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Hi Patton and welcome to the forum. Needlebender has the best option for you in my opinion. Never drill and mount an antenna to the roof of your car unless you fancy doing some serious damage to the bodywork off roading. Been there and done it in my works tractor, not a good idea. Over here we...

Going to try and get rid of the RF from the dc output in the next couple of days. I've sourced some caps and i'm also replacing the 8 single positive and negative 12vdc leads with 40 amp single. Looking at ferrite thats effective at these frequencies also. The stock psu I have uses a 47uf cap...

You can't put em in parallel because the current draw nearly always pulls on one supply much more than the other. Yes there is a mod to change to 13.8vdc, google it. Yes the 8 smaller wires would be better replaced with a 30 amp single. Just slapped a 100 watt kicker on this and there are...

Just recently converted a 650W computer power supply for use with CB equipment. The supply specs were 2x23amp 12v+ on the 12vdc rail, 30amp on the 5vdc rail and 20amp on the 3.3vdc rail. Desoldered the 3.3 and 5v wires off the board apart from one 5vdc + wire which I needed for a shunt resister...

Interesting comments there Robb.

You can use strong hardwood, delrin, glassfibre or any strong insulator that will stand up to wind. We use ash spade and shovel handles because they are really strong and available. I wouldn't expect you to realise any of this though because you deal in making huge caps with insulating tape...

For IDIeselman:- The capacitance is greatest when there is a narrow separation between large areas of conductor, hence capacitor conductors are often called "plates," referring to an early means of construction. In practice, the dielectric between the plates passes a small amount of leakage...

IDIeselman wrote I'd look at that chart again if i were you. You don't know what you're talking about and you havn't got a clue how to isolate an antenna properly.:bdh: Look up capacitance, here's an idiots guide. http://en.wikipedia.org/wiki/Capacitor Then look up inductance and capacitance...

Yeah, why? Are you still sniffing cocaine and looking bald while claiming your SS benefits? :tongue:

There is absolutely no way that Imax could have tested thousands of different locations and set ups. Everyone is different, has different radio gear, different surroundings etc etc. If you use tape or plastic tube between the mast and the antenna you will create a capacitive coupling between the...

Nice work there DXbowler. Just goes to show if people isolate their antenna PROPERLY instead of wrapping tape around their mast results can be obtained. It's another victory for the isolating method.:whistle:

Marconi wrote emmmmm

Wavrider wrote Wav, you could solder a 50ohm resister at the end of your 50ohm coax and the swr looks sensational but it won't bloody resonate. Were taking about phase relationships between half and quarter waves here not what looks nice on a swr meter. Giz a clue we folk.

Read this simple dipole explanation Marconi. Dipole antenna :: Radio-Electronics.Com Then explore what happens to the voltage and the current on an end fed half wave antenna.

I never mentioned an Imax's radials?!! The arrows represent the electrical current flowing on the mounting pole and the coax in both directions and include all currents. I only put the arrows in one direction but they will be reversed depending on RX or TX. Marconi, take a look at a simple half...

Yes, I've made both a coil shortened quarter wave ground plane from a mobile antenna and i've made a full quarter wave ground plane. In essence its a dipole type of arrangement but if you try and straighten the lower radials that also has a profound effect on SWR. At 90 degrees they have an...

Marconi wrote Did he ever have a choice?:oops:

My opinion is more or less what you said earlier Booty - we all suffer different circumstances in our locations and our surroundings. For example, soil conductivity can change how one antenna behaves compared with the same antenna in another area. Attenuation from the local surroundings, the...

This is what I mean. The current has to flow down the coax and up the mounting tube to get to the radials increasing the electrical length of any radial attached.

Marconi wrote: You've misunderstood me Marconi. Where the SO239 is located on the A99 is approx 10 or 12 inches from the tuning section (the length of the short piece of coax inside). This arrangement has a disadvantage over a standard half wave GP if you want to mount radials. The reason...