OzSTOC
Farkles, Gear & Accessories => Comms and Audio => Topic started by: bluehonda on November 08, 2012, 11:23:56 AM
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Whilst looking throught the internet I saw that Dick Smith is selling a Uniden CB, 5 watt, compact size and 80 channel for $149.00
I can't find any other 5 watt compact cb for the money.
The model number is in part 7700, think I'll get one when I check if it will connect to my Starcom intercom like my old GME cb did.
Brad
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No reason why not, as long as you can find the pinouts to make up an interface cable. Dale should be able to advise on this. I have only made up cables for the GME 3420 to Autocom, and one other older CB that was really noisy compared to the new one - it turned out to be too big to fit on the bike anyway.
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Brad, just be a little careful, the Spec says nothing about it being weather or waterproof, so it might well die horribly the first time it gets wet! :well :well
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Yeah, got ya Whizz, good advice
Brad
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Cable for UH7700 to StarCom ? do 'em all the time :thumb
But best hidden away as mentioned, not for outside use, also need a good Ground independant aerial to go with
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Thanks Dale,
I'll mount it away from the weather and the aerial I had with my GME tx3400 seemed to work okay but how would I really know.
How can I tell if an aerial is ground independant?
Brad
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Dale,
I have a Uniden Uh 7700NB safely tucked away int he LH fairing pocket.
Can you make a cable that terminates in a headphone jack, microphone jack and PTT. I normally run mine through the Bluetooth mic but sometimes would like the reliability of a hardwired system. My mic plugs into the unit with an RJ 45 plug... I have a quality mini boom mic and single ear head set that I would like to use... Both jacks are the standard 3.5mm.
I would really appreciate any assistance.. Happy to pay what you think it is worth!!!
Much appreciated...
Cheers,
Doug
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Brad,
Most cheaper antennas are really only half an antenna, the other half being the metal ground plane to which they are bolted, like the car roof or wing etc. A "Ground-independent" antenna is both halves together, so a relatively easy way to recognise such an antenna is that they tend to have a fat, elongated base unit, or have a chunky coil assembly half-way up. Any antenna that looks like a thin stick which ends in a small unobtrusive screw connector is almost certainly an 1/4 wave antenna, i.e. the half-an-antenna version. The 1/4 wave antennas rely on the metal body-work to work properly, the Ground-independent one's don't.
Take a look at the following URL for pictures and explanations of differing types of antenna, they explain it far better than I can;
http://www.mobileone.com.au/antennas/cb477.html (http://www.mobileone.com.au/antennas/cb477.html)
The Ground-independent antennas are good for bikes because there really isn't enough metalwork under a 1/4 wave antenna to effectively act as the 'other-half' so they can be horribly inefficient. A measure of efficiency of the antenna is called VSWR which stands for Voltage Standing Wave Ratio, and a VSWR of 1:1 it the absolute ideal, anything up to about 2:1 is acceptable but getting progressively closer to the limit, and anything over 2.5:1 will probably stuff the transmitter because it's a measure of how much power is reflected back into the output stage of the transmitter rather than going out of the antenna.
Hope this helps
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At least at UHF the wave length is pretty short, so at 477Mhz the 1/4 Wave ground plane is only about 31 cm (or 12" )
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Half that again Brock.....or a little more accurate would be 14.88 cm for a unity gain 1/4 wave at the middle of the UHFCB band.
More importantly in this thread.....wonder if Brads old radio is retrievable, save him some coin.
Cheers
Chris
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Brad, let me know if you want the cable - give us a ring :thumb
Doug "standard" 3.5mm doesnt quite tie it all down :|||| both mono, stereo, quad contact??
Also experience has taught me that style jack connector is fine for (comparatively) large amplitude signals like audo/music but generally a mic input will get too much noise to be useful as it is a very small signal. I do a "budget B-B" that is purely a wired headset (2 speakers so you dont len to one side :rofl) and mic with a PTT for any radio. Give us a yell to discuss too, it takes too long to type.
We COULD woffle on with all sorts of technicamal jargon re aerials (antennae :nahnah) but suffice to say a commercially available ground independant with moderate gain is best on a bike :thumbs.
I supply these http://www.rfiwireless.com.au/mobile-antennas/uhf-mobile/uhf-ground-independant/uhf-ground-independent-mopoletm-cd51-68-70.html (http://www.rfiwireless.com.au/mobile-antennas/uhf-mobile/uhf-ground-independant/uhf-ground-independent-mopoletm-cd51-68-70.html) flexible so they cant hurt you or someone else, 4db gain :thumbsup and work really well. Been running one for 5 years or so
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Yep RFI aerials are the GO !!!! The CD 50/51 and the CD 63 if its still made are Sooooo easy to terminate at the aerial end.....
Up early again Dale....... :hatwave