Dan KD2EE
  • Member for 8 years, 3 months
  • Last seen more than 7 years ago
How do I find a frequency to call CQ on during a contest?
3 votes

You can also use anything with a waterfall display to help you find open space. If you're set up for digital mode operation, you can run fldigi even for CW contests, use that to find the best "gap", ...

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What are the most common RF connectors encountered in amateur radio?
6 votes

Connector use varies based on frequency band and also based slightly on power. The most common that I see, I have bolded, and while they are sorted by band, a VHF/UHF connector can be used on HF - it ...

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What are the electrical differences between smaller and larger coaxial cables?
Accepted answer
2 votes

There are three basic electrical characteristics: characteristic impedance, loss per unit distance, and velocity factor. Most amateur radio rigs and antennas expect to see a characteristic impedance ...

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Buddipole model comparison
3 votes

All of the buddipoles appear to be electrically the same antenna. The mini takes the two longest parts and puts a joint in the middle, so instead of having two 22" parts, you have four 11" parts, so ...

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What type of solder is best suited for radio and electronic use?
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6 votes

First of all, acid-core solder is never used for electronics any more, that just isn't what it's for. I think it's still used for plumbing or other soldering where there aren't sensitive components ...

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Does modulation affect propagation?
4 votes

Usually, the answer is no. While modulation may affect the acceptable Signal to Noise ratio, allowing a given signal to be received from further away or in worse conditions than a different modulation,...

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Are there any antennas I shouldn't use in my car?
Accepted answer
5 votes

There's nothing particularly wrong with them. Cars, being mostly made of metal, do a pretty good job of shielding any RF signals, which is why you probably get worse reception when your HT is in your ...

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Can antennas have reverse harmonics
7 votes

The answer is yes (sort of), but it isn't because of "reverse harmonics". That doesn't actually mean anything. Quarter-wave antennas work for the same reasons as dipoles do - due to the physics of ...

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Do electronic ballasts for fluorescent tube lamps cause HF interference?
2 votes

To the question in your title - do they cause interference - the answer is absolutely yes. However, it's hard to answer which causes more simply because there is a lot of variation between ...

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What causes ground losses in a HF antenna system?
7 votes

While ground effects are common concerns in almost every antenna and radio system, they are particularly important in the case of a monopole antenna. Monopole antennas, including quarter wave ...

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What does TX/RX Exchange refer to?
Accepted answer
10 votes

It's intended for contest logging. Most contests require that you "exchange" some information. Sometimes it's as simple as an RST signal report and you'd just enter whatever signal report you gave an ...

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Power dissipation in transmission lines?
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5 votes

No. The cause of power loss in a feed line is not due to the characteristic impedance, it actually varies among transmission lines of the same impedance. Otherwise all 50 ohm coax would be the same - ...

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How do club codes stay secret?
5 votes

They stay secret because it takes a certain amount of effort and time to decode them - at the very least you need to record the tones and then feed them into a computer program. That means you need to ...

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2m or 70cm FM mobile radio for digital mode operation
8 votes

Sure, most radios have the ability to patch in audio. If it isn't through the front microphone connector, it's through an accessory connector, which is available on every commercial radio I'm aware of ...

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Will anodizing or powder coating or wetcoating (painting) antenna elements affect performance?
2 votes

It almost definitely won't - but there are effects that could be some coatings that would cause problems. It isn't just metal content, there's also the possibility that some coatings could absorb RF ...

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Has a vehicle magnetic antenna mount ever caused a road accident?
1 votes

They can absolutely come off. Here is a forum thread with numerous posters reporting antennas falling off from the wind of passing a semi - it's a storm chaser forum, but the storms weren't even ...

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75 watts and a mag mount antenna
6 votes

It's hard to make guesses about this sort of thing because there are too many different factors. The mag mount antenna certainly is better than your FT60 antenna, and the 75 watts is certainly better ...

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How to improve VHF/UHF Baofeng UV-82 HT reception in vehicle
1 votes

Mag mounts really aren't all they're cracked up to be. You'll see some improvement just because the antenna is outside of the car, but a through-roof mount gives you a good ground connection and no ...

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What is generally considered "too much" power for JT-65 on HF?
Accepted answer
7 votes

5 watts is probably what most JT-65 purists will tell you to use, but in practice, I tend to aim for 20 watts. That gives you a good 6dB boost (every doubling of power is equal to +3dB) which is ...

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Does iron ore in the ground affect my signal?
12 votes

If anything, living in an area with high metal deposits near to the ground will improve your conditions by improving the conductivity of your ground. That said, unless it's very near to the surface ...

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How to calculate power loss between radio and antenna
Accepted answer
4 votes

There are a few possibilities. First of all, in larger assemblies (mostly important in repeater design) each component will have a parameter called insertion loss. This is the loss, in dB, through ...

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Understanding "ground" in ham radio
2 votes

There are two traditional meanings of an electrical "ground". In DC systems, we often refer to the return conductor (the negative lead) as "ground". You won't encounter that meaning very often in ...

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What are CQ/ITU zones used for?
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4 votes

Many contests use them as a convenient measure of how many different "regions" you've managed to contact. Since using countries as a contest multiplier isn't necessarily very accurate (within a ...

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With solid-state equipment, when would one use a dummy load?
Accepted answer
6 votes

Any time you don't want to transmit RF. For example, if you have an oscilloscope and spectrum analyzer and would like to test the output of your transmitter (e.g. to make sure it's on frequency, that ...

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Is Morse code allowed on FM in the USA
Accepted answer
17 votes

Completely legal. In fact, it's common practice to identify repeaters (both in the amateur service and in public safety/commercial) with exactly this method. That said, you likely won't make many ...

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Why do concurrent FM signals not mix together?
Accepted answer
9 votes

I understand why you think it should mix - that's what happens with SSB, for example. The difference with FM is that in FM, at any instant, each station's signal is only at one frequency. If you ...

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When may a ham operate beyond the privileges of their licence class?
14 votes

In the US, any person may operate under the direct supervision of an operator of a higher class. This is how the GOTA (get-on-the-air) stations work at field day, but it's applicable at any time. In ...

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How do I determine antenna spacing?
5 votes

If the antennas are at least one wavelength apart, you could use the Friis transmission equation. This would allow you to determine, based on the power of the transmitter and the antenna gains, the ...

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How do I power my radio in a vehicle mobile install?
Accepted answer
6 votes

While many transceivers and scanners can be powered by a cigarette lighter adapter, you typically want to run at most one transceiver in this way, and should make absolutely certain that you know ...

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How do I discover APRS coverage?
Accepted answer
9 votes

Coverage maps are a thing that is notoriously difficult to do right. There are some very complex programs (Radio Mobile is the one I know the most about) which can generate coverage maps if you're ...

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