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Kenwood Repeater Index Page
Compiled, HTML'd and maintained by Mike Morris WA6ILQ
Formerly Maintained by Robert Meister WA1MIK
 

Comments, suggestions, corrections to this page (actually to any page at this site) are welcome...
Just drop a note to the page maintainer... (even one that just points out a typo)

Note: On this page an "x", as in TKR-x50 means either 750 or 850,
likewise on the x51s and the NXR-x10 means the 710 or 810.
Likewise NXR-1x00 means 1700 or 1800.

DONATIONS OF INFORMATION WOULD BE GREATLY APPRECIATED, ESPECIALLY PDFs OF MANUALS WE DON'T HAVE.

Kenwood repeater model numbers are TKR-7xx, NXR-7xx or NXR-1700 for VHF / highband,
TKR-8xx, NXR-8xx or NXR-1800 for UHF, and
TKR-9xx for 900 MHz.

NXR-1700 / NXR-1800 Information and Modifications

This is the current production unit that can fit two independent units in a one rack unit (1 RU) vertical space (134 inch). Conventional wideband and narrowband analog is included, however enabling DMR or NXDN is an additional charge, and the entitlement is software that is keyed to the serial number.
Note that the VHF range is 136-174 MHz and the UHF-low range is 400 to 470 MHz, so this product line can pack two independent repeaters or one repeater and one continuous duty 25-watt full duplex link in ONE unit of rack space.
Henry Radio Amplifiers can supply a 2RU 10 watts-in / 100 watts-out continuous duty amplifier, and Samlex makes the SEC-40/60/80/100BRM (a 2RU 40 / 60 / 80 / 100 amp redundant battery-backup power supply) so you can have a 100 watt continuous duty repeater and a 25 watt continuous duty full duplex link with power supply in 5RU of rack space!   That's 834 inches! (plus duplexer(s))
Model Frequency Range (MHz) Transmit Power
"Type 1" "Type 2"
TKR-1700 (VHF) 136 to 174 1 to 50 Watts @ 50% Duty Cycle or 1 to 25 Watts @ 100 % Duty Cycle
TKR-1800 (UHF) 450 to 520 400 to 470 1 to 40 watts @ 50% Duty Cycle, 1 to 25 Watts @ 100 % Duty Cycle
NXR-1700 and NXR-1800 Product Brochure   725 Kb PDF
Actually more of a sales flyer.
NXR-1700 / NXR-1800 Instruction Manual   3.4 Mb PDF
NXR-1700 Functional Reference   3.1Mb PDF
Also applies to the UHF TKR-1800 model since the CPU and other control circuits are common to both units.
NXR-1700 Service Manual   19.6Mb PDF
This is noted as "Revision 1", the first revision after the original.
NXR-1800 Service Manual   17.3Mb PDF
This is noted as "Revision 2", the second revision after the original.
NXR-1800 DB-25 Accessory Connector Pinout
This is a web page that was developed from a PDF that was extracted from the NXR-1800 Service Manual.

NXR-x10 Information and Modifications

Model Frequency Range (MHz) Transmit Power
"K" "K2"
NXR-710 (VHF) 136 to 174   1 to 50 Watts @ 50% Duty Cycle or 1 to 25 Watts @ 100 % Duty Cycle
NXR-810 (UHF) 450 to 520 400 to 470 1 to 40 watts @ 50% Duty Cycle, 1 to 25 Watts @ 100 % Duty Cycle
NXR-710 and NXR-810 Product Brochure   262 Kb PDF courtesy of Mark Abrams WA6DPB
An NXR-710 / NXR-810 programming note:
The programming software for the NXR-710 and NXR-810 is KPG-129D.   At the time this paragraph was last updated the current version was 3.20 and didn't enforce narrowband. It is "out there" and findable on the internet.
Note: Any KPG software with a DN suffix will not allow programming a channel to wideband mode.
Your page maintainer can report that the interfacing of the NXR-710 / NXR-810 and programming for an external controller is VERY similar to that of the TKR-x50 / x51. The interface cable connector pinout is the same. In most cases you can unplug the DB25 cable from the back of a TKR-x50 / x51, program your new NXRx10 (including the the DB25 I/O pins) and then plug the cable into the connector on the back of the NXR. Then set audio levels and you are done! (please see the note on setting transmit CTCSS tone deviation below).
NXCore Setup on the Raspberry Pi   428 kB PDF by Alex KD6VPH and Robert Thoelen III N1XDN
Apparently goes with the NXRx10 Setup article below.
Setting up the NXR-710 / NXR-810 with the Raspberry Pi and NXCore   743 kB PDF by Alex KD6VPH
Apparently goes with the NXCore Setup article above.
NXR-710 Service Manual   3.85 MB PDF
Manual number B51-8901-00 (N) 527, dated 2009-12.
NXR-810K Service Manual   2.8 MB PDF
Manual number B51-8902-00 (N) 427, dated 2009-12.
NXR-810 Service Manual Revised dated July 2010   4.04 MB PDF
Manual number B51-8902-10 (N) 567, dated 2010-07.
From the title sheet:   "This service manual has been revised due to the addition of type K.
This service manual applies to products with B07xxxxx (NXR-810(K2)), or subsequent serial number."

Information Common to the TKR-x50 / x51 and the NXR-x10 Series

The rack mount trays for the TKR-x50 / TKR-x51 / NXR-x10 units are identical. The units as delivered have the radio module in the right half of the cabinet, and the left half is identical but vacant. You can place your choice of a power supply, a flatpack duplexer, an Allstar linking module or whatever you want into the left half.   If you don't have any of that extra hardware, need to mount two repeaters and are short of rack space, well... Novexcomm.com offers a replacement front panel that allows you to have two radio modules in one cabinet... i.e. in half the rack space. Here is a photo that shows five radio modules in the same space that three used to fit in... (two doubles and a stock single)
Why are the speaker grilles different? It saves start/stop/start/stop cycles on the laser! And the guys at Novexcomm discovered the slots actually sound better.
Novexcomm has an ebay store or you can order directly (and save the ebay markup) by calling 310-534-4456 from 10am to 6pm Pacific time. Tell Bob that Repeater-Builder sent you.
Disclosure: The author / maintainer of this page - Mike WA6ILQ - has known the owner of Novexcomm (Bob, WB6SLC) for 40+ years. And he didn't pay me (or even ask me) for this pointer.
The TKR-x50 / x51 / NXR-x10 are usually programmed with the KPG-46 programming cable through the front panel microphone jack. The NXRs can also be programmed through the DB-25 Control / Accessory Port using regular RS-232 signals on pins 2, 3, and 7.
A TKR-x50 / x51 / NXR-x10 programming note:
The four units are multi-channel repeaters in the sense that the control circuits have 16 "modes". Many groups program two modes identically except that the first one is for an external controller and the second uses the repeat function of the internal controller (somtimes referred to as "in-cabinet repeat" or "internal repeat"). Both modes have identical frequency and CTCSS programming. The idea is that the internal repeat will only be used if the external controller needs to be disconnected or it fails, after all this backup controller is free – all it costs is a bit of programming time. Look for a setting labeled "DUPLEX" or "REPEAT" in the KPG programming software. REPEAT mode enables the internal control and audio paths, DUPLEX mode completely disables the internal controller and the TKR becomes a basic full duplex radio, and requires an external repeater controller to do anything.
In the REPEAT mode set the hang timer to a few seconds and program the IDer appropriately.
In the DUPLEX mode leave the hang timer programmed for zero and leave the IDer text field empty.
Program the Auxiliary In / Out ports 5 and 6 for OUTPUT on the AUX Select tab, then on the AUX tab program Aux In/Out 5 for TOR (tone detect) and Aux In/Out 6 for COR (carrier detect). Progam the Active state for active high or active low (whatever the external controller wants to see). COR will appear on pin 25, TOR on pin 24,
If you have a TKR-x50 or x51 Version 2.0 repeater you can program Aux In/Out 4 for QT / DQT Encode Enable (transmit tone). QT / DQT Encode Enable on pin 23.
Don't forget that the TKR-x50 repeaters are only 50% duty cycle at 40 watts, and 100% duty cycle at 25 watts. The TKR-x51 are rated at and capable of 25 watts continuous duty. Note that the TKRs and NXRs have internal fans. Don't let the fans die. My TKR-x50s that are in commercial service are run at 5 to 10 watts out and feed 100 watt continuous duty Henry Amplifiers. The fans are programmed in thermal mode (as opposed to always-on mode) and hence never turn on. This configuration just plain works and has for over a decade.
Note that there is interaction between the transmit level / deviation adjustments in the TKR and NXR series. If you adjust the transmitter deviation limit it will affect the CTCSS encode deviation as well (whether you use the internal tone generator or the external TD input). You need to do the alignment procedure step by step and set the main transmitter deviation with audio going into the TA input without tone encode. When that is finished only then you turn on the tone and adjust that level, then go back and verify the total deviation.
Interfacing to the Kenwood TKR-x50 / x51, NXR-x10 repeaters By Mike Morris WA6ILQ
After getting dozens of emails over 6 months I decided to put together all the info that they asked for into one web page.
The TKR-x50 / x51 / NXR-x10 Control / Accessory Port is a DB-25 female connector on the back of the unit but you need a jumper in the 15 pin Molex connector to enable the front panel speaker. And since you need the Molex plug you might as well add two more wires since they can supply +12v DC power for your external controller. You might as well make up a cable with both a DB-25 male and a 15 pin Molex male on one end and a connector that mates with your repeater controller on the other. (the red-black pair inside the yellow sleeving just loops through the DB-25 shell and feeds a pair in the grey cable to power the external controller)
The RD / TD connections on the TKR-x50 / x51 / NKR-x10 are capable of D-Star, IDAS and P25. I've seen a setup with four TKR-850s configured as a P25 (Phase 1) control channel and 3 voice channels and it works.
The TKR-x50 and NXR-x10 repeater use an 80mm square fan that is 15mm thick. Replacing it required a full disassembly of the rear end, and can be done on site but it is much easier done on a workbench. This is an acceptable replacement. One of the most annoying parts is that you have to take the entire back assembly apart to cut a well buried tie-wrap… (sorry about the focus)

TKR-x50 / x51 Series Information and Modifications

Kenwood TKR-750 / TKR-850 Product Brochure 651 Kb PDF Courtesy of Mark Abrams WA6DPB
Kenwood TKR-751 / TKR-851 Product Brochure 626 Kb PDF Courtesy of Mark Abrams WA6DPB
The TKR-x50 repeaters are manufactured in multiple frequency ranges, and are labeled with a "Type" number like "-1", "-2" or "-3".
This "Type" number indicates the operational frequency range (or "split") has nothing to do with the hardware Version number.
There are "pre-Version-2.0" units, and "Version 2.0" units.   Referring to the earlier units as "Version 1" is incorrect, but is done almost universally. Note that the label is found on the actual radio module, and on the rack mount tray. Don't believe the tray label. Modules can be switched, I've seen a pre-version-2.0 unit in a Version-2.0-labeled tray. Another way to identify pre-version 2.0's from version 2.0's: the version 2.0's have serial numbers later than 508xxxxxxxx. Read the module and see what the electronic serial number says.
Click on the photos below for a larger image.

Program these Pre-Version-2.0 units with KPG-66D software.
 
Program these Version 2.0 units with KPG-91D software.
Model Frequency Range (MHz) RF Power
w=Watts
Notes
"-1"
"K"
"-2"
"K2"
"-3"
"K3"
TKR-750 (VHF) 146 - 174 136 - 150   25-50w
(100% duty at 25w)
You can get a "-1" ("K") down to 144.5 but you DO have to retune the front end. Do it exactly per the Service Manual by sweep tuning it, looking at both response and match. If you are going buy a new TKR-750 for the amateur 2 meter band then make the extra effort to find a K2 (low range) unit.
TKR-751 (VHF) 146 - 174     100% duty at 1-25w Your page maintainer has no personal experience with this model.
TKR-850 (UHF) 450 - 480 480 - 512 400 - 430 25-40w
(100% duty at 25w)
Your author has programmed a "-1" ("K") down to 441 MHz. You DO have to retune the front end. Do it exactly per the Service Manual by sweep tuning it, looking at both response and match.
TKR-851 (UHF) 450 - 480     100% duty at 1-25w Your page maintainer has no personal experience with this model.

The TKR-x51 were manufactured after the TKR-x50 Ver 2.0 units. So all TKR-x51 repeaters are "Ver 2.0", but they aren't labelled as such because there was never a TKR-x51 "Pre-Version-2.0" (also known as "early version", "older version" or Version 1).
A programming note: The older units are programmed with KPG-66D. The Version 2.0 units are programmed with KPG-91D. At the time this paragraph was last updated the current version for KPG-66D was 2.01, and for KPG-91D was 2.13. Both have a programming option for the fan: Thermal or Full Time. The Thermal operation mode has the fan turn on when the transmitter module reaches around 40°C (105°F) with a hysteresis of about 5°. Depending on the firmware version and KPG version if you program an older unit with the KPG-91D everything appears to work as expected except the fan will run full time without regard to the thermal sensor. I was told that KPG-91D Ver 2.13 was supposed to fix this but I've not seen a release note or had the opportunity to verify this.
A second programming note: Any KPG software that is ID'd with a "DN" suffix (i.e. KPG-91DN) cannot program a channel wideband. Unlike most Motorola software you can revert to a previous version (without the "N" suffix) and enable selection of wideband or narrowband.
Here is a "gotcha!": KPG-91D can access up to COM20 but KPG-66D can only access COM1 through COM4 ! This fact bit your author at one mountaintop site where COM1 and COM2 of the on-site laptop was connected to the primary controllers of two LTR systems, the site alarm system was hooked to Com3, and we wanted to connect USB programming cables from a pair of pre-V2.0 TKRs to allow remote programming. And Kenwood says that KPG-66 is off maintenance and will not be updated. The fix was to move the alarm system to COM5 and connect COM3 and 4 to the early version TKRs. I'm hoping that I will be able to abandon KPG-66 and use KPG-91 Ver 2.13 for all of the TKR-x50 / x51s.
Interfacing to the Kenwood TKR-x50 / x51, NXR-x10 repeaters By Mike Morris WA6ILQ
After getting dozens of emails over 6 months I decided to put together all the info that they asked for into one web page.
The TKR-x50 / x51 / NXR-x10 Control / Accessory Port is a DB-25 female connector on the back of the unit but you need a 15 pin Molex connector to enable the front panel speaker. You might as well make up a cable with both a DB25 male and a 15 pin Molex male on one end and a connector that mates with your repeater controller on the other. And the Molex plug can supply +12vDC to power your controller.
And the RD / TD connections on the TKR-x50 / x51 / NXR-x10 are capable of D-Star, IDAS and P25. I've seen a setup with four TKR-850s configured as a P25 (Phase 1) control channel and 3 voice channels and it works.
Do you have a a TKR-x50 Version 2 repeater and need gated QT / DQT (tone encode), like for an Allstar node?
Try this:
1) Program Aux In / Output 4 as an Input and select QT / DQT Encode Enable.
2) Program Aux In / Output 6 as an Output and select COR for Active Low.
3) Jumper pins 23 and 25 on the accessory DB-25 plug.
The CTCSS encoder will now follow the COR.
This only works on a Version 2 repeater. The early repeaters would not let you alter the Transmit tone encode (PL / DPL) on / off state while the unit was transmitting.
Repairing a 'No Transmit Output' on a TKR-750 VHF Repeater   by Henry Clark II KC4KZT
This same condition may exist on other makes and models of radios.
Repairing 'Low Sensitivity' on a TKR-850 UHF Repeater   by By Tim Czerwonka WO9U
Tim had a IF demodulator chip die on him.
Repairing 'Low Sensitivity' on a TKR-x Repeater   by By Mike Morris WA6ILQ
These paragraphs is a placeholder for a photo article... the photos haven't been taken yet. One common issue with older TKR-x50s is the 455 KHz low IF filter. The Kenwood engineering / design group slipped up and didn't include a DC blocking capacitor between the circuitry and the filter. The DC voltage across the filter slowly kills it... I've seen TKR-x50s work perfectly for well over 10 years and then suddenly lose sensitivity... Replacing the filter restores the sensitivity and buys you another decade of operation (or you could add a DC blocking capacitor on the filter input when you swap the filter). They fixed this oversight in the NXR-x10s .
How to diagnose it: Just take advantage of the switchable wideband / narrowband feature that's built into the unit... the other bandwidth filter is unbiased when unselected (i.e. out of the circuit) and therefore is not affected. If the repeater failed in wideband mode then test it by temporarily reprogramming it for narrowband. If the sensitivity comes back while in narrowband and it fails again if you switch it back to wideband then you can be assured that you need to change the wideband filter (if your repeater lives in narrowband mode then test it by switching to wideband).
In our most recent case we had an early TKR-850 go from normal (the site logbook said 0.25-0.3µv) to deaf (6-7 µv) over a 4-day period. We made a trip to the mountaintop site and swapped the repeater module to get the customer back on the air. Fixing that particular repeater module is a lower priority as the shop has a couple of good spares still on the shelf so I don't have any photos yet.
Part Marking
on part
Murata part number Mouser part number
Catalog Sheet
Kenwood part number and source Notes
Wideband Filter W455E CFULA455KE4A-B0 81-CFWLB455KEFA-B0 L72-0366-05   Available from PacParts here. Data Sheet (from Mouser)
Narrowband Filter W455G CFULA455KG1A-B0 81-CFULA455KG1A-B0 L72-0376-05   Available from PacParts here Data Sheet (from Mouser)
If someone has already swapped a filter and would like to contribute a how-to-do-it photo article please let me know.
The actual MuRata data sheet is here   The actual filters used in the TKR-x50 / x51 are on pages 31 and 32.
Useful Part Numbers:     (anyone have the industry standard part numbers and a source for any of these?)
TKR-750 early version RF power transistor: ?     (transistor has a round ceramic body)   (anyone have the 2SCnnnn or 2SKnnnn transistor part numbers?)
TKR-850 early version RF power transistor: ?     (round ceramic body)
TKR-750 V2.0 RF power transistor: RD70HVF1-101 (square ceramic body)
TKR-850 V2.0 RF power transistor: RD60HUF1-101 (square ceramic body)
TKR-750 / 850 PA deck Thermistor: PTH9M04BE471TS (anybody know who actually makes it?)
TKR-750 Service Manual   6 MB PDF
Includes option KES-4 (external speaker).
TKR-750 Service Manual Revised II   3.6 MB PDF
Includes option KES-5 (external speaker).
TKR-750 Service Manual Supplement   500 kB PDF
TKR-850 Service Manual Revised   6 MB PDF
Includes option KES-4 (external speaker).
TKR-851 Service Manual   16.3 MB PDF
Includes option KES-5 (external speaker). Donated by Brad KB9BPF.
Connecting an Arcom RC-210 to a TKR-x50 repeater   62 kB PDF courtesy of Ken Arck
The RC-210 uses a simple enough interface that the information will be of value with most any repeater controller.
Function Reference (FUNC) for the TKR-x50 Version 2.0 and TKR-x51   648 kB PDF
Field Programming Reference (FPRG) for the TKR-x50 Version 2.0 and TKR-x51   1.8 MB PDF
An emailed note to repeater-builder from Rick Eastwood W6RE:     (in early 2024)
There are a number of Kenwood repeaters that have been retired for several years now and many key parts are no longer available.
These include: (7xx=VHF, 8xx=UHF)
  • TKR-720 / 820
  • TKR-740 / 750 / 751 / 840 / 850 / 851
  • NXR-710 / 810     As of early 2024 some dealers still have a few "NOS" ("new old stock") of the 710 and 810, and there are a few web sites caliming stock of the 750 and 850.
NONE of the above are recommended for purchase (even used) to anyone that cannot service the equipment themselves. And don't forget, it's mostly surface mount.
If you are acquiring a new repeater then plan on the NXR-1700 / 1800 units. They can be configured for wideband or narrowband conventional analog or digital, in NXDN or DMR. There are plenty of spare parts are readily available, PDF service manuals can be obtained for free on-line and the print manuals are available from Kenwood. These manuals have a full parts list, schematics and board layout X-ray views. They also contain alignment and diagnostic flow charts which are useful if you are a tech with self-repair in mind.
It is recommended that buyers who are not able to do their own repairs consider the purchase beforehand making sure it is in good working order prior to purchase. Purchase of the new series of NXR-1700 / 1800-2 (400-470MHz) low split repeaters will avoid any "NOS" old stock 710 / 810 repeaters for future troubles due to lack of service parts availability in the supply channels. SOME dealers may stock or have some parts to fix them but many parts are NLA and out of stock at this point in early 2024.
Note that the final PA devices for the TKR-x40, x50, x51 and NXR-x10 are no longer available from Kenwood.

TKR-x40 Series Information and Modifications

Model Frequency Range (MHz) Notes
"Type 1" "Type 2" "Type 3"
TKR-740 (VHF) RX 146-162 RX 158-174 RX 136-150 All three types are TX 136-174 MHz
TKR-840 (UHF) 450-480 480-512 400-430  
TKR-740 / TKR-840 brochure   130 kB PDF
TKR-740C / TKR-840C brochure   87 kB PDF
TKR-740 / TKR-840 description   62 kB PDF
TKR-740 Service Manual, E Version   10.3 MB PDF
Includes options KES-4 (external speaker), KPG-46 (programming cable).
TKR-840 Service Manual   4.83 MB PDF
Unfortunately this PDF is a scan of a paper manual, not computer generated... it's therefore not text serchable.
Trying to get a TKR-x40 to operate without the internal controller? Program the channel with REPEAT and SIMPLEX both turned off or unchecked in the software. You must also remove the REPEAT DISABLE front panel button function in the "Key Assignment" portion of the software. Just change that box to "NONE" and the software will now function without giving you a "repeat function" error message.
Trying to get a TKR-840 to operate below 450? This comment thread may help.   (Off-site pointer, opens in a new browser tab)
A local copy of the program mentioned in the comment thread is here. Note that it can only be used with KPG-47D.
TKR-740 Service Manual Supplement   5 MB PDF

TKR-720 and TKR-820 Series Information and Modifications

Model Frequency Range (MHz) Notes
"K", "M",
"NM" or "AM"
"K2", "M2",
"NM2" or "AM2"
"K3"
or
"M3"
"K4" "M4", "NM4"
or "AM4"
TKR-720 (VHF) 150-174 136-150       "K" and "K2" are 30 KHz channel spacing (wideband)
"M", "M2", "AM" and "AM2" are "30/25 KHz spacing"
"NM" and "NM2" are 12.5 KHz (narrowband)
TKR-820 (UHF) 450-470 470-490 490-512 406-430 400-430 M5 & AM5=340-360 Mhz,
M6 & AM6=360-380 MHz, both not available in USA.
For part numbers of the housings and pins of the 15-pin connector on the back please see the article above titled "Interfacing to the Kenwood TKR-750...". That article is oriented to the newer repeaters but the housing and pins are the same.
TKR-720(N) / TKR-820(N) brochure   122 Kb PDF courtesy of Mark Abrams WA6DPB
TKR-720/N/A schematics   2.4 MB PDF
The pages are full-size and will need to be printed out and taped together for full sheets.
TKR-720/N/A Service Manual Revised   12.2 MB PDF
Includes option KMC-9 (base station microphone). Gray-scale scan with color as required. Also has some service bulletins and several component datasheets at the end.
TKR-720/N/A Service Manual Revised   5.7 MB PDF
Includes option KMC-9 (base station microphone). Black&White scan with color as required. Also has some service bulletins at the end.
TKR-820 Service Manual   28 MB PDF
Includes option KMC-9 (base station microphone). This file has gray-scale views where applicable.
TKR-820/N/A Service Manual Revised II   36 MB PDF
Includes option KMC-9 (base station microphone). This file has color views where applicable.
Disabling the Internal Controller on the TKR-720 / TKR-820 Repeaters   by Mark Tomany N9WYS
You need to do this if you'll be using ANY external controller with these repeaters.
Some notes on identifying, programming and interfacing the TKR-720 / TKR-820 repeaters   A "quickie" page that was put together to share two pages of ancient handwritten notes from my file cabinet that cover interfacing a TKR-n20 repeater to an external repeater controller. If anybody wants to turn them into a photo article, feel free to do so and send it in.
Interfacing a TKR-720 / TKR-820 to a CAT-300 Repeater Controller   by Mark Tomany N9WYS
A list of the various connector signals and what connections you need to make.
Interfacing a TKR-720 / TKR-820 to an S-Com 5K, 6K, 7K or 7330 Repeater Controller   by John "Jake" Eckardt N3FU
One cable is all it takes. Jake's article uses an 5K but the Scom 5K, 6K, 7K and 7330 interface the exact same way, all that changes is the connector pin numbers. Click here for more details.
Controllers from Arcom and RLC companies interface similarly.
Brute Force Hacking the TKR-720 / TKR-820 Series Repeaters   By Matt Krick K3MK
This writeup shows you how to move a TKR-720 or TKR-820 around the band when you don't have access to either a KPT-20 or KPT-50 programmer box.
Additional Information about Hacking the TKR-820 Series Repeaters   150 kB PDF by Brad Andrews KB9BPF
Spurred by Matt's hacking article above, Brad further decoded the QT (CTCSS tone) and DQT (DCS code) information for these units.
He also provided an Excel spreadsheet file that lets you enter frequencies and see the coded result. The file can be downloaded here.
Adding a Ham Gadgets ID-O-Matic II Controller to a TKR-720 / TKR-820 Repeater   11.1 MB PDF by Bob Lawrence KI4RWL
A photo article that walks you through the installation of an inexpensive commercial controller board to a popular desktop repeater.
Adding a Com-Spec ID-8 CW ID to a TKR-720 / TKR-820 Repeater   by Butch Herring W5BE
A short article that gives you connection info for this popular CW ID board.
Com-Spec has hookup information for their TP-38 community repeater panel to the TKR-720 / TKR-820 at their web site. There is enough information buried in their web page to guide you in hooking up a generic repeater controller (like an ACC, an RLC or an S-Com) to the TKR-720 / TKR-820. A local copy can be found here as an 87 KB PDF file.
Converting a TKR-820 to use with D-STAR   414 kB PDF by John D. Hays K7VE
Also works with a TKR-720.
The TKR Guy sells refurbished repeaters, accessories (CW ID, DTMF Control, Courtesy Beep), and programming services and EEPROM kits for the TKR-720 / TKR-820 repeaters.

Photo Gallery

TKR-720 / TKR-820
The black rectangle at the lower right is a 6-pin microphone jack.
TKR-740 / TKR-840
TKR-750 / TKR-751 / TKR-850 / TKR-851
The NXR-710 and NXR-810 are packaged in an identical housing.
TKR-730 / 830


Miscelaneous Manuals and Sales Brochures

TKR-900 / TKR-901 Product Brochure 248 KB PDF courtesy of Mark Abrams WA6DPB

Frequency Range (MHz) Notes
TKR-900 / TKR-9300S TKR-900K2 / TKR-9300S NPSPAC TKR-901 / TKR-9301S
RX 806-821 / TX 851-866 RX 821-824 / TX 866-869 RX 896-901 / TX 935-940 All three types are TX 250 mw
TKR-901 Service Manual   8.8 MB PDF
900 MHz trunking repeater unit. The "transmitter" is simply an exciter and requires an external power amplifier.
TKR-7400 / TKR-8300 / TKR-8400 brochure   53 kB PDF
The photo on this brochure shows a conventional single-channel repeater system.
TKR-7400 / TKR-8400 brochure   88 kB PDF
The photos on this brochure show a 3-channel and a 5-channel trunked system using Kenwood-labeled Trident controllers and Kenwood-labeled TPL amplifiers.
KSG-4500 UHF Repeater Preliminary Installation and Operation Manual   579 kB PDF courtesy of Tim Childers KB9FBI
This is a preliminary Manual (unfortunately no schematics) for the KGS-4500 100 watt UHF continuous duty repeater, which is based on the TKR-820 design. The KSG-4500 has a DA-15 accessory connector which is VERY different than the Molex 15 pin connector on the TKR-820.
There's about 3.15 GB of additional Kenwood documentation that was sent to repeater-builder anonymously. It's stored at our sister-site that can be found here.


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This page originally posted on 14-Oct-2004.
It was split into more logical pieces 27-Dec-2017 by WA1MIK.

This web page, this web site, the information presented in and on its pages and in these modifications and conversions is © Copyrighted 1995 and (date of last update) by Kevin Custer W3KKC and multiple originating authors. All Rights Reserved, including that of paper and web publication elsewhere.