Shorter Antennas
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The Tech
Shorter Antennas
Okay, I know this is a newb question. I'm sorry. But as I was coming out of the office today, parked next to me was a police interceptor with antennas all over the car. There were 4 antennas on the trunk and two on the roof (beats me what all are for). And not one was much taller than my little wil (which rides on my roof). Now here's my question. I know police don't talk on CB, but I can only imagie on their on private band somewhere. I also know those guys have to get some pretty good range. Now what kinda of band, frequency, whatever do agencies like those talk on? And how do they get so far out without having an eight foot whip up in the air?
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BobOstro61
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hotrod459magnolia
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The Tech
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5H Outlaw
I'm pretty sure you could talk to the Russian space station if you had the right equipment.
I've heard LE, parks service etc, has trouble like that all the time. No problem finding the tx/rx on their radios and going from there. But I'm pretty sure the guys that are doing that are up to no good. lol
I've heard LE, parks service etc, has trouble like that all the time. No problem finding the tx/rx on their radios and going from there. But I'm pretty sure the guys that are doing that are up to no good. lol
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BigBopper
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Shane
That is exactly right , Most mobile radios are in the 40-60 watt range , and the handheld radios are 5 watt . Repeaters are placed strategical through out the State/County and most time you can talk on a 5 watt handheld anywhere within your county.BigBopper wrote:Police radios use repeaters, that's why they don't need really big antennas and big watts
Yes anyone can buy a public service radio (UHF-VHF-Etc.) but it is a felony to interfere with communications , the FCC actually does try to enforce this .....
the major manufactures of public service radios are : Motorola , Kenwood , Vertex Standard and Icom .....
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Mr RadioActive
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Phaze91460
DxKnight1 wrote:That is exactly right , Most mobile radios are in the 40-60 watt range , and the handheld radios are 5 watt . Repeaters are placed strategical through out the State/County and most time you can talk on a 5 watt handheld anywhere within your county.BigBopper wrote:Police radios use repeaters, that's why they don't need really big antennas and big watts
Yes anyone can buy a public service radio (UHF-VHF-Etc.) but it is a felony to interfere with communications , the FCC actually does try to enforce this .....
the major manufactures of public service radios are : Motorola , Kenwood , Vertex Standard and Icom .....
GREETINGS Shane and Welcome back !
Thank ya Phaze-
The Tech
So if I went around two installing repeaters (my office downtown, my bro's house out at the county line, but other bro's property at the other end of the county, etc) could I improve the CB range around town here? Do they make such a repeater for the CB freqs? haha :Peace!:Mr.RadioActive wrote:Police usually use VHF around 155.000 mhz, 400+ UHF, or 800 MHZ, the higher the freq the smaller the antenna. That added with repeaters high on towers, or mountains greatly improves range.
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Phaze91460
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The Tech
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eltee49
In addition to what has already been posted about repeaters, trunking systems, frequencies (we go from low-band, VHF, UHF through 800Mhz in our police cars) the antennas are also used for the rat system and LoJack systems. The RAT system is for Radio Assisted Tracking which is a transmitter hidden in bags of money given to bank robbers. This uses 3 short antennas mounted in a triangle pattern and there is a little arrow indicator and strength meter in a box on our dashes that tell use which way to go and how close we are. Lo Jack uses two antennas (IIRC) and is used to track stolen cars with the Lo Jack transmitter. Another antenna is sometimes for the MDT (Mobile Data Terminal). Some of our cars look like mobile antenna farms. A "loaded" superviory car will have one long 102" whip for the low band radio, a VHF (hi-band) antenna, an 800Mhz trunking system radio antenna, 3 antennas for the RAT system, 2 for Lo Jack and one more for the MDT. Oh yea, and one for the AM/FM broadcast radio. In the event of a big quake or major power outage, the antiquated low bands may be the only things working since they are simplex and do not rely on repeaters, cell systems, trunk systems, etc.
FYI, since so many news media people and occasional bad guys monitor our transmissions, our low tech way of privately communicating is through cell phones or Nextel's walkie talkie function.
FYI, since so many news media people and occasional bad guys monitor our transmissions, our low tech way of privately communicating is through cell phones or Nextel's walkie talkie function.
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Phaze91460
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Mississippifrog
