just 3.
     
    Last edited: May 31, 2013
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  8. RollingWave

    RollingWave Bobtail Member

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    Jun 8, 2013
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    Why not

    Does ontario have laws against rooftop antennas

    Im running a realistic navaho on a 5 foot firestick mounted on an old fashinoed tv antenna fixture on the roof of our trailer gets out pretty good ev
     
  9. 305-Hillbilly

    305-Hillbilly Bobtail Member

    28
    1
    May 30, 2013
    Ontario, Canada
    0
    Living quarters, not able to set up an antenna on the roof/eave troughs. I'm considering the dipole idea, this is just a temporary setup i.e. why it's in the garage. My range is usable for now but once I get it rigged up in a mobile fashion my antenna will work fine. My thread is about getting my rig to perform better with the setup I have though.
     
  10. 305-Hillbilly

    305-Hillbilly Bobtail Member

    28
    1
    May 30, 2013
    Ontario, Canada
    0
    Apologies Handlebar I hadn't noticed your comment last time I checked on here. The 401 is parallel to the side of the house/shop lights (East/West). The front garage door faces West and the antenna is mounted on the garage door support and faces South towards the highway. Also there is only about a maybe 2 ft gap between the top of the light and the garage roof so the antenna can't be mounted vertical anywhere as it has a 60" mast.

    I'm attaching some more photos in case I don't sound clear:
    View attachment 49742 View attachment 49743
     

    Attached Files:

    Last edited: Jun 27, 2013
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  11. handlebar

    handlebar Heavy Load Member

    OK, gotcha. I understand there's not enough clearance above the shop lights. Your antenna, despite the impression that it works like a fencer's foil, radiates off the sides, not out the end of the whip. Since it looks like you've got a little spare coax wrapped up on that truss, how about repositioning the antenna so that the tip points towards the back of the garage, i.e., so it goes past that spinning reel on the wall.
    You can do it by just moving the magnet from the side it's on 90 degrees around, to the right as you stand in the middle of the garage and look at the antenna. And if you can get it up above the shop light as high as you can, it won't interact with the light as much as it does now.

    The antenna will still be cross-polarized with nearly any other CB station out there, including mobiles, because it's lying horizontally instead of standing vertically. But at least if you change the way its pattern is facing, you'll be putting more signal out onto the highway that interests you.

    Dat be all I can suggest until/unless you're able to mount the thing vertically. Even upside-down, hanging from the "indoor end" of one of the garage door guide rails, will at least be vertically polarized. Worth a try: try moving the magnet on the piece of metal it's currently mounted to so that the whip runs past the spinning reel, and then try hanging it off the door rail, and see which seems to work better.

    Good luck; please keep us informed on how it works for you.

    73
     
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