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1500 questions
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1 answer

Using NanoVNA to tune antenna

I'm extremely new to this, so I'm mostly asking for tutorials and so on. I have tried configuring the device according to one tutorial I found. When I hook up the cheap antennas that came with a couple of my radios. I could see the attenuation dips…
Jesse Knott
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60kHz WWVB receiver help

I have built a large ferrite loopstick antenna based off this video. I live in Washington state and am trying to receive and decode WWVB. I can get my antenna to resonate at 60kHz with ~700 pF of capacitance. I am lost on the receiver/preamp…
Max686
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What are the geographical restrictions in using the 70cm band in the United States of America?

Geographical restrictions exist for various frequencies in terms of usage in the United States of America as stipulated in 47 CFR 97.303. What are the restrictions, if any remain, in terms of geography where you cannot use all or part of the 70cm…
Stephen Michael Kellat
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How can an HT antenna be half wave?

There's a model of HT antenna for the GMRS band by Nagoya (NA-771G) that's specified as a half wave. How can that be? An end fed half wave antenna needs a 49:1 impedance transformer to match with the transmitter? Is it more like a 5/8 or 3/4 wave…
Paul
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2-blade or 3-blade coax stripper: when would you use one vs the other?

I've been looking for a RG8x/LMR240 coax strippers and found that they come in both 2-blade and 3-blade models. So far I haven't found a reason to use one over the other. I did notice that the 3-blade version does not list rg8x specifically (only…
KJ7LNW
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Can an American General licensee operate in Portugal during a visit?

I am an American and I have an American General License (k8axf), and I tried to make sense of all the legal documents to see if I can operate while visiting Portugal and I think I can under a CEPT CAT 2 Novice operator. Can anyone verify if my…
Alan K8AXF
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Are there any modes that use pseudo-random noise codes to "amplify" signals?

GPS for example uses them to allow receivers to decode extremely weak signals far below the noise floor. From https://blank005.tripod.com/gps/psedo_random.html : If we tuned our receivers to the GPS frequency and graphed what we picked up, we'd…
2080
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Chimney Flashing Affect on Dipole Antenna Resonance

I put up a 40m dipole off a metal mast attached to a chimney mount on a 25' roofline. The chimney has metal flashing on the top with a metal spark arrest dome on top. I have 125' of RG8X feeding an MFJ 1:1 Balun which is strapped to a metal mast and…
K5KUE - Conrad
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How does tuning in 2.4 GHz Wifi radios work?

I'm working with a Wifi chipset that has very poor documentation and I was wondering whether I should wait a bit after switching the channel or if I can send a Wifi frame right away. That's when I realized that I have no idea how tuning in Wifi…
AndreKR
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What frequency ranges are most common for Amateur radio astronomy and why are most parabolic antennas tuned to such high frequencies?

What frequency ranges are most common for amateur radio astronomy? I am mostly interested in radios for the purpose of astronomy. In general I was expecting that the lower frequencies would be more useful, since hams usually can receive and transmit…
Hack-R
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3 answers

Power connector for a HPA

I've got two Kuhne's HPAs rated at 12V, 10Amps. The HPAs have power connectors circled in blue. Is there a specific jumper with a compatible head that I could plug directly into this connector? I'm trying to avoid soldering if possible.
Moses Browne Mwakyanjala
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Why do radio operators sometimes use meters and other times use hertz?

I understand the conversion between meters and Hz, kHz, MHz, etc. but I don't understand why ham operators frequently switch between using one or the other.
Hack-R
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After I call out "Monitering" how long should I wait until I switch frequency?

Sometimes, when I am trying to make contacts, I call out on a bunch of repeaters due to low activity on individual repeaters. I usually call out, wait 10 seconds, then change repeater. Is there a specific length I should wait to see if anyone is on…
Skyler 440
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What is the radiation pattern and feedpoint resistance of a raised feed point vertical?

If you put a vertical 1/4 wavelength antenna on a pole of about 15 feet and tie the base of the pole to a massive grid of radials and the ground itself how does it affect the radiation pattern and the feed point resistance? It is like an infinitely…
david
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Using old vehicle through glass cell antenna

My old (2001) Seville had a cell phone with antenna mounted on the rear glass. The coax connects inside the glass, with signal passing through the glass to the whip mounting plate. I'm wondering if I can use the old cell antenna mount (through…
TSG
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