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DAB+ conversion kit for tube radios

mstrey@strey.biz — Mon, 07 Dec 2015 10:00:00 +0200

Since autumn 2014, I am endeavouring promoting and selling the DAB products of the Korean chip maker Glovane. Though nobody makes consumer radios anymore in old Europe and even their development takes place in Shen Zhen more and more. Nevertheless, besides the development departments of car radio manufacturers who request Glovane's automotive chips of the GL351X series, there are still some niche markets even for the GVM140X DAB modules.

A first project of this kind is a nifty conversion kit of the German company HSE Schmidt Elektronik that allows to turn a vintage valve radio into a modern DAB+ receiver. The interesting thing about that is that the radio remains virtually unchanged and can be operated in exactly the same way as before. Even the tuning indicator, the Magic Eye, works as usual and, if the pointer on the scale is between two DAB services, noise is coming out of the speaker. Key to this solution was the ingenious idea to replace the mixer tube of the tuner by a new receiver module. Following this concept, Herbert Schmidt and his colleague, Gerhard Oed, already had made a FM conversion kit for AM radios. The tuning voltage is available at the socket of the mixer valve and it is possible to feed-in the amplitude modulation signal from the receiver module. The plate-supply acts as power supply for the module. With Glovane's module becoming available even in small quantities, finally the way was free for the DAB solution.

Figure 1: The DAB conversion kit for tube radios consisting of two parts. Below the main board a corner of Glovane's stamp-sized DAB module GVM140H01 is visible. Its RF input is directly connected to the antenna cable.

After a good amount of work, a well tested solution is available now that already stands the test in the first customer radios. The two PCBs the solution is consisting of are still assembled by hand at HSE Elektronik. The adaptation to the certain type of radio and its tube socket needs some manual labour and know-how. HSE Elektronik is therefore looking for craftsmen who are specialized on refurbishing of vintage radios and who want to integrate the conversion kit into their offer. With this prospect of larger sales quantities, it would become possible to rework the conversion kit for industrial series production with SMD components. Thus the kit could become much smaller and more economic in production.

Figure 2: The conversion kit mounted in a Philips Saturn B6D41A from the 1960s. On the left side, the antenna cable leads out of the photo. The conversion kit consists of two parts and thus even fits into devices with little space around the mixer tube that has to be replaced by the conversion kit.

DAB module GVM140X

mstrey@strey.biz — Fri, 21 Nov 2014 00:00:00 +0200

With the DAB modules of the GVM140X series, the Korean chip maker Glovane accommodates to the growing demand for economically priced receiver modules, that allow to built high quality portable and stationary DAB receivers easily and with minimal number of external components. The modules base upon the DAB chips of the GL314X series, and thus inherited all the features of these SoCs.

The following modules are belonging to the GVM140X series:

Master module GVM140H01: This module is intended for devices where the radio function clearly dominates the over-all functionality.
Slave module GVM140S01: This module was made for multi-purpose devices that already have their own controller that shall be used to control the DAB module.

Figure 1: Block diagrams of the master module, GVM140H01, and the slave module, GVM140S01, respectively.

Glovane's business offer comprises not only the receiver module and an appropriate development kit but as well development services for customer-specific hard- and software adaptations.

Development kit

Figure 2: The evaluation kit for the GVM140H01 module is already a complete portable radio.

The development kit of the GVM140X demonstrates the functionality of the module and allows access to the application interface via its USB port. At the same time, it is already a complete battery-powered device with integrated loudspeakers, thus allowing the evaluation of the module in daily use.

The evaluation kit demonstrates impressively with how few external components a full-featured DAB+/FM receiver can be built.

DAB SoC GL351X

mstrey@strey.biz — Fri, 21 Nov 2014 00:00:00 +0200

The DAB decoder chips of the GL351X series from the Korean Manufacturer, Glovane, are so called systems on a chip (SoC) that are developed for the specific needs of the manufacturers of car radios. In particular

they comply with all requirements of the automotive industry regarding environmental conditions and reliability (AEC Q100),
as GL3512D, they contain two DAB demodulators that can be either used for diversity reception or for tracing a second ensemble in the background,
they are equipped with an integrated audio processor with service following engine for seamless DAB to DAB and DAB to FM service following,
they are optimised for use with an external host processor, that will be required in any case in order to control the various functions of a modern car radio.

Other than the SoCs of the GL314X series of the same manufacturer that are designed for applications in consumer devices, the chips of the GL351X series do not have integrated RF tuners. Instead of that, the baseband signal can be supplied in analogue form or alternatively via a digital baseband input, thus gaining a high flexibility for system design.

Table 1: Comparison between the members of the GL351X series
	GL3512D	GL3511S	GL3510C
Package	169B, 11 × 11 mm², 0.8 pitch	169B, 11 × 11 mm², 0.8 pitch	161B, 8 × 8 mm²
Service Following	seamless DAB to FM & DAB to DAB	seamless DAB to FM	DAB to FM
SDRAM	8 MB	4 MB	2 MB
Baseband	Dual diversity demodulator	Single	Single

Glovane's business offer comprises not only the SoCs and an appropriate development kit but as well development services for customer-specific hard- and software adaptations.

DAB SoC GL314X

mstrey@strey.biz — Fri, 21 Nov 2014 00:00:00 +0200

The DAB chips of the GL314X series, built by the Korean manufacturer Glovane, integrate as so called systems on a chip (SoC) various functions belonging to a DAB receiver on one 11 mm × 11 mm BGA chip. On the chip are integrated:

the analogue RF front end for DAB in band III and L-band and for FM in band II,
the demodulators for DAB and FM,
a 32 bit RISC controller with up to 100 MHz clock rate and real time operating system (RTOS)
audio decoders for DAB (MUSICAM), DAB+ (HE-AAC V2), as well as for MP3, WMA, and OGG,
an interface controller for digital audio in- and outputs,
a digital analogue converter with analogue audio output,
an USB interface,
2 or 8 MB memory resp. with the appropriate controller,
a display controller for the direct connection of an LCD,
an analogue digital converter for the monitoring of an external battery and to interface a key matrix,
an internal DC linear voltage regulator (LDO) reducing the number of required external supply voltages.

With their integrated RF tuners and low power consumption of only 103 mW in DAB+ operation, the SoCs of this series are predestined for portable and mobile battery powered devices. The GL3142 is most favourable for mobile applications. In addition to the functions of the GL3140, this chip offers seamless service following between DAB and FM as well as functions for recording and playback. With this feature set, this chip is suitable as well for retrofit receivers to upgrade older car radios with DAB+.

Table 1: Comparison of the members of the GL314X series
	GL3140	GL3142
Package	169B, 11 mm × 11 mm (pin compatible)
Support	DAB/DAB+/DMB-A/FM-RDS
		MOT/SLS
		Recording/Playback,
		Seamless DAB-FM Service Following
SDRAM	2 MB	8 MB

Glovane's business offer comprises not only the SoCs, receiver modules of the GVM140X series, that are derived from them, and an appropriate development kit, but as well development services for customer-specific hard- and software adaptations.

In software aspects, in addition to the audio decoding, Fast Information Channel (FIC) decoding, and decoding of the data services, MOT and Slidshow, is provided by the software development kit.

News

mstrey@strey.biz — Thu, 13 Mar 2014 00:00:00 +0200

Version 2017.9 of DAB-XPlorer available

October 31, 2017 — The newest version of the DAB-XPlorer can be downloaded from the website of Ingenieurbüro Mulka. At the same place, you will find the release notes with a complete list of improvements compared with earlier versions.

STREY becomes sales partner of GLOVANE

December 8, 2014 — STREY Consult undertook the representation of the Korean company GLOVANE in German speaking countries. GLOVANE's track record with DAB reaches back to 2001; in 2011 the company was founded under its today's name. GLOVANE is manufacturing highly integrated systems on a chip (SoC) and DAB receiver modules. We will sell GLOVANE's products to Germany, Austria and Switzerland.

Supervision of synchrony in DAB SFNs by measuring the temporal position of DAB signals

mstrey@strey.biz — Wed, 29 Aug 2012 10:00:00 +0200

An essential feature of the quality of single frequency networks is the time synchronisation of the transmitters. The same COFDM signal is emitted by all the transmitters at the same time — except for a time lag of a few microseconds sometimes intentionally inserted for reasons of fine-tuning.

Figure 1: Service areas of a single frequency network consisting of seven transmitters in different operation states. The respectively covered area is printed in green.

Figure 1 illustrates what happens if this synchronisation condition is not met. It shows the service area of a single frequency network consisting of seven transmitters, computed with a simplified propagation model. The service area in the case of a synchronisation failure (b) is smaller than that resulting from the failure of the transmitter in the center (c). It is therefore absolutely necessary to react promptly to a synchronisation failure.

In order to compensate varying delays during the transmission of the signal from head end to the transmitter locations, a dynamic delay compensation is generally applied today with time stamps inserted into the ETI signal. In such a DAB single frequency network, the time position of the emitted COFDM signal is determined; time marks in the transmitted DAB signal, such as the periodically occurring Null Symbol, occur at the same, reproducible time at all the transmitters in the single frequency network.

The principle of synchronisation monitoring applied for the SDMB 100 and the DAB-XPlorer with UEB400-DXP receiver takes advantage of this fact in order to detect synchronisation failures. Both devices continuously monitor the time of transmission of a particular Null Symbol with respect to a standard time. Whilst the UEB400-DXP uses its integrated GPS receiver as time standard, the SDMB 100 relies on an external 1 PPS clock in combination with the time delivered by an NTP server. Optional an internal GPS receiver is avialable for the SDMB 100 as well.

Figure 2 shows which time marks within the DAB signal are used for synchronisation monitoring.

Figure 2: Time marks in the DAB signal in the time interval. The figure shows the first section of a transport frame of a length of 96 ms (mode I), with the synchronisation channel consisting of Null Symbol and Phase Reference Symbol. After the decoding of the FIC contents, the CIF counter from FIG 0/0 is also available.

At the start of each Null Symbol, the DAB receiver integrated in the monitoring device provides a periodic frame trigger signal; its time position can be correlated to the 1 PPS pulse given by the internal or external GPS receiver with an exactness of one microsecond by appropriate hardware.

Figure 3: Measurement principle of the time position of the Null Symbol during stationary on-site monitoring.

The CIF counter encoded in FIG 0/0 of the FIC counts the Common Interleaved Frames (CIF) modulo 5,000. A CIF has a length of 24 ms; a CIF counter 0 therefore occurs exactly every 120 seconds. With the help of the CIF counter from the decoded FIC, we can determine to which frame the frame trigger used for the determination of t_n in figure 3 belongs. The time of the pulse per second used for the measurement is also known, either from the integrated GPS receiver or from NTP. Thus it is possible to compute the time of the start of the Null Symbol belonging to the frame with CIF counter 0. The time difference Δt between the 2-minutes limit of the standard time and the start of the Null Symbol of frame 0 is the value measured in microseconds by the monitoring device as the quality criterion for the synchronisation.

Figure 4: Definition of the delay as the time difference between the 2-minutes limit of the GPS time and the occurrence of the Phase Reference Symbol in the transmission frame, which includes a Common Interleaved Frame with the counter 0.

In the case of an error-free operation, the delay Δt must remain constant at a transmitter location during the entire runtime of the single frequency network (i.e. as long as the multiplexer is not shut down). If this value is also identical from transmitter to transmitter, we can speak of an ideal synchronisation of the network. The delay Δt, measured with a resolution of 1 microsecond, can have values from 0 to 119 999 999 µs.

Analysis of DAB audio errors with the DAB-XPlorer

mstrey@strey.biz — Wed, 29 Aug 2012 00:00:00 +0200

I’m sorry, this article is only available in German.

Analysing structured traffic information — TPEG Decoder Software

mstrey@strey.biz — Fri, 17 Aug 2012 00:00:00 +0200

The TPEG Analyser allows the graphical representation and interpretation of several data streams in real time, as well as the interpretation of recorded data. Meaningless byte data streams turn into TPEG data blocks that are easy to analyse. At first glance differences between the various services can be spotted, and the most important parameters can be compared.

Under www.WEcanTPEG.com bmt is offering further TPEG products and services.

TPEG applications and toolkits

RTM / TEC / TFP / PTI / PKI / SNI / CAI / FPI / LRC / MMC / DLR1 / TMC / ETL / GLR

Demonstration video

Demo video

The TPEG Analyser from BMT can be very well combined with the DAB-XPlorer from Ingenieurbüro Mulka.

ETI-Analyser — DAB-XPlorer

mstrey@strey.biz — Fri, 17 Aug 2012 00:00:00 +0200

For historical reasons the term DAB-XPlorer stands for two things a) the DAB-XPlorer software suite providing a collection of software tools to analyse DAB data streams and b) for the DAB-XPlorer hardware providing an ETI/RDI-to-USB interface. Originally, both the software and the hardware have been one product, the DAB-XPlorer, developed and manufactured by Ingenieurbüro Mulka. In the course of the evolution of this product, the software was modified and extended to support additional hardware products from other vendors. At this time the DAB-XPlorer software suite supports and can be delivered with

the ETI/RDI-to-USB converter DAB-XPlorer from Ingenieurbüro Mulka,
all Ethernet interfaces that can be used to receive EDI data streams,
the DAB test receiver UEB400-DXP provided under the trademark VAD, and
the products of VDL’s DABSTOR family.

The DAB-XPlorer software application is modular. The following tools are available:

Ensemble Viewer
ETI-XPlorer
FIC-XPlorer
FIC-XTractor
PRBS-Analyzer
Message Viewer
Recorder / Player / Timeshift Buffer
RDI-ETI-Converter
GPS-Campaign-Converter
Triggered Recorder

Together with the various hardware options, the software modules can be combined to support a great variety of use cases by broadcasters, transmitter network operators and manufacturers.

The DAB-XPlorer can be combined with BMT’s TPEG Analyser.

STREY - (RSS Feed)

DAB+ conversion kit for tube radios

DAB module GVM140X

Development kit

DAB SoC GL351X

DAB SoC GL314X

News

Version 2017.9 of DAB-XPlorer available

STREY becomes sales partner of GLOVANE

Supervision of synchrony in DAB SFNs by measuring the temporal position of DAB signals

Analysis of DAB audio errors with the DAB-XPlorer

Analysing structured traffic information — TPEG Decoder Software

TPEG applications and toolkits

Demonstration video

Related products

ETI-Analyser — DAB-XPlorer

Related products