KB2LJJ Radio Mods · PDF file TS-850S Distorted TX w/TNC connected TS-850S Low/no Receive sensitivity TS-850S No audio from VS-2 TS-850S Mixer FET change TS-850S "Click noise" with - [PDF Document] (2022)

  • KB2LJJ Radio Mods Database


    Home Radio Mods Database and Manuals

    Modifications for the Kenwood TS-850Expanded RF M/C

    1 Disconnect the power and antenna.2 Remove the 16 screws top and bottom covers from the radio. Be careful no tobreak the speaker wires.3 Remove the top and bottom screws from each side of the front panel assembly.4 Pull the front panel forward to expose the DIGITAL Board.5 Locate and cut the lead DIODE D11 6 Reassemble the radio.7 Reset the microprocessor ( Holding the [ A=B] Key while turning the power ON.

    Click to view picture

    TS-850S observations

    TS-850S All band transmit

    TS-850S Broadcast Band Sensitivity

    TS-850S Additional Front Panel Functions

    Step by step instructions to disable the broadcast band attenuation for TS-850S

    TS-850? ACC-2 audio problem

    Adjustable moni. on CW, TS-850S

    TS-850 service manual, error corection

    TS-850S and speaker/headph

    TS-850 and Ten-Tec Titan 425 PA

    http://www.kb2ljj.com/data/kenwood/ts-850.htm (1 di 31)01/09/2009 0.13.59


  • KB2LJJ Radio Mods Database

    KAM-PLUS Problems!! with TS-450 & 850

    TS-450,TS-850 feedback,ACC-2 Conn

    Modification for External keying, while using the internal keyer

    TS-850 Separate Receive Antenna Modification

    TS-850 Separate RX antenna input mod

    The switch box

    Computer Interface for the TS-850, without using the IF-232 Level Converter

    TS-850 Power Output Control

    TS-850 Level Attenuator for DRU-2 playback audio

    TS850 + Transverter oder Preselektor German language

    TS-850S Distorted TX w/TNC connected

    TS-850S Low/no Receive sensitivity

    TS-850S No audio from VS-2

    TS-850S Mixer FET change

    TS-850S "Click noise" with NOTCH ON

    Full transmit for the UK version of TS-850S

    TS-850 2nd RX output mod

    A Band Decoder for the Kenwood TS-850 HF-Transceiver

    TS850s alc problem

    Noise Blanker Mod Kenwood TS-850

    TS-850S observations

    Observations of KC2CT

    Having lived with Kenwood's TS-850S tranceiver for 5 days, here are some of my observations:

    ● While the manual shows 35 power-on front panel adjustments, there really are 36. Function number 35 is set from the factory to the OFF state. Well, what exactly is this unknown function? Well Bunkies, this enables the tranceiver to transmit on 27.500 through 28.000 mhz! Do yourself a favor, and set this option to ON for TX inhibit! DO NOT JEAPORDIZE YOUR LICENSE! Why in the world did the factory allow this??? Maybe they don't want the Chicken Banders butchering up the rigs....

    ● Tone control. The setup only allows Burst or Continuous modes, there is no way to turn it OFF, even though the manual indicates there is a way.

    ● Quick memory function. You MUST pass through either the VFO A or VFO B registers to program these.. You cannot go from standard memory to quick memory directly.

    ● My 850S came out of the box running low power (50 - 75w PEP), so I called the local ham radio dealer inquiring about service manual availability. Well they had them in stock, but at a price of $50.00! Unbelievable! Kenwood wants fifty dollars for (in the continuing Kenwood tradition) a terribly organized, incomplete, and horrible reading manual!!! Well, I dug into the schematics and opened up the the radio, here's a list of items that might be of interest to some:

    RF Board Controls

    http://www.kb2ljj.com/data/kenwood/ts-850.htm (2 di 31)01/09/2009 0.13.59

  • KB2LJJ Radio Mods Database

    ----------------- VR - RX BAL VR - TX BIAS VR - TX BAL VR - TYP (50W output power adjust, used with S1 below) VR - MIN (?????) / internal antenna tuner VR - TUN (Tune mode power adjust) VR - VSF (THIS IS THE 100W POWER OUTPUT CONTROL) VR - SWR Protect activation VR - PWM (Forward power meter calibration) VR1 - RWM (Reflected power meter calibration) VR1 - AL0 (ALC meter zero) VR1 - ALM (ALC meter calibration) VR1 - CPM (Processor meter calibration) VR1 - ALG (ALC gain adjustment)

    S - All Band Power Down Switch (Decreases power to 50 watts)

    IF Board Controls ----------------- VR - VR - VR - VR - Beep volume VR - Sidetone volume VR - Processor adjust VR - ????? VR8 & VR9 - ????? VR1 - ????? VR1 - VR12 & VR13 - S Meter adjust VR14 & VR15 - AGC adjust VR1 - Notch filter adjust

    ● PLEASE NOTE!Most of these controls are 1/8" pots, so if you intend to adjust them use a VERY SMALL non-metallic tool.

    ● My 850S also came out of the box with the RIT/XIT control not dis- playing 0.00 khz at fiducial (12 o'clock position) center. Behind the front panel in the upper right corner is the control for center adjust. It just needed a wee bit of tweaking... Along with this control on the circuit board are the master adjust- ments for the SSB slope tuning (High Cut and Low Cut).

    ● When both top and bottom covers are removed, on the left-hand side is the FM board. There are 3 (three) pots on the board. They are FM Wide (12khz) deviation, FM Narrow (6khz) deviation, and FM Mic gain.

    ● FM mode defaults to WIDE (12khz). This is WAY too wide for accessing any 10m repeater. Hit the 455khz filter button again for FM-N (narrow). This will set the IF to 6khz width, and you be able to work FM 10m stations. Note: The 8.83 filters are NOT selectable in FM mode.

    ● Memory scrolling via M CH./VFO CH. You can bypass all unused channels if you press the 1 mhz button. With the button active, only stored memory channels will be displayed as the knob is rotated.

    ● Tunable memories. Out of the box, the radio is set up for non- tunable memories. Just bring up setup function xx on the display, and set it to ON, and ALL memories can be tuned via the VFO. When use the M.CH/VFO CH. switch you will be returned to the original frequency & mode setting in the memory.

    ● It may or may not be obvious to some, but the radio is capable of cross-band and/or cross-mode operation. Just pump the required modes and frequencies into memory channels or VFOs, and you're off and running. Hope you have a very broad banded antenna!

    ● CW message storage is lost when you power off the radio. I didn't order the DRU-2 option (yet), so I don't know whether these messages will be saved. You'd think that with everything else that is stored in RAM and backed up by battery, that Kenwood would have made pro- visions to keep recorded messages alive also. A modification????

    ● When adding additional filters, is is necessary to set the corresponding switch on. Under the hatch on top, is a 4 position dip switch. The manual shows a picture of it, but makes no mention of their settings. This switch is necessary to inform the micro- processor of the filters' absence or presence. ON is for presence, OFF is for absence.

    http://www.kb2ljj.com/data/kenwood/ts-850.htm (3 di 31)01/09/2009 0.13.59

  • KB2LJJ Radio Mods Database

    Below is the switch diagram:

    ----- | = |

  • KB2LJJ Radio Mods Database

    Kenwood markets this radio worldwide, and has made orovisions to allow the radio to transmit between 1.625 mhz and 29.999 mhz.I am providing this modification for INFORMATIONAL PURPOSES ONLY! DO NOT TRANSMIT OUT OF BAND, THIS WILL JEAPORDIZE YOUR LICENSE, AND HAVE THE FCC, AND/OR INTERNATIONÁL AUTHORITIES KNOCKING AT YOUR DOOR!!!

    The All-band transmit modificatéon requires the removal and re- location of a diode on the the digital board which is located behind the front panel. The US version of the radio has diode D11 installed, and diode D9 removed. D11 must be removed, and installed in the D9 position. This modification IS NOT for the faint of heart, as it entails removing the front panel, and the digital board. Note that the digitál board has solder holes thát are through-soldered; that is, there are circuit traces on both sides of the board, so make sure that ALL solder is removed from the holes. This modification will also allow the antenna tuner to tune anywhere the receiver is tuned. This modification should ONLY be performed ây those familiar with soldering and de-soldering techniques, and requires patience, and dexterity.

    Thanks to Bill K0ZL for this picture.

    ser comment From: Max VE3TMT

    Subject: Diode not needed in D position

    http://www.kb2ljj.com/data/kenwood/ts-850.htm (5 di 31)01/09/2009 0.13.59


  • KB2LJJ Radio Mods Database

    On some TS850's it is not necessary to install a diode in the D9 spot. Clip D11 (the one on the right end) and check for proper results first. On my TS850 it worked without putting a diode in D9.

    User comment From: Jaye

    Subject: Full TX on the Kenwood TS-850s

    I have recently preform the modifcation on the TS-850s for full TX, i have to coment that i did'nt have any dramas with this procedure,But!where it explanes to remove the diode D-11 then replace in the D-9 postion this is not nessary, just clip D-11 and you will also have remove diode D-12 that is in parallel series on the back of the dig

Top Articles

You might also like

Latest Posts

Article information

Author: Kerri Lueilwitz

Last Updated: 11/07/2022

Views: 5888

Rating: 4.7 / 5 (67 voted)

Reviews: 82% of readers found this page helpful

Author information

Name: Kerri Lueilwitz

Birthday: 1992-10-31

Address: Suite 878 3699 Chantelle Roads, Colebury, NC 68599

Phone: +6111989609516

Job: Chief Farming Manager

Hobby: Mycology, Stone skipping, Dowsing, Whittling, Taxidermy, Sand art, Roller skating

Introduction: My name is Kerri Lueilwitz, I am a courageous, gentle, quaint, thankful, outstanding, brave, vast person who loves writing and wants to share my knowledge and understanding with you.