A common question I hear from new hams is “how do I get a vanity call sign?” The process is probably harder than it needs to be but certainly something any ham can do. In this article, I’ll keep things as simple as possible, focusing on what a new ham must do to get a vanity call. That is, this piece is focused on the new Technician or General that wants to get a special callsign. As part of the recent FCC license application fees, there is now a $35 charge for an amateur vanity application. (It used to be free.)

The basic steps to getting your special call sign are:

1. Choose one or more call signs that you’d like. 2. Find your FCC Registration Number (FRN) 3. Log onto the FCC Universal Licensing System (ULS) 4. Apply using “Request Vanity Call Sign”

5. Pay the FCC license application fee

To go deeper on this topic take a look at the ARRL page, which describes the vanity call sign program in greater detail.

1. Choose A Call Sign

The first step is probably the most fun, choosing what call sign you’d like to have. I chose my callsign KØNR because of its short length and the traditional KØ prefix. My buddy Stu chose the call sign WØSTU to match his name. Steve WGØAT chose his call sign to reflect his passion for hiking with pack goats. Many people choose a call sign with their initials in it. You certainly may have other ideas on what constitutes the right call sign for you.

Tech and General class licensees are allowed to choose either a 1×3 call sign (beginning with prefix N, K or W), or a 2×3 call sign (beginning with prefix letter K or W), referred to by the FCC as call sign Groups C and D. Of course, you must choose a call sign that is not assigned, which you can check by doing a search on the FCC ULS web site. RadioQTH has a useful tool for searching for available call signs.

You should probably choose a few call signs that you’d be happy with and submit them in order of preference (see #4below). Your first choice may not be available for a number of reasons, such as someone else may have just applied for it.

2. Find Your FCC Registration Number (FRN)

If you have an FCC radio license, you have an FRN. It was probably assigned to you when your license was first issued. Think of this as your user name for the ULS web site. To find your FRN, search for your call sign on the ULS page.

3. Log onto the FCC ULS

Next you need to log into the ULS, which will probably be the most difficult part of the process — select the Online Filing login option. You’ll need your FRN and your password for the site. Hopefully, you just found your FRN but you may not have a password assigned yet. If not, you’ll need to follow the Forgot Your Password? instructions on this page and get assistance.

4. Request a Vanity Call Sign

Once you log into ULS, it should show you a list of licenses assigned to your FRN. You probably only have one, so click on that one to open the License Manager page. You should see a blue menu box near the right edge of the page, titled Work on This License. This menu box includes a Request Vanity Call Sign selection. Continue past the ‘Applicant Questions’ page (answer ‘no’ to each) to the ‘Select Eligibility’ page. Select your category, most commonly Primary station preference list unless you are requesting a vanity call formerly held by you or a close relative. Continue to the next page to provide a list, in order of preference, of vanity call signs you would prefer to be assigned. Continue through the remaining self-explanatory steps of the application process after you have entered your set of preferred call signs.

5. Pay the FCC Application Fee

Follow the FCC instructions on how to pay the $35 application fee.

This should get your application into the FCC for your call sign. It will probably take a few weeks to get action from the FCC, so be patient. Good luck with your new call!

73, Bob K0NR

Postscript

This article provides the basic information for getting a vanity callsign, one that is readily available. Some hams may want to get callsign that has been previously issued, perhaps a 1x2 or 2x1 callsign. (You'll need an Extra class license for that.) Competition for these callsigns is usually strong, so you'll want to apply on the day they first become available, which is usually after the 2 year grace period expires.

Here some tools that will help you figure that out: https://www.ae7q.com/

https://vanities.k2cr.com/

In the world of amateur radio, we use a variety of modulation schemes to encode our voice or digital data onto an RF carrier. These modulation types include Continuous Wave (CW), Amplitude Modulation (AM), Frequency Modulation (FM), Phase Modulation (PM), and Single Sideband (SSB).

CW uses Morse Code to turn the RF carrier on and off, which is a simple form of controlling the amplitude of the signal. For voice communication, AM was developed to impose audio modulation onto the RF carrier by varying the amplitude of the carrier based on the modulating signal. Similarly, FM and PM modulate the frequency and phase of the carrier signal based on the modulating signal.

Like the analog modulation techniques, digital modulation is based on controlling the amplitude, phase, or frequency of the RF carrier. As digital modulation techniques became more common, it became useful to view modulation in a totally different way. Rather than showing the time domain representation of the RF carrier, the phasor diagram shown in Figure 2 shows just the carrier's amplitude and phase. The amplitude is represented by the length of the vector, and the phase is represented by the angle relative to the horizontal axis.

Graphically, we see that the amplitude and phase of the phasor can also be described using the horizontal axis (the inphase component, or I) and the vertical axis (the quadrature component, or Q). These two ways of defining the phasor are equivalent: we can work in terms of amplitude & phase or the inphase and quadrature (I/Q) coordinate components. This observation led to the development of versatile modulators that produce radio signals by controlling these inphase and quadrature components.

The quadrature modulator works by multiplying the inphase signal (I) by a local oscillator while the quadrature signal (Q) is multiplied by the same oscillator shifted by 90 degrees. This corresponds to and maintains the 90-degree relationship of I and Q shown in Figure 2. These two signals are then combined to produce the desired output - a signal of specified amplitude and phase. Again, the key idea here is that by controlling I and Q, the desired phasor shown in Figure 2 can be produced. The phase between the I and Q signals remains constant at 90 degrees but the amplitude of I and Q change based on the modulation being applied. I and Q can be produced based on analog modulation or some type of digital data stream.

As shown in Figure 3, the quadrature modulator is implemented using digital circuits and the I and Q signals are normally a stream of digital numbers representing the modulating signal. This could also be implemented using analog circuits but modern transceivers use digital. At the output of the modulator, a Digital-to-Analog Converter (DAC) converts the digital stream to an analog signal to be transmitted over the air, often with additional analog signal processing.

Binary Phase Shift Keying

Let's examine a simple digital modulation scheme used in PSK31 transmissions, called binary phase shift keying (BPSK). BPSK uses just two phases of the carrier to present either a logic 1 or 0. The amplitude remains constant.

The phasor arrow is shown in Figure 4 for the two different states that the carrier takes on. Often, the arrow is left out of the diagram and a dot is plotted at the place where the arrow would point. Figure 5 shows such a diagram, called a constellation diagram.

Quadrature Phase Shift Keying

PSK31 has another mode available called QPSK31, which uses Quadrature Phase Shift Keying (QPSK). This modulation format also keeps the amplitude constant while changing the carrier into four distinct states.

Because QPSK has four logic states available, these can be used to encode two bits of information. This doubles the digital throughput of the signal at the expense of degraded noise performance.

Although not commonly used for amateur radio, this approach can be expanded to implement Quadrature Amplitude Modulation (QAM), which varies both the amplitude and phase of the carrier. Figure 7 shows 16 QAM, which has sixteen states that can be represented by the carrier, each one representing four bits of information. Again, the digital throughput is increased but at the expense of degraded noise performance. Unlike BPSK and QPSK, the amplitude is modulated along with the phase to create these different states. Now you can see why these plots are called constellation diagrams as they start to look like a constellation of stars in the night sky.

In many high-bandwidth digital communications formats, higher-order QAM is used. For example, WiFi may use 64-QAM, 256-QAM, or 1024-QAM. You can imagine that the constellation diagrams for these modulation schemes get quite crowded, requiring precise signal generation and detection.

Quadrature Detector

A quadrature detector extracts the I and Q signals at the receiver. Figure 8 shows a typical configuration that is essentially the reverse of the modulator shown in Figure 3. A quadrature detector can be implemented using analog circuits but modern transceivers do this digitally. The incoming analog signal is converted to digital form by an analog-to-digital converter (ADC) and then fed into the quadrature detector. The detector multiplies the incoming signal by two oscillators offset in phase by 90 degrees to extract the I and Q information from the incoming signal. The output of the multiplier is normally followed by a lowpass filter to remove any high-order mixing products, leaving just the desired I and Q signals.

Legacy Analog Modulation

We have looked at how I/Q concepts support some of the common digital modulation formats. But what about the common analog modulation types such as AM, SSB, PM, and FM? For AM, it will be pretty simple to use the I and Q modulators to produce an amplitude-modulated signal. SSB is a form of AM so it is similar to the AM case. However, it will require some additional signal processing ahead of the quadrature modulator to eliminate one of the AM sidebands. Analog PM is implemented similarly to BPSK and QPSK, but with an analog (not digital) modulating signal. That is, I and Q are controlled to produce the desired phase shift in the phaser.

That leaves FM, which is a bit more elusive. You may recall that FM and PM are both forms of angle modulation. That is, they both affect the instantaneous phase angle of the carrier. The difference is that for a change in the modulating signal, PM does a one-time shift of the carrier phase on the current cycle only, while FM changes the frequency slightly which affects the phase of the current and future cycles. Well, it turns out that FM and PM are so closely related, that one can be derived from the other using digital signal processing. The net result is that FM signals can be supported as a variation of PM. Again, additional signal processing is required ahead of the modulator.

Software Defined Radio

This brings us to the concept of software-defined radio (SDR), which is a radio design approach that implements as much functionality as possible in software. Many of the traditional analog amplifiers, mixers, detectors, and modulators are implemented using software algorithms.

Figure 9 shows a simplified block diagram of a low-cost SDR receiver. This receiver has an analog-to-digital converter that directly samples the antenna's signal, after the low-noise amplifier. A Digital Signal Processing (DSP) section implements the quadrature demodulator, producing a digital stream of I/Q data. This I/Q data is transferred to an external computer via a USB interface. Most of the signal processing and detection is done in the computer. Because the I/Q data contains all of the signal information, almost any type of signal can be demodulated using the computer software. This is why it is called "software-defined", indicating a high degree of flexibility. Figure 9 shows just a receiver but a similar approach can also be used to create a software-defined transmitter.

Many but not all ham transceivers are implemented using SDR technology. However, the trend line is clear so we will see the use of this design approach increase which will provide all sorts of new radio capabilities at a reasonable cost.

The Technician and General license exams emphasize the concept of impedance matching to achieve maximum power transfer. This is often described as making sure the 50 Ω output of your transceiver drives a 50 Ω transmission line that connects to a 50 Ω antenna. In this article, we will go a little deeper to understand the role that phase plays in power transfer.

Figure 1 shows a resistive source and resistive load connected with the aim of transferring power from the source to the load. Most signal sources such as your transmitter have an internal resistance shown as RS in the figure. The load resistance, RL might represent the antenna or dummy load. The maximum power transfer principle can be stated as: “Maximum power is transferred when the internal resistance of the source equals the resistance of the load, when the external resistance can be varied, and the internal resistance is constant."

Figure 1. Circuit diagram showing a resistive source connected to a resistive load.

Figure 2 shows how the power to the load varies as a function of RL/RS. Power delivered to RL depends on both the current through the load and the voltage across the load. Large values of RL increase the voltage (EL) but starve the current (IL). Similarly, small values of RL increase the load current but diminish the load voltage. A bit of math can show that maximum power occurs when RL= RS.

Figure 2. The plot of PL vs. RL/RS shows maximum power to the load when RL/RS =1.

Complex impedance Now consider the AC case where the impedances are complex, as shown in Figure 3. The source impedance is ZS = RS+ jXS and the load impedance is ZL= RL +jXL. The maximum power transfer occurs when ZLis the complex conjugate of ZS, which means RL= RSand XL = –XS. This is sometimes referred to as complex conjugate matching. As expected, if XS =0, the situation reduces back to the resistive case.

Figure 3. Circuit diagram showing a source connected to a load where both have complex impedances.

It's all about the phase Interestingly, when XL= –XS, the voltage source, ES sees a pure resistance (RS + RL), which means the current out of the voltage source is in phase with the voltage. This is not a coincidence; the phase between the voltage and current waveforms plays an important role in the average power in the load. Let's examine the time domain representations of instantaneous voltage, current, and power for a complex impedance.

Instantaneous power is given by

p (t )= e(t )i (t )

Assuming e(t ) and i (t ) are both sinusoids

where ϴ is the phase difference between the voltage and current waveforms.

Figure 4 shows the time domain waveforms e(t ), i (t) and p(t ) for the case ϴ = 45°.

Figure 4. Plots of e (t ), i (t ) and p (t ) for the case ϴ = 45°.

We will skip the math, but the power equation can be reduced to:

The expression for p (t ) is made up of a constant term and a cosine function at twice the original frequency. We are often interested in the average power in a waveform, which we can find by integrating p(t ) over one waveform period. The double frequency cosine term will average to zero, leaving only the constant term, so that

The plot of p(t ) in Figure 4 shows that the instantaneous power varies sinusoidally and even goes negative for part of the cycle. This is going to happen for all cases where ϴ does not equal zero. Also notice from the plot the average value of p(t ) is positive, indicating that power is delivered to the load.

Power engineers use the concepts of True Power and Apparent Power to quantify the effect that phase has on power. True Power represents the actual power transferred, which includes the effect of the phase between e and i , measured in units of Watts. Apparent Power is a more simplistic concept of just the raw current times the voltage, measured in units of Volt-Amps or VA to distinguish it from True Power.

Power engineers also use the concept of Power Factor (PF),

And it turns out that for sinusoidal waveforms, PF is equal to the cosine of the phase angle between the voltage and current waveforms.

Power Factor is a straightforward way to describe how much of the apparent power is being translated into useful (true) power. If ϴ = 0, then True Power and Apparent Power are the same and PF =1. When ϴ = ±90°, the True Power drops to zero and PF = 0. The example shown in Figure 4 with ϴ = 45°, PF = 0.707, which means that the True Power is 70% of the Apparent Power.

Wrap up We’ve reviewed the basics of maximum power transfer and the importance of phase relationships, tying it together with the power engineering concepts of power factor, true and apparent power. I intentionally ignored any discussion of transmission lines but these power transfer concepts have a lot in common with the usual transmission line concepts (standing wave ratio, return loss, reflection coefficient).

73-- Bob KØNR