Home |
Search |
Today's Posts |
|
Home Repair (alt.home.repair) For all homeowners and DIYers with many experienced tradesmen. Solve your toughest home fix-it problems. |
Reply |
|
LinkBack | Thread Tools | Display Modes |
#1
|
|||
|
|||
OT?: AM stereo receiver hookup
I have a relatively new hi fi stereo reciever. I also have regular
(properly grounded) TV Antenna (because I'm too cheap to afford cable). The reciever has a hookup for an FM Antenna into which I run my regular TV antenna and it works great for FM radio. Now, I'd like to pick up AM stations. For some reason there is a different hookup on the reciever for AM stations. Also, there is an outgoing ground hookup on the back of the reciever which is supposed to be just for AM Antenna ground. I'm curious as to why there are separate antenna hookups for FM and AM, but mostly I just want to know if I can safely and effectively use my regular TV antenna for both FM and AM, ignoring the AM ground because I know the antenna is already properly grounded. Any help? Thanks. |
#2
|
|||
|
|||
"Mak Wilson" wrote in message oups.com... I have a relatively new hi fi stereo reciever. I also have regular (properly grounded) TV Antenna (because I'm too cheap to afford cable). The reciever has a hookup for an FM Antenna into which I run my regular TV antenna and it works great for FM radio. Now, I'd like to pick up AM stations. For some reason there is a different hookup on the reciever for AM stations. Also, there is an outgoing ground hookup on the back of the reciever which is supposed to be just for AM Antenna ground. I'm curious as to why there are separate antenna hookups for FM and AM, but mostly I just want to know if I can safely and effectively use my regular TV antenna for both FM and AM, ignoring the AM ground because I know the antenna is already properly grounded. Any help? Thanks. Antennas have to be designed for the kind of radio frequencies and modulation that are quite different for am and fm. It just so happens that tv and fm signals need very similar antennas, so you can hook up your fm to the tv lead in. You can buy a small desk or sill mounted AM loop antenna that hooks up to the am antenna connections on the back of your receiver. Often stereos have no internal am antenna, as most folks use them for fm, due to better sound, low noise, and stereo reception. Sometimes I have found a separate ground does indeed help reduce interference typical of am reception. |
#3
|
|||
|
|||
the ideal receive antenna will be 1/2 the wavelength of the
radio signal, so: AM .5 -1.6 MHz = 150 meters FM 88-108 MHz = 1.5 meters TV VHF 54-316 MHz = 2.3 - .5 meters an antenna works best if it is "di-pole", two halves, each side half the length above, the antenna wires(2) connect to the middle. a meter is about 3 1/3 feet. your TV antenna is good for FM because FM is sandwiched between TV channels 2 and 13. a tv antenna is really a series of antennas, an array of short, medium, and long "rods" to cover the very wide range needed. AM would require an antenna 250 FEET on each side, which is not real practical. Most folks using an "outside" AM antenna will settle on a wire 50-100 feet long to the "antenna" connector, and as a substitute for the other "half" will connect a good ground connection to the "ground" connector. The ground used to be a water pipe, but since it's now plastic, an 8 ft "ground" rod is driven into the soil near where the "antenna" wire enters the house. At this point it's a great idea to install a "lightning arrestor". Lightning has a real affinity for "long wire" antennas, but it's something you really don't want in your house! AM and FM energies are not compatible on the same wire or cable, that's why there are to sets of connectors. Radio Shack has the wire, insulators, arrestor, and ground rod to do this (or did a year or two back). You will find there are AM radio stations on EVERY frequency on your dial, in fact SEVERAL. Day, eve, night, late night, and early morning you will hear different stations at the same spot on the dial. For some folks, "logging" these stations is a hobby. have fun, (it's good you don't have "short wave" on your receiver ;-) google "short wave listener" -larry / dallas Mak Wilson wrote: I have a relatively new hi fi stereo reciever. I also have regular (properly grounded) TV Antenna (because I'm too cheap to afford cable). The reciever has a hookup for an FM Antenna into which I run my regular TV antenna and it works great for FM radio. Now, I'd like to pick up AM stations. For some reason there is a different hookup on the reciever for AM stations. Also, there is an outgoing ground hookup on the back of the reciever which is supposed to be just for AM Antenna ground. I'm curious as to why there are separate antenna hookups for FM and AM, but mostly I just want to know if I can safely and effectively use my regular TV antenna for both FM and AM, ignoring the AM ground because I know the antenna is already properly grounded. Any help? Thanks. |
#4
|
|||
|
|||
Check the packing box again. Any new sstereo reciever should have come with
an AM loop antenna. (My Onkyo did). Check the manufacurers website and see if they sell one. Crutchfield sells one http://www.crutchfield.com/S-Fni7Kht...rch=am+antenna Antennas need to be designed for the frequencies being recieved. FM signals are between TV Channels 6 and 7 (88 to 108mHz) and a TV antenna works good for them. AM signals are way lower in frequency (.54 to 1.7 mHz) and need a different antenna. Long wire antennas work good for AM signals but almost nobody has the room for a hundred foot piece of wire. So they make loop antennas for AM signals (about cigar box size). TO truly get the best reception of FM signals you need to turn the TV antenna sidewaks.(TV signals are horizantally polarized, FM signals are vertically polarized) but for 99% of the cases a plain old TV antenna, mounted normally will work. "Mak Wilson" wrote in message oups.com... I have a relatively new hi fi stereo reciever. I also have regular (properly grounded) TV Antenna (because I'm too cheap to afford cable). The reciever has a hookup for an FM Antenna into which I run my regular TV antenna and it works great for FM radio. Now, I'd like to pick up AM stations. For some reason there is a different hookup on the reciever for AM stations. Also, there is an outgoing ground hookup on the back of the reciever which is supposed to be just for AM Antenna ground. I'm curious as to why there are separate antenna hookups for FM and AM, but mostly I just want to know if I can safely and effectively use my regular TV antenna for both FM and AM, ignoring the AM ground because I know the antenna is already properly grounded. Any help? Thanks. |
#5
|
|||
|
|||
Rather than worrying about an external antenna, first hook any old
convenient length of wire to the AM terminal and see if you can pick up the stations you want to pick up. If so, you are done. Your car radio(both AM and FM)is making do with a a piece of wire (antenna) that's probably considerably shorter than 5 feet. Mak Wilson wrote: I have a relatively new hi fi stereo reciever. I also have regular (properly grounded) TV Antenna (because I'm too cheap to afford cable). The reciever has a hookup for an FM Antenna into which I run my regular TV antenna and it works great for FM radio. Now, I'd like to pick up AM stations. For some reason there is a different hookup on the reciever for AM stations. Also, there is an outgoing ground hookup on the back of the reciever which is supposed to be just for AM Antenna ground. I'm curious as to why there are separate antenna hookups for FM and AM, but mostly I just want to know if I can safely and effectively use my regular TV antenna for both FM and AM, ignoring the AM ground because I know the antenna is already properly grounded. Any help? Thanks. |
#6
|
|||
|
|||
Thanks for the overflow of intelligent replies. I've read then saved
all this good info. I now realize my reciever DID come with an AM antenna, but I mistook it for a cheapy FM antenna (which I didn't need) and trashed it. Just using a 5 foot piece of wire made a big difference. In fact, going from the TV/FM antenna to the 5 foot wire was a noticable improvement, so I guess you guys know what you're talking about. I'd still like to do better so I'll keep looking around and experimenting. The Crutchfield link offered seems a little expensive, but the only other one I've found so far is Radio Shack, and it really doesn't look like it's made for AM despite the description: http://www.radioshack.com/product.as...t%5Fid=15-1859 Anyway, thanks again. I'll keep working on it. All replies were helpful and appreciated. |
#7
|
|||
|
|||
Mak Wilson wrote:
Radio Shack, and it really doesn't look like it's made for AM despite the description: try this link instead- http://www.radioshack.com/product.as...t%5Fid=278-758 $10.49, but they don't have the arrestor, i guess the $1 "twinlead" arrestor is a thing of the past. check the discount stores that have do it yourself tv stuff for an arrestor. ground the base, and hook the antenna to both terminals. you can make an arrestor, use an old fashion NON-RESISTOR spark plug, ground the body and connect the antenna to the stud. .016 gap works well. -larry / dallas |
Reply |
Thread Tools | Search this Thread |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Forum | |||
Pioneer stereo receiver SX-737 repair book/figures | Electronics Repair | |||
Mitsubishi DA-R45P Stereo Receiver | Electronics Repair | |||
Pioneer Model RX-1190 Stereo Cassette Deck Receiver - NO VOLUME | Electronics Repair | |||
Stereo receiver hit by lightning | Electronics Repair | |||
Kenwood Stereo Receiver KR-5040 problem. | Electronics Repair |