Nanfone CB-328

Nanfone CB-328

CB Radio Wide frequency: 25-30Mhz

Product Details

  • PC programming
  • Automatic change power supply 12/24V
  • Hight 12W/low 4W power switchable
  • Wide frequency: 25-30Mhz
  • Auto scanning
  • Dual channel standby
  • Backlight selective (red, green, blue)
  • ANL function
  • ASQ
  • Big LCD display
  • CH9/19 emergency channel

Functions

The station in functional terms is not something outstanding, it has everything you need to work on the air and almost nothing more.

Nanfone CB-328

  1. (POWER) button to turn the radio on / off. With the radio turned off, a short press turns on the station. When the radio is on, a short press inverts the color scheme on the display. A long press on the switched on station turns off the device.
  2. Button (MT / LOCK) a short press on the included radio turns off the speaker, Mute mode. A long press turns on / off the key lock. All keys except PTT and POWER are locked.
  3. The buttons (VOL + / VOL -) are used to adjust the volume of the radio station. The station does not have a minimum volume control. Either 0, when there is no sound at all, or 1, which already has a certain minimum volume level.
  4. The (CH UP SCAN / CH DOWN SCAN) buttons are used to switch channels and adjust menu parameters.
  5. The buttons (SQ ASQ + / SQ ASQ- / ASQ) are used to control the squelch. The ASQ button switches the type of squelch, threshold SQ and spectral ASQ, and the +/- buttons allow you to change the adjustment of the selected type of squelch (the current setting is displayed in the upper left corner of the display, as well as its current setting).
  6. The (BAND / M1) button is used to select the frequency grid and store channel 1 in the memory of the radio station (via the MEM / FUNC button)
  7. The button (-5kHz / M2) is used to select the frequency standard 0/5, as well as to save 2 channels of the radio station memory (via the MEM / FUNC button)
  8. The button (AM / FM / M3) is used to select the type of modulation AM – amplitude and FM – frequency, as well as to save 3 channels of the radio station memory (via the MEM / FUNC button)
  9. The button (15D-AM / M4) is used to quickly switch the radio station to the truckers channel, as well as to save 4 channels of the radio station memory (via the MEM / FUNC button).
  10. Button (MEM / FUNC) a short press allows you to work with memory channels, a long press allows you to get to the menu of the radio station.

Work with memory channels

The station has 4 memory channels for quick access to the desired channels. To write a channel to memory, you must select a channel, modulation, frequency standard, then briefly press the MEM / FUNC key and while FUNC is lit on the display, press and hold one of the M1-M4 keys until M appears on the display (1- 4) approx.

The channel is recalled from the memory in the same way, only the M1-M4 key does not need to be held, just a short press

Menu

In order to get to the menu, you must press and hold the MEM / FUNC button. In this case, the station should be on an arbitrary channel. If you recall a channel from memory, you will not be able to get to the menu until you leave the selected memory channel.

  1. POWER (HI / LO). The output power of the radio station (8W and 4W, respectively).
  2. NB (ON / OFF). Turn on / off the jammer. Simultaneously with the inclusion of NB mode, a Hi-Cut filter is activated, which cuts off the high frequencies in the received signal and reduces the load on the hearing aid of the operator. Why these functions are not spread across different points is a mystery. In fact, these are two completely different functions.
  3. DIMMER (0-2). Adjust the brightness of the display backlight.
  4. AUTO RFG (ON / OFF). Turn on / off the automatic attenuator in AM (anti-plug). It is recommended to keep it on always!
  5. RFG (0-6). Adjustment of the built-in attenuator. But this point should not be touched if you do not clearly know why to reduce the sensitivity of the station.
  6. SCAN (SQ / TI). Setting the channel scan mode, by timer or by squelch.
  7. M-SC (?). Apparently, setting the way to scan memory channels.
  8. CH-VFO (CH / VFO). Switching a station from channel mode (CH) to frequency (VFO).
  9. AUTO ON (ON / OFF). Control of the automatic inclusion of a radio station when applying power to it. In other words, the station will automatically turn on when power is supplied to it.
  10. BEEP (ON / OFF). Turn on / off the beeper keys.

Nanfone CB-328 Inside

Quite interestingly organized internal arrangement.

Nanfone CB-328 Inside

 

The board of the radio unit is not on top, as is usually the case with other radio stations, but on the bottom, and all the components are turned upside down and stand on the board rather than hanging, if we take other manufacturers as the standard. There is no washed flux on the board, but, as I understand it, this phenomenon is temporary and applies only to the first test batch.

The station’s processor is also very unusual, it is a rather powerful ARM, STM32F103, but this is not surprising, since on board we have a display almost like a cell phone, and someone should manage it, and everything else too.

Switching voltage converter. The station can be powered by 13.8V and 24V. There are no problems using the truck. The converter microcircuit itself is screwed to the chassis through thermal grease. Very well. It does not create any interference with the receiver.

I tried to power the radio station both directly, bypassing the converter, and through the converter, no decrease in the sensitivity of the receiver and other interference was noticed.

At the entrance are diodes filled with “Sopleton” preventing polarity reversal.

This is a definite plus. The station will not burn from the classical problems associated with the carelessness of the user, namely from 24V and, in fact, polarity reversal.

There was supposed to be a Bluetooth module, the same one, for working with a wireless headset.

Typically, he was on an engineering model and looked like this.

The VCO is hidden under the screen, that’s good. The second module is not soldered, which should have been difficult to say here. It is also important that the VCO is removed from the speaker, which reduces the likelihood of acoustic ties.

The DAC on the M62364FP is located nearby, for which it is needed here, it’s not very clear, most likely it is a volume control, which, by the way, unlike the Optim Voyager , does not work in steps and jerky, but smoothly, I like it.

Apollo inherited two filters of the first intermediate frequency, which is also good.

In general, in circuit design, the Optim Truck receiver is very similar to the receiver Apollo and this is great, since the Apollian receiver was designed quite competently, it was simply copied practically unchanged in Optim Truck and correctly done.

ULF performed on the usual TDA2003 . Here, as in Apollo, a modulation transformer is used.

The output stage is built on transistors 2SC2314 and IRF530 and is hidden together with the low-pass filter behind a blank metal screen, which is also very good.

If you quickly analyze the circuit, you can see a lot in common with the circuitry of AnyTone radio stations. In fact, the Nanfone guys just copied the company’s successful solutions. Good or bad, it’s hard to say. But in general, the station is showing itself not quite badly.

Practice use

I skated with this radio station for about a week or two. The station was installed in my Chevrolet Lacetti personal car. It was powered by a cigarette lighter, and the antenna served as a Lemm AT-2001 Turbo embedded in the roof.

What is our asset. A good sensitive receiver, modulation, in my opinion, is quite controversial, if everything is more or less normal in FM, then in AM the signal is somewhat jammed and deaf, it really lacks volume. There is no difficult way to make it much more readable. The station sounds pretty nice, the sound spectrum is well-chosen.

Noise suppressors work quite adequately. The threshold squelch has hysteresis, which positively affects its operation. But that is not all. In this station, the operation of noise suppressors is partially detached from the AGC system, unlike how it is done in most other radio stations, as a result, interesting effects appear in the work.

For example, strong fluctuations in the signal strength do not affect the operation of noise suppressors, and noise suppression does not close even with a strong drop in transmission intelligibility. In other words, the station works out very well interference and fading.

It is very comfortable to listen to the walkie-talkie on the move, the noise cancelers hardly clap. I also really liked the work of the machine. However, in FM, the noise canceler is “tailing”, that is, it passes noise before closing, and we hear a loud PShShShSh from the frequency discriminator striking our ears! In AM, noise cancelers work great! Management, as I already wrote, is quite convenient, you get used to it quickly.

And the intuitive adjustment of noise suppressors is a completely different story, you just need to use this to evaluate it. The idea behind this visualization is great! It remains to bring it to mind, but this is a purely software task, from the point of view of iron, the station works wonderfully.

About firmware

It is worth mentioning the processor firmware, since these stations are closely related to the processor in almost all functions, which is both good and bad at the same time. This is bad, since it is impossible to promptly, surgically, influence some moments in the behavior of the radio station, as it could be done previously on analog devices, this can only be done through firmware, but on the other hand, this is good, as the Chinese correct firmware quite quickly. so software upgrades are likely to be possible.

Now directly about the firmware. The first copies of these stations were with glitches. Later they were fixed, and the radio stations with new firmware work great! So if you are not comfortable with the work of your radio station, most likely you just have an old version of the processor firmware.

How to determine the firmware version? Visually nothing! It is not reflected anywhere, it is not indicated, there is no menu where you can see it, you can only understand if there are certain problems in your station or not. For example, in normal mode, we press the 15D-AM button and the station at us switches to a frequency of 27.135 MHz in amplitude modulation, while the frequency at the top of the display starts flashing.

The problem is that in this mode on the old firmware you cannot switch to zeros, that is, switch to the frequency of 27.130 MHz. The station will simply not respond to your attempts. In the new version, everything is fixed, everything switches.

This is not the only glitch of the old firmware, but I will not describe all of them, it makes no sense, this is enough to check. With the new firmware, the station works fine, the only thing that annoys is the loud PShShSh in FM when closing the noise cancelers. But, I think, over time, this point will also be fixed.

The performance characteristics

  • Frequency Range: 25.615-30.105 MHz
  • Number of frequency channels: 400E + 400R
  • Transmitter Output Power: 4 to 8 W
  • Sensitivity: FM at 12 dB sinad 0.5 μV / AM at sinad 10 dB 0.5 μV
  • Squelch Type: Threshold, Auto (ASQ), Adjustable
  • Modulation Type: AM / FM
  • Supply voltage: 10.5-30 V
  • Maximum current consumption: no more than 3 A
  • Antenna Connector Type: UHF-female (PL259-Female)
  • Sound power of the speaker: 4 W
  • Operating temperature range: ° С -10 … + 50 ° С
  • Dimensions: 178x46x158 mm

Summary

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