Amateur Radio Stack Exchange
Amateur Radio Stack Exchange

Most Popular

more tags
1500 questions
8
votes
1 answer

How restricted is the eastern edge of the National Radio Quiet Zone?

In several years we may be moving to just west of Charlottesville, VA (North Garden to be specific). It looks like that is just barely west of the eastern edge of the National Radio Quiet Zone and so is in the NQRZ. As that's a pretty good distance…
QuantumMechanic
  • 1,005
  • 3
  • 12
8
votes
1 answer

Can club stations register callsigns on the D-Star network?

Some of the members at my local radio club are interested in working with D-Star. Since the equipment is very expensive, it was proposed that the club purchase and operate one rig collectively. Is there any precedent for registering a club station's…
mtrberzi
  • 872
  • 1
  • 5
  • 19
8
votes
1 answer

Is there anything special about 4.9152 MHz intermediate frequency?

I noticed that there are several QRP transceivers that use 4.9152 MHz intermediate frequency. For instance, John Dillon, WA3RNC uses it in Penntek TR-25, TR-35 and TR-45 transceivers. Also a very close frequency (4.914 MHz) is used in Elecraft…
Aleksander Alekseev - R2AUK
  • 4,272
  • 15
  • 52
8
votes
5 answers

Wifi passive repeater (antenna to antenna connection)

I have two buildings. Building A has wifi (2.4GHz) infrastructure, Building B doesn't. One side of building B can pick up the wifi signal from building A. I want to passively extend the signal through to the rest of building B, using two antennas…
askvictor
  • 191
  • 1
  • 1
  • 3
8
votes
1 answer

What will the *amplitudes* of mixer products be?

The key fact about mixers, which iirc is even part of the FCC amateur radio exam(s) in the USA, is that they output "the sum and difference" of the input frequencies. And iiuc in practice it's usually assumed that besides those products the mixer…
natevw - AF7TB
  • 7,411
  • 2
  • 28
  • 60
8
votes
2 answers

New operator struggling to make a contact

I got licensed a couple of weeks ago and after making 4 attempts on different days, I have made no contacts on SSB, only FT8. What I have (done): Xiegu x6100; tried 5W and 10W Par EndFedz® EFT-10/20/40 Trail Friendly antenna Antenna deployed as a…
Amanda Helgström
  • 81
  • 2
8
votes
1 answer

Why is 9 kHz the lowest frequency for spectrum analyzers?

I researched a number of spectrum analyzers and it seems that the lowest frequency that these operate at is 9 kHz. Why is the lowest frequency supported by spectrum analyzers 9 kHz?
kittygirl
  • 610
  • 3
  • 11
8
votes
6 answers

Learning morse, but I can't write fast enough?

EDIT below with collected thoughts so far... I've been learning morse lately, and thought I was doing tolerably well until I learned that doing this at 5 wpm/15 Farnsworth, is evidently considered essentially pointless. So, now I'm trying at 20 wpm,…
Toby Eggitt
  • 383
  • 2
  • 9
8
votes
1 answer

How long should I wait to claim a frequency?

Let's say you want to go on air and you don't want to invade on someone else's frequency. How does one make sure the frequency isn't occupied before claiming it. And how long should you take to make sure the frequency isn't occupied before starting.
Ben Madison KO4UXC
  • 564
  • 2
  • 16
8
votes
2 answers

How to reduce VFO sensitivity to the hand capacitance?

I got a little tired of Si5351 and decided to build an analog CW transceiver. It's almost done and works pretty well. However, I discovered one problem. When I reach the VFO control with my hand the frequency shifts a little, about 100 Hz or so.…
Aleksander Alekseev - R2AUK
  • 4,272
  • 15
  • 52
8
votes
4 answers

Tuner at antenna side versus transmitter?

I figure the transmitter has a 50-ohm pure resistive output and that the transmission line is 50-ohm as well. I think it's usually the antenna itself that actually needs to be tuned, yet it sounds like everyone places the tuner at the transmitter…
pgibbons
  • 444
  • 2
  • 8
8
votes
2 answers

How does a Dual Band Handheld Antenna work?

Looking to get a (highly recommended) NAGOYA NA-771 37cm "Dual band (2M/70cm) handheld antenna" for my Baofeng UV-5R. If my math is correct - this is about a half-wavelength antenna for 70cm, but doesn't seem to correlate to anything for 2m. What…
Brad
  • 223
  • 1
  • 3
  • 6
8
votes
3 answers

What sort of radiation efficiency can one expect from a folded dipole?

It is pretty well established that folded dipoles have much greater acceptable-SWR bandwidth than ordinary dipoles. Radiation efficiency is simply the quotient of radiated power to the antenna feedpoint input power. Seeing that folded dipoles are…
user
  • 4,878
  • 2
  • 31
  • 60
8
votes
3 answers

Why don't I hear the CTCSS tones when listening on the repeater input frequency?

I am newly licensed (Technician) and bought a UV-5RA as a cheap way to check out what's going on in my area and see if I'm finding it interesting enough to get a better UHF/VHF HT. The other day I was listening to a conversation happening on a local…
QuantumMechanic
  • 1,005
  • 3
  • 12
8
votes
1 answer

S Parameters in HFSS

I'm new to HFSS Software and I'm trying to plot Scattering parameters for a dielectric resonator excited by a probe (shown in image). I know that the top cylinder has a higher dielectric than the bottom cylinder. I also know that the cavity is a…
JOHN
  • 81
  • 1
1 2 3
…
99 100