Amateur Radio Stack Exchange
Amateur Radio Stack Exchange

Most Popular

more tags
1500 questions
9
votes
3 answers

receiving AM radio station on UHF frequency

I'm studying for my Technician license, and listening in to HF, VHF and UHF bands just to get a feel for how to work with frequencies, squelch, antennas, etc. Had something happen today that I couldn't explain. I was doing a scan through the 70cm…
K. Kerby
  • 91
  • 1
  • 1
  • 3
9
votes
5 answers

On which of these frequencies can I transmit without a license?

I have a Baofeng UV-5RA, and I need to know what frequencies on the "channel mode" (what the lady says when you press the "V/M" button on the radio) don't require a ham license. I am in Philadelphia, Pennsylvania. Frequencies: 138.550, 155.700,…
SPC Philadelphia
  • 105
  • 1
  • 1
  • 8
9
votes
5 answers

Why do Hams refer to bands by wavelength and not frequency?

I've noticed while reading literature and websites geared towards and written by amateurs and ham radio enthiuasts that frequency bands are commonly referred to by wavelength. In professional environments I have been a part of, we always used…
YetAnotherRandomUser
  • 557
  • 1
  • 4
  • 13
9
votes
1 answer

Is there a name for the demodulation technique described here using the parallax propeller?

Is this a recognized SDR technique with a name, or is just a combination of DSP, r/f techniques ? I asked the author, but didn't receive an answer, perhaps because he thought it was "obvious" (not to me, though, an SDR / electronics…
mstram
  • 213
  • 1
  • 5
9
votes
2 answers

What is the largest gauge (thinnest diametre) wire I may use as an antenna?

A follow-up to Good wire for wire antenna? I'm QRT at present - thanks to fooling around with just a couple of diodes and PVC capacitors instead of a well-regulated supply. The antenna I used earlier was a mono-bander inverted-vee for 20M. I may be…
VU2NHW
  • 2,834
  • 2
  • 20
  • 43
9
votes
1 answer

What's this "crossover" toroid winding called and what is its purpose?

I am winding an EFHW matchbox and many of the designs I've found (including the diagram provided with the kit I bought) include a sort of "twist" when winding them: (Image taken from this post and similar can be seen here and here and here.) My…
natevw - AF7TB
  • 7,411
  • 2
  • 28
  • 60
9
votes
1 answer

How do I know if my dummy load is working?

I understand why a dummy load is used, but (aside from it getting hot) how do I know if it's doing it's job and doing it's job well? In my specific case, I'm using a Hack RF One SDR and a Souked SMA Dummy Load 50 Ohm.
M6JNY
  • 356
  • 1
  • 3
  • 14
9
votes
6 answers

How is a 1:1 current balun different from a choke?

I have a 10m dipole and am going to feed it with 50 ohm unbalanced feed line (coax). My understanding is the feed point of this style antenna is about 50-75 ohms, and since it is a balanced antenna I'm thinking I need some type of balun. I'm…
Java42
  • 193
  • 1
  • 1
  • 5
9
votes
1 answer

Digital-mode signal reports

When operating analog voice, we give a qualitative (or possibly just arbitrary) signal report, 'scoring' the signal either out of a maximum 'five by five', or a maximum '599'. How do you report the quality of the received signal when using digital…
Dan KD2EE
  • 3,966
  • 1
  • 17
  • 45
9
votes
3 answers

Can cellular radio be used for communication with a balloon?

(Sorry, I don't know if this is the right forum for this question, but maybe someone will know the answer. If not, which StackExchange forum could be more suitable?) Me and a few friends of mine are planning to build a remote controlled balloon…
ruthra
  • 91
  • 1
9
votes
3 answers

Drones for lifting verticals?

I would like to lift a 5/8 wave wire vertical for 160m, using a drone, over my lovely saltwater swamp. The thing must be powered from the ground, capable of being left aloft for a couple of hours while I work DX, and capable of hovering in position…
VE6MRV
  • 211
  • 1
  • 6
9
votes
1 answer

Can two diodes be parallelled in RB to get double the capacitance?

It's a fact of life that air-gang capacitors, are increasingly more difficult to come by - having been superseded by the far more compact varactor diodes. My part of the world components such as the venerable BB212, MPN3700, MV1662 are almost…
VU2NHW
  • 2,834
  • 2
  • 20
  • 43
9
votes
1 answer

What is the correct procedure to beam long-path?

I'm new to directional beam antennas, and saw that K9W Wake Island DXpedition was working 10 meters "long-path" at 1230z, or 6:30a.m. in Texas. This was late enough for the sun to be coming up, but is it even possible to make the "long path"…
Bill - K5WL
  • 1,194
  • 1
  • 11
  • 18
9
votes
2 answers

Marine VHF whip antennae - what are they?

For marine VHF (156~162 MHz), the most commonly used antenna is a 1/2-wave dipole or a collinear array in the form of a fibreglass rod. Collinear arrays are used to increase gain in some antennas. Dipoles/collinear arrays by their nature do not need…
user5314
  • 91
  • 4
9
votes
3 answers

How would I modify a satellite dish to transmit and/or receive to a Baofeng UV-5r plus? ( A handheld transceiver) If it's possible

I have an old satellite dish just lying around and was wondering how to hook it up to my baofeng uv-5r plus.
Sudo_Cats
  • 91
  • 1
  • 1
  • 3
1 2 3
…
99 100