149:, with passband widths of 250 Hz, 500 Hz (for CW), or 1.8 kHz (for SSB). These narrow filters require that the receiver uses a first IF well below
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electronics. It blocks strong signals outside the receive channel which can overload following
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79:("buzz") even if the overload occurred on frequencies whose signal is not heard directly.
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filter, all of which allow a much tighter filtering curve than a typical roofing filter.
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signals, a roofing filter is required that gives a smaller passband appropriate to the
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determined by the roofing filter passband, but instead by a follow-on
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28:
190:"HF-band radio receiver design based on digital signal processing"
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59:(which normally contains an amplifier) to limit the first
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of the received signal. It is often used at a high first
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171:– an external device that serves a similar function
90:filter types, with a passband for general purpose
218:
129:For more demanding uses like listening to weak
187:
188:Coy, R.J.; Smith, C.N.; Smith, P.R. (1992).
55:is usually found after the first receiver
165:– category that includes roofing filters
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153:range, perhaps 9 or 11 MHz.
13:
14:
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67:. It prevents overloading later
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20:is a type of filter used in a
1:
242:Wireless tuning and filtering
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94:reception of about 6–20
82:Roofing filters are usually
7:
156:
31:in the early stages of the
10:
258:
71:stages, which would cause
46:
61:intermediate frequency
208:10.1049/ecej:19920016
145:stage above 40
106:). The receiver's
75:("distortion") or
227:Radio electronics
120:mechanical filter
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237:Receiver (radio)
232:Radio technology
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27:that limits the
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163:Bandpass filter
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92:shortwave radio
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116:crystal filter
53:roofing filter
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25:radio receiver
18:roofing filter
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63:(IF) stage's
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73:nonlinearity
52:
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17:
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169:Preselector
221:Categories
176:References
202:(2): 83.
108:bandwidth
69:amplifier
37:amplifier
157:See also
77:clipping
65:passband
43:stages.
33:receiver
29:passband
88:ceramic
84:crystal
47:Purpose
122:, or
98:(for
57:mixer
41:mixer
139:mode
51:The
39:and
204:doi
151:VHF
147:MHz
135:SSB
133:or
124:DSP
112:not
110:is
104:NFM
96:kHz
86:or
223::
198:.
192:.
143:IF
131:CW
118:,
100:AM
22:HF
16:A
210:.
206::
200:4
102:–
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