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Kenwood TS-700G CTCSS

This page was last updated : 11-Mar-20 23:08:53

CTCSS for a Kenwood TS-700G

Please read the update on the bottom of the page.

Because most of the dutch repeaters now need CTCSS to operate, I couldn't use my old Kenwood TS-700G anymore for operations on those repeaters. I was thinking about building my own CTCSS encoder when a other Ham in the Netherlands PD0AQK posted a ad on Markplaats.nl in which he offerd to make a very small CTCSS encoder and sell it as a complete kit for just euro 5,00 (when the demands where high enough). Well for that 5 euro I couldn't make one my self especialy including a nice PCB, so I signed up for 2 kits (one to use and one for spare).

The results : the demands where more then high enough and he needs to make a new batch of kits :-)

I build one of the kids and added it in a small box with a BCD thumb switch and a small support PCB holding a variable resistor to adjust the subtone output and a extra 100nF capacitor to remove the DC component.

The injection of the signal was done at the junction R21 (33K) / R22 (22K) / C23 (1uF) on the Generator unit of the TS-700G.

Feeding the cable throw a existing hole on the bottom a used adhisive tape to mount the box on side of the TS-700G.

A few tests with my TSQL capable handheld looked promising and after that I hooked up in a QSO on the repeater of Apeldoorn (PI3APD). That day the repeater switched to CTCSS and a lively discussion was going on about the technical implementation of the CTCSS in the repeater and testing.

I came through nice and clear, and could keep the repeater open.

So I'm happy with this mod :-)

Update : The link to the CTCSS encode kitt is a dead link. But when you want something simulair like the kitt the website of the Repeater Bergen Op Zoom. They have the schematic online of a nice little CTCSS encoder :  http://repeater.hvde.nl/pi3boz/ctcss.stm

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