|
Unregistered guest | Hi, I am a TOTAL novice but I had an old receiver (AM/FM) that I wanted to hook up for a cheap system at home. I set it up on a hutch with my TV, cablebox, and DVD player so it would be my media center. I have two problems. One is that I barely get AM. I cant find an antenna anywhere that isnt very expensive. I tried using wire to make my own (based on an article I found somewhere on teh interenet) but my AM is still very bad. Second, my FM has a bit of static. Not too much but when I tested the unit in my garage it was crystal clear. Some things Im pretty sure are suspect in my setup are: A) 2 of 4 Speakers sit right next to TV B) other two speakers about 20 feet away, but the wire runs down my basement and up walls. So I know it crosses over and rests on, in many places, my house electrical wiring. C) Wire to one of the 4 speakers was not long enough so I spliced and connected with a wire-nut D) 2 farther speakers may or may not be in phase (dont know how to check) C) On the hutch where i set all this up, all cables come through the same hole in the back so they all rest and touch behind the unit ina big mess of wires (although Im sure this must be fairly common). (Cable wires, speaker wires, FM antenna, homemade AM antenna, power cords for TV, DVD, receiver, and cable box, AV cables for DVD player) D) The 2 farthest speaker wires go throug a hole in the floor along with a ground that is connect to the back of the receiver. The ground is connected to a water pipe in my basement. E) None of this equipment is expensive or high end. So, which of these matter to my problem of no AM and static on FM. If all, what is the most likely to be the biggest contributor and what can I do to clean this up as best as possible. Any ideas? If so, can you email me at rmathome@yahoo.com. Thanks in advance for any help. |
|
J. Vigne Unregistered guest | Your problem with AM is not uncommon in low priced recievers, most manufacturers put in AM as an afterthought and did not make good reception possible. If you are in need of very good AM get a Tivloi Table Radio ($99 in mono and $159 in stereo) it has the best AM and FM performance of any tuner under $1000 (http://www.tivoliaudio.com/home.php). Otherwise run a single wire antenna as high and as long as you can possibly make it. This needs to run outdooors and should be at least 15-20' in length. If you still have bad AM you can try a stereo shop that has been around for awhile. Just ask if they have a spare AM loop antenna that they will sell you. Most shops aquire a few over the years and will usually give one away. If you still have bad AM get a Tivoli. FM is a tricky item to get good reception due to the wavelength they broadcast. Again many receivers had poor FM capability but if you had decent reception in the garage you probably have to try relocating your antenna. Just move it around your room until you find a quiet spot. There may not be one in that room and that would not be uncommon with FM. But if it was quiet in the garage you can find a place where you can get good reception. Antenna location is the key with FM. A good choice is a roof top TV antenna. Most cities broadcast their FM from the same antennas as they do TV. If you have a TV antenna and get even half way decent TV reception you can get a splitter at Radio Shack that will allow you to use it as your FM antenna. You can also use a pair of TV rabbit ears, they are more directional than a standard folded dipole that is provided with a reciever. Hook it up and rotate it until you get the best reception. Audio cables should never run parallel to AC lines. When they cross they should cross at right angles and then the cables should be at least 2' apart. To check for phase you will need a 9 volt battery. Take you speaker grills off and take the speaker wires off the amp. Touch the two speaker wires of each channel (+ and -), one channel at a time, to the + and - posts of the battery. When the speaker cone moves outward you have the correct polarity. Mark the cables with + and - and reattach them to your system. Unless you have a ground problem you do not need a separate ground for most amps. You may actually introduce noise with the hook up you have made. Cold water pipe grounds are now out of code in almost every city. Unhook the ground wire and see if anything changes in the way of ground noise (60 Hz hum). If not then leave the wire disconnected. If you are going to ground anything at all you should ground to the center screw of your electrical outlet. (This rule does not apply to turnatbles.) This is connected to the house ground and will do the best job of putting all your gear at the same ground potential. |
|
Gold Member Username: John_aPost Number: 2030 Registered: Dec-03 | Thanks for the flag from "Definitions", Jan. I will reply, here. Sorry guys if this is off-topic. Just to say that radio broadcasting is another area where "the switch to digital" has far-reaching pros and cons. It is just like discs; you get no noise, and some would argue, no life. A lot depends on the sampling frequency etc. and the potential is there, with digital, for hi-res (also multi-channel) but many broadcasters opt for low-res ("CD quality" or worse) in favour of conserving bandwidth. And this is an area where the encryption/regionalisation story scares me much more than with discs. You can ship discs around the world, and two fingers (or one) to the "regionalisers". However, your are not allowed to sign up and get a digital broadcasting de-cryption key without having a certain address, a certain method of payment, etc., because of "rights issues". And then, your every reception is logged, and a modem in the receiver reports back periodically to HQ. So a lot of the technical development is going into finding ways of STOPPING unauthorized people from receiving broadcasts. Digital is the way to do it. With analogue, you would have to jam someone's transmitter (when I was young, height of the Cold War, the European AM bands were just full of jamming signals). WIth digital, control is selective to the point of the individual receiver, painless, invisible, unobtrusive, and the broadcasters even deny they are doing it, offering technical bullshit as the reason, if they bother to explain at all. Even the dear old BBC now plays this game, and their technical standards for digital audio are very low. One day soon, everything we can receive will be the "property" of a commercial cartel or a political system. And its consumption will be logged and monitored. Frankly, it scares me. Even George Orwell did not foresee this one. How old I feel. PS and "Public Service" broadcasters are coming increasing under direct, explicit, political control. (I wonder if the Hutton report reached the US. - its result has been to emasculate the Beeb's independent news/current affairs programme, on which the whole story turned, FOR TELLING THE TRUTH). This is really off topic. Sorry. J.V., I think you will appreciate the raw nerve touched. |