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1500 questions
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2 answers

Communications : Ground wave propagation

I was studying ground wave propagation, my book writes the lines about it without explaining it. I really do not know any explanation for these queries coming in my mind. I've Googled it, and you will get nothing so good for these queries on Ground…
Selena
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1 answer

Variable phase antenna

I'm thinking about phased antenna arrays, and am wondering if it's possible to have three fixed position antennas, and vary the length of their individual feedlines to the common point through mechanical means. The best way to describe what I'm…
Adam Davis
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Are there any rules/conventions for transmitting coordinates in CW?

I am wondering how hams transmit coordinates in Morse code. Considering that coordinates can be represented in many different formats (such as DD, DDM, DMS, WGS84, etc.) and that an error in the decoding of the coordinates can mean a lot, it seems…
codeaviator
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8
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2 answers

calculating all specifics for a 5/8 antenna

So, I've built a couple 1/4λ ground plane antennas for Airband and Marine band. I don't transmit, I'm just listening, etc. So, constructing ground plane antennas with the radials and getting the impedance to be 50Ω is rather easy, not so for the…
polemon
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Who should announce the call sign when an unlicensed operator is transmitting?

If an unlicensed operator is operating phone on an amateur frequency under the direct supervision of a licensed operator for, say, longer than ten minutes, should the unlicensed operator say the call sign of the licensed operator, or should the…
Noji
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2 answers

What is the point of a SWR/power meter where the needles cross over each other?

There are SWR/power meters with two separate gauges, and others that have them mounted so the gauge needles cross over each other. Aside from looking cool, does the cross-over point of the two meters provide specific or useful information?
Adam Davis
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Are ionospheric predictions useful in practice for ham radio operators?

A number of government agencies around the world provide ionospheric predictions, such as vertical foF2 or oblique path useable frequency range advice. Examples include IPS, SWPC and DIAS. Typically, the major customers of these agencies are in…
Bogdanovist
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3 answers

How do I extend broken coaxial cable?

I have a piece of 75 ohm coaxial cable of unknown type (outer diameter is around 7 mm) which has developed a breakage in the center conductor (which is stranded). This cable is an adapter cable which connects my RG-6 type coaxial cable to my RTL-SDR…
AndrejaKo
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6 answers

Use a TV coax and balun for a poor-man's OCFD?

Can I use TV coax and a cheap TV balun to build a poor-man's OCFD? Marginal performance is acceptable if it saves money. If I could listen to 10% of transmitters within a 100 mile radius that would be acceptable. And as for the coax length, probably…
SlowBro
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Is FM appropriate for foxhunting?

I'm thinking about an inexpensive way to create a foxhunt kit for youth groups, and am wondering if the cheap dual band HTs could be used. However, it occurs to me that FM doesn't provide any good audio queues for signal strength, and the SWR meters…
Adam Davis
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Simple cheap foxhunting?

I'm currently looking to do a foxhunt for a youth group, and need to keep it inexpensive and easy enough that it won't be impossible for those new to foxhunting and ham radio, but difficult enough that it will still be rewarding. I'm a relatively…
Adam Davis
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Is any licensing require to receive in the amateur radio bands?

I'm considering hosting a foxhunt for a local youth group (scouts, in this case), and one of the questions asked was whether those searching for the hidden transmitter need have a license of any sort. Will they need licenses if they are handling…
Adam Davis
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2 answers

Is it possible to overload APRS?

Does APRS have a limited capacity in terms of beacons? What happens when an APRS frequency experiences a large number of packets?
JC Hulce
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8
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2 answers

HF Digital Mode Band Plan for the USA

I recently started playing with the digital modes, but have been frustrated with the difficulty in finding where certain modes are commonly used. Is there a digital mode band plan for the HF bands, to the level of which modes are commonly used on…
PearsonArtPhoto
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4 answers

Two Antenna Tuners in Series

My radio has an internal antenna tuner that can be activated to rapidly tune for the frequency in use. My antenna has a disgusting SWR for the band I want to use (as measured with an AA-54 antenna analyzer). When activating the internal antenna…
Steve
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