heyhey Posted May 10, 2012 Report Posted May 10, 2012 Hi Folks, I have a GME 4705 and it is just that bit too high for my garage. I was wondering if I could trim a bit off the top and reduce the height. BUT if I do this I'm afraid it will detune it and make it pretty crap (not that it is overly good anyway). Otherwise I need a really heavy duty antenna that is between 4.5 and 6db and 700-1000mm high. Need to be used for a mix of flat and hilly driving (mostly hills). Cheers,
Ray! Posted May 10, 2012 Report Posted May 10, 2012 All UHF antennas are tuned to length, if you cut them, you'll make them really poor performers. I have the 4705 and find it very good, are you sure you don't have an issue with the cabling or radio? Why don't you get a small rubber ducky UHF antenna for around town and use the longer one for the bush, that's what I do. Cheers Ray
mk tank Posted May 10, 2012 Report Posted May 10, 2012 What type of antenna do you have. Is it a fibre glass type whip Is it a metal rod, as the metal ones are usually a bit shorter. Rays correct in his comment regarding the tune to length. Effectivly a antenna is a pice of wire that is cut to the required frequency - i have made antennas out of fencing wire in the past. KMsMK 1
heyhey Posted May 11, 2012 Author Report Posted May 11, 2012 mk tank - It is a GME 4705. I also have a small whip (think its like 1.5db and about 150mm tall including base). Connections for the 4705 and the GME radio are standard and unchanged. It just doesn't work as well as the Uniden with the 1.5db whip for closer proximity chat.
mikegq Posted May 11, 2012 Report Posted May 11, 2012 The 4705 is a heavy duty gibreglass pole co linear about 1200 high I think from memory. U could take 5-10mm off the top but no more
Brett Posted May 11, 2012 Report Posted May 11, 2012 I got the 4075 too and it stays off unless I intend to use it, as I cant park it in my garage and shopping centres are a no no too... as it is, my 'troll only just, and I mean just, clears the roller door(few mm)... the 4075 is the shortest mast that fits into that base as I've already looked into it... you can get a base attachment that can be allow the aerial to preposition backward on an angle, but its too much of a hassle for my liking...
Sooty_10 Posted May 11, 2012 Report Posted May 11, 2012 I had a fibreglass GME one and after a few too many knocks the tip broke off about 60-100mm. The wire is just a flat ribbon in plastic inside the fibreglass tube. I took the rubber cap off the busted bit and simply tucked the little bit of wire sticking out back in trimmed the top and siliconed it back onto the remaining antenna. Had no noticeable issues with reception or tuning length etc, however the actual antenna wire was never shortened physically, just maybe folded back on itself? At the end of the day the antenna was now no higher than the roof, and it never hit anything again whilst still worked good for what I needed.
heyhey Posted May 11, 2012 Author Report Posted May 11, 2012 Brett, what are these base attachments you speak of? Are they quick to use? Sooty_10, So you lost 60-100mm on yours and it still transmitts and receives ok? Interesting.
gottheshits Posted May 11, 2012 Report Posted May 11, 2012 Have a look on the gme site heyhey. Im pretty sure they hve them on there. It undoes and folds back at an angle. Sorry mate I'd link it but I'm on my phone again.
The Big Rig Posted May 11, 2012 Report Posted May 11, 2012 I just got bored and put my fibreglass antenna back on i'll take some photos of the gme aerial I usually use tomorrow. I have had no issues of reception at all. I just found out with the 4075 on its over 2.2m tall without a lift
mikegq Posted May 11, 2012 Report Posted May 11, 2012 Gme 4013 screws onto the 4705 spring base and is 30cm long 1/4 wave 2db antenna good for around town
Ray! Posted May 11, 2012 Report Posted May 11, 2012 This is one that I've thought about replacing my fairly old rubber ducky with either this one: http://www.prestigecom.net.au/index.php?main_page=product_info&cPath=371&products_id=2116 or this one: http://www.prestigecom.net.au/index.php?main_page=product_info&cPath=371&products_id=2163. as I think both fit the 4705 antenna base. Cheers Ray
mk tank Posted May 11, 2012 Report Posted May 11, 2012 I use a simalar antenna from RFI that has 3 db gain and is a GPI.
The Big Rig Posted May 11, 2012 Report Posted May 11, 2012 Mines is the same as mikegq http://www.gme.net.au/products/antennas/land-477-mhz/AE4013
Brett Posted May 11, 2012 Report Posted May 11, 2012 the base for the 4705 is AS004 http://www.gme.net.au/products/accessories/accessories-antennas-springs/AS004 the SO239 base has a different attachment system... I cant find the adjustable mounting block that (cant remember where) the 4b shop showed me, but I didn't like it... unless the aerial Rays talking about just sits in the base and doesn't thread in then i cant see how it would work???
mikegq Posted May 11, 2012 Report Posted May 11, 2012 the base for the 4705 is AS004 http://www.gme.net.au/products/accessories/accessories-antennas-springs/AS004 the SO239 base has a different attachment system... I cant find the adjustable mounting block that (cant remember where) the 4b shop showed me, but I didn't like it... unless the aerial Rays talking about just sits in the base and doesn't thread in then i cant see how it would work??? S0239 refers to the UHF style connector on the spring base. So as I said the 4013 screws on dispite the fact the spring is as004
Ray! Posted May 11, 2012 Report Posted May 11, 2012 I contacted Prestige probably over a year ago and they said one of these two fit the same base as the 4705, ie screw in, but I can't remember which one. Cheers Ray
gottheshits Posted May 11, 2012 Report Posted May 11, 2012 (edited) These are the fold downbrackets I was thinking of but it looks like they aren't cheap. http://www.pefabrica...ome.php?cat=249 Edited May 11, 2012 by gottheshits
The Big Rig Posted May 11, 2012 Report Posted May 11, 2012 Mine screws on to to the centre thread of the aerial not to the actual spring base thread
mikegq Posted May 11, 2012 Report Posted May 11, 2012 Exactly right big rig. And only 30 bucks retail
gottheshits Posted May 11, 2012 Report Posted May 11, 2012 small screw in for round town. heyhey, The Big Rig and Frosty 3
The Big Rig Posted May 11, 2012 Report Posted May 11, 2012 Now I don't have to go get a photo tomorrow cheers gottheshits
dronus4x4 Posted May 11, 2012 Report Posted May 11, 2012 By some strange coincidence the tip of my RFI 6db on its mount is a couple of mm higher than my roof cage. It doubles up as a warning guide for me when entering carparks or drivethroughs :-) Sent from my GT-P7100 using Tapatalk 2
Ray! Posted May 11, 2012 Report Posted May 11, 2012 (edited) This is my day to day antenna, a rubber ducky shielded by an alloy housing a mate of mine had machined up, so that it locks in the same way as the 4705 and can't be pilfered: I just wanted to add that years ago, before I had this made up, I'd contacted GME Electrophone in Melbourne and asked them if it was possible to make a shorter antenna with the same base as the 4705, just so that it could be used around town and not interfere with carparks, garages etc. I was met with a resounding no, there's no point. Excellent Australian innovation, not. Cheers Ray Edited May 12, 2012 by Ray!
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