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TKB-720 - Packet, TNC

Posted: Tue Nov 22, 2005 9:35 am
by ve3wpj
Hey thre folks, I have a TKB-720 Base radio which I would like to convert over to packet for the ham bands, I have the radio programmed but am now seeking soem advise on best way to hook up a TNC to the Radio, usign the 15 pin connector on the back sufficent? or will mods be needed? Will be on 2M 1200bps packet for an APRS digI runnign 15W

Thanks
Will
VE3WPJ

Posted: Tue Nov 22, 2005 10:53 am
by n5tbu
The 15 pin connector should work fine.
1-hook
2-line audio groung
3-mic hi
4-dectector audio out
5-line audio input
6-speaker out
7-switched voltage 1 amp max
8-ptt
9-speaker in
10-line rec audio out
11-dc ground
12-speaker out
13-cor/tor
14-nc
15-nc

mod

Posted: Tue Nov 22, 2005 11:26 am
by ve3wpj
Great thanks thats a big help.....I'll give it a shot over the next few days

Will

Posted: Sat Nov 26, 2005 11:19 pm
by ve3wpj
just to make sure I get this right

TNC - 720
Ground - 2 line audio ground
Audio out - 5 line audio input
Audio in - 4 dectector audio out
ptt - 8 ptt
sense - 13 cor

n5tbu, also just wondering if this i sthe same pin out for the tk-630....thanks

Will

Posted: Sun Nov 27, 2005 5:40 am
by n5tbu
no the 630 is different

Posted: Sun Nov 27, 2005 10:58 am
by ve3wpj
OK but I got the 730 corect.

thanks

Posted: Mon Dec 19, 2005 4:09 pm
by ve3wpj
OK I build the radio end of the cable last night

TX Audio to Radio Pin 5 Line Audio Input
RX Audio to Radio Pin 4 Dectector Audio Out
PTT to Radio Pin 8
RX Detect to Radio Pin 13
TNC Pos Power to Radio Pin 7 Switched voltage 1 AMP Max (TNC take 60mw)
GND to Radio Pin 11 DC Ground

Now a few questions, I have not attched this to my TNC as of yet.

GND to DC ground or shoudl it go to audio ground.

I temporarily jumpered the Pin 11 to pin 8 and the Radio didn't go into TX so I am assuming that the DC ground is not the same as the line audio ground.

if that is true then I need a another wire one gound for ptt and audio and another for 12v power.

or can I use the Radio Pin 2 and not have to worried about the DC ground?

Thanks

Will

Posted: Tue Dec 20, 2005 7:30 am
by n5tbu
If you jumpered 11 to 8 and it did not transmit,you have problems!
All those grounds are tied together internally,btw.
mod

Posted: Tue Dec 20, 2005 9:29 am
by ve3wpj
Mod, thats what I though, .....the Power to the ground gave me 14.01 volts.

I will ahve to check things out a bit more.

thanks

Will