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#1
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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. |
#2
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#3
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![]() 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. |
#4
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![]() 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 |
#5
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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 |
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