Most Popular
1500 questions
8
votes
4 answers
Required SSB sideband and carrier suppression?
Is there a legal (U.S. FCC) or a commonly accepted standard requirement for SSB opposite sideband and and carrier suppression for either manufactured or kit built transmitters?
Does the 43+ dB down spurious emissions CFR 97.307 rule apply? Or…
hotpaw2
- 13,316
- 6
- 45
- 76
8
votes
3 answers
Does LOTW have an interface document?
I want to be able to sign my own LOTW entries, without using the provided library (My application is pure Java). Is there a document that explains in enough detail how to do this, assuming of course that I'm provided with a certificate (.tq8 I…
PearsonArtPhoto
- 6,208
- 2
- 33
- 61
8
votes
5 answers
How far can a 2.4 GHz, 1 watt signal go in a rural area?
What's the approximate range achievable by a 2.4 GHz signal of 1 watt in semi-urban areas? I can see 2 km from our rooftop. Will a 2.4 GHz signal go that far, i.e. if I send WiFi signals from our rooftop is it possible to catch them on my phone 2…
user40713
- 225
- 1
- 2
- 4
8
votes
2 answers
help identifying a vacuum tube
I recently bought this tube for use in an art project and would like to know what it is and what it was originally used for. Unfortunately, the silkscreen labelling on the glass envelope was worn off and unreadable and there are no other obvious…
niels nielsen
- 937
- 5
- 13
8
votes
2 answers
How to keep a disconnected coaxial connector weatherproof?
The advice I have seen on lightning safety is that if you don't have high-quality lightning protection (and associated grounding) installed on your feed line, it is advisable to, during a storm and preferably whenever you are not using your station,…
Kevin Reid AG6YO
- 24,506
- 7
- 51
- 103
8
votes
2 answers
What are some drawbacks to delta loop antennas?
They seem to be broadbanded, small, and ground-independent relative to other cheap wire antennas, so what's the catch?
Bill - K5WL
- 1,194
- 1
- 11
- 18
8
votes
6 answers
International characters in Morse Code?
Does the official International Morse code include alphabetic characters other than the 26 letters of the English alphabet? If so, what are the most common other alphabets or characters that one might find used on HF CW bands?
Added:
How do Greek…
hotpaw2
- 13,316
- 6
- 45
- 76
8
votes
1 answer
Would I still be a valid volunteer examiner?
I'm currently an ARRL member, and a volunteer examiner under the ARRL/VEC. I find myself needing to cut back on expenses this year and may end up dropping the ARRL membership. If I do so, am I still a valid examiner under the ARRL/VEC? If so,…
Brian Knoblauch
- 227
- 1
- 5
8
votes
1 answer
Power limit of 50 ohm BNC connector?
Is there a limit to the power a 50 ohm BNC connector can handle?
Timtech
- 2,336
- 2
- 25
- 40
8
votes
2 answers
What does QSL mean in a CW conversation?
When the other party sends QSL, do they just want to know whether I received the previous message and expect RR or AGN? Or, are they asking for a QSL Card to be sent to them?
Qi Fan
- 183
- 4
8
votes
1 answer
How do I identify a genuine Nagoya antenna?
I recently purchased a Nagoya NA-771 that I believe is counterfeit given the overall feel of the antenna. How do I identify a genuine Nagoya antenna vs. a counterfeit?
Amin Shah Gilani
- 832
- 1
- 7
- 19
8
votes
1 answer
PL tone removal?
How are PL tones (CTSS, et.al.) typically removed from the audio of received VHF FM repeater signals?
Is it done with a fixed high-pass filter? Or a notch, when using a transceiver with the PL tone configured correctly? Or dynamically, by assuming…
hotpaw2
- 13,316
- 6
- 45
- 76
8
votes
3 answers
Estimating the efficiency of a shortened (loaded) antenna
Recently I've build a trap dipole for 20/40/80m bands. I followed an article by John DeGood, NU3E and got following measurements:
From balun to 20m trap: 485 cm
From 20m trap to 40m trap: 362 cm
From 40m trap to the end of the arm: 530 cm
You can…
Aleksander Alekseev - R2AUK
- 4,272
- 15
- 52
8
votes
2 answers
How does signal strength relate to bandwidth?
Let's say I have a 25 W transmitter. First I transmit some SSB signal with 2500 Hz bandwidth (no audio compressor is used, etc...). Then I transmit a BPSK31 signal with at most 100 Hz bandwidth using the same power.
Is it accurate to say that…
Aleksander Alekseev - R2AUK
- 4,272
- 15
- 52
8
votes
1 answer
Testing a possible grounding point?
Some multi-story buildings in my region require earthquake isolation on some of the piping. Thus my question. Is there a way to determine whether a nearby metal water pipe is actually Earth grounded, versus floating? Does this make a difference…
hotpaw2
- 13,316
- 6
- 45
- 76