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1500 questions
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1 answer

Can this 960 MHz CelWave fiberglass antenna be retuned for the 70cm band?

I recently inherited a CelWave fiberglass antenna pictured below. It is marked that it's for 959.9875 MHz. The model number appears to be either 339 or 359. It is 96 1/2 inches from base to tip. I checked it on my MFJ Antenna Analyzer and found it…
Lance
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How do I have a full signal of noise on a handheld?

I'm new to ham (although I've had a license for a long time) and I'm having issues with receiving on a basic handheld. I have a cheap BaoFeng UV-82HP and I keep getting full signal noise at random times. I have gotten this on different channels in…
Eric Fossum
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Radial length for vertical antennas?

I plan on installing a vertical antenna soon. I expect it to cover from 80 meters to 10 (or perhaps 6). I plan on putting down 32 radials. I am wondering if 16 66' and 16 33' radials will be just as efficient for the higher bands as would having…
MarqTwine
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4 answers

Do signals have to be more separated on higher frequencies?

Someone told me that 10 meters was the biggest band because you can fit the most channels in it. He said that in higher frequencies like 2 meter etc, you have to separate the signals more apart for them to work. Is this true? Can HF frequencies…
Skyler 440
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Do Loading Coils Supply "Missing Degrees" to Electrically Short Radiators?

References are made on this and other websites to the effect that loading coils can/will supply "missing degrees" to electrically short radiators. But do they?
Richard Fry
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2 answers

What are the effects of different feed-line incidence angles?

Consider a dipole antenna fed by a coax (say, longer than the antenna) with a signal reasonably close to the dipole's resonant frequency. Various sources say that the feed-line should approach the antenna perpendicularly. What are the effects (SWR,…
hotpaw2
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What is the record for highest successful (automated) CW transmission rate?

I understand high speed CW is used with meteor scatter, because the path only exists for a few seconds after the meteor passes. I was wondering if automated high speed CW has an effective "speed limit". I suppose bandwidth regulation would impose a…
Paul
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Twisting copper wire for a less-flexible DIY antenna

I am making DIY antenna for a home project. The antenna is going to be "V-dipole" with leg length about 53cm. Unfortunately, I didn't find a thick copper wire, but I have a lot of thin core from tv antenna cable. I am attending to twist a few thin…
Deliaz
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1 answer

FM spectral amplitudes during silence

General setting I'm playing around with an RTL-SDR and recently captured some FM spectrum in Hannover, Germany. I want to undersand what's going on, so I've read a lot about FM and its spectra, but I can't completely make sense out of…
Hemanti
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5 answers

Simple DIY AM receiver for 25/28 MHz

I'd like to build a simple AM receiver for 25 and/or 28 MHz to receive DCF77-formatted time code. It doesn't have to be extremely sensitive or selective - the local clock oscillator will keep time while it cannot receive the time code during my rare…
oh7lzb
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2 answers

Website for Sat details

I used to use the Amsat website for finding out the status of Sats and other info, like operating frequency etc. It was proving useful, and I like the pass predictor also. Seems nowadays though there's error messages with the database, I get: *…
user521
5
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3 answers

Does a Canadian amateur radio operator’s certificate expire?

I obtained my Canadian Basic with Honours certificate in the late 90's and haven't done much with it since. Was looking to get back into the hobby. Has my certificate expired? Do I need to take the test again?
wkm
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Do vacuum variable capacitors have higher Q than air variable capacitors?

Do vacuum variable capacitors have higher Q than air variable capacitors? They are not commonly seen in tuners or crystal sets. But they are mentioned as superior to air variables for resonating magnetic loop antennas opposite the feed point --…
Paul
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Does the Crystal Radio really work?

I am in 12th std, the reason why I am mentioning this is that we are given a PROJECT to do in Physics subject. And then one day I searched the internet and found this amazing thing called 'Crystal Radio'. And when I showed it to my group(since it is…
radiantshaw
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Relicensing after a decade, can I reacquire my old call sign?

The background, I got a US Tech+ license back in the 1990's when I was in middle school. At the time I did it for the novelty of getting licensed in something and not a bit to imitate my brother. Since I wasn't using the license at the time I let it…
BSteinhurst
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