I hesitate to use the phrase “product review” for something that’s been out of production for a long time. I used the Wayback Machine to scroll through the listings of the G4000A at Universal Radio. They announced it as discontinued on the archived page for February, 2008, but it reappeared a few years later and was once again discontinued, with their last blow-out sale unit offered in May of 2012. I bought my previous one in 2011.
Features
Here are some of its main features: 🤖
- Compact and Portable Design: Dimensions are 7-3/4”W x 4-1/2”H x 1-1/4”D, and it weighs 1 lb. 5 oz.
- FM-Stereo, LW, MW, and Full Shortwave Coverage: It covers a wide range of frequencies, including 1711-29999 KHz.
- Dual Conversion AM/SW Circuitry with SSB: This enhances reception quality and allows for Single Sideband (SSB) communication.
- PLL Digital Tuner with LCD Display: Provides precise tuning and a clear digital display.
- 40 Programmable Memory Presets: Allows you to store and quickly access your favorite stations.
- Memory Scan and Direct Memory Access: Makes it easy to navigate through stored frequencies.
- Dual 24-Hour Clocks with Alarm, Snooze, and Sleep Timer: Convenient for timekeeping and setting alarms.
- High/Low Tone Control and Wide/Narrow Bandwidth Filter: Offers customizable audio settings.
- Stereo Earphone Socket and Stereo/Mono Switch: Enhances listening experience with headphones.
- DX/Local Switch: Helps optimize reception based on signal strength.
- Built-In Antennas and External Antenna Socket: Provides flexibility for improving reception (SW only).
Specifically the frequencies are:
- LW: 144 – 351 kHz
- MW: 520 – 1710 kHz (10 kHz steps)
- 527 – 1606 kHz (9 kHz steps)
- FM: 85.7 – 108 MHz
- SW: 1.6 – 30 MHz
One attractive feature is the way direct frequency entry is accomplished. With this radio the user enters either the frequency (including a required decimal point on FM), followed by a FREQU/METER button. The radio figures out which band or which frequency by considering what was entered. Below 144 kHz indicates a SW meter band, more digits indicates LW, MW or SW selected based on value, and FM is identified by the decimal point. Meter bands and their frequency ranges are presented on a label on the back of the radio.
Setting the two independent 24-hour clocks is straightforward. Having two clocks is of course convenient for the SWL–one for UTC and one for local time.
There is no regular tuning knob, only a fine tuning knob that works only on SSB. Tuning is accomplished by up and down buttons, plus an Auto Tune button. The one thing I do not like about tuning is the fixed FM step of 50 kHz, which cannot be changed with the STEP button; this means in North America four presses of the button are required to advance to the next frequency.
The radio is powered by 6 AA batteries that it cannot recharge. Plugging in the AC adapter is supposed to disconnect the batteries.
Technology
Most radios introduced today, unlike the G4000A, are DSP based receivers.
🤖Digital Signal Processing (DSP) in a radio receiver involves using digital techniques to analyze and manipulate signals. It replaces traditional analog components with algorithms run on processors, offering greater precision and flexibility.
🤖In a receiver, DSP is used for tasks like filtering out noise, demodulating signals, equalizing distortions, and enhancing signal clarity. For example, it can separate a desired radio signal from interference or apply complex modulation schemes for better performance. DSP plays a critical role in modern radios, making them more adaptable and efficient compared to their analog counterparts. One drawback to DSP radios is that they have to reset their processing each time the frequency changes, resulting in muting or a “chuffing” sound whine tuning.
Older radios such as the G4000A employ analog circuits. Tuning is accomplished by generating a variable frequency local signal and mixing it with the incoming signals. The result is one or more intermediate frequency (IF) signals. One mixing stage is “single conversion,” two is “dual conversion,” and three is “triple conversion.” Each step can amplify the signal, reject images from other frequencies, and increase selectivity. The overall technology is called “superheterodyne” or “superhet.”
In a few modern radios, the analog tuning results in an IF that is then digitally processed to provide more bandwidth control options, noise reduction and demodulation of single sideband signals.
🤖Some radios employ a Phase-Locked Loop (PLL), a control system used to synchronize the phase of an output signal with a reference signal. It ensures that the receiver’s local oscillator locks onto the frequency of the incoming signal, maintaining stability and accuracy. This is crucial for demodulating signals, reducing noise, and improving overall performance in communication systems.
🤖A Beat Frequency Oscillator (BFO) is a component used in radio receivers, particularly in devices designed to process Morse code (CW) or single-sideband (SSB) signals. It generates a frequency close to the intermediate frequency (IF) of the receiver. When the BFO signal mixes with the incoming radio signal, it produces an audible tone at the difference (or “beat”) frequency, allowing the operator to hear and interpret the signal.
The G4000A is a dual conversion PLL radio with a phase looked loop. It decodes CW/SSB using a BFO.
First impressions
This is a big radio, a bit wider and taller than a Tecsun PL-660 but a full inch and a half thick. The antenna is a whopping 37 inches. The speaker sounds very good and the radio can be turned up quite loud although I was fooled at first thinking the volume control wheel on the side turned upward to raise the volume. And at first I thought the shortwave reception was awful — but then I turned off the SSB switch.
The one other step on the Quick Setup list in the manual was also necessary — setting the MW step to 10 kHz.
It chuffs! This is not a DSP-based radio, but because it tunes with a button in discrete steps, there is a distinct chuff every time the frequency changes.
MW/FM Daytime Band Scan
The daytime band scan is always done at home so that every radio is tested the same way. The telescopic antenna is used for FM and MW is tested with its internal antenna on a NW/SE axis where most stations lie.
I make the assumption that in the middle of the day, MW and FM reception are local, and unaffected by the season or the variability in solar radiation. The accumulated results are a quick way to compare many radios. Here are the results:
The G4000A received 21 stations on MW, a virtual tie with the best of the best.
FM was a total mess. I had the Local/DX switch set to DX and the local stations were bleeding all over each other. It’s probably just my unit but the frequency calibration on FM was more than 50 kHz off. While I counted 56 stations, that’s just a wild guess. Weak stations would be lost in the swamp. The radio sounded less murky with sensitivity set to local, but of course that weakens distant stations.
End of Part 1. Part 2 is about shortwave.