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Antenna
Sci.Electronics.Basics is a worldwide Usenet news group that is used to discuss basic electronics questions.
We found 189 threads matching "antenna"
You are looking at page 1 of 5.
The most relevant threads are listed first
AM/FM tuner, cannot get AM stations?
Robert Blass - 2008-10-06 10:26:00
I have this AM/FM tuner, bought about 10 years ago. I tried connecting
an AM antenna to it. All it does is make a LOUD humming noise. Is
there some configuration I need to make the AM side of the antenna
work properly?
It has [3] places to put wire that attaches to your antenna. The FM
antenn...
Need circuit for antenna up from Sirius radio
2007-07-14 13:16:00
I need a circuit that knows when the power is on at my Sirius Stratus
radio to tell the antenna to go or stay up.
Problem- my current auto radio has an aux input which I can use for my
satelite radio. Great direct connection.
The problem is that when I set the auto radio for aux the antenna goes...Re: DAB antenna.
Jasen Betts - 2009-04-08 07:34:00
On 2009-04-07, ian field wrote:
> These radios typically have a length of wire dangling out of the back for an
> antenna, is this just a random length of wire in the hope of catching some
> signal or do the manufacturers cut it to a specific tuned length?
givem the wid range of frequen...Crystal Radio Questions
Joe - 2009-07-20 03:07:00
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 on...Replacing a headphone cord antenna with with an external one: how to do it?
Tron - 2006-09-16 20:49:00
I have a portable radio that uses the headphone cord as the antenna. The
radio's reception is very sensitive to movement of the headphone cord. I
want to build a plug-in device so that a telescopic antenna will replace
the antenna function of the headphone cord. The headphone will connect
to the...Generating Power through Induction with a HAM radio Antenna
Aaron S - 2007-03-06 07:00:00
Is it possble to use an inductor with a stepdown transformer to generate
power by using the power ouput of a ham radio through it's antenna? My
friend states his antenna is a 40Watt'er. If I can, about how much power
can i expect to gather using a n inductor.
...radio reception oddity
RichD - 2009-06-18 18:26:00
I have an armband digital FM radio, for running.
The earphone cord is the antenna.
Reception is very sensitive to antenna orientation,
unsurprisingly. (a problem as I circle a track)
It's not the signal strength so much, but the noise
level varies greatly.
Anyhow, here's my question: the ...Distributed capacitance effects inductor Q?
Bill Bowden - 2007-04-29 00:41:00
Does anyone know why the distributed winding capacitance of a loop
antenna, or any inductor, degrades the efficiency?
It would seem that a loop antenna with 100pF of winding capacitance in
parallel with a external capacitor of 200pF would resonate at the
same frequency as a antenna with no wi...Re: Choice of a frequency and antenna for a wireless sensor
Tom Biasi - 2008-12-28 11:42:00
"vic" wrote in message
news:49579caa$0$18986$426a34cc@news.free.fr...
> Hi,
>
> I'm currently designing a wireless weather station/generic sensor system
> (I know it can be bought for a fraction of what the components and time
> will cost me, but I'm doing it because it is fun.). ...Re: Connecting Digital Converter Box to an old TV
Jamie - 2008-12-07 20:20:00
Rattler wrote:
> I admit it, I don't get it. Digitally illiterate. I don't know the
> difference between an ohm and a mho.
>
> I have this TV I bought in 1975, RCA XL-100. Still works, why junk it?
> Uses a remote control that operates on no batteries, just ultrasound,
> I think. Cool.
...2 Transistor AM Radio
Dave.H - 2008-02-05 05:11:00
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 ...Re: 300 ohm to 75 ohm impedance matching "transformer"
Rich Grise - 2008-05-22 15:09:00
On Thu, 22 May 2008 00:30:28 -0700, Joe wrote:
> 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...Why is a Theremin volume antenna a loop?
Kasterborus - 2008-03-11 16:20:00
Does anyone know why the volume antenna on a Theremin is nearly always
a loop? Wouldn't a horizontal straight bar work as well?
Dave
...Antena question
Claude - 2008-04-14 13:26:00
Greetings dudes.
I am building a 3 volt FM transmitter, just strong enough to scare the
bejesus out of the wife when she is listening to her crappy music :o)
The project suggests using a half wave antenna instead of a single wire. I
understand the use of a 50 Ohm coax , it is the wire the...Wireless RF
Jon Slaughter - 2009-11-03 10:25:00
Are pretty much all modern transceiver IC's the same as far as the circuit?
All the ones I have looked at recently use a crystal and some passives for
the antenna which I assume are for impedance/resonance matching?
Obviously the IC capabilities are different and the impedance matching
tech...VSWR doesn't matter?
billcalley - 2007-03-11 21:08:00
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...VSWR doesn't matter? But how about "mismatch loss"?
billcalley - 2007-03-29 16:10:00
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" ...Wifi antenna plug std: Apple Airport, etc
Dominic-Luc Webb - 2006-10-24 06:53:00
Can anyone tell me if there is a standard for WiFi antenna
plugs/contacts? For instance, Apple laptops have the so-called
Airport card, which has a miniature BNC-like adapter. I wish
to know what kind of contacts WiFi antennas typically use,
and with luck, maybe someone even knows impedence va...Antenna power injector and splitter
Captain Dondo - 2007-04-05 09:26:00
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
i...Re: antenna grounding
Rich Grise - 2009-11-13 14:09:00
On Fri, 13 Nov 2009 10:09:49 -0600, jfisher864 wrote:
> I'm about to get of the cable tv merry go round and am installing an
> antenna on my roof. The problem is that the service entrance for my coax
> is on the side of the house and the most direct downward line for the
> grounding wire ...Re: reflected ir receiver design
G K - 2006-10-14 03:34:00
On Oct 12, 11:59 am, "alex" wrote:
> hi all im trying to make a ir transmitter and a receiver for receiving
> reflected ir from an obstacles .Can any one suggest some starting tips
> and future problems,
for the above if u confidential about your circuit then take special
measurements...what enclosure to use ?
Archimedes - 2008-03-14 00:10:00
Hi All
I built a super-regen radio and want to enclose this in a box of some
sort. I have two options -
1. Plastic box
2. Aluminium Box
Now I want to listen to this radio when I am sitting next to my
computer. I know that the best option is to use the aluminium box as
it provides the be...MIMO and AAS
karthikbalaguru - 2007-10-01 17:03:00
Hi,
What is the difference between multiple input multiple output (MIMO)
system and
Adaptive antenna system (AAS) ?
I find the WiMAX uses MIMO and AAS . But, the definition appears to be
the same.
Both the systems are exploiting more than one antenna to improve the
coverage and the sys...BASIC
din25390 - 2009-01-29 07:10:00
1.what is diff between log base "e" &log base "10"?
2. why we cant transmit all cabel channels in antenna?
3.cable operators use dish antenna to get the channels &
why india can own a dish & transmit the channels?
4.how dd channel is transmitted all over india & why not for other
countries?
...Re: Antennea
2008-10-06 13:54:00
On Mon, 6 Oct 2008, Wayne wrote:
> Hello,
>
> I am all but finished completing a copy of the radio shown at the link
> below. The antennae required is described in the Description paragraph.
>
> I would like to take and show it to a friend of mine who would be
> interested in it. It ...Re: Trying to bias a JFET...
whit3rd - 2009-11-22 16:15:00
On Nov 22, 7:40=A0am, "Dave" wrote:
>
> JFET in question is an NTE451, and I am wanting to bias it in the active
> region, not at pinchoff (I now realize). =A0It is intended as a small-sig=
nal
> amplifier, in the front end of a "hearing aid" for my shortwave radio.
Two beneficial asp...Litz wire for AM ferrite Rod Antenna?
Bill Bowden - 2007-03-24 00:50:00
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
...Re: radio transmissions at the frequency of light
John Larkin - 2007-01-16 22:12:00
On 16 Jan 2007 18:39:27 -0800, "jjoensuu" wrote:
> Hi all,
>
> just wanted to ask, what would be the problems that make it
> difficult/impossible to build a radio that transmits at the frequency
> of visible light (between 430 and 750 Tera Hz)?
>
Radio waves at the frequency of light...Re: DAB antenna.
ian field - 2009-04-08 11:00:00
"Tom Biasi" wrote in message
news:49dbe7fb$0$22521$607ed4bc@cv.net...
>
> "ian field" wrote in message
> news:ClMCl.2$bq4.1@newsfe29.ams2...
> >
> > "Tom Biasi" wrote in message
> > news:49db8c99$0$22510$607ed4bc@cv.net...
> > >
> > > "ian field" wrote in message
...Re: Homebrew radar?
danand - 2007-12-15 18:00:00
Sorry if this is a bit late answer but here it is anyway.
A Slovenian chap - S53MV, build a 4GHz altimeter.
This is a small radar that tells you the distance to objects in front of
the antenna. No fancy sweeps etc, just a raw plot on a cheapo LCD.
http://lea.hamradio.si/~s53mv/radalt/radalt....Re: Waveguide
Gareth - 2007-03-25 16:13:00
Roger Dewhurst wrote:
> "Gareth" wrote in message
> news:yKadnaqxyN4lxJvbRVnyvQA@brightview.com...
> > Roger Dewhurst wrote:
> > > I want to feed a single pulse of, let us say, 10 to 100 microseconds
> > > duration, into a short length of waveguide and detect that pulse upto
> 1000
>...Re: An RF question
Jon Slaughter - 2007-02-09 21:12:00
"Eric R Snow" wrote in message
news:345qs2pv50vj25k7d4efl32gjch10kneat@4ax.com...
> After listening to the RF interference radiated from a PDA on a
> portable radio it got me to thinking. When pulses are sent down a wire
> the wire will radiate RF. A lamp cord plugged into the wall radi...Re: 50 ohm load
John Fields - 2007-07-24 17:26:00
On Tue, 24 Jul 2007 01:36:13 -0700, sperelat@hanmail.net wrote:
> I'm studying op-amp circuit combined with rf mixer.
> While I was reading articles on the circuit,I found that the term like
> "50 ohm load"
> or "50 ohm ( )" occurs frequently.
> I also remember that one of the input optio...Use a Ground or Lightning Rod?
W. eWatson - 2009-06-10 15:00:00
Last week we had a terrific lightning storm, and it hit the TV mast, rotor,
and antenna. That was witnessed by a neighbor. Although I had turned off a
lot of computer equipment and unplugged quite a bit of it, I was on a trip
but my wife was here, it knocked out the internet card on this compu...? on twin-lead...
Dave - 2008-09-05 16:45:00
I have an *old* VHF/UHF passive TV antenna with a 12-position switch that
used to help with TV reception. Problem is, it is so old that the
insulation on some of the twin-lead has become brittle and broken away,
leaving the wires exposed, one of which broke. Just for a lark, I am
wanting t...Re: RF stage question
Bill Bowden - 2006-11-24 21:58:00
ec wrote:
> Hi
> I want to build an AM radio receiver by myself.
>
> My question is: what is the right amplification that the first RF amp stage
> should have ?
>
> Is there any rule ?
>
> Thanks
> ec
If you want to build a superhet receiver with a tuned RF stage, you
will ne...Re: Wanted: Capstone Project Suggestions
John Woodgate - 2006-09-13 05:38:00
In message , dated Tue, 12
Sep 2006, Rich Grise writes
> > By the end of the semester, I need to turn in a capstone design
> > project. I'm looking for ideas for a project that will be challenging.
> >
>
> Start with a crystal set, then add a transistor, then add another
> transis...coax stub and series section line transformers
kell - 2007-06-16 00:25:00
Looking at this wifi antenna design:
http://wireless.gumph.org/articles/homemadeomni.html
got me thinking of a series of articles Jerry Sevick wrote for CQ
magazine about twenty years ago showing how to do impedance-matching
using pieces of coax cut and soldered together, often reversing the
ce...www.cellphonepartszone.com sell:palmOne Treo 650 new housing
jimma - 2007-09-21 22:56:00
www.cellphonepartszone.com is a leader of oem PDA accessories,such as
PalmOne accessories:
Palm Treo 270 housing,Palm Treo 300 housing,Palm Treo 600 housing,Palm
Treo 650 housing,
Palm Treo 680 housing,Palm Treo 700w housing,Palm Treo 700wx
Hosuing,Palm Treo 700p housing,
Palm Treo 750 Housing...Re: HowTo Wire Radio Speakers to Audio-In on TV-VCR Combo
Jasen Betts - 2007-09-02 05:15:00
On 2007-09-01, 911 Was An Inside Job wrote:
>
> I am down but not out -- all the way -- I had this entire thing setup in my
> bedroom with a combo cassette-DVD audio box outputs to a stack of an old
> Marantz stereo amp with TV sending video to a VCR which also records the AM
> radio...