|
Tech Square Technical and speculative discussion of amps, cables and other topics. |
|
|
|
Tech Square Technical and speculative discussion of amps, cables and other topics. |
|
In Reply to: check your earthing and connections as well asthe screening of your IC's posted by chris_w on June 6, 2005 at 16:12:22:
A normal short wave antenna is 4-5 meters long. There is something called a 1/4 wave antennna which will receive the same signal at a lower level. A short wave antenna is a dipole antenna connected at the one end by a resistor and at the other end by the input of the tuner.A phono cable is usually 1-1.25 meters long, the length of a 1/4 wave antenna, is terminated by a resistor, the cartridge and inputs to a very high amplification factor amplifier, the phono input being many 1000s times amplification with a given input capacitance which will correlate with a given short wave radio frequency. Thus all the conditions are met to build a short wave radio receiver.
Not all setups will in fact receive something. Maybe there is nothing being sent to that area, it is too far away, the signal is too weak or the actual input capacitance (where the preamp it "tuned to") is wrong. But when the conditions are right the result is radio Moscow or Madrid or Morroco (just a few colourful examples).
The way to prevent this is to have proper value RF blocking caps on the inputs of the phono section which will eliminate this.
This post is made possible by the generous support of people like you and our sponsors:
Follow Ups
- it is not a ground or shield problem - garth 18:35:28 06/06/05 (1)
- Re: it is not a ground or shield problem - chris_w 13:00:43 06/07/05 (0)
Top of Page ]
[ Contact Us ]
[ Support/Wish List ]
[ Copyright © 2025, Audio Asylum, all rights reserved ]
