Need Help With Antenna

[ScanPEI]

I have used a UHF/VHF TV antenna for years with excellent results for my local 800mhz trunk system. But last year I moved into a mini home (aka: trailer) that is surrounded by metal eaves, trimming and trees and my excellent working antenna is not so excellent anymore. I do get some reception but it comes and goes. I've tried it on the roof with no improvements. I then thought of throwing the antenna up in a tree but after doing some reading, thought it would only lead to more problems. Even walking around the yard with the rubber duck antenna signal is hit and miss. Anyone have any suggestions as to what I could do. Could a signal amplifier make an improvement? I rent, so attaching anything to the house is not likely. Scanner is a Pro-97 scanning the 800mhz range.

Input much appreciated!

[gewecke]

Have you tried rotating your antenna towards your desired signals? I'm assuming your tv antenna is directional right?
You could also try ground mounting it to a mast so it would be away from obstructions?

73,
n9zas

[rfradioconsult]

If you haven't tried turn your antenna so the elements are vertical not horizontally as TV antennas are normally installed. LMR uses vertical polarization, OTA TV is normally horizontal.

[Dewey]

Just a personal opinion, but it you were happy using a TV antenna, Radio Shack's 20-176 (affectionately known to many of us here as "Sputnik") may please you. The 20-176 is a small very low cost (shows $29.99 on line right now, so they've raised the price a little) antenna that can perform up there with the big boys. Due to its size, and low number of elements, just 3 ground radials, it will fit in a lot of tight places. Again, just a personal opinion, your mileage may vary.

[benbenrf]

Originally Posted by ScanPEI

I have used a UHF/VHF TV antenna for years with excellent results for my local 800mhz trunk system. But last year I moved into a mini home (aka: trailer) that is surrounded by metal eaves, trimming and trees and my excellent working antenna is not so excellent anymore. I do get some reception but it comes and goes. I've tried it on the roof with no improvements. I then thought of throwing the antenna up in a tree but after doing some reading, thought it would only lead to more problems. Even walking around the yard with the rubber duck antenna signal is hit and miss. Anyone have any suggestions as to what I could do. Could a signal amplifier make an improvement? I rent, so attaching anything to the house is not likely. Scanner is a Pro-97 scanning the 800mhz range.

Input much appreciated!

Nope a signal or pre amp is not going to solve this for you - unless you also add a filter with a nice steep roll off on both bandwidth edges.

Try resolve this problem trying out the tricks other members have mentioned.

The problem with a pre-amp is that while its going to boost the signal it's also going to boost all the trash around the P25 signal, and unless you can measure (or make a good guestimation) regards your existing CNR level, there's a fair old chance that no matter how much you boost the signal, you are not going to realise any improvement to the Signal/Carrier to Noise Ratio.

Get an antenna setup so that you can at least realise constant or consistant demodulation - no matter how quiet or low the demodulated audio is - then add a preamp, but not before.

[papillon]

Throw it up in a tree or at least tie a string with a weight, throw it up a tree , then pull your ant up there. Don't believe everything you read, in your case, height is the important thing
Let me know how it works out

[benbenrf]

Originally Posted by papillon

Throw it up in a tree or at least tie a string with a weight, throw it up a tree , then pull your ant up there. Don't believe everything you read, in your case, height is the important thing
Let me know how it works out

Don't laugh - a 3m or 4m (cubic volume of course) balloon filled with helium is another great way of raising an antenna!

Using the coax both to carry the signal back to ground level as well as to tether the balloon to whatever height you want to tether it at. To secure the coax at ground level obviously you don't tie it into a knot - use a length of cheap braided type rope of suitable diameter: compress the braiding in the axial direction (so that the braiding expands), slip the coax & connector through this section of the chord/rope, and then stretch the rope out again so that it compresses in a radial fashion around the coax.

6" to 8" of "glove fitting" around the coax will provide more than sufficient friction & resistance to withstand several times the (-)gravity force been exerted upwards by the helium and will do no damage to your coax.

If I am not mistaken in the USA you can freely & without any regulation of any sort raise a helium balloon to 60m or 198' above surrounding ground level (using 3.3' x p/meter conversion rate).

Obviously impractical if it's a Yagi or someother directional type antena, but with an omni-directional raised to this height you are going to be enjoying Fresnel Zone clearance thats likely to realize for you pretty much as much extra dB/gain as your typical small off-the-shelf Yagi would in any case.

[ab5r]

I noticed that you "moved" from point a to point B. Details of "Point B" are not included: Terrrain, Mountains or hills, distance to the trunking site you wish to monitor. ALL are important to know. A directional antenna is absolutely ineffective if you live in a hole. Give us some more info, please.