TS440 DSP
Contents
1. this saturation level is not reached The adjustment of P1 the output level is made easily As for P3 which controls the beeps volume it should be adjusted to be able to correctly control the DSP by the sound Photo 3 Manufacturing of the support to fix the DSP module The flat part approximately measures 40 mm x 40 mm ne i P Er i Photo 4 T Wr support is fixed on the TX frame on a fixing point of the IF Unit board The main board and the command board are fixed on the support with a two part epoxy adhesive The mass is screwed on a board fixation in bottom of the photo The wire is plugged in pin 2 of the connector J3 orange wire with 8V in the white connector Photo 5 The TS440 in modification You can see the DSP module installed in top on the left of the IF Unit board which was raised 2 B Use of the push button Voice to control the DSP The control of the DSP module without seeing the LED control only by the beeps is very easy Only by hearing its effectiveness is such that you immediately recognize if it is on or off by the noise level especially on the low bands In case of doubt making a cycle Stop Start makes possible to check operation You can also see the red LED through the ventilation holes when the system does not function As for the DSP level you can control it entirely by the beeps in the loudspeaker In the left higher angle of the front of the TS440 you find2. The answer is yes and the result is really spectacular We will see where to find this DSP and how to install it in a transceiver The fitting was made in Kenwood TS 440 as an example it can be adapted to many transceivers as well as receivers Just a remark to benefit of all the possibilities of the DSP you need that the chain of reception is already well filtered in particular by the very selective filters on the intermediate frequencies The DSP in a radio receiver In a transmitter or receiver various methods are used to be able to make understandable the weakest possible signals in the noise A significant step was made by the use of DSP Digital Signal Processor to detect the useful signals Many recent transceivers and receivers are equipped with this technology The DSP functions by digitalization then treatment of the signals A DSP is built around a specialized microprocessor Now more and more often we find DSP on BF of the modern TX and we begin to see DSP on the last IF However its remains a complex and expensive technology reserved for top of the range TX For the non equipped transmitters or receivers we can find devices connected on the earphones output These systems MFJ Telereader or bhi NEIM 1031 for example can be connected on the audio output of the receiver and mainly function like adjustable filters and like noise reducer We also begin to find loudspeakers with an integrated DSP which notably improves the ratio si
3. connection of a positive tension 2 C Use and operation of the DSP When the TX is switched on the DSP remains in a non service state but it sends a number of beeps corresponding to the state where it was at the time of the preceding stop The LED lights in red under the ventilation holes of the TS440 A one second pressure on Voice and you hear a short beep of confirmation of order the red LED dies out and the DSP starts to function on the level where it was previously In one or two seconds you can hear the background noise disappear and then the correspondent can be heard clearly The effectiveness is impressive One second short pressure on Voice and the DSP stops functioning and you hear the background noise to go up immediately If you push more longer the PB Voice the DSP passes sequentially by the various levels level 1 then 2 3 4 then 1 and the cycle starts again It is necessary to stop at the selected level This level can be identified by the series of beeps heard in the loudspeaker When the various levels are tested you can very clearly hear the reduction of the noise according to the level of the DSP With the use level 1 or 2 very quickly becomes the usual level Level 4 is to be used in the event of difficulties of reception because the voices start to be transported by bubbles in water But even while being limited to the first 3 levels the effectiveness is remarkable Summary To tell the truth when you have teste
4. entirely be ordered by the pushbutton Voice on the front face of the TS440 When the TX is fully assembled you can see the red LED through the ventilation holes As soon as you push one second on the PB Voice the DSP is on You can initially hear the operation by the beeps then by the loudspeaker sound nes Voice Synthesizer is net inside this push button is available to control the DSP Photo 7 Preparation of two wire connector between the command board of the DSP and the PB Voice The connector is made with from a standard Harwin style 0 1 pitch pin header The wire colours purple and blue were chosen to conserve the colours used in the J54 connector which arrives on the Control Unit board Photo 8 View of the back of the TS440 front face which was rocked The PB Voice is connected to the Control Unit board by the J54 connector which should be dismounted This connector is very easily locatable with its two wires only blue and purple on a connector with 6 pins and its proximity of the setting diodes of the TS440 microprocessor On this photo this connector is half raised is not plugged any more in the Control Unit board it is now connected only to the connecting cable with DSP module Photo 10 The two other wire ends are welded in parallel with the legs of the push button of the command board of the DSP module Attention to strictly respecting the colours because the pushbutton functions by ground
5. Short Wave Magazine Dec 2003 pp 32 33 6 http Awww bhinstrumentation co uk html nedsp1061_pcb html http www bhinstrumentation co uk html nedsp1 061 kbd html 7 Service Manual TS440 documentation Kenwood 10
6. Translation of the article Comment installer un DSP dans un emetteur recepteur non equipe Comment donner une seconde jeunesse a un TX d il y a quelques ann es Published by the French magazine MEGAHERTZ Issue n 271 octobre 2005 pp 34 39 http www megahertz magazine com How to install the bhi DSP Noise Cancelling Module into a non DSP transceiver or receiver How to give a new life to an old Transceiver Jean Paul YONNET F1LVT F1LVT yahoo fr This article shows how it is possible to fit a DSP in a not equipped transceiver or receiver By using a module made by the British company bhi Ltd we will see how the fitting can be made and how the system functions As an example the insertion of this module was made in Kenwood T8440 which allows testing its operation and appreciating its performances Photo 0 How to install a DSP in a non equipped transceiver or receiver Part 1 DSP and bhi NEDSP1061 KBD module Everyone cannot buy a modern transceiver wit the latest technologies of filtering to improve the reception The most recent add on is the DSP Digital Signal Processor which constitutes a notable progress in very weak signals detection in the noise We have begun to find these DSP on the audio frequencies and even now on the last IF carrier because it is necessary to treat the signal as soon as possible in the reception chain But for the older TX is it possible to improve them by integrating a DSP inside
7. acitor that you must remove TEA 3 Part of the EEN of the TS440 IF Unit board onni the BF chain When you follow the BF signals you go successively by Preamplifier Q12 Coupling capacitor C69 to be removed for the DSP fitting J2 connector of the volume potentiometer C7 BF amplifier J4 loudspeaker connector IF UNIT X60 1300 00 Component side view Figure 4 Comporient location The C69 eh is located between the 2 transistors Q12 and Q13 The signal arrives on the pin of the condenser to be connected to Audio In red wire and goes out near Q13 to be ed to Out Audio blue wire The other located points are the mass connections in top on the right photograph and the 8V on the J3 connector Photo 2 The corner of the board IF Unit as saw when the upper case is removed You can see the C69 capacitor at the rear behind C76 between the 2 connectors J2 blue and J6 white close to board edge You can also see the J3 connector white with its orange wire connected to the 8V 2 A Fitting of the DSP module It is initially necessary to open the case of the TS440 and to locate the various elements correctly It is also necessary to make the support bracket which will be used for fixing the module inside the transmitter Photo 3 Fitting of the DSP module 1 Remove the upper and lower parts of the TS440 case 17 screws to be removed The IF Unit board a
8. d the effectiveness of the DSP module on the reception you cannot hear the radio traffic without it Even if the cost of this module is not negligible about 140 euros all included this cost remains very modest compared to very spectacular improvement which it brings on the receiver audio The presented DSP was fitted in a Kenwood TS440 a powerful transmitter receiver and rather largely widespread but is about fifteen years The bhi NEDSP1061 KBD DSP module brings a second youth to it and allows it to partially catch up with technical progress which is made regularly on the performances of newer receivers Its complete name which was TS440SAT with the coupling unit integrated should now become TS440SAT DSP The bhi NEDSP1061 KBD DSP module can in the same way be integrated in many other receivers or transmitters But it is necessary to have the circuit diagrams to make the modification References 1 Kevin Nice NEIM 1031 Noise Eliminating In Line Module Short Wave Magazine March 2003 pp 45 46 2 Denis Bonomo F6GKQ bhi NEIM 1031 et NES 10 2 Eliminez le bruit MEGAHERTZ Magazine n 250 Jan 2004 pp 18 19 3 Chris Lorek G4HCL DSP Noise Reduction Module for Yaesu FT 817 RadCom Dec 2003 pp 24 25 4 Denis Bonomo F6GKQ Reducteur de bruit DSP pour FT 817 bhi NEDSP 1061 MEGAHERTZ Magazine n 252 Mars 2004 pp 20 22 5 Kevin Nice In the Ed Shack the NEDSP 1061 inside ICOM R 8500
9. e grey cable Wire connected to the supply red wire connected to a point for a supply between 5 and 15 V Mass wire to fix on a screw mya Output Overload Input EO ieee LED level P2 Pushbutton Keyboard PCB Bi Colour LED Mounting holes Bel Ta9 Red wire 4 off 5 15VDC Beep volume NS control P3 Figure 1 Module NEDSP1061 Doc bhi On this drawing the two boards of the module are represented On the main board you can see the 3 potentiometers of adjustment P2 for the input level P1 for that of output and P3 for the beep level as well as the LED which indicates the overload On the command board the two colour LED which indicate the state of the DSP and the push button for the operation control can be seen Screened Audio Lead Audio In Out Remove this Coupling Capacitor Pre amp Loudspeaker Control Power Amp Place the NEDSP1061 In place of the Coupling capacitor Figure 2 Fitting of the NEDSP1061 module Doc bhi You must insert the module at the place of the last coupling condenser before the volume potentiometer Part 2 Fitting in a TS440 and DSP operation The fitting of the DSP module is relatively easy when you know where and how to insert it In the TS440 the module was fixed under the upper case near the ventilation holes above the rear part of the IF board This place is near the capacitor to be removed as well as a point with 8V for
10. gnal noise like the NES 10 2MkIl of the British company bhi R1 2 The company whose name bhi is written with lower case letters builds specialized DSP modules which can be integrated in non equipped transceivers or receivers like YAESU FT817 or KENWOOD TS50 R 3 4 or in the professional range of ICOM Radios You can find information in English magazines like Practical Wireless or Short Wave Magazine bhi also makes also a generic DSP module called NEDSP1061 KBD which can be integrated inside receivers 5 in the BF part before the final amplifier It is this type of module that we will present photo 1 Documentation is available on bhi s website www bhi ltd co uk but it exists only in English for the moment 6 We can suppose that the French version will follow soon The principal interest of this integrated module is to work on constant level before the BF amplifier More the signal treatment is made early in the reception chain more it is effective The module NEDSP1061 KBD Photo 1 shows this module It is very small the dimensions of the main board are only 36 mm by 26 mm The main integrated circuit is soldered under the board The small switch control keyboard 16mm X 10mm has a two colour LED and a pushbutton Connexions are only four BF input BF output a wire connected to supply and a wire for the mass It is necessary to fix the main board in the receiver not too far from the BF chain and the small switch con
11. lso necessary to connect the supply The DSP module can be supplied between 5V and 15V and its consumption is about 45 mA As for the maximum audio level it must be about 300 mV RMS on the input level of the DSP Audio In Where to find this module DSP module The company bhi sells its products by a network of distributors Ordering the module NEDSP1061 KBD on the website is only possible for the countries where no distributor exists In France the distribution is by company GES well known of the French ham radio GES holds especially in stock the module adapted to Yaesu Ft 817 The electronic part of the module for the FT817 is identical to the generic module the difference is only in the fitting and the support or fixing Anyway for the fixing support it will be necessary to make one adapted to your TX or your receiver The fitting in a receiver In this article we will describe the fitting of this bhi module in a transmitter Kenwood TS 440 It is only an example because the module can be fitted in very many receivers or transmitters The results are really spectacular The very weak signals in the noise become clearly audible When you install this type of device in a receiver the improvement is so impressive that you cannot use your TX more without it Photo 1 DSP module NEDSP1061 KBD from bhi The central part is connected to small command board with a pushbutton and a LED Connections are done by input output BF cabl
12. ppears under the upper cap it is articulated on its metal support 2 Dismount the board IF Unit of its support 7 screws to be removed to be able to have access to the tracks It is not necessary to dismount the different connectors it is enough to raise the board to be able to reach the tracks 3 Unsolder and remove the C69 capacitor 4 Weld in the place of C69 always on the track side the connection cables of the DSP module red wire Audio In on Q12 side and blue wire Audio Out on Q13 side and mass on point GND of the J2 connector of blue colour 5 Reassemble now the IF Unit board with the cable going up on the side of the board 6 Connect the supply of the DSP module The mass of the module is connected to the mass of the TX see Figure 4 and Photo 4 The red wire is plugged in the connector J3 orange wire with 8V 7 Fix by two sided adhesive the DSP module on the support Photo 4 8 Test the DSP module All must function Photo 5 With the power on the red LED of the command board must light A second pressure on the pushbutton and the DSP gets on the LED emits some green pulses then dies out beeps are heard in the loudspeaker at the same time as the pulses It is the moment to adjust the potentiometers P2 P1 and P3 on the board Attention the potentiometers do not have stop The input level must be adjusted by P2 for the maximum of level without saturation detected by the LED near P2 In a TS440
13. the supply As for the piloting of the module we have used the key Voice so that no drilling is necessary in the TX case First of all it should be noted that the DSP will be more efficient if the receiver is correctly filtered i e will be equipped with sufficiently narrow filters For example for the TS440 it is preferable that it is equipped with the adapted quartz filters at 8 83 MHz Figure 3 shows the TS440 IF Unit schematic more precisely the BF part 7 The BF signals come from the Q12 preamplifier and then go to the volume potentiometer connected to the connector J2 they are then amplified by IC7 The coupling capacitor between the BF preamplifier and the potentiometer is C69 which is a polarized electrochemical condenser of 0 1 uF It is this capacitor which must be removed to insert the DSP The component location on the TX board is presented on figure 4 The C69 capacitor is located between the 2 transistors Q12 and Q13 The signal arrives on the pin of the capacitor to be connected to Audio In red wire and goes out near the Q13 side to be connected to Audio Out blue wire The other located points are the connections of mass in top on the right photograph and the 8V on the J3 connecior On photo 2 you can see the part of the IF board corresponding to figure 4 seen from the lateral side The C69 capacitor is situated near the board edge with its clear part indicating his negative pin It is this cap
14. the command of the option VS1 Voice Synthesizer If VS1 is not installed this push button is available to be able to control the DSP Photo 6 In the contrary case it remains the traditional solution which consists in making two holes in the upper case We will see how it is possible to command the DSP with the push button Voice One of the difficulties comes from the fact that the pushbutton is not insulated but it is connected in a circuit with a diode You should be careful for the connections 1 Prepare connection wire The connector with 2 pins is manufactured with a Harwin type pin header Photo 7 The wire colour purple and blue was selected to conserve the colours used on the connector J54 2 Dismount the two higher screws which retain the front face and to make it rock downwards Take away the shielding that protects the back of the Control Unit board Locate the J54 connector near the setting diodes of the microprocessor Disconnect the J54 connector from the Control Unit board Photo 8 3 Insert the two wires cable in the J54 connector Photo 9 4 Connect the cable to the DSP command board by welding the two wires on the pins of the push button Photo 10 Attention with the respect of wire colours because the two systems the PB Voice and the PB of the command board are polarized The PB of the DSP functions by ground connection of a positive tension and PB Voice is in series with a diode The DSP module can now
15. trol keyboard in an accessible place for example near the upper case Figure 1 presents the DSP module The main board has the adjustment potentiometers The input signal is adjusted by P2 In overload case of the DSP input the LED near P2 light up It will be necessary to adjust P2 to avoid this saturation P1 allows the output level regulation after signal treatment by the DSP The beep level generated by the DSP at the starting phase and level modification is adjusted by P3 As for the control board it has a two colour LED that is red when the DSP is not in service and which transmits green pulses at the adjustment phases The starting and the adjustments are made by the push button It is possible to obtain four levels of signal treatment characterized by a number of beeps from 1 to 4 11 dB 13 dB 20 dB 35 dB Table 1 The four levels of filter adjustment of the NEDSP1061 KBD The fitting principle is shown on figure 2 It is necessary to place the DSP in BF line where BF level is constant i e before the volume potentiometer It is necessary to remove a coupling capacitor to catch the BF signal on preamplifier side to be connected to the red wire Audio In and to send the signal after the DSP treatment towards the volume potentiometer to be connected to the blue wire Audio Out These wires are shielded it is necessary to solder the shield onto a point of mass close to the capacitor which was removed It is a
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