Kenwood Tk-862G repeater build

[NeptuneMan]

Firstly, glad to finally be here. Been a lurker for a while, and the FCC got back to be a few weeks ago, so now I can key up

Back story summed up, I'm working on a repeater for my family using a pair of Kenwood TK-862G/HG mobile radios (the 862G for RX, 862HG for TX @ 25 watts). I know there a lot of 'better' options out there for repeaters and mobiles aren't the best of the best, but its what I've got, so I'm using them.  I'm also using Tk-863G for mobile units and looking for TK-3402 HTs, but they aren't 'part 95a'....oh well, still looking.

Current situation, I'm trying to interface the two radios using the KCT-19 accessory cable. I didn't want to use the front mic ports, (I wanted a clean look in a cabinet) I figured the accessory port would be fine for this.  But, I cant figure out the pin-outs. I figured I could just take RX unit and run Receive detect output (CN4 #1) to the TX unit External PTT input (CN4 #7). Plan was to use CN4#1 to activate the PTT and just route audio out from RX to the mic in on TX. But that didn't work...anyone got any ideas?  I think I'm having issues because one is an active hi, and the other is active low?

I'll try to attach any information needed, .pdf, pics, anything anyone needs.  The pic shared is the PCT-19 accessory pin-out. CN1 is used for a separate control unit (I believe GPS), so ignore it. CN3 is horn alert, CN7 is PA..so disregard those too. CN4 and CN8 where the logical ports to use IMO.

 

[NeptuneMan]

I guess I should specify... this set is meant to run without a repeater controller, just radio to radio. The nearest registered repeater is 35+ miles south of me, and I've been monitoring GMRS traffic on the channels I wish to use.  All I should need is a PL/CTCSS tone to keep any stray traffic out of my system. If worst case arises, I'm fairly certain I can set a DTMF relay for remote shut down via the ignition sense cable.

If this little project doesn't turn out the way I want, I had planned to use the ICS Basic Controller. https://ics-ctrl.com/basic-controller/

[gortex2]

Use AFO and not speaker out to the mic input. You want a flat audio aka discriminator. 

[Lscott]

Firstly, glad to finally be here. Been a lurker for a while, and the FCC got back to be a few weeks ago, so now I can key up

 

Back story summed up, I'm working on a repeater for my family using a pair of Kenwood TK-862G/HG mobile radios (the 862G for RX, 862HG for TX @ 25 watts). I know there a lot of 'better' options out there for repeaters and mobiles aren't the best of the best, but its what I've got, so I'm using them.  I'm also using Tk-863G for mobile units and looking for TK-3402 HTs, but they aren't 'part 95a'....oh well, still looking.

 

Current situation, I'm trying to interface the two radios using the KCT-19 accessory cable. I didn't want to use the front mic ports, (I wanted a clean look in a cabinet) I figured the accessory port would be fine for this.  But, I cant figure out the pin-outs. I figured I could just take RX unit and run Receive detect output (CN4 #1) to the TX unit External PTT input (CN4 #7). Plan was to use CN4#1 to activate the PTT and just route audio out from RX to the mic in on TX. But that didn't work...anyone got any ideas?  I think I'm having issues because one is an active hi, and the other is active low?

 

I'll try to attach any information needed, .pdf, pics, anything anyone needs.  The pic shared is the PCT-19 accessory pin-out. CN1 is used for a separate control unit (I believe GPS), so ignore it. CN3 is horn alert, CN7 is PA..so disregard those too. CN4 and CN8 where the logical ports to use IMO.

 

 

How about looking at these handhelds?

 

https://www.ebay.com/itm/184489981820

 

I have several of them and they work great for GMRS. The battery packs are cheap and easy to find along with the accessories, programming cable and software. The software will work on Win 10 BTW.

 

https://mra-raycom.c...ct-Brochure.pdf

 

They are also Part 95A certified, old FCC GMRS section, and are fine under the new rules.

 

https://fccid.io/ALH29473110

[NeptuneMan]

I had completely forgotten about the Tk-370/372! Thanks @Lscot

A friend helped me out a bit to figure some stuff out.  I'll be using Squelch detect output (busy high, 5v) (CN4 #8) on the RX unit to signal the TX.  Problem is that the PTT is 5v active and needs to ground in order to key.  My plan was to use a 5v solid state relay controlled by SQL out on the RX, which would ground PTT on TX upon receive. 

[NeptuneMan]

Upon further discussion,a relay just isn't necessary. A NPN transistor is more than adequate (I'm just use to larger, higher amperage electronics in my work like relays...I'm more mechanically inclined than electronic).

[Steve (WRDR 762)]

Very interested in this build! I currently have a TK-880H and am considering buying another similar radio to use for exactly this purpose. I'm thinking of starting out with a direct radio to radio connection and then have option of adding a controller at a later date if so desired. When you get this all working, would love to see pics and know what connections you made. A wiring diagram may be asking too much, but would be AWESOME if you could provide that!

 

Steve

[NeptuneMan]

Most definitely, Steve.  Unfortunately, this is the definition of a back burner project.  For example, I've had a 40ft Rohn tower for about 6 years, and its not set up yet But of recent, the project has gained quite a bit of traction, so I doubt this repeater build will take that long to finish....hopefully.  I do plan on doing lots of pictures and a detailed reasoning/breakdown on equipment and why I chose what I used.

At the very least, I'll throw a bit of eye candy (pics) of what I'm working with in a later thread.