Quad Band Antenna?
We need to rebuild the antennas and feed lines at the county's Emergency Op
erations Center. We would like to be able to use 50, 144, 220, and 440 MHz radios at any position and we would prefer not to have to resort to diplex ers and separate antennas on the roof if it can be avoided. Does anyone ha ve a suggestion for a reasonably high quality quad band antenna for base st ation use. Wind survival rating would need to be one hundred miles per hou r. We are presently looking at six hard lines to the roof some seventy fee t up in order to feed the following antennas: Horizontal Loop HF antenna with remote antenna coupler powered by Bias-T. ATV receiving antenna with rotor unless testing shows a directional antenna to be unnecessary Six meter Yagi-Uda, vertically polarized, for inter county traffic. Three Multi Band antennas or equivalent. Any on point suggestions about the multi band antennas would be helpful. -- Tom Horne W3TDH |
Quad Band Antenna?
Tom Horne wrote:
Three Multi Band antennas or equivalent. Any on point suggestions about the multi band antennas would be helpful. For VHF/UHF omnidirectional use a discone would be a practical solution. 50-500 MHz is easily possible but I would rather go for 140-500 and put 50 MHz on a separate vertical to reduce wind loading. |
Quad Band Antenna?
On Sun, 29 Dec 2013 20:56:46 EST, Tom Horne wrote:
Does anyone have a suggestion for a reasonably high quality quad band antenna for base station use. At the hospital we are using twin Comet 3-band omnidirectional antennas - 144/222/450 bands - each with a triplexer and a bank of single band filters. We are very close to the TV/FM/2-way antenna towers - a high intermod zone. Even though we have the filters we get some garbage from time to time. That converts our dual-band transceivers into single-band transceivers but that's the price we have to pay. We don't have capability on HF or 6-meters but I have a B&W All-Band Folded Dipole/Resistor available if we ever get HF capability. 73 de K2ASP - Phil Kane From a Clearing in the Silicon Forest Beaverton (Washington County) Oregon |
Quad Band Antenna?
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Quad Band Antenna?
In article ,
Tom Horne wrote: We would like to be able to use 50, 144, 220, and 440 MHz radios at any position and we would prefer not to have to resort to diplex ers and separate antennas on the roof if it can be avoided. Tom- Phil and CRN have good suggestions that directly address your needs. Another approach for common local frequencies, is to have a single base station for each frequency, with a remote control at each position. This allows the base station to be located (in a separate equipment room?) closer to the antenna to minimize feed line loss. All it takes is telephone wires to connect between the base stations and remotes. Each remote could have a switch to select base stations. Fred K4DII |
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The problem with American's is - they refuse to pay someone to do something professionally when they can screw it up themselves for free! Most anything related to a county operation should be done by a competent installer, due to the fact that most counties will not let you climb their towers or be on their roofs or install anything that might interfere with their public service radios'..... |
Quad Band Antenna?
On Mon, 30 Dec 2013 20:59:38 EST, Fred McKenzie wrote:
Another approach for common local frequencies, is to have a single base station for each frequency, with a remote control at each position. This allows the base station to be located (in a separate equipment room?) closer to the antenna to minimize feed line loss. All it takes is telephone wires to connect between the base stations and remotes. Each remote could have a switch to select base stations. At one time one of our clients' RACES installations contemplated putting an ICOM ham transceiver up near the antennas in the equipment room (attic) and using the detachable head in the EOC. The head was designed to be "remotely" located in a vehicle via a CAT5-type cable. ICOM said that they had tested it for 50 feet. We were going to test it on the bench for 250 feet using a spool of CAT5 (no need to unroll the whole length) but the client ran out of money for that project and we never got to do it. 73 de K2ASP - Phil Kane From a Clearing in the Silicon Forest Beaverton (Washington County) Oregon |
Quad Band Antenna?
On Tuesday, December 31, 2013 12:23:44 PM UTC-5, Phil Kane wrote:
On Mon, 30 Dec 2013 20:59:38 EST, Fred McKenzie wrote: Another approach for common local frequencies, is to have a single base station for each frequency, with a remote control at each position. This allows the base station to be located (in a separate equipment room?) closer to the antenna to minimize feed line loss. All it takes is telephone wires to connect between the base stations and remotes. Each remote could have a switch to select base stations. At one time one of our clients' RACES installations contemplated putting an ICOM ham transceiver up near the antennas in the equipment room (attic) and using the detachable head in the EOC. The head was designed to be "rem otely" located in a vehicle via a CAT5-type cable. ICOM said that they had tested it for 50 feet. We were going to test it on the bench for 250 feet using a spool of CAT5 (no need to unroll the whol e length) but the client ran out of money for that project and we never got to do it. 73 de K2ASP - Phil Kane From a Clearing in the Silicon Forest Beaverton (Washington County) Oregon Phil We are now looking at the equipment available that allows one to control co mpatible radios over any Ethernet cable. Since an Ethernet Cable can be up to One Hundred Meters long without needing amplifiers that would allow us to have any of the compatible separate control head radios up to 328 wire f eet end to end. That is more than enough length to allow the radios to be l ocated at the roof line of the facilities we have to operate in and still h ave the operating positions located at an appropriate location that is conv eniently accessible to served agency staff. -- Tom Horne W3TDH |
Quad Band Antenna?
On Monday, December 30, 2013 8:59:38 PM UTC-5, Fred McKenzie wrote:
In article , Tom Horne wrote: We would like to be able to use 50, 144, 220, and 440 MHz radios at any position and we would prefer not to have to resort to diplexers and separat e antennas on the roof if it can be avoided. Tom- Phil and CRN have good suggestions that directly address your needs. Another approach for common local frequencies, is to have a single base s tation for each frequency, with a remote control at each position. This allows the base station to be located (in a separate equipment room? ) closer to the antenna to minimize feed line loss. All it takes is teleph one wires to connect between the base stations and remotes. Each remote co uld have a switch to select base stations. Fred K4DII Fred I take it that would involve using only identical radios so as to be able t o use any control head with any radio. -- Tom Horne W3TDH |
Quad Band Antenna?
In article ,
Tom Horne wrote: On Monday, December 30, 2013 8:59:38 PM UTC-5, Fred McKenzie wrote: In article , Tom Horne wrote: We would like to be able to use 50, 144, 220, and 440 MHz radios at any position and we would prefer not to have to resort to diplexers and separat e antennas on the roof if it can be avoided. Tom- Phil and CRN have good suggestions that directly address your needs. Another approach for common local frequencies, is to have a single base s tation for each frequency, with a remote control at each position. This allows the base station to be located (in a separate equipment room? ) closer to the antenna to minimize feed line loss. All it takes is teleph one wires to connect between the base stations and remotes. Each remote co uld have a switch to select base stations. Fred K4DII Fred I take it that would involve using only identical radios so as to be able t o use any control head with any radio. Tom- That may also work with same-family radios on different bands. But someone with more experience than I, might design a universal remote that could be adapted to several different model radios. One approach would be to develop a standard interface consisting of transmit and receive audio pairs operating at line level, plus a keying pair. To reduce the number of wire pairs, you could use split-winding transformers to accomplish DC keying on the transmit audio pair. Fred |
Quad Band Antenna?
On 12/30/2013 8:59 PM, Fred McKenzie wrote:
In article , Tom Horne wrote: We would like to be able to use 50, 144, 220, and 440 MHz radios at any position and we would prefer not to have to resort to diplex ers and separate antennas on the roof if it can be avoided. Tom- Phil and CRN have good suggestions that directly address your needs. Another approach for common local frequencies, is to have a single base station for each frequency, with a remote control at each position. This allows the base station to be located (in a separate equipment room?) closer to the antenna to minimize feed line loss. All it takes is telephone wires to connect between the base stations and remotes. Each remote could have a switch to select base stations. Fred K4DII Fred, This isn't a good idea for several reasons (as have been explained to Tom by others and myself several times via email). The main one being lack of backup. When you have a radio remoted like this, if the radio or control head (or even the connecting cable) fails, you are in trouble. Often times the equipment room is not readily available, especially if there are other radios nearby. And even if the radio is available, you can generally only replace it with the same make (and often model) of radio. That would be great if everyone used the same radio. But they don't. And in an emergency, the number one consideration is reliability. And since these radios aren't used or tested regularly, chances of a failure going unnoticed are higher than your home or mobile station. When the radio is at the operating position operating off of 12VDC, you can replace it with generally any mobile radio. And if the power supply fails, you can replace it with almost any other power supply (as long as current demands can be met in both cases, obviously). In an EOC or similar situation, there are "necessities", "recommendations" and "nice to haves". Reliability is at the top of "necessities". IMHO, "being able to operate any radio from any position" is at the bottom of "nice to have". Sure, it would be nice - but would it actually be used? And what are you giving up to get it? -- ================== Remove the "x" from my email address Jerry, AI0K ================== |
Quad Band Antenna?
For single frequency use without all the bells and whistles,
I use CPI tone remote units. http://www.cpicomm.com/ Reasonably priced on eBay. -- Jeff-1.0 wa6fwi http://www.foxsmercantile.com |
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