Kenwood TK8180

[m1geo]

Hello all.

New to working with Kenwood PMRs. I'm trying to setup something very simple, and wondered (a) if it could be done, and (b) how to do it. Fairly sure it can be done.

I want to transceive 9600 baud data. I need the audio to be as flat as possible and the minimum phase distortion on both TX and RX, so the data as the best chance of recovery and thus BER.

On the back of the PMR, there is a 25-way D connector. I assume that I can use that. A little looking int the programming software reveals that I can select DI (i guess that's for data in, or maybe MI2) and also External PTT (Data) (or maybe Data PTT). I guess they're all programmable so just set to match? I basically want to go directly to the VCO, no processing, as this is all done externally by the data modem. I guess STE=squelch tail eliminator, and QT/DQT are CTCSS or similar? How to I turn off TX audio shaping, or is this done when I use a data input?

On the receive side, I am a little more lost. I want to do the same thing, basically; Get a signal out of the radio that is directly from the discriminator, without audio shaping and deemphasis, etc. Again, the phase distortion and audio bandpass flatness are paramount. I need this to be open-squelch, but I guess if it's discriminator audio, it probably will be output before the squelch circuitry.

Sorry for the long (first) post, and hopefully someone can guide me in the right direction.

George
M1GEO

 

[mmckenna]

Should be pretty straightforward.

You do use the DB-25 on the rear of the radio for data in/out. Setting up the DI input for your data is what you need to do. The data output should already be there.
If you are set up for data input, it'll bypass the microphone input and the filtering(don't use the MI2 input, that's for a microphone).

I've done this with the NX-900's, which the NXDN version of this radio. It's a bit easier in NXDN mode, but you should be able to do what you want. I don't think Kenwood could have made it much easier.

 

[m1geo]

Thanks for the quick reply!

It all seemed pretty easy and logical on the TX side, I guessed the DI input would bypass filtering, etc. Just one remaining question. You say "The data output should already be there." - could you give me a clue as to what it could be labelled? I was looking for a matching "DO", but can't see it. A picture of the pinout: http://www.m1geo.com/files/tk8180_25pin.png

Thanks so much.

George M1GEO

 

[mmckenna]

I'm using a standard DB-25/RS-232 cable on my NX-900.

On the DB25:
Pin 2 is serial data input 1
Pin 3 is serial data output 1

Pin 5 can be used as the DI input
Pin 7 is ground.

Pin 19 is a detector signal output.

If you just use a standard RS-232 cable, the pins should match up already for serial communications. Just make sure you don't have any of the other pins assigned, as some of them will dump 12v dc into the RS232 port of your equipment, which may not go over very well.

 

[m1geo]

The data I'm sending isn't RS232. It's just 9600 bitrate to go over air.

I'm fine soldering up my own cable, but, it was pin 19 which is flat detector out (Kenwood diagram says "DEO"?) that I wasn't sure of.

Pin 5 and a DataPTT pin (software defined) is fine, with Pin 7 as ground.

Thanks again!

George M1GEO

 

[kd4efm]

The data I'm sending isn't RS232. It's just 9600 bitrate to go over air.

I'm fine soldering up my own cable, but, it was pin 19 which is flat detector out (Kenwood diagram says "DEO"?) that I wasn't sure of.

Pin 5 and a DataPTT pin (software defined) is fine, with Pin 7 as ground.

Thanks again!

George M1GEO

George, I am wondering if your saying 9600bps Packet Radio, for ham radio use?
If so, then yes. The audio out of the TNC goes to MI2.

I have to go and see if I have my ancient notes on TNC hook-ups for the TK-x180's but
like McKenna said, it's fairly simple.


EFM

 

[m1geo]

It's actually not for a TNC, but is for digital voice projects instead.

From this advice, I got hold of a few TK-8180 and a TK-7180. Connecting up as suggested, I have problems with the receive side of things. With the TK-7180, the system works perfectly. With the TK-8180 and the same settings, I cannot get the system to work. A scope shows the same RX audio level coming out of both radios. This is true for multiple TK-8180 transceivers; none work.

Just a very strange circumstance; with the TK-7180, It's almost impossible to make it *not* work, any twiddling on the modem levels, etc, still give a usable result. Nothing at all works on the TK-8180.

I see in the service manual there are options to adjust parameters not presented in the KPG-92D. Is there some other piece of hardware or something needed to set up the DEO output? The service manual says the level is adjustable, but, then again, it says it's also DC-coupled (and looking at the schematic it clearly isnt!).

Thanks all.

George M1GEO

 

[mmckenna]

Not sure about the TK-7180/8180 pair, but on the NX-x00 radio, which use the same chassis and some of the same interfaces, it's in the "extended function" page of the KPG software, under <edit>

 

[m1geo]

Cheers. After about 5 hours of faffing around, I found the problem about 3 minutes after posting. The issue was with the modem settings. Apparently, the TK-7180 does not invert the received audio, but the TK-8180 does. Changing the setting in the modem worked

Weird, but at least it's working! Thanks!

 

[vk6tux]

NX5xxx P25/DMR dual band APP

George, I am wondering if your saying 9600bps Packet Radio, for ham radio use?
If so, then yes. The audio out of the TNC goes to MI2.

I have to go and see if I have my ancient notes on TNC hook-ups for the TK-x180's but
like McKenna said, it's fairly simple.


EFM

Hi Evans, Good to see you online. If you have time could you email NX5800 (DMR/P25 > UHF/VHF > two bodies/one head) pricing to

vk4tux at bigpond dot com please? for the same project as the OP please.

I think you are a Kenwood dealer in Florida these days ?