Hey all, I was wondering if any of you guys do this, I'm visiting family in the mountains this thanksgiving break, and I would really like to broadcast, I was just wonder what type of inverter I would need for my car, I know almost nothing about power inverters, or basic circuitry, so any help would be great. I would be broadcasting at about 20 watts, so i was wondering if this www.walmart.com/ip/Schumacher-XI14-Power-Inverter/15140199 would work? Thanks for the input.
13 amps is a heavy load for a car's electronic system. It will almost definitely blow the fuse for your cigarette lighter outlet. You could always swap out the fuse for a larger 15 amp one, it might not be the safest idea, but may still work.
As far as the inverter goes, amps x volts = watts. So with 140 watts and 13 amp, the voltage being pulled needs to be less than 10.7v
Look into running a cable straight from the battery into the interior, through a fender or a hole in the firewall. Check out some car audio amplifier install kits.
Well even with a direct B+ wire ran from the battery into the passenger compartment, that 13 amps is one hell of a load drain. That battery will be depleted in no time, meaning you will have to keep the engine running just to maintain a charge and stable level of current and voltage delivery to that load.
As the battery depletes, both current and voltage drop. If that 13 amp load is sensitive to too much drop in voltage and current, it could damage it.
My advice, find a transmitter that runs directly on 12 volts DC. Plenty of them out there that throw 20 watts and more. And you wont need a 5 amp fused circuit to power the thing. A 2 amp B+ feed will be plenty, and not put such a strain on the vehicles electrical system and charging system.
Also keep in mind, that most vehicles now use in-line fuses on the wiring along with the fuse panel. And sometimes those in-line fuses are buried deep behind the dash or tucked away in a wire harness at a not so easy accessible point.
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Where did you get the 13 amps from, a 20 watt fm transmitter is no way drawing 13 amps, more like 2 amps at the most, a 12 volt car battery will power a 20 watt tx for mobile use, with a new battery fully charged you should get around 20 hours use with a 20 watt rig.
yeah agree he won't get 20 hours running through an dc/ac inverter at 13 amps, that inverter as a few bad reviews, probably wouldn't last that long in constant use. if he runs a 20 watt tx operating directly on a 12volt dc supply, he'll get somewhere close to 20 hours from a car battery.
Post by sgtpeppers on Nov 11, 2011 14:24:40 GMT -6
if you have an empty fuse slot, see what it's used for and check the rating. if you can get power from one of these it's much safer to run one from there to your transmitter than to run from the battery. if you cannot, run some heavy guage wire from the battery. if you run from the battery, put a fuse in the positive wire as close to the battery as possible (this will keep your car from catching fire in an error or break in the wire. I also suggest this. www.sacskyranch.com/altnoise.htm
Post by highmountainradio on Jan 12, 2018 21:08:58 GMT -6
Greetings Imcoolkid !
Indeed, I admire your spunk, mobile broadcasting, 'eh ? Indeed, it is very easy to do just that ! For a mere small cost of $35.00 US, here is a dandy little 5 watt transmitter on Ebay and it works quite well for it's meager size, it will literally fit in the palm of your hand and will deliver 5 watts 24/7 without overheating.. Here: www.ebay.com/itm/87-109MHz-Stereo-Digital-FM-Broadcast-Transmitter-Radio-Station-Adapter-Wire/311931447606?hash=item48a0902936:g:Xv0AAOSwSdFZhA8Z Just hook it up to a good ground plane antenna and supply it with 12 VDC, regulated and dial in your target frequency ! When using ANY type of antenna, be certain to use a 'balun' at the antenna feedpoint ! This is easily fabricated by winding 6 turns of whatever coaxial cable you are using to feed your antenna into a circumference of 6 inches, placing each turn or circle of cable, adjacent to the preceeding loop of coax. Keep it all in a neat and tidy side by side coil, you can easily secure it into this formation by cutting small pieces of wood to keep the windings of coax all nice and uniform and side by side across it's depth. Use electrical tape to secure the wood 'form keepers', one on top of the coil of coax and one underneath and wrap the tape around the wood pieces to hold and keep the coaxial cable in place to form the balun. Connect one end of the coax to the antenna feedpoint and the other end to your feedline. This balun will prevent your feedline from radiating and giving you a high VSWR (Voltage Standing Wave Ratio) which is quite harmful to your transmitter. The idea here is to deliver all of your power to the antenna and not losing it going up the feedline and being reflected back to the transmitter.. Be sure to match your antenna carefully by extending the driven element length or shortening it in very small increments from the initial calculated length for your intended operating frequency until you get as close to a 1:1 match as possible, measuring it with a cheap 'SWR Bridge' you can find on Ebay or a local CB radio shop aid of how it is easily fabricated in 15 minutes..
Good luck and welcome to the forum ! Do come back regularly, the group of guys here are more than happy to educate you and there are quite a few here who have advanced technical knowhow to lead you in the right direction and as cheaply as humanly possible.. If you have any questions, feel free to post them and I'm sure you will get an education here !
73... Spooky... "Broadcasting From Somewhere High In The Remote Appalachian Mountains" - 'High Mountain Radio"