Kenwood Th 75e Manual Transfer
This manual or by KENWOOD documentation. • When using a regulated power supply, connect the specified DC cable (option) to the DC IN jack on the transceiver. The supply voltage must be between. 12 V and 16 V to prevent damaging the transceiver. • When connecting the transceiver to a cigarette lighter socket in a. TH-45 instruction manual. TH-46A.AT.E service manual. TH-55AT TH-55E service manual. TH-75 schematics. TH-75 user manual. TH-75A TH-75E service manual. TH-77 instruction manual. TH-77A 77E schematics. TH-78 A-E service manual. TH-78 Instruction manual. TH-78 TX-RX-RF schematics. TH-79 schematics.
19-07-1998TX across entire tuning range TH-75AI have a couple of mods that you may or may not have. For the TH-75A MARS/CAP mod, removing D4 will allow TX across entire tuning range, except that actual TX range will be limited by tuning of the PLL.
For the TM-731A, there is a 'Beyond MARS/CAP transmit Modification'. It provides TX from 136 to 174 and 400 to 500 MHz. Again, actual TX range limited by PLL tuning. If you don't already have this and would like it, I'll send a copy if you furnish me your address. It involves cutting R25 on the control unit, and installing a jumper (diagram required to locate position), then two resets in a row.
I have tested these mods on my own rigs.
73 - Kevin, KD2SL @ KC3BQ
19-07-19989600 baud with the TH 75
I tested the follwing modification only for the 430 MHz part. Perhaps it works also on 2 meters if you try the modification on the 144 MHz IF-Unit.
For opening the TH 75 follow the instructions of the manual page 31 ( installation of the TSU-Unit ).
After opening the handy, it is not necessary to disconnect any connectors between the front and rear part. All connections have to done at the rear part.
-TX-
On the right side of the open handy is a connector (No. 201). The wires of this connector are leading to the lower board of the rear Part.
Disconnect this connector. Next remove the five screws holding the upper board. Now it is possible to lift this board for about 5 mm.
On the lower side of the board are the solder pins of the connector which was opened before. Solder a thin wire to pin No 5. (Start counting at the antenna side of the TH 75).
This wire can be connected direct to the TX-Exit of your TNC, if this exit has A/C level only. If the TNC has also D/C level add a capacitor of about 4.5 to 6.8 uF.
-RX-
A little bit higher to the connector were the TX line was connected is the UHF - IF unit (X58-3610-00). It is a small additional board over the main board. You will find the IC TK10485M on this small board. Solder a wire to pin No 11, the first one the left side (Start counting again at the antenna Side). This pin is connected to a capacitor. In order to prevent the IC from being demaged, I recomment to do the soldering at this capacitor.
This wire can be connected direct to the TNC.
If you need for some reason the squelch of the TH 75 during 9K6 operation, add a resistor of 10 KOhms in the RX line.
These are all modifications necessary for 9K6, and now you can start closing the TH 75. If you do not instaubber cap of the DC IN Terminal, you have a fine little gap for the wires. But it is also possible to install an additional jack if the TSU-6 unit is not installed. The ground connection can be made via the speaker jack. The PTT line of the TNC should be connected to the MIC jack.
The TH 75 is able to work with a TX-Delay of 150 - 170 ms (> T15) which is a good value for a modified PLL TRX.
19-07-1998TH-75A MARS/CAP modification
This modification will allow the TH-75A to transmit from 142 to 152 MHz and 420 to 450 MHz. Specifications are guaranteed for the Amateur Bands only. Through the transceiver will display 136 to 174 MHz and 335 to 512 MHz, the PLL circuit may not lock through the entire range.
Modification procedure
- Disconnect the battery and antenna.
- Remove the three case screws and two battery plate screws.
- Lift the front panel from the body of the transceiver, but do not disconnect the two flex cables.
- Cut the green jumper wire (W1) that is located to the left side of the CPU in the front panel assembly.
- Assemble the transceiver by reversing steps 1-3.
- Reset the CPU by holding the M key as the power is turned on.
Suresh Kagoo N9GSAInternet : [email protected]
Bitnet : [email protected]
31-03-1999TH-75E auf 9k6
de DL8FCL @ DK0MTV.#RPL.DEU.EU
Seit einigen Tagen benutze ich ein TH-75E mit recht gutem Erfolg für PR mit 9600 Baud. Der Umbau ist sehr einfach durchzuführen, und sollte jedem gelingen, der schon einmal einen Lötkolben in der Hand hatte.
Zuerst öffnet man das Gehäuse. Die zu entfernenten Schrauben kann man sich auf der letzten Seite der Bedienungsanleitung anschauen (Einbauanleitung für CTCSS unit TSU-6). Das Gerät soll selbstverständlich spannungsfrei sein.
Alle Anschlüsse werden an dem rückwärtigen Teil des Handies angelötet, aber man muß die Verbindungen zu dem vorderen Teil (der mit der Anzeige und Tastatur) nicht abtrennen.
Kenwood Th 75e Manual Transfer Video
--TX--Auf der rechten Seite sieht man eine Steckverbindung (Nr. 201), deren Kabel nach unten in das Gehäuse verschwindet. Diese Verbindung muß man vorsichtig lösen. Nun löst man die 5 Schrauben, mit denen die gesamte Platine mit dem Rest verbunden ist. Jetzt kann man die Platine etwas nach oben biegen und sieht an der Unterseite die Lötstifte der Steckverbindung, die man zuerst gelöst hat.
An den Stift Nr. 5 von oben gezählt lötet man einen dünnen Draht. Diesen Draht kann man direkt mit dem TX-Ausgang des TNC verbinden.
--RX--
Ein Stück oberhalb der Steckverbindung, an der das TX-Signal eingespeist wird befindet sich die UHF IF Unit (X58-3610-00) als eine separate Platine, die auf die Hauptplatine aufgesetzt ist. Hier muß man den RX-Anschluß anlöten, da dies direkt an dem Diskriminator geschehen muß. Der richtige Punkt ist der Pin Nr.11 des IF-IC TK10485M. Dies ist der auf der linken Seite der 1. von oben gezählt. Von diesem Pin geht die Leiterbahn zu einem Kondensator. Ich habe den Draht an dessen Kontakt in Richtung IC angelötet, damit ich auf gar keinen Fall das IC beschädige.
Das war es, man kann das Gerät wieder zusammenbauen. Die Drähte kann man neben der Stromversorgungsbuchse nach außen führen, wenn man die Gummikappe wegläßt. Dort gibt es dann einen kleinen Spalt der sich dafür eignet. Man kann aber auch eine kleine Buchse in das Gerät direkt über dem Lautsprecher einbauen. Dies geht allerdings nur, wenn die CTCSS-Unit nicht eingebaut wurde. Die PTT-Leitung des TNC schließt man ganz einfach an die Mikrofonbuchse mit einem 3,5 mm Stereo-Stecker an. Dadurch ist auch das eingebaute Mikrofon abgeschaltet. Die Masseverbindung stellt man am Besten über die Lautsprecherbuchse her. Das hat den Vorteil, daß auch der Lautsprecher abgeschaltet ist. Er neigt sonst zu Knackgeräuschen, selbst wenn die NF ganz zugedreht ist.
Ich habe noch keine Messungen (Augen-Diagnostik, BERT) durchführen können, aber praktische Tests auf DB0SPC haben zu vorzüglichen Resultaten geführt. Das TX-Delay habe ich auf 150 ms eingestellt, und bin in der Lage 5000 Bytes in weniger als 15 Sekunden auszulesen. Ich verwende einen TNC2H der Fa. SYMEK und habe bei der Einstellung des Sendefilters die besten Erfahrungen mit der Einstellung Nr. 1 gemacht. Die Einstellung des Hubes im TNC war auch nicht sehr schwierig, ich habe ganz einfach mit dem geringsten Hub angefangen und dann langsam aufgedreht, bis der Digi mir antwortete. Danach habe ich etwas oberhalb dieses Punktes hin und her gedreht, bis ich die besten Resultate erziehlte.
Für eventuelle Fehler übernehme ich natürlich keine Haftung, bin ich aber gerne bereit Fragen zu beantworten.
Ich wünsche viel Spaß beim Basteln und bei PR mit 9K6.
vy 73 es 55, Walter DL8FCL @ DK0MTV
20-04-2000TH-75A No TX on VHF using a vehicle battery supply
Author: Trio-Kenwood Communication, inc.
When the TH-75A is connected to a vehicle battery, ignition or alternator noise can be induced on the DC line. When the transceiver is in the automatic battery saver mode, the noise pulses overcharge C348 on the RF board causing it to short. The supply current opens L218 and the foil trace at this coil. To protect the transceiver, a Zener diode will be used to clamp the SBR line.
The Zener should be solder between the SBR side of L218 and the shielding case of L221 on the component side of the RF board (X53-3370-11) (A/3). The Service Manual disassembly instructions will be required to perform this modification.
Note: This modification has already been performed on models stating with serial number 007xxxx.
Required part:
22V Zener diode (UZP-22B)
This is an optional change that is not covered under warranty.
Time to perform this modification is 1 hour or less.
21-04-2000TH-75A Intermittent memory loss
Author: Kenwood Communication, inc.
Some TH-75A owners have reported that the transceiver intermittently loses its memory channel information after transmitting. Other users have reported symptoms such as key board lock up after transmitting. The following modification will re-configure the PTT input to the microprocessor to correct these conditions.
Required parts:
- Disconnect the battery and antenna.
- Remove the three case screws and two battery plate screws. Figure 1.
- Lift the front panel from the body of the transceiver and disconnect the two flex cables. To open the connectors push the tabs towards the flex cables and gently lift up. Figure 2.
- Remove the 4 screws from the Control board inside the front panel. Figure 3.
- Remove the 3 screws from the speaker mount. Figure 3.
- Carefully lift the Control board, PTT switch assembly, speaker, and mic element from the front panel. Do not break any wires.
- Lay the Control board on a soft cloth to avoid scratching the LCD.
- Locate chip capacitor C2 on the Control board. Figure 4.
- Replace C2 with a 33 Kohm chip resistor.
- Remove the protective coating from the foil between pin 58 of the microprocessor and chip resistor R8. Presolder the exposed foil. Figure 5.
- Size, cut, and bend the leads of the 470 pF ceramic capacitor and then install the component between pin 59 of the microprocessor and the ground side of the 33 Kohm chip resistor. Figure 6.
- Remove the screw from the PTT switch assembly and then remove the rubber PTT cover from the board. Be careful not to lose the black plastic plate that fits inside the rubber cover.
- Remove the PTT switch from the board.
- Cut the tabs off the bottom of the new PTT switch to allow the switch to lay flush on the board. Figure 7.
- Install the PTT switch.
- Assemble the transceiver.
Time required to perform this modification is 1 hour or less.
RMS Client with Kenwood TH-D74 #Winlink
#11 Hi all, I am part of National Emergency Ham radio Network (RVSU) and I am trying to use the new Kenwood portable radio with RMS Client (Packet Winlink) as here are a lot of RVSU members that had this radio. Unfortunately, the radio doesn't work. I also have or had othe Kenwood radios with internal TNC (TM-D710, TH-D72, TS-2000) that use to work well. I tryied to connect the radio in KISS mode and had no luck (Bluetooth or USB cable) and also on 'Kenwood' mode with the presented presets (Kenwood and non-Kenwood presets). Also, no luck at all! The only feedback from the radio I have when I select TM-D710 when the radio put itself onto KISS12 mode but after a couple of seconds I get the 'No TNC' in the Winlink Packet window. It's like the software wait for a confirmation from the radio and that confirmation doesn't meet the expected format or does't came at all. Maybe the developers will take into account a way to put a TNC config file in the process. I hope my English is understandable :-) Best 73, Merry Christmas and a Happy New Year!
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#12 Hello Adrian. Your english was very good :-) Regrettably, other has found exactly the problem you mention, and no solution so far. Very strange and regrettably since TH-D72 does well. Sorry for no more help except letting you know that you are not alone. 73 de LA7UM Finn |
#59 It's confusing when we have one winlink group at groups.io and another winlink programs at google groups. Anyhow for the TH-D74 to work with winlink express they need to add the TH-D74 to the list. The TH-D74 is a KISS TNC so the closest settings are to select TNC-X in winlink express. This doesn't work but could easily be adapted by the developers for the TH-D74. Using the TNC-X settings the software always stops when it's setting the persistence value. ie when winlink is sending the C0 02 80 C0 the software crash and turns off the KISS mode for the TH-D74. I have not found the e-mail address for the developer for the TNC module. I have sniffed the serial communication between the TH-D74 and winlink express so i have some log files. A quick and dirty test would to adapt the TNC-X settings but skip the settings like turning off KISS TNC, do not set persistence etc now i think the software would work as expected. But this is a educated guess. If this works we could properly add the routines to set the parameters like persistence etc and then get a selection for the TH-D74 in winlink express. The manual says that software should use TN 2,0 or TN 2,1 to enable KISS on band A or B and there are no init commands like KISS ON / RESTART. You only have the KISS commands Kai Gunter LA3QMA |
#60 I have contacted John Wiseman and giving him some debug data. If/when he have time he could probably implement the TH-D74. Kai Gunter LA3QMA |
#61 That would be awesome! toggle quoted messageShow quoted textWe are a solid group of TH-D74 owners and we use Winlink for our emcomm activities. 73 de Adrian On February 13, 2017 10:07:30 PM GMT+02:00, 'Kai Günter Brandt - LA3QMA' <kai.gunter.brandt@..> wrote:
-- Sent from my Android device with K-9 Mail. Please excuse my brevity. |
#62 Hello Kai, toggle quoted messageShow quoted textI have the same problem here. I was wondering if there is a way to use some .ini files for initialising various TNCs like in the gateway software! Might be useful for further 'tuning' on the RMS Express for various tipes of TNC. I also want to use some Arduino-based TNCs and have some trouble. 73 de Adrian yo3hjv On February 12, 2017 10:37:33 PM GMT+02:00, 'Kai Günter Brandt - LA3QMA' <kai.gunter.brandt@..> wrote:
-- Sent from my Android device with K-9 Mail. Please excuse my brevity. |
#63 I'm pretty sure that the tuning has to be in the software. Comparing different results sniffing the serial data the TH-D74 is not transmitting. But you can transmit using i.e TNC-X testing software, aprsisce, sartrack etc.Going to connect my radio to the network so that the developer can debug directly trough my radio.73 de LA3QMAKai Günter |
#64 Kai, Do you reffer to other manual or just the User manual? On Sun, Feb 12, 2017 at 10:37 PM, Kai Günter Brandt - LA3QMA <kai.gunter.brandt@..> wrote:
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#65 'The manual says that software should use TN 2,0 or TN 2,1 to enable KISS on band A or B and there are no init commands like KISS ON / RESTART.'
This is from the Kenwood TH-D74 user manual chapter 15. Kai Günter LA3QMA |
#66 Edited Anyhow PAT is working with the TH-D74 via USB cable. Have not yet tested via BlueTooth. |
#67 I got the following message on FB TH-D74 page: toggle quoted messageShow quoted text*************************************** There's a bug in the 1.05 firmware and KISS packet mode. I've sent the following to Kenwood directly but perhaps it might help others. I have a recently purchased TH-D74 running firmware 1.05 and I've discovered a bug in the KISS encoding feature in the radio. It's taken me a couple of days to find. The KISS spec requires that when a TNC receives a packet from the radio channel and that packet contains any bytes with the value of the KISS Frame End FEND byte (0xC0), all such FEND bytes must be encoded as the two-byte sequence FESC TFEND (0xDB 0xDC) when transmitted upwards to the host. This is documented in the KISS protocol by its designers, Mike Chepponis and Phil Karn and can be found at: http://www.ax25.net/kiss.aspx The correct behavior is described in section 3: 3. Transparency Frames are sent in 8-bit binary; the asynchronous link is set to 8 data bits, 1 stop bit, and no parity. If a FEND ever appears in the data, it is translated into the two byte sequence FESC TFEND (Frame Escape, Transposed Frame End). Likewise, if the FESC character ever appears in the user data, it is replaced with the two character sequence FESC TFESC (Frame Escape, Transposed Frame Escape). I know for certain that version 1.05 of the firmware for the TH-D74 is not performing this conversion on packet reception. Instead it just passes the 0xC0 byte straight through. This is a violation of the KISS protocol and it causes any packets with such bytes to be received improperly on the host end. I have audio snippets which should be able to recreate the problem, but I imagine that someone in Kenwood engineering should be able to find this problem rather quickly if given a description of it. ************************** On February 20, 2017 3:33:08 PM GMT+02:00, 'Kai Günter Brandt - LA3QMA' <kai.gunter.brandt@..> wrote: Anyhow PAT is working with the TH-D74 via USB cable. Have not yet tested via BlueTooth.http://getpat.io/Next step is to get the radio online so that the winlink team can fine tune their software.Kai GünterLA3QMA -- Sent from my Android device with K-9 Mail. Please excuse my brevity. |
#68 Adrian: tnx this is probably the reason why PAT is failing on some winlink messages using the TH-D74.PAT is working ok with the TH-D74 connecting to a local winlink node. But it fails often with 'unexpected EOF' and time out when sedning the checksum to the node.73 de LA3QMAKai Günter |
#74 Kenwood has fixed the TNC bug as others have reported in this group. So PAT 0.2.3 and most likely PAT 0.2.4 is working with the TH-D74 in KISS mode. Both USB and bluetooth are working. To use the Winlink Express there is a work around using bluetooth. So maybe a quick fix for the Winlink Express is going to solve the USB trouble :-) 73 de LA3QMA Kai Günter |
#105 I hope this link about “Winlink on Mac OSX with a TH-D74 over Bluetooth” helps advance understanding on this topic: http://www.lothlorien.com/kf6gpe/?p=840 |
#107 Do you know if Pactor using a SCS-TNC and even Winmor has proven to run fine on the Macs using Wine? I believe it works now using Parallell or Fusion, but have never tried myself. Finn LA7UM |
#130 Kenwood may have fixed their TNC bug.. but I think Winlink still has issues with our TH-D74. I have posted a video of my experience and have posted on Winlink.org requesting any new information. Essentially, Winlink over USB does not activate TX and Bluetooth needs quick manual intervention to re-enable KISS 12 after Winlink START is pressed to initiate transmission. https://winlink.org/content/winlink_programs_group?place=msg%2Fwinlink-programs-group%2FSS9jDmuFNHU%2FdBj_poVOCQAJ I am running firmware 1.08 on my D74. Keep pressing this issue and it will (hopefully) find its proper resolution. Regards, John WA7UAR |
#131 Hi John, What is the URL to your video? Thanks, Scott K7JSG From: Winlink@groups.io <Winlink@groups.io> on behalf of WA7UAR <jspady@..> Sent: Saturday, March 17, 2018 8:30 AM To: Winlink@groups.io Subject: Re: [Winlink Programs Group] RMS Client with Kenwood TH-D74 #Winlink Kenwood may have fixed their TNC bug.. but I think Winlink still has issues with our TH-D74. I have posted a video of my experience and have posted on Winlink.org requesting any new information. Essentially, Winlink over USB does not activate TX and Bluetooth needs quick manual intervention to re-enable KISS 12 after Winlink START is pressed to initiate transmission. https://winlink.org/content/winlink_programs_group?place=msg%2Fwinlink-programs-group%2FSS9jDmuFNHU%2FdBj_poVOCQAJ I am running firmware 1.08 on my D74. Keep pressing this issue and it will (hopefully) find its proper resolution. Regards, John WA7UAR |
#132 Edited Hi Scott, |
#136 Enabling idle poll in Winlink will enable periodic 'keep alive' packets to be exchanged between connected stations when no other traffic is being sent. In theory, this should not be needed with Winlink, but I have found that at times the session stalls and idle polls seem to get it going again. Doesn't seem to cause any harm. -Scott, NS7C |