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| uhf install https://auszookers.com/forum/viewtopic.php?f=5&t=15282 |
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| Author: | bone [ Tue Sep 21, 2010 6:10 am ] |
| Post subject: | uhf install |
any tricks for new players as far as uhf install goes?? ive heard shortening the lenght of the areial cable to in dash unit can actually improve reception, any truth to this?? and is there a specific way to attatch areial cable to areial?? many thanks in advance from your resident idiot 
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| Author: | Ben_Sierra [ Tue Sep 21, 2010 6:20 am ] |
| Post subject: | Re: uhf install |
If you buy a decent antenna, designed for UHF CB then it should be tuned to the appropriate frequency. If you shorten it, you will make it worse... |
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| Author: | dunnjab [ Tue Sep 21, 2010 6:33 am ] |
| Post subject: | Re: uhf install |
yeah i always got taught never to shorten it. Try and keep the cable away from any heat and noise also use rubber grommets when going through the firewall. |
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| Author: | royce [ Tue Sep 21, 2010 6:38 am ] |
| Post subject: | Re: uhf install |
dont loop the cable as well, though in real life that or making the lead shorter will make bugger all difference dont short the 2 conducters in teh coax together refitting the plug on, dont join coax, if you stuff that connection up youll stuff the radio so if you arent sure ask for help |
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| Author: | MacDaddy [ Tue Sep 21, 2010 6:52 am ] |
| Post subject: | Re: uhf install |
bone wrote: any tricks for new players as far as uhf install goes??
ive heard shortening the lenght of the areial to in dash unit can actually improve reception, any truth to this?? and is there a specific way to attatch areial cable to areial?? many thanks in advance from your resident idiot Never shorten an Antenna/Areial, unless you know what you are doing, at min you will stuff an antenna, at worst you will stuff your UHF rig... But if you mean shorten the coax, then yes some antenna's with coax say cut it to length when installed and solder on the plug... however. nearly all coax is low loss, which means it maintains signal strength over the length of the coax, and most antenna's come with 3 to 4mtrs of coax... in my opinion that 4 mtrs of coax isnt going to make any significant difference to signal strength for in car units... the only way to get almost Zero signal loss, is to connect the antenna directly to the UHF rig, he he... there will always be some signal loss, but its so small, its not even worth worrying about...  
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| Author: | sleeperzook [ Tue Sep 21, 2010 7:34 am ] |
| Post subject: | Re: uhf install |
Yeah as long as you do a decent solder job on the connector, you cant go too wrong. Try keep it away from high current wires, or if you cant avoid it, the best way to make sure it won't induce noise is to cross it at right angles. Contrary to common belief, the 5w that most off the shelf uhf's will output is a decent amount of power. As was mentioned be careful to not short the coax shielding braid to the center conductor when terminating. All off the shelf antenna/uhf options will have impedance matching issues. This can be tuned with specialist shunt plugs, but i'll bet your local arb shop doesn't do that, so you'd never know the difference
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| Author: | Ben_Sierra [ Tue Sep 21, 2010 7:59 am ] |
| Post subject: | Re: uhf install |
MacBear wrote: bone wrote: any tricks for new players as far as uhf install goes?? ive heard shortening the lenght of the areial to in dash unit can actually improve reception, any truth to this?? and is there a specific way to attatch areial cable to areial?? many thanks in advance from your resident idiot Never shorten an Antenna/Areial, unless you know what you are doing, at min you will stuff an antenna, at worst you will stuff your UHF rig... But if you mean shorten the coax, then yes some antenna's with coax say cut it to length when installed and solder on the plug... however. nearly all coax is low loss, which means it maintains signal strength over the length of the coax, and most antenna's come with 3 to 4mtrs of coax... in my opinion that 4 mtrs of coax isnt going to make any significant difference to signal strength for in car units... the only way to get almost Zero signal loss, is to connect the antenna directly to the UHF rig, he he... there will always be some signal loss, but its so small, its not even worth worrying about... With 3-4 metres of the sort of stuff they preterminate cheapish CB antennas with, your probably going to find that you lose 1.5-2 dB... So you'll end up with maybe 3.5W into the antenna from a 5W radio... Get a decent preterminated antenna and that'll come up to 4.25W maybe... Of course you could use the sorta stuff I use at work for antenna cables, and then you'll end up with 4.8W.... Trouble is its half and inch thick and not very flexible...
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| Author: | bone [ Tue Sep 21, 2010 11:55 am ] |
| Post subject: | Re: uhf install |
haha, i should mention i got a uniden uh500sx uhf with a gme ae4705 aerial if that makes a difference?? i reckon i was asking about said coaxial cable for shortening and to recap... by the sounds no real need to shorten, as most is low loss yes??
ive noticed my little plug thing (uhf novice) has an internal thread which maches to the coax cable, is it a matter of just stripping some off the end, threading it to the plug and soldering?? haha, fuck i hope i havent asked too many dumb questions 
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| Author: | atari4x4 [ Tue Sep 21, 2010 12:00 pm ] |
| Post subject: | Re: uhf install |
there are no dumb question...
i used this link when i was doing mine http://www.k3lr.com/engineering/pl259/ so you're getting ready for a weekend of sandy goodness? |
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| Author: | bone [ Tue Sep 21, 2010 12:20 pm ] |
| Post subject: | Re: uhf install |
thanks gus, googled some images very similar to this. but thats got a better overall description
yeah, been keeping busy with the jim getting her ready. built some storage, got new tyres, got the uhf to set up.. need to get some camping gear so the missus can tag along. one swag for two people = not comfy haha
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| Author: | oozuk [ Tue Sep 21, 2010 12:32 pm ] |
| Post subject: | Re: uhf install |
I was always under the impression that cutting the aerial lead down only affected AM cb's and their SWR settings and not UHF cb's as UHF cb aerials aren't ground dependent. I've been cutting down the aerial leads on UHF aerial leads for installs for years with excellent performance and no problems. |
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| Author: | matty87 [ Tue Sep 21, 2010 12:41 pm ] |
| Post subject: | Re: uhf install |
you can get ground dependent and ground independent antennas for uhf radios what you use is based on where you wish to mount it on the vehicle ie the middle of the roof or the bull bar. as for dB and watts as mentioned before you do get what ya paid for. |
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| Author: | dm90 [ Tue Sep 21, 2010 1:46 pm ] |
| Post subject: | Re: uhf install |
atari4x4 wrote: there are no dumb question...
only dumb people
thats what our lecturer always says |
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| Author: | bakerboy [ Tue Sep 21, 2010 1:50 pm ] |
| Post subject: | Re: uhf install |
matty87 wrote: you can get ground dependent and ground independent antennas for uhf radios what you use is based on where you wish to mount it on the vehicle ie the middle of the roof or the bull bar. as for dB and watts as mentioned before you do get what ya paid for.
edzacery
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| Author: | MacDaddy [ Tue Sep 21, 2010 2:39 pm ] |
| Post subject: | Re: uhf install |
Ben_Sierra wrote: MacBear wrote: bone wrote: any tricks for new players as far as uhf install goes?? ive heard shortening the lenght of the areial to in dash unit can actually improve reception, any truth to this?? and is there a specific way to attatch areial cable to areial?? many thanks in advance from your resident idiot Never shorten an Antenna/Areial, unless you know what you are doing, at min you will stuff an antenna, at worst you will stuff your UHF rig... But if you mean shorten the coax, then yes some antenna's with coax say cut it to length when installed and solder on the plug... however. nearly all coax is low loss, which means it maintains signal strength over the length of the coax, and most antenna's come with 3 to 4mtrs of coax... in my opinion that 4 mtrs of coax isnt going to make any significant difference to signal strength for in car units... the only way to get almost Zero signal loss, is to connect the antenna directly to the UHF rig, he he... there will always be some signal loss, but its so small, its not even worth worrying about... With 3-4 metres of the sort of stuff they preterminate cheapish CB antennas with, your probably going to find that you lose 1.5-2 dB... So you'll end up with maybe 3.5W into the antenna from a 5W radio... Get a decent preterminated antenna and that'll come up to 4.25W maybe... Of course you could use the sorta stuff I use at work for antenna cables, and then you'll end up with 4.8W.... Trouble is its half and inch thick and not very flexible... So what do you class as a " Cheapish " antenna, just so people who read this know what to avoid ? I thought most of the " Good " set/rig manufacturers, compensate for the coax signal loss, as thats a given, by actually making the output power, a little higher than the stated 5W, like 5.1 to 5.5Watts... as all the old 27mhz sets/rigs i owned, from new, never had a power reading as a definite 4 or 12Watts, it was always just over to some degree, and i am sure if i had a UHF power meter, i would find the same...
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| Author: | MacDaddy [ Tue Sep 21, 2010 2:49 pm ] |
| Post subject: | Re: uhf install |
bakerboy wrote: matty87 wrote: you can get ground dependent and ground independent antennas for uhf radios what you use is based on where you wish to mount it on the vehicle ie the middle of the roof or the bull bar. as for dB and watts as mentioned before you do get what ya paid for. edzacery X 2
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| Author: | royce [ Tue Sep 21, 2010 8:48 pm ] |
| Post subject: | Re: uhf install |
MacBear wrote: Ben_Sierra wrote: MacBear wrote: bone wrote: any tricks for new players as far as uhf install goes?? ive heard shortening the lenght of the areial to in dash unit can actually improve reception, any truth to this?? and is there a specific way to attatch areial cable to areial?? many thanks in advance from your resident idiot Never shorten an Antenna/Areial, unless you know what you are doing, at min you will stuff an antenna, at worst you will stuff your UHF rig... But if you mean shorten the coax, then yes some antenna's with coax say cut it to length when installed and solder on the plug... however. nearly all coax is low loss, which means it maintains signal strength over the length of the coax, and most antenna's come with 3 to 4mtrs of coax... in my opinion that 4 mtrs of coax isnt going to make any significant difference to signal strength for in car units... the only way to get almost Zero signal loss, is to connect the antenna directly to the UHF rig, he he... there will always be some signal loss, but its so small, its not even worth worrying about... With 3-4 metres of the sort of stuff they preterminate cheapish CB antennas with, your probably going to find that you lose 1.5-2 dB... So you'll end up with maybe 3.5W into the antenna from a 5W radio... Get a decent preterminated antenna and that'll come up to 4.25W maybe... Of course you could use the sorta stuff I use at work for antenna cables, and then you'll end up with 4.8W.... Trouble is its half and inch thick and not very flexible... So what do you class as a " Cheapish " antenna, just so people who read this know what to avoid ? I thought most of the " Good " set/rig manufacturers, compensate for the coax signal loss, as thats a given, by actually making the output power, a little higher than the stated 5W, like 5.1 to 5.5Watts... as all the old 27mhz sets/rigs i owned, from new, never had a power reading as a definite 4 or 12Watts, it was always just over to some degree, and i am sure if i had a UHF power meter, i would find the same... this is from overdriving the outputs due to poor swr |
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| Author: | PJ.zook [ Tue Sep 21, 2010 8:55 pm ] |
| Post subject: | Re: uhf install |
Im now running ZCG Scalar antenna (Aus made and owned), they recommend to cut down the coax to whatever length you need, so thats what I did. Picks up more than my previous GME antenna. |
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| Author: | Reubs [ Tue Sep 21, 2010 11:12 pm ] |
| Post subject: | Re: uhf install |
bone wrote: ive heard shortening the lenght of the areial cable to in dash unit can actually improve reception, any truth to this??
and is there a specific way to attatch areial cable to areial?? I have a fibreglass GME 6.5dB with an elevated feed on the base. The antenna is designed to have the cable cut to length, and is terminated by a screw connection of-sorts. I think you would see a difference if you compared 2 identical setups side by side - 1 with 5m of lossy thin coax and 1 with 2.5 metres of lossy thin coax when listening to faint signals. Don't forget also where you mount the antenna is probably more important then how much cable is on it. E.g. using a ground independent antenna unless the antenna is in the middle of your roof, get an elevated feed kit if your base is lower then your bonnet (i.e. if mounting on front bumper), don't put your antenna right next to another one, and don't put an antenna directly next to a pillar such as roll cage or a-pillar. |
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| Author: | Ben_Sierra [ Wed Sep 22, 2010 12:02 am ] |
| Post subject: | Re: uhf install |
MacBear wrote: Ben_Sierra wrote: MacBear wrote: bone wrote: any tricks for new players as far as uhf install goes?? ive heard shortening the lenght of the areial to in dash unit can actually improve reception, any truth to this?? and is there a specific way to attatch areial cable to areial?? many thanks in advance from your resident idiot Never shorten an Antenna/Areial, unless you know what you are doing, at min you will stuff an antenna, at worst you will stuff your UHF rig... But if you mean shorten the coax, then yes some antenna's with coax say cut it to length when installed and solder on the plug... however. nearly all coax is low loss, which means it maintains signal strength over the length of the coax, and most antenna's come with 3 to 4mtrs of coax... in my opinion that 4 mtrs of coax isnt going to make any significant difference to signal strength for in car units... the only way to get almost Zero signal loss, is to connect the antenna directly to the UHF rig, he he... there will always be some signal loss, but its so small, its not even worth worrying about... With 3-4 metres of the sort of stuff they preterminate cheapish CB antennas with, your probably going to find that you lose 1.5-2 dB... So you'll end up with maybe 3.5W into the antenna from a 5W radio... Get a decent preterminated antenna and that'll come up to 4.25W maybe... Of course you could use the sorta stuff I use at work for antenna cables, and then you'll end up with 4.8W.... Trouble is its half and inch thick and not very flexible... So what do you class as a " Cheapish " antenna, just so people who read this know what to avoid ? I thought most of the " Good " set/rig manufacturers, compensate for the coax signal loss, as thats a given, by actually making the output power, a little higher than the stated 5W, like 5.1 to 5.5Watts... as all the old 27mhz sets/rigs i owned, from new, never had a power reading as a definite 4 or 12Watts, it was always just over to some degree, and i am sure if i had a UHF power meter, i would find the same... I would say a cheapish antenna is something that you get from Supercrap or similar.... Go to a specialist radio store or buy from reputable antenna manufacturer and you'll be right... You'll get a better product all round. And as for the overpowered radios, if they are indeed overpowered then they are in breach of the class licence. But I suspect that they aren't... |
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| Author: | bakerboy [ Wed Sep 22, 2010 12:28 am ] |
| Post subject: | Re: uhf install |
the ones from supercheap are actually benelec units http://www.benelec.com.au/mobile_ant/02635.htm what im running atm with my benelec radio, not bad twin pack antenna for under 100 |
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| Author: | Ben_Sierra [ Wed Sep 22, 2010 12:32 am ] |
| Post subject: | Re: uhf install |
Personally if it was me and I was looking for a good antenna I'd go to one of the suppliers that we use at work (RFI or ZCG Scalar). But it depends on what performance you need and also hoe much you are willing to pay... |
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| Author: | MacDaddy [ Wed Sep 22, 2010 6:34 am ] |
| Post subject: | Re: uhf install |
Ben_Sierra wrote: Personally if it was me and I was looking for a good antenna I'd go to one of the suppliers that we use at work (RFI or ZCG Scalar). But it depends on what performance you need and also hoe much you are willing to pay...
Yep i agree, doesnt matter how good/expensive your set/rig is, put a cheap antenna on, you will get cheap crap performance... I went to prestige and got a ZCG Scalar Elevated feed, and ground independent, with dual antenna's, little 3dbi and a 6.6dbi... i will always buy ozzie made over anything else, and ZCG Scalar is ozzie made, so added bonus...
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| Author: | Chop [ Wed Sep 22, 2010 7:27 am ] |
| Post subject: | Re: uhf install |
bakerboy wrote: the ones from supercheap are actually benelec units
http://www.benelec.com.au/mobile_ant/02635.htm what im running atm with my benelec radio, not bad twin pack antenna for under 100 I got the same one, and they arent cheap rubbish! Australian company and have been around for a very long time. Chop |
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| Author: | Lockie666 [ Wed Sep 22, 2010 9:29 am ] |
| Post subject: | Re: uhf install |
If you are worried about losing signal to your cable being shorted. Not that you'd ever notice the difference, why don't you buy a BIGGER Aerial?
That's the theory isn't it? |
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| Author: | Pezooki [ Wed Sep 22, 2010 10:20 am ] |
| Post subject: | Re: uhf install |
Hi all, This is a thread from a while ago: http://www.auszookers.com/index.php?nam ... 1733#61733 It should help answer some of the questions here relating to coax length etc... Cheers, Pez |
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| Author: | bakerboy [ Wed Sep 22, 2010 12:33 pm ] |
| Post subject: | Re: uhf install |
Chop wrote: bakerboy wrote: the ones from supercheap are actually benelec units http://www.benelec.com.au/mobile_ant/02635.htm what im running atm with my benelec radio, not bad twin pack antenna for under 100 I got the same one, and they arent cheap rubbish! Australian company and have been around for a very long time. Chop never said they were shit haha its what alot of us run over here |
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| Author: | Chop [ Wed Sep 22, 2010 1:04 pm ] |
| Post subject: | Re: uhf install |
Nah you didnt, but Ben did
Chop |
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| Author: | MacDaddy [ Wed Sep 22, 2010 2:25 pm ] |
| Post subject: | Re: uhf install |
Pezooki wrote: Hi all,
This is a thread from a while ago: http://www.auszookers.com/index.php?nam ... 1733#61733 It should help answer some of the questions here relating to coax length etc... Cheers, Pez Ahhh ok... well that makes sense to me... so if i cut the coax to the length i need, i will not only get a better power through put, but i will also be able to receive weaker signals... my antenna came with 4m of coax, i only need 2.5m, so me thinks that even though its only 1.5m longer, it may be better to remove it, than leave it on...
I also learnt something new about how a tranciever sends the signal down the coax, RF is basically an attenuated/tuned magnet field, and that it does not go down the coax through the wire, it goes down the coax on the surface of the central wire, and this is how antenna's work, and in general, giving the RF more surface area to radiate from at the antenna, will provide not only better distance but better receive... so shortening the coax, allows the RF to maintain the strength of that magnetic field... there are alot of other factors, but that is the basic's of it... anyway i go on... he he...
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| Author: | Ben_Sierra [ Thu Sep 23, 2010 12:36 am ] |
| Post subject: | Re: uhf install |
Chop wrote: Nah you didnt, but Ben did
Chop OK OK, so it was a bad example, I didn't know what brand SC sold.... I assumed it was cheap shit like everything else in those stores.... But I would still buy a ZCG or RFI antenna... |
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