Wide Band Antenna

Started by M. Hamed in sci.electronics.basics3 years ago 14 replies

Is there such a things as an antenna that will get me everything from HF to VHF with reasonable strength? I have a BNC telescope antenna that...

Is there such a things as an antenna that will get me everything from HF to VHF with reasonable strength? I have a BNC telescope antenna that seems to get FM broadcast and higher but very little once you start going below 100 MHz.


Antenna Lightning Protection

Started by W. eWatson in sci.electronics.basics4 years ago 18 replies

I have a mast, rotor and yagi TV antenna on my roof. The antenna is probably 15' feet above the roof. It has 12 or so large elements, and a...

I have a mast, rotor and yagi TV antenna on my roof. The antenna is probably 15' feet above the roof. It has 12 or so large elements, and a similar amount of smaller elements. There are three guy wires. It was struck by lightning about eight years ago, and took out the rotor control in the house. There was no apparent damage to the antenna it is not in use, disconnected from the TV, but ...


Crystal Radio Questions

Started by Joe in sci.electronics.basics8 years ago 10 replies

I'm winding a coil for a crystal radio. The original plan says to wind the antenna coil on top of the tuning coil, whereas another version...

I'm winding a coil for a crystal radio. The original plan says to wind the antenna coil on top of the tuning coil, whereas another version says to wind the antenna coil *adjacent* to the tuning coil, separated by about 1/4 inch. If I wind both versions of the antenna coil on the form, will one winding interfere with the other? That is, I would only hook up one antenna coil at a time, so ...


Re-activating a Roof-top TV Antenna

Started by Joe in sci.electronics.basics9 years ago 3 replies

I would like to help a relative "re-activate" a roof-top TV antenna on a single storey house in southern California. From the ground, it...

I would like to help a relative "re-activate" a roof-top TV antenna on a single storey house in southern California. From the ground, it looks to be physically in good shape, each of four corners has 4 guy wires holding the mast, which looks to be something close to 20 feet tall. I need a how-to to get the antenna in shape. It currently has its feed cable dangling on the mast, not...


VSWR doesn't matter? But how about "mismatch loss"?

Started by billcalley in sci.electronics.basics11 years ago 43 replies

What I gleaned from the excellent answers for the original "VSWR Doesn't Matter?" thread is that high VSWR doesn't really matter in...

What I gleaned from the excellent answers for the original "VSWR Doesn't Matter?" thread is that high VSWR doesn't really matter in a lossless transmission line environment between a transmitter's antenna tuner and the antenna, since any reflected RF energy will simply continue to "bounce" back and forth between the tuner's output impedance and the antenna's input impedance until it is, ...


300 ohm to 75 ohm impedance matching "transformer"

Started by Joe in sci.electronics.basics9 years ago 3 replies

I bought a 300 to 75 ohm "matching transformer" to hook up to a home built TV antenna. The matching transformer looks exactly like the one on...

I bought a 300 to 75 ohm "matching transformer" to hook up to a home built TV antenna. The matching transformer looks exactly like the one on this URL: http://www.solidsignal.com/prod_display.asp?PROD=WMXFMRPT I have a couple of questions: Can these matching transformers be used in either direction? That is, my antenna will get the 300 ohm end, and the TV antenna input will get the ...


Antenna impedance

Started by riccardo manfrin in sci.electronics.basics4 years ago 19 replies

With reference to this schematic: http://www.pyroelectro.com/projects/pyro_rf_transmitter_27mhz/img/schematic.png I'd like to know if there is...

With reference to this schematic: http://www.pyroelectro.com/projects/pyro_rf_transmitter_27mhz/img/schematic.png I'd like to know if there is a general rule of thumb for determining the antenna impedance Z(w) and therefore the matching inductance L3. Also, I'd like to know what is the meaning behind the choice of the "12 inches of AWG 28" (cause 12inches do not seem to me like any fraction...


Antenna power injector and splitter

Started by Captain Dondo in sci.electronics.basics11 years ago 3 replies

I have a couple of Winegard powered antennas. The power injector has developed an intermittent failure, so I took it apart to see what...

I have a couple of Winegard powered antennas. The power injector has developed an intermittent failure, so I took it apart to see what was going on. It looks like there is an invisible break in the circuit somewhere. I could try to fix it, or I could build a new one and address some other issues. So... The injector consists of two RF jacks, one for the TV and one for the antenna. ...


long antenna

Started by RichD in sci.electronics.basics2 years ago 4 replies

During my workout yesterday, I attached a 3 meter extension to the earphone cord of my radio, as I wanted to place it at a distance. The cord...

During my workout yesterday, I attached a 3 meter extension to the earphone cord of my radio, as I wanted to place it at a distance. The cord is the antenna. I was indoors, where the reception is usually crummy. I figured the longer line should improve performance, right? No! The reception was barely decipherable. Can anyone explain the physics here? -- Rich


radio antenna ?

Started by mowhoong in sci.electronics.basics5 years ago 7 replies

My country has only one radio broadcast station with different channel playing music,news,etc. Why is it that I need to readjust my radio antenna...

My country has only one radio broadcast station with different channel playing music,news,etc. Why is it that I need to readjust my radio antenna ( Direction ) when I listen to the different station or channel ? Can any members explain to me , Thank you . Best Regards


2 Transistor AM Radio

Started by Dave.H in sci.electronics.basics10 years ago 19 replies

Not sure if this is the correct place to ask, but here goes... I've found plans for a simple two transistor AM radio receiver, but I'm not sure...

Not sure if this is the correct place to ask, but here goes... I've found plans for a simple two transistor AM radio receiver, but I'm not sure how the ferrite loop antenna is connected to the radio. I'm not at all good with schematics, I can understand most of it except for the ferrite antenna bit. I would appreciate any help on this. http://www.techlib.com/electronics/crystal.html#Simp...


High Gain Antennas

Started by Phil Allison in sci.electronics.basics7 years ago 3 replies

** Hi all, inspired by a series of posts on the subject of antenna gain - I did a little Googling. My quest was to find the highest gain...

** Hi all, inspired by a series of posts on the subject of antenna gain - I did a little Googling. My quest was to find the highest gain antenna ever uilt - I guessed it might be a large parabolic dish as used by NASA etc. But what is the actual * gain * in dBi ?? There is a famous 305 metre diameter dish in a place called Arecibo in Puerto Rico - it is reckoned to have a gain...


TUTORIAL - Example 2, Using Femm to Calculate Component Values of Simple buried Stripline configured like a coax to use in LTspice/PSpice

Started by RobertMacy in sci.electronics.basics2 years ago

These anlayse work at 2.5GHz in FR4 type PCB material for those of us who want to drive ?? or an antenna = Bluetooth, Wifi, zigbee, or GPS...

These anlayse work at 2.5GHz in FR4 type PCB material for those of us who want to drive ?? or an antenna = Bluetooth, Wifi, zigbee, or GPS antenna module and want to see how much a 'longer than desirable coax' run detriorates the NF of the Receiver. The skin effect is in there, but I did NOT want to make this a 'broadband model' Skin effect issimply at 2.5GHz. Boradband Model is res...


VSWR doesn't matter?

Started by billcalley in sci.electronics.basics11 years ago 61 replies

We are all told that VSWR doesn't matter when using low loss transmission lines, since the RF energy will travel from the transmitter up to...

We are all told that VSWR doesn't matter when using low loss transmission lines, since the RF energy will travel from the transmitter up to the mismatched antenna, where a certain amount of this RF energy will reflect back towards the transmitter; after which the RF will then reflect back up to the antenna -- where the energy is eventually radiated after bouncing back and forth between th...


Litz wire for AM ferrite Rod Antenna?

Started by Bill Bowden in sci.electronics.basics11 years ago 28 replies

How much improvement can I expect using Litz wire to wind a AM ferrite Rod antenna as opposed to using solid copper wire? Is it worth the...

How much improvement can I expect using Litz wire to wind a AM ferrite Rod antenna as opposed to using solid copper wire? Is it worth the trouble to obtain Litz wire, or can I expect almost the same response at say 1 MHz using regular solid enamaled copper wire? -Bill


1 Micron Antenna for Solar Power

Started by Bret Cahill in sci.electronics.basics1 year ago 5 replies

I always wondered why you couldn't do this: http://nextbigfuture.com/2015/09/solar-cells-will-be-made-obsolete-by-3d.html

I always wondered why you couldn't do this: http://nextbigfuture.com/2015/09/solar-cells-will-be-made-obsolete-by-3d.html


Paparazzi drones

Started by Roger Dewhurst in sci.electronics.basics3 years ago 11 replies

I suspect that little more than a dish antenna and a spark plug is required to over-ride the radio control of these things. The use of these will...

I suspect that little more than a dish antenna and a spark plug is required to over-ride the radio control of these things. The use of these will piss off nearby TV users but not as much as a shotgun will piss off the police. Comment please.


When we listen to the radio ?

Started by mowhoong in sci.electronics.basics6 years ago 1 reply

I would greatly appreciate if someone can explain to me the need to angle the radio antenna at 45 degree for FM and 90 degree for AM or SW...

I would greatly appreciate if someone can explain to me the need to angle the radio antenna at 45 degree for FM and 90 degree for AM or SW mode. Thank you .


1N5819s? Or just a couple of 1N4001s?

Started by Dave in sci.electronics.basics4 years ago 4 replies

I have been wanting to make use of a pair of 1N5819s to protect an RF amplifier I am building from static discharge, should someone touch the...

I have been wanting to make use of a pair of 1N5819s to protect an RF amplifier I am building from static discharge, should someone touch the antenna, but haven't been able to obtain any of these just yet. I DO have some 1N4001s however, and am honestly wondering what advantages the 1N5819s would have over the the more readily available 1N4001s (which are already sitting on my workbench....


I need an Arnold Schwarzenegger plug

Started by Anonymous in sci.electronics.basics6 years ago 15 replies

I'm installing an antenna system for my tv. Using a coax splitter, it says in the instructions that if there are any unused connectors on...

I'm installing an antenna system for my tv. Using a coax splitter, it says in the instructions that if there are any unused connectors on the splitter, I need to install a Terminator. I guess that means I need to get a plug from Arnold Schwarzenegger. Does he sell them on rbay, or do I need to meet him in person to get one?