All Questions

I am looking for an antenna rotor controller with a TCP/IP interface. Most rotor controllers (like the ones for YAESU series) are either serial or USB-based. I was wondering if there are alternatives ...

Is this author correct about using a λ/2 of wire for a coil to get the proper delay on a λ/2 collinear antenna? Improving the Super-J August 5, 2012 by John S. Huggins I agree with him that there has ...

I'm using Winlink with a laptop hooked up to an IC-7300. The registered version of Vara theoretically supports speeds up to 8,500 bps, but I'm seeing speeds more like 700 bpm. Is there anything I can ...

My Baofeng UV-5R came with a shorter 6.5” antenna and a “high gain” 15.3” RH-771 antenna. In your experience, how much of a difference in range does the use of the longer antenna achieve?

Consider a normal array model with $N$ element. The output of the array is given by, $$y=w^Has$$ where $s\in\mathbb{C}^{1\times T}$ is the desired signal ($T$ is the number of snapshots and the power ...

I just bought a Baofeng UV-5R. I programmed in some channels and have been scanning these channels for activity. I have had a situation come up on a few occasions where there is some activity on a ...

I'm beginning to learn CW. Stumbled upon hardware tutor devices: this or this. Can't understand how the tutor mode works... the manual says it plays out random number/letters/callsigns etc, but there'...

I have a multiband vertical antenna mounted onto the railings of my balcony apartment high up on the 6th floor of an apartment building. The antenna is not grounded. This antenna comes without radials....

I just bought a 2m/70cm handheld. I programmed in the local repeaters and have been scanning them for a couple of days. Only about twice have I heard one of the repeaters come up and identify itself. ...

I'm very new to RTL-SDR and signal processing in general, but have managed to get my device (NOOELEC NESDR Mini) working and data into Python (via the pyRTLSDR library). I am able to output a complex-...

I am looking for any technical/scientifical/specialized reference describing in some detail the moonbounce for VHF/low UHF frequencies. More precisely, I would be interested in a paper or publication ...

Why, for realistic directional antennas, are its nulls sharper (deeper, narrower, etc.), than the radiation pattern’s lobes (local angular maxima)? Is there some physics or mathematical geometry to ...

I have a situation where I'd like to get a network signal from my house to the end of my driveway for security cameras and the like. My driveway is long (about 1km). Its also non line of sight from my ...

I am using these Adafruit LoRa radio microcontrollers: M0 radio paired with these parts to make up the antenna system: antenna connector cable And for some reason I am unable to get much further than ...

Can I use sub-ghz (433 Mhz) to transmit audio.I already used radiohead library with RFM96 to transmit small packets of data and built a point to point mesh chat application. Now i wanted to test FSK ...

I’m buying a used IC-718 from a local ham. I can verify its function before I decide to buy. I’ve read the manual and know the functions and capabilities. What should I check / look for, apart from ...

I have a property that I am trying to figure out the right antenna setup for. Currently running the following Antennas: 1x Hustler 5BTV Vertical with radials 1x Chameleon in a NVIS configuration 1x ...

I'm considering buying ICOM IC-718 as a main rig and also to use it for SWL. Read contrasting opinions on the Internet, with an article reviewing dedicated SW receivers saying "That receiver's ...

For dipole antennas in an array system, for any configuration of the dipoles, how does change angle of orientation in one or more of the dipoles affect the mutual coupling between them. Is there a ...

I run a λ/2 vertical dipole for 20M that's fed to a 1.5:1 balun at its center with coax that is perpendicular to the dipole (parallel to the ground), for about 30 feet before it comes down to the ...

I need to transmit frequencies as low as 1Hz and I know the wavelength is the speed of light but wondered if there has been any breakthroughs in this field? I need a handheld antenna or at least one ...

I play airsoft here in Quebec Canada, and I have 2 Baofeng BF-888s that I got a few years back. Now people are mostly using UV-5Rs. I used CHIRP to program my radio to the same frequency used by the ...

My favorite HF bands are 20 meters and 10 meters. I am currently using a multiband vertical antenna, but really it's not so great for DX'ing. I am looking for a good upgrade. I'm still learning alot ...

I got an anytone 778uv that I want to add to my car. I'm looking at adding it with a add a fuse to an open fuse slot, however I see many people just saying to add it to a chassis bolt. I am new to ...

I plan to build a receive-only longwire/Beverage antenna. The wire will be at least 40m/120' long and strewn at about 7m/21' above ground. Tried "regular" thin insulated wire but it was an ...

I'm tuning a wire dipole. Cross-needle SWR meter shows the same SWR on the lower end of the band as on the higher end. However, the needles move much higher on the lower end. They cross on the same ...

With my ICom 9700 the CI-V reference manual says that I should be able to send the command 0x07, subcommand 0xD0, to select the Main band, and 0xD1 to select the Sub band. subcommend 0xB0 to exchange ...

I just got 4 BF-F8HP radios, 2 knockoffs, and 2 "legits"; definitions of knockoff and legit come from a website I found. All 4 of them are having this issue. I can transmit fine on both 2m ...

I want to make a longwire/Beverage receive antenna that will work on a wide range of bands (80-10m or wider). I've got a place where I can put a wire of at least 50m/150'. The only problem is — the ...

I live on a high floor in an apartment block and have a radial-free multi-band vertical antenna attached to my terrace railing. This is the antenna : https://www.thunderpole.co.uk/amateur-radio-...

Would the skin effect provide benefits or would capacitance/inductance cause problems?

I'm trying to learn how to correctly calculate (cascade==RF system cascading) the connection of 2-port networks, taking into account mismatch losses. For example There is a first 2-port network, its S ...

I've installed EchoLink on my Windows machine and on my iPhone, and EchoHam on my Mac. At the moment, I have the TCP 5200 outbound allowed from any device on my LAN and UDP 5198-5199 forwarding to my ...

A faulty in vehicle DCDC charger has fed 16V or so into my brand new IC7100, killing the main board and preventing it from transmitting. I've replaced the mainboard with a brand new one however I'm ...

My D710G has APRS built in. How can I get that data displayed on a laptop?

I just installed a new Titan DX antenna and I am using psk31 with fldigi. When I transmit on 20m at 14072, the SWR is 1.65 and it shuts off my computer and the radio keeps transmitting. However, on ...

Our Skywarn group is looking for a way to feed the positions of our spotters (reported via APRS) to into GRLevel3 to be displayed on the map. Does anyone know of a tool for doing this, or ...

I'm trying to get this working for the first time on a vhf/uhf radio. PTT is working and it seems to be transmitting, but neither I nor the program can hear any response. I' ve tuned the radio to the ...

I have a GMRS radio and VHF/UHF radio in car. I have an antenna mount and cable installed. I install appropriate antenna for the radio in use and manually remove and attach cable to matching radio. It’...

I've started playing with VOACAP to better plan and predict conditions on 27 MHz (CB). To my utter astonishment, VOACAP says that I won't be able to communicate on that frequency, regardless of ...

Has anybody had success in running CHIRP on a modern Mac? I am running OSX 10.15.7 and the download I found for Mac looks like just source code, no app file at all. I'm considering trying a build from ...

Trying to build an homebrew receiver for MF band broadcast (Navtext). Usually working on VHF, where all parts are easily found as an IC, but here I'm trying to get back to roots, so I may be missing ...

I can't seem to figure out how to set it to the simplex frequency, 146.520. Always skips to 146.525 or 146.500.

How do you measure the two to one bandwidth of an antenna using a Bird Watt meter? Tom Planer KJ9P

Can a HUGE ham radio antenna on a house with an array of RING devices (5 in total) cause interference and high-frequency reverberation? The attached shows one of these devices (there's 2 under the ...

Minuteman missile silos used an interesting hardened UHF antenna. What kind of antenna is this? Does anyone have a drawing with a cross section? Edit: Jay Moore added a picture to a different type of ...

What are the radiation limits in U.S. HF bands in terms, not in terms of uV/M, but in dBm or uV levels transmitted though an HF dipole antenna? I assume that if the antenna is connected to a receiver ...

Romanian amateur radio license Hello. I am wondering how to get a amateur license in Romania, and whether there is any material on this. I am licensed in the US, am a Romanian citizen, and can speak ...

I'm putting up antennas on a tower, and have a couple of 7/8" cables style on hand. One is Hj5-50 air dielectric cable and the other AVA5-50 "Virtual Air" cable. I notice that the HJ5 ...

Is there a name or common descriptive term for a linearly loaded dipole or end-fed, where a (near) parallel loading element or elements are not connected (galvanically isolated) to the fed element or ...