Please invert everything left of the @ to reply wrote:
Looking to buy used a small TNC, to connect a small notebook PC and a
Yaesu VX-5R. Everything (1 kg notebook, its 12v power adapter, TNC,
X-5R with its 12vDC power adapter) must fit in my briefcase with room
to spare.
You kind on-topic assistance is appreciated.
Don't get the KPC-3! It is TOO big and bulky. (I have one. It is too big
to be used with a handheld radio for portable use).
Personally, I would NOT buy a North American TNC from Kantronics,
AEA/Timewave or MFJ. All these TNC's have their own proprietary host mode
(used to communicate with a specially designed computer program running on
your PC). There are very few FREE programs out there that support these
proprietary host modes. (And in my view, none are very good). As a result,
these companies all try to nail you with expensive terminal PC software.
The TNC option will start to get very expensive.
(One way to get around this expense is to put the TNC into KISS mode and
use one of the free KISS mode terminal programs. There are a couple out
there. Or use the TNC in KISS mode with the AGW packet engine which will
then act as an interface to many great FREE WA8DED terminal based programs).
To make matters worse, these North American companies mentioned above have
done next to nothing to update the firmware in the TNC's to support the new
emerging needs of Hams. (e.g. None of these TNC's support Smart Beaconing
for APRS, etc).
I hate to say it but it would appear that the only true innovation in packet
TNC technology lately is coming out of Europe where packet radio is still
very popular. (see
www.symek.com)
Instead, I would buy a good European TNC. Almost all the European TNC's
support the WA8DED hostmode. There are lots and lots of GREAT FREE terminal
programs that you can download off the net that support this industry
standard. (e.g. Do a Google on "Paxon").
Here is a great SMALL 1200 baud TNC from Europe. It is called the USB micro
TNC. And it is not that expensive. See
http://www.elcom.gr/sv2agw/tnc.htm
It is a fraction of the size of the KPC-3. It also uses a USB interface
which makes it ideal for use with a laptop. It is also powered by the USB
interface. No need to install a battery like you would need to do with a
KPC-3.
If you are looking for another USB based TNC, see
www.baycom.org. They
have one that supports both 1200 baud and 9600 baud. But it is the size of
the KPC-3. It is about the same price as the USB-micro-TNC.
If you really want to support a North American TNC company, then I would
recommend that you buy MFJ. (I thought I would never say that!) They make
a good TNC2 clone. If you do that, I would recommend that you replace the
firmware with The Firmware (TF) v 2.7b which supports the WA8DED hostmode.
This firmware is FREE but you will have to find someone to burn you a WA8DED
host mode chip for you.
Alternatively, you can easily build a very small KISS based TNC. As noted
above, there are a couple of very good KISS terminal programs that will run
under MS Windows. (see WinTNC). Or you can use the AGW packet engine to
act as an interface between the KISS modem and many great free WA8DED based
terminal programs out there.
Here is the link to building a low cost KISS based TNC, called the TNC-X --
http://www.john.hansen.net/PICTNC.htm
And finally, as noted by another poster, you can consider whether you really
want a TNC after all. You can easily use your sound card in the laptop as
your packet modem. The interface is very easy. You can build it yourself
for $10 to $20 US or buy an expensive rig blaster interface. The FREE AGW
packet engine or the Flexnet32 software is all you need to make it work.
The advantage of the soundcard is that is will also let you use other modes
other than packet. e.g. SSTV, etc.
The disadvantage is that is ties up the sound card. (You can't easily add a
second one to a laptop).
So if you want to play NHL 2004 and have the packet gear hooked up and
running at the same time, then forget the sound card approach.
For more info on sound card packet see
www.qsl.net/soundcardpacket
I hope you find this post helpful.
73's
Rob