# All Questions

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20 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 ...
23 views

### Can't identify old chinese(?) and american radio/telephone

Hi I have searched image banks and googled period radios but I can not identify these old units. I picked them up overseas in SE asia and I got them as projects to teach myself enough to challenge the ...
56 views

### Should I not have “painted” my YAGI?

I have a 5 ele YAGI which, once we can go multi-op portable again in the UK, I shall be taking to the hills with me. The idea being to make it quick and simple to get the dimensions and element ...
37 views

### How to repair my single strand antenna? [migrated]

I have a Roberts Blutune 50 which is generally in good working order, but all it has as an antenna is a piddly wee wire snaking out the back - I reckon it to be about .8mm or thereabouts. ...
702 views

### Beginner listening to a repeater - only hearing one station

This morning I tuned in to a repeater about 12km from me (in the UK). I could hear activity, but from only one station. I could tell that there were other stations using that repeater from the ...
81 views

### Variable polarization Yagi using two antennas on the same boom, joined together with variable feedpoint phase?

I have been trying for ages to find a way to mount a 10 m vertical Yagi properly, so that the mounting pole doesn't stuff up the impedance and radiation pattern, and have had no luck so far. Apart ...
47 views

### What is the formula for coupling between non-parallel wires?

I want to solve the equations for wire antennas where the wires are not all parallel. The classic method for parallel wires is to compute the magnetic potential at points on one wire due to current ...
13 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 ...
45 views

### Vertical antenna near power and cable lines

I have a 40M vertical on top of my roof. When I transmit at 100W, my internet drops. My neighbor's internet too (different cable company). At 50W it seems to be OK. As an expermient, I used a smaller ...
292 views

### Any reason not to choose a discone antenna over a Wide/ MultiBand mobile antenna for TX/RX operations

We are setting up a all-band radio in an emergency com center that's intended most for amateur band use, but since its' for emergency use will also be used in the public safety bands; (150-170)MHz, (...
29 views

### On a horizontally setup 20m delta loop I am looking to determine the calculations for the proper length of a feed wire

Base of loop will be about 6 feet above ground. RG-8 or 213 will be used for the feed wire. Ugly balun as well.
49 views

### Contesting dialog

I have noticed that participants in an HF exchange will often give number and a letter followed by a state, e.g. 1E Wisconsin. What does this mean?
57 views

### How Much Does the Radiation Pattern of an “EFHW” Antenna System Vary Across its Bands?

This NEC4.2 analysis shows one example of such variation.
80 views

### When are licenses required for 900 MHz operation in the US? When are they not required?

Forgive me if this is not the proper forum, but I am an electrical engineer and a total radio novice. I am designing a product that may contain off-the-shelf industrial radios that act as repeater ...
65 views

### Antenna Basics - Open/Short Circuit & Half-Duplex/Full-Duplex

I am beginner in the Antenna theory and I have a few basic questions. Please help me to clarify my understandings related to the basics which I have read. And this question has 3 basic questions. ...
71 views

### Modelling a “fan dipole” or “fan inverted vee” using EZNEC - unexpected result

I plan to put up a "fan inverted vee" but for various reasons I will not be able to take it down, adjust wire lengths, put it up, test, etc: I will basically have to cut the wires, put it up and leave ...
26 views

### How to connect IC-271 DC power connector to 12 V battery

What I am trying to do Radio is an IC-271, ~ 20 years old. I want to run it with a 12 V lead acid battery. I need to connect the battery to the radio. The radio's DC power connector is a 6-pin molex(?...
198 views

### Significance of 1/4 wavelength with respect to antennas

I am a fresher in the radio design field. My question is, 'What is so significant about 1/4 wavelength with respect to antennas.' From the information I have gathered from various sources, it is my ...
105 views

### Need antenna for mobile mag-mount LPFM broadcast 88.3 MHz

I am doing some temporary FM broadcasting for car events such as COVID-safe car parades and drive-in movies. The terrain is horrible, urban areas with lots of buildings. The cars snake around a city, ...
150 views

### Using a trap out of its resonance frequency?

I have a vertical antenna, about 7M total length, with a loading coil at 6M height. This is just because aluminium tubing is sold in 6 meter lengths. The loading coil is used to make it resonate at 7....
63 views

### Can these in-band spurs from rpitx be eliminated somehow?

I'm putting together a 2m NBFM transmitter/receiver combo using rpitx and rtl-sdr. During testing my low-pass filter I discovered that rpitx is generating spurious signals within and around the band (...
120 views

### Determining one exact antenna length for a whole band (e.g. FM/AM broadcast, Bluetooth and others)

How does a single FM antenna length work in the entire FM frequency band range, when there are theories which state that the antenna size should always be close to wavelength/4 for proper reception &...
60 views

### Yaesu FT-817 Won't transmit Dig, SSB or CW

I have a problem with my Yaesu FT-817 it Won't transmit Dig, SSB or CW, But it does transmit AM, FM and Pkt on all bands. Does anyone know what the problem might be. The Radio receives fine on all ...
123 views

### Virtual Testing | How would it be done

How would testing be done on Zoom? Or would testing be pushed off until after COVID-19?
65 views

### Is a balun really necessary for a small loop antenna?

I am in the process of designing a small receiving loop antenna for the lower HF bands. By small I mean a circumference of less than $0.2\lambda$. Thus, a uniform current distribution can rightly be ...
96 views

### Grounding for lightning safety - upper floor (UHF/microwave antennas)

I have some UHF, microwave antennas and an antenna rotator on a roof mounted mast. The "radio room" is in the second floor just below the antennas. Also the service entrance for building electricity ...
28 views

### Bias Tee for HF: noise and losses?

I have a homebrew remote antenna switch. It uses relays and it has a nRF24L01-based wireless link to the band selector (Arduino, taps into CAT and switches antennas accordingly). I would like to ...
130 views

### Can half of a directional antenna (Yagi-Uda, HB9CV) be replaced by a ground plane?

Consider a center-fed dipole antenna. It‘s well understood how the bottom element can be replaced by a ground plane (in practice, generally a few rods but in principle a conducting plate would work as ...
41 views

### Problem of two SAW fitler?

When I series two SAW filter, why the attenuation less than sum both of them in stop band region. Each of them (in stop band) have 60dB attenuation but when series them, the attenuation is equal to ...
47 views

### how does this collinear antenna work?

I was looking for a cheap and easy to build 2M/70cm vertical. I found this: http://vk2zoi.com/articles/dual-band-high-gain-flower-pot/ Here are the plans to build it: But I don't really understand ...
31 views

### How do I get my Windows 10 PC to consistently recognize my RigExpert AA-35 ZOOM?

I have connected my brand new RigExpert AA-35 to my Windows 10 PC via the provided USB cable, but the AA-35 does not show up in Device Manager. There is no COM port assigned to it, nor does it show ...
89 views

### How do I tune my EFHW 40-10 to have the lowest SWR in the 40, 20 and 15 meter bands?

This is a reading from my RigExpert AA-35 ZOOM of my EFHW 40-10 inverted L with radials, and feedpoint 2 feet above the ground. Any thoughts as to how I can tune or move this antenna to get the ...
79 views

### Is the Alinco DJMD5 illegal for ham use?

I am quite interested in buying the Alinco DJMD5TGP as it seems like a full-featured radio for a low price. And I have already started studying for my Technician license so I can transmit. And then I ...
6k views

### Are Baofeng radios illegal in the U.S?

Having a low price budget, my search for my first ham radio to buy has led me towards Baofeng. A quick Google search on baofeng showed a lot of results that said that certain model baofeng handhelds ...
757 views

### Why is my diplexer such a spectacular failure?

I'm trying to create a diplexer for the 2m and 70cm bands so that two antennas can share a feedline to my "shack". My radio is a Yaesu FT60 handheld, 5W max. I have home made a j-pole for 2m, and a ...
40 views

### Podcasts for Technician Test

Is there a podcast to listen to that teaches in-depth the technician class questions? All I could find is podcasts that just read the questions and answers. Is there a podcast that goes in-depth to ...
121 views

### What does an antenna analyzer tell me about these coaxial cables?

Note: more measurements added after graphs below I recently acquired a RigExpert antenna analyzer and I am trying to learn how to use it to test cables. I took two cables to start with to try and ...
173 views

### How do you find a test location?

I'm new to ham and I'm wondering how to find test locations/study guides. I heard about this from a friend.
76 views

### Can a ham radio pickup police signals?

Can you pick up police signals with ham radio? Secondly, are you able to contact emergency services with ham radio. For example: In the middle of a hurricane, with no power, can you technically use a ...
99 views

### Is it possible to detect encrypted communications [migrated]

I'm writing a detective novel, in which a series of terror attacks are carried out in the United States by a group of mercenaries using military grade, channel hopping radio to communicate. I would ...
1k views

### Can you use a satellite dish for a ham radio antenna?

Can I use a satellite dish as a ham radio antenna? I was thinking that because there are two unused, working satellite dishes that have all appropriate wires attached conveniently to the roof of my ...
63 views

### Transmitting Callsigns

I started learning for my technician test and I noticed one of the FCC guidelines is that you have to Transmit your callsign at the beginning of radio contact, and every 10 minutes How does ...
155 views

### Ham Radio and Space Communications

I hear a lot of people talking about getting in contact with space with their ham radio. What do you hear? Do you talk to astronauts? Or: Is it just an expression?
61 views

### Setting up an Outdoor Antenna

If I would buy a ham radio with an outdoor antenna, what would I need to do to make it work (e.g can I just stick it outside) especially because I live in Miami and Miami doesn't exactly have the best ...
141 views

### Space Requirements

As I progress in my path to getting a ham license I notice that a lot of radio enthusiasts avidly talk about their radio shacks (or do they call it cabins?). Do I need that much space to start? Do I ...
74 views

### What does a License look like?

What does the HAM license look like? Is it a card? A document? All I could find on google is ham radio license plates.
3k views

### Can a ham license be used for a job?

If you get a ham license, can you, later on, get a job with that license, or at least display it on a resume? Or are there further licenses after ham radio licenses?
70 views

### Equipment Pricing

I am wondering about the exact pricing of kits. What is the range of each radio? How long do they last? Should I buy a portable or not? My complete budget is \$100.