[TenTec] Re: hp Z3801A Interface Unit

[Jim Reid]

Well..............

This thing has been up and running now for a few hours!

Solution:

Just forget all that 422 to 232 interface stuff,  and all the
rest!  Simply connect as follows:

On the PC end,  the RS232 connector,  which is almost 
certainly DB9;  and to the RS422 DB25F connector
on the hp GPS unit connect directly these wires:

PC com port DB9,  pin 2 (Rx) direct to hp DB25F pin 2 (Tx)
PC com port DB9, pin 3 (Tx) direct to hp DB25F pin 3 (Rx)
PC com port DB9,  pin 5 (sig gnd) direct to hp DB25F pin 7(gnd)

That's it!  Worked great for me,  immediately after setting up.
That is what Bill Jones,  K8CU, calls this, PC to hp GPS
hook up, his "blow out" connection!  Forget all the differential
and differing level stuff.  Just do it.  Harms nothing,  and
most important,  it worked!

See his web site:
http://www.realhamradio.com/GPS_Frequency_Standard.htm

Anyone want a Telebyte Model 260 422 to 232 Interface
converter! 

At the moment,  my unit is "locked" onto six GPS satellites,
and is providing high precision location,  altitude and time
signals.....hoo,  haw!

Now,  in the morning,  to connect the precise 10 MHz signal
into my RX-340.

73,  Jim  KH7M