Glenn W9IQ
  • Member for 4 years, 8 months
  • Last seen more than a week ago
3 answers
6 votes
752 views
Alinco DJ-500T handheld radio will not transmit, why?
5 votes

This indicates that you are attempting to transmit out of band. This is typically a symptom of having the wrong offset (+/-) programmed for that channel. If you visit the Alinco FAQ page you will ...

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3 answers
4 votes
421 views
Antenna suggestions for 160m band in smallish yard?
5 votes

Almost any 160 meter antenna is a compromise. With limited space or budget, the compromise tends to be larger. At first glance, a dipole that is shortened by loading coils might appear quite ...

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1 answers
3 votes
184 views
Electrical Earth
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5 votes

Congratulations on getting permission to install an antenna. There are many hams that rent that would love to be in your position. As Phil correctly asks, why do you need an earth connection? Here ...

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1 answers
3 votes
99 views
Antenna Patterns and Multipath Effect
5 votes

On HF (1.5 to 30 MHz) amateur radio operators use antennas with the major directive lobe close to the horizon in order to maximize the distance the signal will travel. At these frequencies the signals ...

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4 answers
4 votes
2k views
Can a CB SWR meter be used for HF amateur bands?
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5 votes

Many hams have re-purposed CB SWR meters but there are so many variations that some caution and testing is warranted. Many CB meters were not designed to handle the higher power levels of amateur ...

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5 answers
5 votes
2k views
How important is the impedance and resonance of a receive antenna?
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5 votes

The answers given so far provide good food for thought. I would like to add a slightly different perspective. Today's home is loaded with sources of RFI (radio frequency interference). Routers, ...

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2 answers
7 votes
1k views
What is the maximum number of turns in a ferrite core used as a common mode choke?
5 votes

The primary issues with coax wound common mode chokes are; The inductive reactance of the choke can cancel out the capacitive reactance associated with the feedline shield thereby worsening the CM ...

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6 answers
4 votes
7k views
BF-F8HP: "Radio did not respond" when trying to use CHIRP
5 votes

The most common error is not selecting the correct COM port for the virtualized USB cable.

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2 answers
2 votes
3k views
How do you calculate the field strength at a given distance?
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5 votes

The field strength in volts/meter as a function of effective radiated power and distance is given by: $$E=\frac{7.01\sqrt{P_{ERP}}}{d} \tag 1$$ where d is the distance from the radiating antenna in ...

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3 answers
3 votes
468 views
How do I get my crystal radio to receive?
5 votes

This design of a crystal radio relies on the capacitance of the antenna and the inter-winding capacitance of the inductor as well as the inductance of the inductor to form the tuned circuit. The ...

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3 answers
1 votes
495 views
Weird Harmonic Issue on Raspberry PI FM Transmitter
5 votes

You are observing a practical example of harmonics. Harmonics of a Square Wave You do not mention how you are generating the signal with your Pi but it probably uses a simple square wave generator. ...

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2 answers
3 votes
2k views
How low can a vertical dipole be mounted?
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5 votes

Here is an analysis of a vertical, 1/2 wavelength, 2 meter dipole suspended at various heights above ground: As you can see, as you raise the bottom end of the antenna from near ground level up to ...

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1 answers
1 votes
347 views
Intermittent High SWR
5 votes

The MA5B is rated for 1,200 watts PEP. 200 watts is certainly well below that threshold. Things to check: Arcing, corrosion or moisture inside the match box A loose or corroded connection from the ...

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3 answers
4 votes
741 views
Why are carrier waves necessary?
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5 votes

The simplest answer is that the modulating signal, while it could be electromagnetic, will not have the desired propagation characteristics to carry out effective communications. By mixing the ...

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1 answers
8 votes
384 views
SWR Measured at the Transmitter versus SWR at the Antenna
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5 votes

Given the matched loss of the feedline and the SWR at the transmitter, we can calculate the SWR at the antenna in three simple steps. First convert the SWR at the transmitter to the corresponding ...

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2 answers
3 votes
2k views
Using two short mobile HF antennas to make a vertical dipole
5 votes

To begin the discussion, it is helpful to understand the effects of shortening any antenna to a length below resonance. In all cases, the directivity of the antenna is reduced but this tends to be a ...

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4 answers
5 votes
1k views
Can a vertical antenna be used for NVIS?
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5 votes

Knowing that 1/4λ verticals are known in VHF/UHF applications to have nearly isotropic patterns This is not a valid assertion. A UHF/VHF vertical antenna has > 0 dBi gain (more succinctly a ...

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4 answers
5 votes
10k views
UV-5R 4W BFB297 vs UV-5R 8W BFP3-23 (difference 4W vs 8W)
5 votes

The exact answer is given by the Friis equation. If you double the power, your range will increase by 1.413 times whatever it was before doubling the power if you change nothing else. This assumes you ...

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1 answers
3 votes
78 views
Can I estimate range of a low power transmission based on power (in mW)?
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5 votes

When a transmitter and receiver antenna are in line of sight with one another, we can calculate the effective loss of the path based on the distance between the transmitter and receiver antenna, the ...

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2 answers
2 votes
89 views
Antenna Q vs pattern shape
5 votes

In general for a given antenna evaluated on a given frequency, if whatever is changing the Q occurs uniformly or universally and does not result in a change to the effective aperture, phasing, or ...

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6 answers
4 votes
620 views
Cordless phone consistently experiencing RFI
5 votes

If the interference is coming into your telephone via the RJ-11 cable, then the type of ferrite material you use to suppress the interference will matter. Engineers refer to the type of ferrite as the ...

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3 answers
1 votes
383 views
Would the antenna described work?
5 votes

The purpose of a turnstyle antenna for satellite work is to generate a circularly polarized radiation pattern off of its axis. By adjusting the phasing of the feed to the two crossed dipoles, the ...

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2 answers
4 votes
2k views
My Baofeng UV-5RV2+ will receive a signal with rubber duck antenna but not with a new Nagoya
5 votes

The fact that you have a static free signal when you press the monitor button or open the squelch sounds like you may have CTCSS or DCS decode (receive squelch) turned on. This feature is normally ...

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1 answers
3 votes
2k views
Difference between Iambic keyer modes?
5 votes

An iambic keyer is used with two paddles. The concept is that you can hold down one paddle, say the dah paddle, to send out a string of dahs. While doing this, if you tap the dit paddle, it will ...

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1 answers
3 votes
174 views
Why is repeater post-xmit "burst" stronger than repeated signal?
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5 votes

You are probably experiencing what is called "desense". The strong signal of your transmitting radio is getting into the receiver on the receiving radio and blocking its ability to receive the ...

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2 answers
3 votes
480 views
Antenna connector name
Accepted answer
5 votes

That is a standard female SMA connector.

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2 answers
2 votes
201 views
What equipment and software do I need to read raw civilian GPS signals on my Mac?
4 votes

Start with a GPS receiver that outputs NMEA data. This data will be made available through a serial connection such as RS-232, USB, or Bluetooth. Pick a serial connection that you can use with your ...

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1 answers
1 votes
514 views
Should I add call signs with /R suffix to the logbook?
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4 votes

FT8 decoding can use a technique called a priori (AP) whereby it uses naturally accumulating information for the purposes of increasing apparent sensitivity by about 4 dB. There is an increased chance ...

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3 answers
3 votes
2k views
Baofeng DM-1801 DMR: Language switched to Chinese
4 votes

According to the manual: This radio supports both Chinese and English language. The menu functions as follows: Press [MENU] to enter menu mode. Press [ ]/ [ ] to set, then press [MENU] to select. ...

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3 answers
2 votes
930 views
Why long wire antenna length shouldn't be a multiple of λ/2?
4 votes

Start with a standard 1/2 wave, center fed dipole. Close to earth, the impedance will be ~50 ohms with very little reactance. Now start moving the feedpoint towards either end of the antenna and the ...

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