can anybody help

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oasis

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hi guys, im new to the scanning scene so please bare with me. i have a uniden ubc9000, with an indoor discone, but im not getting that good a reception, and i think it may be to do with the length of my cable, its around 4-5 metres long but i have the discone right next to the scanner. any tips on how to pull in more signals and improve the ones i have would be greatly appreciated. thanks.
Chris
 

texasemt13

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Oasis,

First, welcome to RR! You're on the money when you think a "loss" may be because your feed line is too long. The longer the line, the more signal loss. Another could be bad connections between connectors (or mismatched impedance). If your coax has a 50Ohm impedance but your conectors are rated at 75Ohms, you're going to have some reflection and subsequently, some loss. Along the line of connectors, make sure they're still soldered well (or if they're crimped, make sure they aren't loose).
 

oasis

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Thank you for the welcome texasemt13, i thought it may have been due to the cable, i think the connectors are ok because i was getting pretty good signals with the discone and psr295, i havent looked into impedance, but will do now you have mentioned it. thank you again.
 

texasemt13

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Oasis,

Other than that, there are many directions you can go to get better signals. An outdoor antenna with as much height, tuned to the specific frequency, is as good as you can get (keeping in mind, the run length of the line, impedances, SWR, etc.). One definitive answer for better signal strength can be hard to give at times.

Oasis- do you have to feed line in a coil? That could be creating some wicked inductance or something...
 

SkipSanders

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One question is, just what are you trying to receive? No matter what antenna you have, if it's out of line of sight, it's not going to be receivable.

Most setups, you will have a maximum range of maybe 25 miles, up to 50 if the transmitter is on a good high mountain. Much, much less if you're in a valley.
 

oasis

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i understand, there must be a massive multitude of options on this problem, iv'e thought about getting a signal amplifier as well, as having an outdoor ant is unfortunately not an option. My real interest is military aircraft- 220 up to 390 (as you know), and sometimes i can get f15s all day long then others, barely a squeek. im uk by the way, in a town with houses all around, so that wont help.
 

oasis

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hi skipsanders, i am trying to recieve military aircraft, and on my handheld, i could sometimes get the bombing range which is at sea level, and around 35 miles away.
Chris
 

oasis

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also, i thought it was possible to recieve aircraft from up to 240 miles away, i dont know if this is correct, but its what is in the uk scanner directory. probably nonsense lol.
 

oasis

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Oasis,

Other than that, there are many directions you can go to get better signals. An outdoor antenna with as much height, tuned to the specific frequency, is as good as you can get (keeping in mind, the run length of the line, impedances, SWR, etc.). One definitive answer for better signal strength can be hard to give at times.

Oasis- do you have to feed line in a coil? That could be creating some wicked inductance or something...
please forgive me, i dont know what feed line in a coil is? i got the discone off the net, its a monnraker skyscan desktop, freq 25-2000 rx 4 metres of cable with rg58 bnc, 90 cm length.
 
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texasemt13

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Simply put, do you have all of your excess antenna cable rolled into a loop? If so, that might be problem.

As Skipsanders suggested, an antenna tuned for the range would help. A wide range receive antenna like you have isn't particularly tuned to any range, but is in average of fractions of multiple ranges. An antenna tuned to the milair range would be better.
 

oasis

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ahh, i see. yes i have the excess coiled and tie wrapped to stay in place. this could be the problem then. so it would be adviseable to shorten length to maybe 1m? i think should also look at a specific band ant.
thank you again for the advice
chris
 

SkipSanders

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Unless you're really good at soldering on connectors, don't try shortening cables. Bad connectors will give worse loss than that short a cable.

Actually, unless you can find a military air specific discone, the discone is best for MilAir, as it's too wide a band for a single normal antenna. But you need to get that antenna up on the roof, to get it clear of obstructions.

If you need a longer cable to get the antenna on the roof, be sure you use nothing smaller than RG-8 cable. (Not RG-8X). Unless you have something special made, you'll likely have to get a 50' length. That's fine, at MilAir frequencies, as long as it's RG-8 or better.
 

oasis

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Unless you're really good at soldering on connectors, don't try shortening cables. Bad connectors will give worse loss than that short a cable.

Actually, unless you can find a military air specific discone, the discone is best for MilAir, as it's too wide a band for a single normal antenna. But you need to get that antenna up on the roof, to get it clear of obstructions.

If you need a longer cable to get the antenna on the roof, be sure you use nothing smaller than RG-8 cable. (Not RG-8X). Unless you have something special made, you'll likely have to get a 50' length. That's fine, at MilAir frequencies, as long as it's RG-8 or better.
hi skipsanders, i have never really soldered anything for about ten years, and i wasnt too good then lol. i have seen some mil air specific antennae but they are outdoor, and as i said, i dont really have that facility. but willl definately keep it in mind. thank you for the advice. chris
 

oasis

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can you get the police where you are skipsanders, weve moved over to tetra here, and i dont understand why everyone else hasnt gone the same way yet.
 

SkipSanders

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Tetra is good for business, but as I understand it, poor for public safety. If your police are using it, it's because they got it very cheap, most likely.

I believe I've heard of some small departments simply buying a business tetra repeater system's time, and operating as though they were a business.
 

Raccon

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Tetra is good for business, but as I understand it, poor for public safety. If your police are using it, it's because they got it very cheap, most likely.
Notwithstanding that some systems are offered at a high discount, dumping prices or even for free at times it is not likely but rather the exception, and against your understanding TETRA is anything but poor for public safety, but feel free to explain.
 
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