All Questions

I have a degree in Electronics and am a Maker with Arduino and Raspberry Pi. Breaking in locally with the proper licenses and finding individuals to guide me through that has been my biggest issue.

My understanding is the earbuds that connect to the aux port act as the antenna. It's a long wire. The problem is that the same wire is being used to power your earbuds so you can hear the radio ...

I have an EFHW 40-10 in inverted L configuration on a fiberglass mast. I'd like to put an aluminum push-up mast nearby for a 6 meter antenna. How close can I get to the EFHW with the push-up mast? ...

Why are notch filters used on the transmit side of a repeater duplexer? The primary purpose of a duplexer is to keep the transmitter output out of the receiver input, since they both operate at the ...

The point I'm confused about is the antenna. Depending on the environment, there are tons of different frequencies passing through you (FM, AM, 4G, SAT, etc). The electrons in the wire will move as ...

This is my first time ever asking a question on stack exchange or any stack site, so please be gentle if I missed something here. I am currently working on building a UHF (GMRS) repeater, and while ...

What are currently the (5 or 10) biggest amateur radio contests in terms of Worldwide participation (total number of stations or operators on the air during the contest)? Are they the ones with "...

ORIGINAL QUESTION I am trying to increase the range of communication between two SDRs to simulate near space communication. The output power of TX is 10dBm but I would need 37dBm for near space ...

I'm looking at a simple FM transmitter output (see picture). It is from the collector of a transistor and it goes through a DC blocking capacitor before the antenna would be connected. The entire ...

I just bought a Diamond CP-5NMO hatch/lip mount and intend to put it on the hatchback lip of our 2018 Subaru Forester and, if it will fit, another one on our 2019 Kia Niro EV. I understand that hatch ...

Are there any requirements to post, carry, or have available an official paper copy of one's radio license in order to operate in the U.S.? Do any states require physical possession of a printed ...

I have studied for and am ready to take my amateur radio license test but there are currently no licensed instructors available in my region to administer the test. Can I start acquiring ham radio ...

I'm building a simple ground plane antenna for VHF, and I'm doing some research on grounding in case I want to permanently install it. I keep hearing that the ground rod is connected to the outer coax ...

I am trying to build an FMCW radar using a USRP N210 with a CBX40 daughterboard. I generate a sweep from 1.5GHz to 5GHz. According to their respective datasheets, the daughterboard and the USRP should ...

I have a general license but I do not know when it expires, please help.

I am curious whether the Anytone AT-D878UV (which is a DMR radio) can be programmed to receive dPMR channels. I understand that the big difference between DMR and dPMR is the technique used to divide ...

A lot of article about 60 cm shielded loop antennas and how to measure antenna factor using antennas with already known antenna factor. But for example if I have one shielded loop antenna (...

The Situation: Very new Ham I have a 2m/70cm 48" Abree whip antenna, originally designed to be connected directly to an HT I would like to mount this antenna to the side of my hiking backpack, ...

I'm a CS college student working on the flight computer of my Rocketry Club's rocket. My flight computer has a 915MHz radio transceiver, and it needs to transmit data to my computer with another radio ...

I'm just getting into ham radio. I'm trying to connect to a repeater here in Ireland: Channel: RU260(RB10) Output: 433.250 Input: 434.850 Call sign:EI7SHR Access: Carrier What does the "...

Hello, what kind of antenna is this? I’ve been trying to figure it out for 14 years. None of my neighbors know. Whomever installed it either moved or passed away.

What’s the best way to connect a station (desk) ground bus to an outside ground rod? Is it viable to double-sleeve a copper tube through existing PVC pipe? For coax pass thru, I have a 1.5” PVC pipe ...

I note that many popular kit and QRP radios do not include any AGC capability. Thus it must be possible to operate successfully without AGC. Are there difficulties involved in manual gain control? ...

Is there a way to determine whether a station or operator still sends physical QSL cards, rather than only uploading some data online? (or doing nothing at all.) If so, what is the current procedure ...

I've been scanning through the bands using WSJT-X to pick up FT8 and WSPR. Using a VHF discone, I decode messages from nearly 10,000 km away, consistently, when listening for FT8. But when switching ...

In the contexte of my reaserch about antenna conceptions, I'm trying to simulate using CST Microwave a cavity antenna based on metamaterial structure and a slot antenna as a GND,However I got as a ...

I am just getting into ham radio, and I find it very interesting, but to make phone calls, you have to be on a 10 meter band. Does anyone know how to infer the band you're on is 10 meter? Thank you ...

I have a K40 Plus CB antenna, which is supposed to be attached to a car roof for the ground plane. However, I would like to set this up as a base antenna. Could I instead attach the ground to separate ...

I'm looking for some QRN/M audio files to "show" someone what said noise can sound like, particularly interested in static crashes or lightening bursts. Have Googled same with no joy other ...

(I'm asking this in the context of a Cobra 29LTD CB, but I think that it also applies to amateur radio in general.) In SWR mode, the needle swings all the way to the right, hitting the limit. The (mag ...

Lots of information about shielded loop antennas is available on the internet. However, antenna manufacturers do not indicate the number of turns. How can I find the number of turns of a manufactured ...

I have the RCS-4 with two MFJ-4116. Prior to installing my motorized HF antenna system topside, I bench-tested the core of the assembly in my shack. The MFJ-4116 near my transceiver was injected with ...

I've been using FT8 on my Yaesu FT-450D for quite some time. I decided to try to talk on phone frequencies and discovered neither one of my mics will transmit. My mics are the original hand mic and a ...

I have a remote wireless water tank level sensor. It transmits at 439 MHz with an apparent max range of 100 metres. Unfortunately I need about 200 metres. How can I extend that range?

I know that there have been many similar threads on this, but I still need clarification. At the moment, the only thing I have is a 500' roll of RG-6 and a (very) tight budget, and I should be ...

Recently licensed technician here, and going straight into my general class, I'm keeping an eye on cheap (sub-$400) HF radios. I keep reading articles that suggest used radios that normally sell for ...

Will the 450D computer control program interface with Winlink and allow Winlink to change radio frequencies/bands?

I've been just scanning through the HF band at night seeing what all I can pick up, and I'm trying to figure out a particular signal. I'm using a VHF discone, which isn't ideal, but it works well ...

I have some Retevis MURS two-way radios model number RT27V. In the programing software there is an option for DCS encrypt. Now I turned on and off the DCS encrypt option and using my NooElec SDR with ...

It is commonly known that electromagnetic radiation from an antenna is polarized; the electric field is parallel to the rod and the magnetic component is perpendicular to it. What does the radiation ...

good morning all, I have difficulties to find the correct formula that allows me to calculate the gain of half wave dipole in parallel with another parasitic half wave dipole. I'm trying to calculate ...

I have a Hustler 5BTV antenna i resurrected after a previous monopole succumbed to birds. It is giving me a world of trouble trying to get it tuned for resonance. For those not familiar with the ...

I had a quick look at a practice exam for the license in my country and had a question on stacked Yagi antenna. I have been looking around but the only thing I can find is the mention of an additional ...

I have a full SSTV transmission pre-recorded. Is there any way that I could take the audio file and decode it? Alternatively, is there a way to select the audio device (for example, to read an audio ...

On some (most?) receivers, if the RF gain is turned up too high, intermodulation distortion increases due to increasing non-linearities (maybe even clipping, etc.) Is it possible, just by examining ...

I noticed that on some higher-end transceivers, the panadapter/waterwall is still being displayed during transmission. How is this possible? If the panadapter is part of the receiver, it should be ...

I am trying to work a 700mhz LTE signal with a DB2 uhf bowtie television antenna. I find the cellular signal to be horizontally polarized. Can the bowties simply be twisted 45 degrees in both ...

Looking for advice/assistance in Retrofitting sans Cabinet Antique 2 and 3 Dialer 1920's TRF tube radios to operate with low safe Plate voltages.Both Hollow State and Solid State. The plan is to ...

I followed an article Antenna Here is a Dipole [PDF] by James Hearly, NJ2L to build a dual band 40/15m dipole: The antenna works more or less as expected. My 40m dipole was resonant at 7.030 MHz and ...

I know how shielded loop antenna work as a receiver antenna. (How behave electric and magnetic field). But I can not understand how shielded loop antenna works as a transmitter. Will it produce only ...