Glenn W9IQ
  • Member for 4 years, 8 months
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1 answers
4 votes
229 views
Two way ham radio to communicate between two stations
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6 votes

The answer to your question involves both technical and regulatory issues. Technical Considerations Radio signals can travel between two locations on earth either by line of sight or by propagation ...

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1 answers
1 votes
740 views
How the performance of the half wave dipole antenna changes as the length changes?
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...if you have a full wave dipole antenna, there would be no transmission... Here begins the misunderstanding of antenna directivity, antenna efficiency, and antenna impedance. Let's analyze each one ...

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3 answers
5 votes
1k views
Are Americans the only hams with four-letter callsigns?
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The type of call signs that you referenced are referred to as 1x2 (one by two) call signs in the USA. Due to the limited number of such call signs and their historical significance, these are the most ...

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1 answers
3 votes
379 views
Using a Duplexer and Diplexer in Series
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Yes, it will work with the proper attention to details. I have done the same in the past at two repeater sites to take advantage of the coverage of the dual band antenna. Do take care as the third ...

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2 answers
5 votes
2k views
Dipole antennas: Will paracord hold up well enough in the sun? Is there a better alternative?
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Paracord is a usurped and abused term for a wide variety of cords. The US Military previously specified 6 different types of paracord. It is also known as parachute or 550 cord. Originally constructed ...

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1 answers
6 votes
697 views
What is "Billion Code" for garage door openers from around 1996?
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The billon code refers to a generation of transmitters that could transmit up to ~3.5 billion different codes. Although there were a large number of codes possible, the transmitter always transmitted ...

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1 answers
3 votes
804 views
What is the turn spacing on a Helix Antenna?
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During his long career, J.D. Kraus studied, and experimented extensively with, helix antennas. There is a large body of published work in college text books on this subject. The following summarizes ...

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1 answers
1 votes
659 views
DC connector type for Baofeng UV5R base charger
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The plug used in the Baofeng base is a 5.5 mm/2.1 mm barrel connector. However, you cannot simply parallel a bunch of base charger units and power them off of a single AC or DC adapter without ...

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4 answers
3 votes
333 views
QSL cards and distance minimums
6 votes

You may also wish to consider electronic QSL sites like eQSL and Logbook of the World. These types of sites allow QSL information to be automatically exchanged between stations. In many cases, they ...

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1 answers
10 votes
267 views
Does Coax Limit the Maximum SWR a Transmitter 'Sees'?
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The source of the SWR limit on the transmitter end is the losses in the feedline. In general, the higher the matched line loss, the lower the maximum SWR that will be present at the transmitter end. ...

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2 answers
3 votes
2k views
proximity of rain gutter to dipole antenna
6 votes

The gutter will be in the near field of the dipole. It may affect the tuning of the dipole or its radiation pattern, but it will not "short out" the dipole as long as the dipole wires are not in ...

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6 answers
11 votes
625 views
Key CW on zero crossings - zero bandwidth?
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You raise an excellent question and your thought processes are indeed on the right track. First some background. An ideal, uninterrupted sinusoidal carrier has zero bandwidth. Real world factors such ...

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3 answers
2 votes
243 views
Does a paint-can dummy load have high voltage on the metal can? Would an insulated container be better?
6 votes

The metal exterior enclosure is an important component for a dummy load. The metal acts as a shield, containing any electromagnetic energy inside the can. Getting a shock is not an issue since the ...

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2 answers
5 votes
8k views
Can I use a CB antenna with a ham radio?
6 votes

Congratulations on earning your General license! You may get the antenna to work using the internal antenna tuner. Make sure the antenna is on a large groundplane. Try tuning it up with low power (&...

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2 answers
5 votes
1k views
How to transmit images and video through a hurricane?
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In general, the HF bands (1.8 MHz through 30 MHz) do not have sufficient bandwidth to support live transmission of a video signal. In the US, the FCC does not authorize an emission mode for live video ...

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5 answers
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4k views
HF Noise Level S5 to S9+18
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Some troubleshooting ideas: Check your radio's power supply for noise by substituting a battery and disconnecting the PS from the wall. Run your receiver on a battery and turn off your main breaker. ...

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1 answers
1 votes
222 views
Need a ferrite suppression material for choking 15 kHz to 60 kHz
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I don't think it will work to add suppression to the fence. The fence charger is designed to support heavily reactive loads by generating pulses every second or two. The pulses are formed by dumping ...

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1 answers
1 votes
458 views
What is the equation for the arm lengths of a half wavelength dipole antenna?
5 votes

There are several factors that come into play in determining the length of a center fed 1/2 wavelength dipole - all of which center on the notion of a near resonant feedpoint impedance. To begin with,...

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1 answers
1 votes
106 views
Cabling question between two devices
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RG-174 cable does not offer very good shielding. This can be a significant problem when you are attempting relatively high levels of attenuation as the cable leakage may provide more signal than the ...

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2 answers
1 votes
103 views
Toroid Coupling Issue in Common-base Amplifier
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The problem is most likely the type 43 core material. It is quite lossy at 21 MHz and is a poor choice for the auto-transformer. Unlike a transmission line transformer, the auto-transformer relies on ...

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3 answers
3 votes
2k views
Pair of Baofeng BF-888s stopped communicating after reprogramming - what to do
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5 votes

One other setting for each channel that may be giving you problems is Duplex/Simplex. Make certain it is set to Simplex or equivalently "no offset". This feature, when turned on, causes that channel ...

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3 answers
3 votes
4k views
How thick should counterpoise wires be?
5 votes

The purpose of the counterpoise is to provide an efficient means of conducting the return RF current of the antenna. In the absence of an efficient counterpoise, the current will return through the ...

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2 answers
6 votes
1k views
Feed-through Capacitors
5 votes

Feed-through capacitors are still commercially available but their use in commercial applications has fallen off so prices have risen over the last few years. The concept with the feed-through ...

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3 answers
6 votes
929 views
Impedance Matching between RF Amplifier Stages
5 votes

There is no need to "pin" an interstage impedance. You may directly transform from the native output impedance of one stage to the native input impedance of the next without going through an ...

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2 answers
1 votes
465 views
Wiring questions: grounding, attic antennas, BNC connectors
5 votes

If you are in a jurisdiction that requires compliance with the US NEC (National Electric Code), you will probably find that there is no requirement for grounding the cable or having a lightning ...

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4 answers
12 votes
4k views
Capacitive hats on wire dipoles?
5 votes

A capacitance hat used on a shortened antenna ($\le$ 1/8 λ for verticals and $\le$ 1/4 λ for dipoles) converts a largely triangular current distribution with the maximum current at the feedpoint, to a ...

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2 answers
2 votes
3k views
Effective area of a dipole
5 votes

The preferred term is effective aperture. Effective aperture is defined as: $$A_e=\frac{\lambda^2}{4\pi}G \tag 1$$ where $\lambda$ is the wavelength of operation and G is the linear gain of the ...

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4 answers
3 votes
2k views
Is a copper J-Pole antenna better than a Slim Jim for transmitting?
5 votes

The slim jim antenna has no more or less gain than a J pole antenna - despite many Internet claims to the contrary. Any perceived difference in gain is likely due to CMC (common mode current) since ...

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1 answers
4 votes
157 views
Why is the insertion loss of my coax cable higher than expected?
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5 votes

Based on your description, I would suspect moisture damage. Moisture ingress in coax cables typically results in the corrosion of the copper braided wires in the shield. The oxide that forms ...

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8 votes
393 views
How were 1920s hams able to measure megahertz frequency?
5 votes

The US National Bureau of Standards (NBS) had a system for basic measurement of frequencies as early as 1911. They used very basic calculations to determine the resonance of an LC circuit. The math ...

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