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wrote: I too have found a tuner will bring up the signal strength for Radio Flyspeck to a nice level. But it will also being up static and other signals on the same frequency in proportion. I don't know how a tuner could select one signal and lift it above all the other competing transmissions on the same frequency. Transmit is of course a whole 'nuther ballgame. And no, transmit in not a whole 'nuther ballgame. The same properties apply to a transmitted signal as it does to a received signal. It's physics. Proper transfer is proper transfer, no matter which way one tries to figure it. dxAce Michigan USA http://www.iserv.net/~n8kdv/dxpage.htm |
MK,
The 'tuner' simply "Optimizes" the MATCH between the Receiver and/or Transmitter and the Antenna and Feed-Line; since most 'tuners' are near the Receiver and/or Transmitter. Both Signal and Noise are transfered equally. For 'noise reduction' look to modifying your Antenna, Feed-Line and Ground [System] to maintain or improve your signal levels; and reduce your noise levels. .. kisap ~ RHF .. .. |
The issue, or question is whether an antena tuner can selectively
increase one signal within the mishmash of other stuff you are hearing. If you receiver is hearing an ambient noise level that is above the internally noise floor within the receiver then an antenna tuner will only bring that ambient noise leveI up. If you were hearing Radio Fly Speck against a background of static and weaker stations, then adjusting an antenna tuner will increase the signal strength of everything including RFS. It won't magically lift just that single station from the mud. Said another way it isn't possible for a tuner change the difference in signal strength between the desired signal and all the other signals that are competing for your ear on the same frequency. I've tried both MFJ and Grove tuners and the end results were the same. Tuners can be fun if you want to twiddle some knobs. |
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The issue, or question is whether an antena tuner can selectively
increase one signal within the mishmash of other stuff you are hearing. If you receiver is hearing an ambient noise level that is above the internally noise floor within the receiver then an antenna tuner will only bring that ambient noise leveI up. If you were hearing Radio Fly Speck against a background of static and weaker stations, then adjusting an antenna tuner will increase the signal strength of everything including RFS. It won't magically lift just that single station from the mud. Said another way it isn't possible for a tuner change the difference in signal strength between the desired signal and all the other signals that are competing for your ear on the same frequency. I've tried both MFJ and Grove tuners and the end results were the same. Tuners can be fun if you want to twiddle some knobs. |
In article .com,
wrote: The issue, or question is whether an antena tuner can selectively increase one signal within the mishmash of other stuff you are hearing. If you receiver is hearing an ambient noise level that is above the internally noise floor within the receiver then an antenna tuner will only bring that ambient noise leveI up. If you were hearing Radio Fly Speck against a background of static and weaker stations, then adjusting an antenna tuner will increase the signal strength of everything including RFS. It won't magically lift just that single station from the mud. But if some of that noise is intermod in your receiver because of nearby strong signals, a preselector may help. A better receiver will, too. Said another way it isn't possible for a tuner change the difference in signal strength between the desired signal and all the other signals that are competing for your ear on the same frequency. I've tried both MFJ and Grove tuners and the end results were the same. Tuners can be fun if you want to twiddle some knobs. I've got a Grove minituner-tun3, and it's useless above about 2 MHz with a 60 foot or so random wire. But it's the only way to get anything on that wire below 500 kHz. So it's real function seems to be matching a short (relative to the signal's wavelength) high impedance antenna to the receiver's 50 ohm input. Mark Zenier Washington State resident |
You've missed the point, as I stated earlier! I use an antenna tuner also. An old Johnson Matchbox. Yes, it indeed will raise up a very week signal which may not even be audible without a tuner. What is occurring is that the tuner will facilitate the transfer of energy from a large impedance (Z) mismatch between the antenna and the receiver when the receiver is tuned far off from the antenna's resonance frequency. The drawback is that you will have to "tune" the tuner each time you change bands. It has nothing to do with static and noise. The tuner will simply optimize the signal transfer , including noise, between the antenna/feedline and receiver. Sometimes this is all that may be required to "hear" the signal which otherwise would be completely lost from the large impedance mismatch. |
If you receiver is hearing an ambient noise level that is above the
internally noise floor within the receiver then an antenna tuner will only bring that ambient noise leveI up. True. If you were hearing Radio Fly Speck against a background of static and weaker stations, then adjusting an antenna tuner will increase the signal strength of everything including RFS. It won't magically lift just that single station from the mud. True. Said another way it isn't possible for a tuner change the difference in signal strength between the desired signal and all the other signals that are competing for your ear on the same frequency. True. However you are missing one more possibility. That is the impedance mismatch between the antenna and receiver is so great that you cannot hear Radio Fly Speck at all. This impedance mismatch is akin to placing an attenuator in-line with your feedline. In which case the tuner will "tune out" the loses caused by the mismatch and allow Radio Fly Speck to rise above the receiver's noise level. Including the static crashes to of course. But there you are - Fly Speck Radio becomes audible. Works for me! |
tianli wrote: You've missed the point, as I stated earlier! I use an antenna tuner also. An old Johnson Matchbox. Yes, it indeed will raise up a very week signal which may not even be audible without a tuner. What is occurring is that the tuner will facilitate the transfer of energy from a large impedance (Z) mismatch between the antenna and the receiver when the receiver is tuned far off from the antenna's resonance frequency. The drawback is that you will have to "tune" the tuner each time you change bands. It has nothing to do with static and noise. The tuner will simply optimize the signal transfer , including noise, between the antenna/feedline and receiver. Sometimes this is all that may be required to "hear" the signal which otherwise would be completely lost from the large impedance mismatch. Yep, you got it! dxAce Michigan USA |
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