Newest Questions
4,999 questions
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Can an isolation transformer be considered a balun / Can you feed dipole with isolation transformer
I'm trying to wrap my head around a concept of unbalanced and balanced transmission lines, baluns, ununs etc. to properly understand how to feed symmetrical (e.g. dipole) antennas.
Currently, i'm ...
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103
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Limiting Frequency for Alinco DJ-VX50
With my Alinco DJ-VX50 which supports frequencies 136-174 MHz and 400-470 MHz I am trying to limit the frequencies between 144-146 Mhz and 434-438 MHz in VFO mode.
For this I used RT System's ...
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0
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1
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154
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GNU Radio block selection window is missing!
I am trying to use Gnuradio but am unable to add new blocks after "find blocks" (blue magnifier icon) button of Gnuradio stopped functioning. I can execute flowgraphs but can't use find ...
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1
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76
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Eliminating the ground: two back to back helicals
Do we get any other benefits aside from the obvious by replacing the big ground pour with another identical helical antenna ? Normal mode operation, not axial, eg. this one
Expecting the radiation ...
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2
votes
4
answers
203
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Software to decode Morse transmissions including explanation of abbreviations (like Q codes)
I am not very good at decoding Morse transmissions. Therefore I am looking for a software assist me. The software should work in real time.
Supported morse codes:
regular morse codes (like A, B, C, .....
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2
votes
1
answer
179
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Help Identify What This Balun Is Please?
I am trying to identify this balun, could someone please help because I have no idea - See picture below.
Is from a triple dipole wire antenna with a resistor pack - See link to more pictures.
Antenna ...
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97
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Any need for a matching network with a proper balun in place?
With a customized balun between a balanced antenna and an unbalanced receiver port, does a pi/tee matching network make any sense - Why?
Found this paper saying the matching network can be merged ...
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2
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100
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Receiving a Distant AM Signal on a Shared Frequency
What are the technical challenges and potential solutions for receiving an AM signal on 950 kHz from a distant country when there is local interference on the same frequency?
Using equipment such as ...
- 109
3
votes
2
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168
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Antenna tuning with a SDR
Was thinking about tuning my PCB trace / helical ISM bands antenna inside a device I am building by continuously emitting CW and looking at received dB level in GQRX or any other software; then swap ...
- 287
-1
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2
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143
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How to calibrate Nanovna for measuring simple wire without grounding?
I got lastly an antenna analyzer, Nanovna. I can calibrate it without problems for testing frequencies. The antenna for testing, is simply a wire for 20cm. I plug it into the middle space of the input ...
user24106
3
votes
3
answers
283
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In software circularly polarization of antennas
I have an RSPduo which has true diversity capability.
Now my question is whether or not I can use this diversity feature to select the optimal amplitude and phase contribution of the horizontal and ...
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4
votes
2
answers
445
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How does FM preemphasis interact with maximum deviation?
I'm trying to design a broadcast stereo FM transmitter in GNU Radio and I'm running against an issue. After preemphasis is applied using the built-in "FM Preemphasis" block, the amplitude of ...
- 151
2
votes
1
answer
55
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What information do I use for PHASEPAT?
What phase and gain information from the nec output do I use as input for PHASEPAT32.
I am dabbling with designing dish feeds and found a great programme by W1GHZ that computes the illumination ...
- 165
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1
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150
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What kind of "balun" or "choke" or device is this? (Picture)
The image suggests that this is called a "1:1 current balun" but I'm not sure that (a) it actually is a true balun and (b) that it's a current balun at all. Also notable is that it doesn't ...
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109
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Passive repeater for metal hangar at airport
I'm looking for a fix to an airport radio communication issue. I have an all-metal hangar and have no communication with tower from inside it.
One side of the hangar has line-of-sight with the tower ...
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