--- INTERFACING THE IC-2AT FOR PACKET ---

To interface an ICOM-2AT to the Kantronics Packet Communicator. You will
have to use an audio transformer to do it right.  (From Kantronics phone
support) White and Black leads from the Packet Controller go to the
primary, the Brown to Secondary, the other secondary lead goes to the 2AT
Mic plug.  They suggest a 1 to 1 transformer, the

-------> WHITE <----- || ------> PTT/MIC ON 2AT
                     )||(
                     )||(
                     )||(
-------> BLACK <----- || ------>BROWN<----+
                                          |
                                          |
------------------------------------------+

White/Black/Brown are from the Packet Controller.  Sent in by Dave  (KE4TZ)
Alexandria, Va

Another way to interface to HT

There have been several items posted recently  on  interfacing  HT's  which
have  a  single wire for both the mike and PTT.  The IC2, IC02, TR2600, etc
all work the same -- they key up when the mike line has  DC  continuity  to
gnd.  The transformer approach posted by KE4TZ in #8123 will work fine, but
there is an alternative cheaper approach too.  Try the following circuit:

 TX Audio <----|(-----+-------------O  (tip)
               C      |                  Mike plug
                       >    +-------   (sleeve)
                      <     |
  TNC              R   >    |
 PLUG                 <     |
                       >    |
                      |     |
 PTT line <-----------+     |
                            |
 GND      <-----------------+

Typically the required C is .1 uf, and the R is about 1k, but may  need  to
be  changed  by  experimentation.   With  the  TNC2,  this  can  be  easily
implemented by taking the "low" end of R57 (560 ohms) off ground and taking
it  instead to the PTT line (Drain end of Q10, the VN10KM power FET).  Sent
in by Tom - W3IWI.

BOOK REVIEW

"Get ***CONNECTED to Packet Radio" by Jim Grubbs, K9EI, QSKY
Publishing, Springfield, IL, 208 pp, $12.95.

"Get ***CONNECTED..." is the first book about Amateur packet
radio to be published since "Packet Radio" by Robert Rouleau, 
ŠVE2PY, and Ian Hodgson, VE2BEN, (TAB Books, Blue Ridge Summit,
PA) was released in 1981. In the intervening five years, the
packet radio mode of Amateur Radio has undergone drastic changes
and Jim Grubbs' new book brings ham radio literature up to date.
In doing so, Jim has managed to cover the state of packet radio
(albeit, only briefly in some cases) as it exists in 1986.

The book is a good primer for the packet radio novice. It briefly
relates the history of packet radio to give the reader some
insight into how the mode got to its present state. It also
describes most of the current production TNCs to inform the
reader what hardware is available.

The highlight of the book is its explanations of the most often
used TNC commands. This helps the reader to interpret some of the
jargon contained in some TNC manuals. (Note that this book only
explains TAPR TNC 1 and TNC 2 commands. VADCG commands are not
covered, while the GLB PK1 commands are cross-referenced in an
appendix.) In addition, the book explains how to vary the com-
mands to optimize a TNC for different modes of operation (HF vs
VHF, direct connections vs repeater connections, etc).

The book consists of the following chapters:

     1. The Land of Aurora (a brief history of packet radio),

     2. It's Not Terminal (terminals and computers emulating
terminals),

     3. Selecting a TNC,

     4. Who's On First (how to install the hardware, set some
parameters, and make your first connection),

     5. Beyond the First Connect (how to set other parameters and
use other TNC commands),

     6. HF versus VHF,

     7. Organizations and Publications (sources of information),

     8. Stuffing the Bits (what is a packet?),

    9. Networking,

     10. The Xerox 820,

     11. Store and Forward (the W0/RLI message forwarding
system),

     12. PAM - A Low Calorie MSO (personal automatic-answering
mailbox),

     13. PACSAT, SAREX, Meteors and More (packets in space),
Š
     14. File Transfers,

     15. Accessories (other packet radio hardware),

     16. The Software Approach (computers emulating TNCs),

     17. Communicators Welcome.

There are also appendices in the book that contain a wealth of
information. Included is a glossary of packet-radio terms, a list
of commonly used packet radio frequencies, a description of the
W0RLI packet-radio BBS command set, and lists of sources for
packet radio equipment and information (publications and
organizations).

One criticism: The book lacks an index. It is very frustrating to
read a nonfiction book and later, try to find something without
an index. As I was writing this review, I needed to refer back to
things I remember reading and I had a hard time finding them. The
book's Table of Contents is too general to be any kind of substi-
tute for a good index. If you read this book, it is good idea to
use a highlighting pen to mark items that you may want to refer
to later.

In conclusion, Jim has written a book that needed to be written.
I recommend it highly to anyone who wants to find out what packet
radio is all about and how to best utilize packet-radio hardware
without being overwhelmed by the technical intricacies of the
mode.

    From WA1LOU