pyromill Posted August 23, 2013 Share Posted August 23, 2013 Just curious as I'm about to put up a mast for my fire/police scanner antenna. Would there be a problem with putting my transmitter antenna on that same mast? Possibly overloading the scanner's feed line even though those frequencies are not able to be tuned on the scanner? Link to comment Share on other sites More sharing options...
Dave Batzdorf Posted August 23, 2013 Share Posted August 23, 2013 Just make sure you have good separation between the two. Seeing how the fire/police is receive only you should be fine. I would think that if you have your show transmit antenna a few feet below you should be fine. Test it out. Link to comment Share on other sites More sharing options...
Orville Posted August 23, 2013 Share Posted August 23, 2013 A couple feet below or above the scanner antenna and you should be okay, too close and you may actually find bleed-over from the transmitter antenna into your scanner receiver. Just don't have both antennas directly in-line with each other and you may also want to keep the antenna cables separated as well, as sometimes bleed-over can occur with the antenna cables tied together. If one goes up inside the mast and the other is on the outside, this way you have some type of shielding between the two antenna cables and you should be fine. Just know when I was able to have an outside antenna mast I had to do it that way. I did get bleed-over into the scanner, but not the transmitter {weird} when the antenna cables were tied together or the antennas were right next to each other. Link to comment Share on other sites More sharing options...
k6ccc Posted August 23, 2013 Share Posted August 23, 2013 Just don't have both antennas directly in-line with each other If they are both vertical antennas and they are separated vertically, your best bet IS to have them directly in line with each other. The minimum radiation from most antenna types (not counting directional antennas such as yagis) is directly off the end of the rod or wire. You want the scanner antenna placed in the minimum signal area of the transmit antenna, so that would be directly in line FM antenna. If your FM antenna is NOT a vertical antenna, please describe what each antenna is, and I can help with ideal placement. BTW, This kind of stuff is part of what I do for a living... Link to comment Share on other sites More sharing options...
Orville Posted August 24, 2013 Share Posted August 24, 2013 If they are both vertical antennas and they are separated vertically, your best bet IS to have them directly in line with each other. The minimum radiation from most antenna types (not counting directional antennas such as yagis) is directly off the end of the rod or wire. You want the scanner antenna placed in the minimum signal area of the transmit antenna, so that would be directly in line FM antenna. If your FM antenna is NOT a vertical antenna, please describe what each antenna is, and I can help with ideal placement. BTW, This kind of stuff is part of what I do for a living...Not sure if you'd call a scanner antenna vertical as mine was not a singe plane antenna {if I'm recalling that correctly}, it looked more like a CB antenna that had 4 vertical radiating arms and the FM antenna was vertical. When in-line with each other, the FM antenna bled over into the scanner when both were on at the same time. So I figured if they were both vertical and directly next to each other the same effect would occur, unless there was at least a minimum of 6' distance between the vertical antenna for each item. Been awhile since I've done any antenna installations for myself, so the way technology has changed over just the past few years could make all of this a moot point I guess, I just don't keep up with it as much as I used too. Link to comment Share on other sites More sharing options...
pyromill Posted August 24, 2013 Author Share Posted August 24, 2013 This is the scanner antenna I built an off dipole. http://wiki.radioreference.com/index.php/Homebrewed_Off-Center_Fed_Dipole the type of FM antenna build is the normal center feed dipole in PVC. Both will be mounted vertical unless I would be better off another way. I have been looking at making a discone antenna for the scanner though and why I was vague in what type of antennas as I just do not know enough to not simply be dangerous to my scanner and or transmitter. But on the dipoles I was reading of stacked dipole increasing gain and worry of doing that. Thanks to all contributing though it's very helpful ! Link to comment Share on other sites More sharing options...
pyromill Posted August 24, 2013 Author Share Posted August 24, 2013 Oh man it didn't post all of what I had.. Dang tapatalk. I'm using a ofc dipole for the scanner antenna and a dipole built from one of the finds on this board or diy Christmas using copper wire and PVC pipe both are planned mounting vertical unless there is a better way. Link to scanner build. http://wiki.radioreference.com/index.php/Homebrewed_Off-Center_Fed_Dipole Planning to possibly build a discone antenna for the scanner to get even more reception Link to comment Share on other sites More sharing options...
Ron95632 Posted August 26, 2013 Share Posted August 26, 2013 All the suggestions sound good, but you might find that the antenna you plan on usingmight exceed the ERP limitations of the FCC? Ron Link to comment Share on other sites More sharing options...
pyromill Posted August 26, 2013 Author Share Posted August 26, 2013 (edited) Ron that has come into my mind many times. Have been looking at regs along with around for who might have a sensitive enough meter to check compliance. Following as a joke ONLY whatever happened to the old days of the us where we could Annoy the neighbors and start a decades long fight Hatfield and McCoy style? Again that was only as a joke folks only looking to get the best signal out front of the house and on the scanner in the house without bending it breaking laws. Edited August 26, 2013 by pyromill Link to comment Share on other sites More sharing options...
pyromill Posted August 26, 2013 Author Share Posted August 26, 2013 Had to edit out a p o as it was seen as foul language Link to comment Share on other sites More sharing options...
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