Most Popular
1500 questions
4
votes
3 answers
How do I construct the driven element of a yagi?
I've been poking around the internet on how to make a Yagi for my HT. I understand all the math for cutting directors and reflectors to length and placing them at the correct spacing for 146.52 mHz. However, I keep finding different descriptions on…
user6099
- 41
- 1
- 3
4
votes
1 answer
Why is 900MHz restricted in some areas in the US?
So I found these rules:
(2)
No
amateur
station
shall
transmit
from
those
portions
of
Texas
and
New
Mexico
that
are
bounded
by
latitudes
31°41
′
and
34°30
′
North
and
longitudes
104°11
′
and
…
Skyler 440
- 7,690
- 9
- 54
- 90
4
votes
4 answers
Low power long distance wireless data communication
I am looking for a communication solution with the following requirements:
wireless
unidirectional, point to point
low power (li-ion battery powered, should operate at least one hour on the single charge)
low baudrate data transfer (cca 40 - 80…
Martin Ždila
- 141
- 4
4
votes
2 answers
2 Meter horizontal or vertical dipole polarization?
When should I use one polarization over the other on 2 meters?
I've looked at the radiation patterns for horizontal dipole and seen how it changes based on mounting height. I haven't been able to find any information on how the vertical dipole…
KM4NTK
- 135
- 1
- 1
- 9
4
votes
1 answer
Warbler vs SoundModem
I'm trying to decode a BPSK 1200 (with no success). In this endeavor I tried both SoundModem and Warbler.
The scenario here is the following: Ettus receiver + HDSDR with speaker plugged into mic via an audio cable.
Warbler and SoundModem both do the…
KcFnMi
- 353
- 2
- 10
4
votes
1 answer
Why there is no AFSK in FLDIGI
I was expecting to see an AFSK option in the Fldigi "Op Mode" menu (as there is one option for CW, i.e.), why isn't it there?
Basically, I want to get the data send according to this.
KcFnMi
- 353
- 2
- 10
4
votes
3 answers
Is it possible to calculate the Q factor for an antenna type, given a frequency?
With only pen and paper, is it possible to calculate the ideal Q-factor for e.g. a dipole antenna, loop etc, given a frequency?
Aard
- 51
- 2
4
votes
2 answers
Is this simple description of SSB correct?
I was recently asked to explain why a "carrier injection oscillator", or CIO is needed in an SSB receiver but not in a transmitter. This is the explanation I gave, and I would be grateful for comments on its validity.
I find the usual diagrams…
Harry Weston
- 533
- 4
- 12
4
votes
1 answer
What is my VE status?
I was an ARRL VE years ago. The info about ARRL VEs says that you remain a VE and the only way one will be dropped is loss of license. However, years ago to be a valid VE one would have to have a current date sticker on one's badge. Am I still a VE?…
Herb Robbins
- 41
- 1
- 2
4
votes
3 answers
How do I connect a GPS receiver to a radio for APRS?
I volunteer with the local search and rescue group as a team medic and a radio operator. The team is new and recently decided to go with the Garmin 64st as our go-to GPS units. Those of us with licenses use the cheaper Baofeng UV-5R and BF-8HP…
john.weland
- 143
- 1
- 5
4
votes
1 answer
Best way for US ham to join RSGB
Overseas hams can join RSGB from their site for 51 GBP, which today is about 79 USD.
USA hams can also join through the ARRL for 75 USD.
Assuming the $4 is not a factor, are there any advantages to joining directly with RSGB in terms of membership…
James
- 91
- 5
4
votes
1 answer
UK Foundation - initial practical assessment, what to expect?
I'm going to be starting the Foundation course in the next few weeks, and have been offered an initial practical assessment at a member's shack to save time for the club during the course.
The call to be made is on 2m with a QSY, so I'm wondering…
luxpir
- 95
- 6
4
votes
1 answer
Comparision between BFSK and BPSK
Why is BPSK preferable over BFSK? On what parameters this comparison is based? What are the advantages of BPSK?
shweta
- 61
- 1
- 1
- 4
4
votes
1 answer
Can a WLAN device be used with GNU Radio?
Can I use my wireless ethernet card with GNU Radio? I have a Broadcom BCM4311 mini PCIe, and Debian / Kali 2.0 Linux.
motoku
- 143
- 4
4
votes
1 answer
Repeater autopatch ("phone patch"): which countries use this?
The section Operating Your Ham Radio in an Emergency from Ham Radio For Dummies recommends using an "emergency autopatch" to reach the emergency services when reporting an emergency from an amateur radio transmitter:
State clearly that you are…
user5147