Page 1 of 1
P25 Trunking - Improving signal at Home
Posted: Sat Feb 05, 2011 4:30 pm
by KB9TFH1
I don't know if there is any suggestions that might be able to help solve this problem... but I felt by sending it out to the experts, someone might have a good suggestion. I have a XTS2500 800 mhz radio that affiliates with the Statewide P25 Motorola Type II SmartZone Omnilink system. The system works great by my residence is right on the fringe for coverage. The radio affiliates with the system fine but when units are speaking it "goes digital" quite often.
I am just curious if anyone has a suggestion of something I might be able to purchase to make it work a bit better. I don't want to hook the radio up to a high gain antenna or connect it to coax for out side antenna. Someone suggested a pass through system with a direction antenna out side with a Preamp pulling in the signal and an antenna inside with a preamp to pull in my radio. They said something about "path of shortest resistance."
Has anyone else experienced this type of issue and what do you suggest to help...
Thanks!
Joe
Re: P25 Trunking - Improving signal at Home
Posted: Sat Feb 05, 2011 5:01 pm
by Bill_G
An outside antenna is the least cost, simplest solution considering you need to transmit.
Re: P25 Trunking - Improving signal at Home
Posted: Sat Feb 05, 2011 5:12 pm
by colby4601
KB9TFH1 wrote:Someone suggested a pass through system with a direction antenna out side with a Preamp pulling in the signal and an antenna inside with a preamp to pull in my radio. They said something about "path of shortest resistance."
We use a solution very similar to this one in fringe coverage ares on our P25 system. Radios affiliate fine, but the voice gets ugly. The government recognized this and rolled out some equipment across the province to help with in-building coverage and better coverage in general. In implementing these "devices", lots of these areas now have much better coverage and there are very little, if any problems with transmissions going garbled.
Re: P25 Trunking - Improving signal at Home
Posted: Sat Feb 05, 2011 7:20 pm
by resqguy911
If you install a Bidirectional amplifier, expect to spend quite a bit for a properly tuned unit and two antennas. I had a user who needed coverage in the home, but was willing to sacrifice mobility in said home. A Yagi inside the attic pointed towards the intended site, out thru a wall plate to an RF adapter on the XTS got him back in business. Then we added an XTVA, which basically gave him a base station. It really doesn't take that much space up in the home office, plus he pops the radio out when he goes to work, and I only need to expend one ID instead of giving him another dedicated radio...
Re: P25 Trunking - Improving signal at Home
Posted: Sat Feb 05, 2011 7:22 pm
by MTS2000des
KB9TFH1 wrote:I don't know if there is any suggestions that might be able to help solve this problem... but I felt by sending it out to the experts, someone might have a good suggestion. I have a XTS2500 800 mhz radio that affiliates with the Statewide P25 Motorola Type II SmartZone Omnilink system. The system works great by my residence is right on the fringe for coverage. The radio affiliates with the system fine but when units are speaking it "goes digital" quite often.
I am just curious if anyone has a suggestion of something I might be able to purchase to make it work a bit better. I don't want to hook the radio up to a high gain antenna or connect it to coax for out side antenna. Someone suggested a pass through system with a direction antenna out side with a Preamp pulling in the signal and an antenna inside with a preamp to pull in my radio. They said something about "path of shortest resistance."
Has anyone else experienced this type of issue and what do you suggest to help...
Thanks!
Joe
just curious, is this a simulcast site ZSOL V6? we have the same problem where I work. Ironically the prime site is on a mountain about 5 nautical miles from our facility, but due to antenna beam tilt on the site, and our building being so close, we get alot of garble and "out of range" indications on our radios. The system is what it is, and the county has said they are providing "x" level of coverage, if you want more, put in your own Intellirepeater sites (and pay for them), or get better radios. We looked into BDA's but they are also a can of worms.
Re: P25 Trunking - Improving signal at Home
Posted: Sun Feb 06, 2011 12:38 pm
by Jim202
MTS2000des wrote:KB9TFH1 wrote:I don't know if there is any suggestions that might be able to help solve this problem... but I felt by sending it out to the experts, someone might have a good suggestion. I have a XTS2500 800 mhz radio that affiliates with the Statewide P25 Motorola Type II SmartZone Omnilink system. The system works great by my residence is right on the fringe for coverage. The radio affiliates with the system fine but when units are speaking it "goes digital" quite often.
I am just curious if anyone has a suggestion of something I might be able to purchase to make it work a bit better. I don't want to hook the radio up to a high gain antenna or connect it to coax for out side antenna. Someone suggested a pass through system with a direction antenna out side with a Preamp pulling in the signal and an antenna inside with a preamp to pull in my radio. They said something about "path of shortest resistance."
Has anyone else experienced this type of issue and what do you suggest to help...
Thanks!
BDA systems are not a can of worms as you say. They just need to be engineered by someone who knows what they are doing. If you have only a small area or a whole complex of different floors, this needs to be considered. If it is in the basement or a weak area of reception, your only solution will be getting an antenna closer to the radio users. You might need multiple antennas inside the facility that are all fed from the master BDA system.
There are a number of good companies that have BDA systems. It may be worth your while to contact them and ask a bunch of questions. If nothing else, it will provide you with an understanding of the advantages and limitations of their BDA equipment. It should also provide some sort of window on the cost of what it will take to solve your problem. Be prepaired to supply some sort of floor plan to allow the company to see just what your problems are. They will also ask how far away from the nearest site your located from. Don't forget to give them any differences in elevation of the transmitter site and your location. Don't forget you will need some wall space to mount the BDA system. Many times these can be mounted in equipment rooms or storage areas.
Also don't forget that you will need emergency power going to the BDA when it is installed.
Jim
Joe
just curious, is this a simulcast site ZSOL V6? we have the same problem where I work. Ironically the prime site is on a mountain about 5 nautical miles from our facility, but due to antenna beam tilt on the site, and our building being so close, we get alot of garble and "out of range" indications on our radios. The system is what it is, and the county has said they are providing "x" level of coverage, if you want more, put in your own Intellirepeater sites (and pay for them), or get better radios. We looked into BDA's but they are also a can of worms.
Re: P25 Trunking - Improving signal at Home
Posted: Sun Feb 06, 2011 2:44 pm
by KB9TFH1
Is there anyway to build a "poor mans" intellirepeater?
Re: P25 Trunking - Improving signal at Home
Posted: Sun Feb 06, 2011 3:35 pm
by Bill_G
Not really. You are in a zone of poor coverage. There is some coverage, but not enough for your portable to operate well. Obviously it can hear the control channel, and the control channel can hear it because it auto affiliates fine. But, when trunking to a voice channel, it cannot hear the site as well as you want. The signal level is too low, and the BER is increased. Fine for short data communications, but not so good for voice even if the voice is all data in a fully P25 system. There is only so much FEC can do. Short data packets get through, but extended data gets farbled. A BDA would help conceptually, but again, you are in a zone of poor, not no coverage, and a BDA could cause more damage to the system than help you because there would be little isolation between the donor and the interior antenna. You would have a fubar generator. Using a CVTM with an external antenna is your best option.
Re: P25 Trunking - Improving signal at Home
Posted: Mon Feb 07, 2011 11:57 am
by wavetar
KB9TFH1 wrote:I don't know if there is any suggestions that might be able to help solve this problem... but I felt by sending it out to the experts, someone might have a good suggestion. I have a XTS2500 800 mhz radio that affiliates with the Statewide P25 Motorola Type II SmartZone Omnilink system. The system works great by my residence is right on the fringe for coverage. The radio affiliates with the system fine but when units are speaking it "goes digital" quite often.
I am just curious if anyone has a suggestion of something I might be able to purchase to make it work a bit better. I don't want to hook the radio up to a high gain antenna or connect it to coax for out side antenna. Someone suggested a pass through system with a direction antenna out side with a Preamp pulling in the signal and an antenna inside with a preamp to pull in my radio. They said something about "path of shortest resistance."
Has anyone else experienced this type of issue and what do you suggest to help...
Thanks!
Joe
Your solution could be quick 'n dirty, or very elaborate. I assume you don't want to have the portable physically connected to coax...that would be the quick 'n dirty solution. If you want to be able to roam around the house, you really only have two choices...a BDA, which has been mentioned, or some sort of in-band patching solution - a working trunked base radio with decent high-gain antenna, cross wired to another 800MHz radio with a simplex channel. Once in place, you simply switch your portable to the simplex channel and tx/rx through the patch. There is of course licensing issues with the simplex frequency. Neither option is cheap.
Re: P25 Trunking - Improving signal at Home
Posted: Mon Feb 07, 2011 2:44 pm
by Astro Spectra
You can use back to back antennas just connected with coax, but it doesn't work very well unless you can place the outside antenna where it can get a really strong signal and the indoor atnena needsto be no more than a few inches away from the radio antenna. It is at least worth a shot and worst case you can hook the indoor end to a convertacom as has been suggested.
You will find that a BDA setup or any sort of repeater idea is going to be more expensive than just buying another radio to use as a dedicated base hooked up to a decent antenna.