KB2LJJ Radio Mods Database and Manuals
Contents
1. fanatics This is the mod you all have been waiting for Are you one of the proud owners of a TR 9500 9000 or TR9130 Is your display erratic and flickering as 95 of these still existing radios on the planet Then this is the cure you have been waiting for during the last 25 years This mod was created because this phenomenon was getting on my nerves and I was so sad nobody did something about it we even kept buying their rigs the TS 930 with the rotten finals the TS440 with the VCO gum problem the TM255 455 with the distorted SSB TX audio the TR2600 with the noisy synthesiser yes we all know that kenwood sucks but the re still on the market I do like the 2000 however but the user interface is designed for aliens So far the commercial break Back to basics Essentially there are three different problems with this rig s processor board Most units I saw suffered from more than one problem Here we go Please start by downloading the service manual from this site I will use the original kenwood reference numbers Don t send me silly mails to ask for foto s showing the component locations If you are a decent ham you do know how to read a schematic and trace components on a board If you re not stop reading and start watching Oprah on the telly The gossip is that the print batch suffered from bad via s this is what the plated through holes are called THIS IS NOT THE TRUTH The whole problem is purely thermal Bad design That s w2. is getting boring and check the voltage on pin 21 of the processor and pin 16 of both other IC s this voltage must be over 4 5 Volts If not ok also check the soldering of D5 This should cure most of the problems There are some other faults I found on some units I just mention them to get you back up and running if the above tips weren t sufficient Defective Q3 1 5 Volts Vbe and no Ic Replace by any NPN transistor but observe pinout Defective Q9 replace by any 7805 and try to improve cooling or increase value of R15 21 to 150R Defective open D1 zener if you have bad luck your processor is toasted by the 8V but I saw some survive this This is it from your favourite Radio Doctor and Transceiver Guru If this mod was useful for you please drop me a small mail with your repair adventures This keeps me motivated to post these funny mod files If you are really wealthy your donations are accepted to keep my multiple repeater sites on the air so I can use my hobby money for my own fun Pedro M J Wyns ON7WP AAQHX Postpigeon Moutstraat 7 B 2220 Hallaar http www kb2 jj com data kenwood tr 9500 htm 3 di 4 31 08 2009 23 59 56 KB2LJJ Radio Mods Database and Manuals Belgium Europe E Mail ON7WP pandora be Remember it is Illegal to transmit out of band This Modification is for Informational purposes ONLY Doing such modifications on your radio may void any warranty and damage your equipment All mods found on thi
3. KB2LJJ Radio Mods Database and Manuals Contact Downloads Radio NWilods Database Niods Manuals ancl Circuits R2 JJ http iww kb 3ljj com www r6 ru4montesecchieta it IZ5CCV TR 9500 fuer 9600bd Hallo 9600 Baud Fans l l Modifications for the Kenwood TR 9500 i l hier ein kurzer Hinweis wie ich mein 9600 Baud Modem von G3RUH an meinem Kenwood TR9500 angeschlossen habe Verbesserungen sind sicherlich moeglich Die Empfangs NF nehme ich ab an der Verbindung R42 R43 auf der IF Unit Das Sendesignal speise ich ein an der Verbindung C18 C19 auf der CAR Unit Die PTT Leitung verdrahte ich wie gewohnt Nun viel Spass beim High Speed PR auf 70cm TRIO TR 9500 UHF All Mode Problems and Modifications 1 For a long time I had this problem on my TR 9500 after a short or long time sometimes 3 30 mins some other times after several hours or days all digits of display are turned OFF except the 2 decimal points Even if without frequency display the radio working normally on TX amp RX 4 Remove the upper cover Now you are looking for the Control Unit which leaves behind of Front panel see my photos By using a long amp bent terminal for your Volt meter check the Voltage on pins 3 4 5 of 74LS247N Q11 TTL BCD to 7 segments If you measure a LOW logic Voltage below of 2 5 3 Volts on these 3 pins the problem is here from some cold solder into PCB The correct Voltage on these Pins it must be 4 8 5 Vol
4. closed the receiver is de activated and as above mentioned the ON AIR Led on Front panel is being lit see picture below Under this condition the transmitter is ready but without Carrier s emission Carrier on the air you have just when the CW Key is pushed down RF GAIN RIT If you need an automatic activation of ST BY that is possible by using a Timer ie 555 timer that it could be activated from CW Key and http www kb2 jj com data kenwood tr 9500 htm 2 di 4 31 08 2009 23 59 56 KB2LJJ Radio Mods Database and Manuals it will keep the ST BY closed through a small relay or switching transistor for a short time ie 0 1 3 Seconds Thus you will have the well known Delay a very common amp useful ability on other transceivers But if you want a QSK Full Break in operation for CW it s much simpler In this case you don t need any SEND switch or Timer Just connect your CW Key to ST BY Jack Yes directly to ST BY and NOT to the KEY Jack Thus every time where your Key is pushed down you have Carrier On the Air but the internal Relay inside of TR 9500 seems to feel not very comfortable especially if you are a super fast CW operator As you know under QSK mode the internal Relay is following your Key step by step Bad news for Relay s health 73 Mak SVIBSX ON4WP s article Fixing TR 9000 9130 9500 display boards Who says technical articles are boring Hello vintage kenwood all mode rig
5. hat Kenwood stands for not that the other brands are any better they just want to get richer using cheaper components all the time There are mainly three possible problems 1 Disappearing display segments Mostly the rigs powers up ok and after some time the christmas tree starts blinking The causes are bad solder joints at the 7 series resistors R15 21 of the display leds If you are good at soldering and have the tools desolder them clean the board and resolder them preferably using silver solder having a higher meltdown point Only resoldering will also help but only temporary It might be a good idea replacing them by 1 2 W resitors having a bigger body so better thermal behaviour Even better is replacing them all by 150R units This lowers the visibility but decreases the heat Haven t tried this myself but I suggest it would be even better Better a faint display than no display at all 2 Disappearing complete digits Same thermal problem at the 5 driver transistors Q22 26 Resolder using preferably silver solder 3 Resetting processor Unit jumps to 3 000 or 5 000 during operation This is caused by unsufficient voltage at the processor You won t believe this On the board is a test point TP1 next to Q10 This big test pin is soldered on both sides of the board but this solid pin behaving as a bad resistor is the reason why the processor doesn t get sufficienty juice Resolder it on both ends again using silver solder this
6. nd Manuals Unfortunately even if re soldered all tracks onto down side of PCB the problem is unsolved On the other hand the Upper Side s re soldering is a really difficult job The Upper side is densely populated with various components The most holes are between these components and sometimes very very close to component s legs Thus is impossible to put your solder iron s nose without possible damage For this reason I suggest the by pass method by using short pieces of cables or wire wrap Trust me Click to enlarge fotos T S247 Control Unit Board of TR 9500 removed 2 Tips for CW Mode On Rear panel of TR 9500 you will find the Jack for CW Key Even if you connect here a CW key the radio is denied to transmit on CW You need also to connect another Mini Jack on the 2nd hole of Rear Panel that is named ST BY Stand By In other words firstly it should be connected in ST BY Jack a switch and when that is ON then it will be lit the ON AIR Led on Front Panel After that your CW KEY is ready for transmittion If you have the original Kenwood s Base for TR 9500 and TR 9000 this unit including the SEND switch precisely for this operation Because you havn t this Base unit it s very rare it s necessary to put on ST BY a small external Switch Every time you need the CW Key in order to send dashes amp dots this switch it must be closed Keep in mind that when the ST BY switch is
7. s database are offered to me by other amateur radio hams or captured by Packet system KB2LJJ take no responsibility or liability for any damage done resulting from any modification ATTENTION The KB2LJJ takes no responsibility for any damage during the modification or for any wrong information made on this modification http www kb2 jj com data kenwood tr 9500 htm 4 di 4 3 1 08 2009 23 59 56
8. ts in other words just the same with Pin 16 VCC of 74LS247 Be carefull during Voltage measurement any accident here ie short circuit with terminal should be probably the source for a serious malfunction inf Easy solution solder a by pass short cable from 5V TP Test Point with these Pins on the upper side of PCB Thus you will save time and hard work which is necessary to de assembling the Radio in order to be able to remove the Control Board Unfortunately this PCB is a real garbage It is not just the very very bad quality of PCB but the main problem it s the dozens of passes holes between Upper amp Down side of double side PCB as these passes are without Plated holes Thus the good connectivity from the upper to down tracks depend on the solder These solder points through the holes after several years of operation they seem to be not good enough especially into the holes which it goes through high enough current like the 5V TTL feeding voltage ees Sa T 7 i a z i a 23022925322 DB A r T e gi a w f E ce tata aes r wists ee epseee i zr Cte Pat ye ri m UE a F a wane sr Al else B g Ap i Se Sota pia eee T ETE ei pee ee N Rana ee ee ge seer rete n phidh H 3 IUEI axe Po Te Sato ee ae oa op oy THELA Te e erie yp eca Me 2 PESTES TTo EEEF ETETE i http www kb2 jj com data kenwood tr 9500 htm 1 di 4 31 08 2009 23 59 56 KB2LJJ Radio Mods Database a
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