# All Questions

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69 views

### How do I trigger hotkeys on AnyTone 878UV?

I've read the manual twice, and watched programming guide videos on youtube, but while I can program hotkey 1-6 just fine, I can't find how to actually trigger them. I found how to trigger the "Fun ...
29 views

### How to program a trunked System into radioshack pro 651?

am new to this forum, so tell me if this question is out of place - as it concerns a scanner. I have an old radioshack pro-651 (same model as pro 106, and whistler 1040) that I am trying to program ...
39 views

### how do you tune blind? [duplicate]

I'm about to axe the display on my radio in pursuit of cheapness. However, I need to know, how do blind hams with older rigs tune to a station?
125 views

### How do I alter the low power setting on a QYT KT-8900

There is no difference between the High and Low power settings. Both being around 25 watts. Is there an internal adjustment or do I have to re-program the radio?
17 views

### What configuration of a BJT IF amp can I use for a superhet receiver?

I am making a superhet SSB CW receiver with a crystal filter on the input after the mixer. Do I have to use IF transformers as the coupling method? Or can I use capacitor coupling with resistors as ...
38 views

### How to calculate combined power of two amplifiers

If I have 1 amplifier running at 95%, and another identical one running at 60%, how may I calculate the output power of the combiner? I believe this combiner is a "Magic T", but if there is a ...
36 views

### Which specification is exceeded for a transistor output stage in a transmitter when there is a high SWR? [duplicate]

For a transmitter which has an output stage which uses one final output power transistor, when the SWR is high, it's common knowledge it seems that the output transistor can get hot and fail due to ...
228 views

I'm trying to understand way which Frequency Mod block works in gnuradio. According to my intuition there should be at least two inputs: signal to encode base frequency / carrier signal Instead ...
67 views

### Is there any 2.4 GHz tuner ICs for SDR receivers?

I have a hackrf one sdr, which i use to transmit test signals. I am using ISM bands, so I can omit transmitting my callsign, checking correct sub band (FM, digital) etc. And one of most interesting ...
21 views

### How are Amateur Radio Callsigns created? [duplicate]

When I took the Amateur Radio Technician Exam, I was given a callsign upon passing the test. How does the FCC create that callsign? Is it completely random or do the letters and numbers have meaning?
63 views

### 50 Ohm Active Termination

I'm looking for a circuit topology that has unity gain, a 50 Ohm resistive input impedance, a 50 Ohm resistive output impedance, and here is the kicker, at least 60 dBm OIP3 over a 2 - 30 MHz HF ...
48 views

### Center-loaded vertical, high SWR at lower frequencies

I built a center-ish loaded coil-shortened vertical. The lower radiator is 3 meters, then the coil, then 5M more radiator, like this (Early prototype with shorter radiators and no covers for the coil ...
65 views

### Text transfer From/To SDR

I bought a hackrf one and I don't think it works. Before I return it can someone show me a grc flowchart on how to send text or a text file from a hackrf to a rtlsdr? I have been told you can do it. ...
29 views

### UHF cubical quad VNA analysis interpretation (part2)

This is the follow up to: UHF cubical quad VNA analysis interpretation This is a S21 and S31 analysis of an oversized 385 Mhz 50 Ohm to 90 Ohm balun between 100 Mhz and 600 Mhz I tested phase ...
48 views

### Gnuradio loopback flowgraph is not working

I found the below uhd_two_tone_loopback example (which is one of the gnuradio provided examples) and I am trying to run it, it runs but I can't receive signal. EDIT: I mean when I run the program I ...
50 views

### What the difference preamble and access code?

gnuradio packetize using access code for start sync packet, but another example attach the preamblee, so what the differences preamble and access code ?
47 views

### A gnuradio program that can output some arbitrary waveform read from a file containing I/Q values

I am trying to figure out how to create a gnuradio program that can output some arbitrary waveform read from a file containing I/Q values. I would highly appreciate any guidance in this topic. Simple ...
69 views

### Can I make a simple Tx/Rx antenna (Radio System) which will receive signal from BTS and broadcast/transmit it, and vice versa? [duplicate]

Consider a situation as below. I am stay in a farm field, which my house is 9.4km distance from the nearest and the only one BTS (Base Transceiver System), a cellular antenna for transmit and receive ...
174 views

### No module named 'analog_swig' [duplicate]

I know guys you gonna tell me tat there is something wrong about GnuRadio or Pybombs installation. Well, this is my third time during the past 48 hours I reformat the OS of my mini pc fitlet2 mint ...
124 views

### No module named _osmosdr_swig [duplicate]

I am trying to run GnuRadio python code in my python web server and got the "No module named _osmosdr_swig" error. Please, what is the cause for this error? I know it sounds like so obvious that I ...
116 views

### Troubleshooting ICOM PS15 Power Supply

I got a power-supply gifted by my friend. When I powered ON, the main (120V) FUSE blows up. I started by disconnecting the transformer from the control circuit and powered ON. This time the fuse is ...
991 views

### Yaesu FT-450D How to troubleshoot problems with the Keyer jack

I am a big fan of the Yaesu FT-450D but there is one really frustrating quirk that took some time to figure out. The FT-450 has a keyer jack on the front panel. It is the lower of two 1/8 inch ...
280 views

### Yaesu FT-8800 + TinyTrak4

I´m using the Yaesu FT-8800 with the Byonics TinyTrak4 as APRS tracker in my car. There is a menu setting to bind the data jack to a VFO, but transmission is always done using main VFO. So if I talk ...
116 views

### Separated audio and ptt

how important and why is the audio, ptt ev. CAT interface separation from PC? I saw solutions with separating transformers and PTT, but directly connected CAT. Does it make sense? And is there any ...
153 views

### Using 'amodem' to transfer digitally using a UV5R

I reviewed docs for amodem, and it looks like I can send files and possibly other things with this. I should only need to prep my computer as per the doc and set VOX correctly. Does anyone have ...
157 views

### Feed line direction for Quad antenna

I am currently getting my EE degree, and I'm trying to build my first antenna for a weather balloon. I understand with a dipole, you want the feed line perpendicular to the antenna for at least l/4, ...
76 views

### Transmit data without line of sight - Legal, fast, cheap and error corrected

I go camping to France every year. There is a wifi station at 200 metres from where I camp, but I don't have a direct line of sight (it's on a slope). I can put a shoebox at the base station, but I ...
65 views

### Power Density Function

A radio receiver needs $1 \textrm{ nW}/\textrm{m}^2$ of power density function, how far away from a 1-watt point source will it continue to work?
66 views

### How does wireless communication like wifi connect to different clients? [closed]

Does wireless communications like wifi, where different clients get different data, use different frequencies for each client? Or do they use the same frequency, but with time-divison multiplexing and ...
114 views

### Why does the HamQSL website say the 40m band is fair and the 20m band is poor during the day?

http://www.hamqsl.com/solar.html Why is 40m shown as "fair" while 20m is "poor" during the day. Shouldn't 7 MHz be getting absorbed by the D-layer more than 14 MHz?
126 views

### Is a lightning arrestor required with a ground rod?

I am building an out building ham shack. I am planning to install an 8 foot ground rod for the antenna. Does the radio require an additional ground to the rod as well or do I need to install a ...
1k views

### Basic QSO format? [closed]

What is the basic format for a QSO? How should I answer to "CQ", how do I know when it is my turn to answer, when should I give the report, etc.?
109 views

### Why can't we use a simple wire for receiving 2.4 GHz signals?

I wanted to build a small drone of my own as a hobby project. My old drones were broken so I wanted to salvage as much as I could to build a small indoor one. I wanted to use an Arduino, however, I am ...
286 views

### Is it legal to transmit scrambled or encrypted voice via SSB on ham bands?

And also, can anyone tell me how? Using Arduino or any other way ...
171 views

### At what watt level is it safe to use metal strips for modulated signals?

In my working design, I have a transceiver TX on low power; Then boost it in a preamp phase in the back. The way I'm sending the signals (RX and TX) through the radio is by a network of 1/8 to 1/4 ...
143 views

### Transmit data over HF signal 10,000km away [closed]

I would like to transmit trinary data (-1,0,+1) on 20-30m wave to be received 10,000km away. From Europe to US. My first thought was this: https://www.researchgate.net/figure/Burst-modulation-mode-f-...
75 views

### What is an optimal amplifier arrangement with ham radios?

As I am settling on a design for a radio I need to figure out one thing: Should I modulate on low power and boost it up with a post amp, or should I go on full power right out of the gate?
153 views

### Are some frequencies regulated ? if not which ones are free to use? [closed]

I could be wrong on this one, but I understand that in some countries, radio frequencies are regulated, with licences being require to OPERATE on the the networks. As mentioned most channels are ...
69 views

### Recommended Books For AM/FM (especially AM) Radio Design

I am trying to gain a better grasp of how to build an AM radio receiver. Can you direct me to some books (or other information) that will help?
55 views

### Skin effect for a modified antenna with a high frequency pulsed DC

A direct current will be interrupted by a high frequency switch. It seems , that in a wire, connected to the source (the antenna rod), instead of pushed back- and forwards electrons, the electrons get ...
3k views

### Is it legal to use BAOFENG BF-888S 16-CH 400~470MHz 5W Walkie Talkie in India?

If not, what can be used as mode of communication for group trekking. It is very urgent and important Please suggest some better options for walkie talkies
980 views

### Call dialer sound on start/end of transmission?

I have a friend who has a HAM license and a ham radio, and when he first pushes the button to talk, I hear a "call dialer" sound. It sound like someone is dialing a phone number in. The tone starts in ...
42 views

### remote push to talk or process background sound out

how to set up remote push to talk I work in an extremely really noisy area headset connected to some radio but others can do remote push to talk and hear me answer I need my hand for working what ...
1k views

### I want to wire a cigarette lighter plug to the back of my uhf radio to make it portable can I do this

i have a uhf radio I want to wire a cigarette lighter plug to so it can be removed from the car and be put into another car is the possible or not plz help me with this matter It is just a standed ...
405 views

### Choosing a type of array antenna

I want to design a steerable beam array antenna which has 15 dBi directivity using uniform fed infinitesimal dipole elements at 1GHz frequency occupying physical aperture. Considering that phases of ...
123 views

### How would I calculate aperture efficiency for an antenna?

How to calculate aperture efficiency for an antenna with the following parameters: Big reflector diameter= 24 mm Gain= 9.265 dbi Frequency= 11.60 GHz
179 views

### Output power curve of an antenna

My approach is that a radio wave is made from zillion of accelerated electrons which emit zillions of photons. Since the current flows in a open circuit, the antenna generator works against something ...
124 views

### Reflection behaviour of the radiation as a function of the used voltage

According all the answers to a question about What is the advantage of making an antenna resonant different lengths of the antenna rod could be tuned to resonance with the antenna generator. You ...