[1000mp] MK5 cw transmit lockup on 40 & 80m

[Pete Smith]

At 10:04 AM 3/21/04, you wrote:
>I am using a simple parallel port interface with
>just a 2n2222 and 1k resistor. Should I be considering
>something else?


I would try an opto-isolator, but before that, try bypassing the key line 
out of the interface, and the line in from the port with .01 disc 
caps.  Make sure the case of your computer is well grounded, and that the 
radio is grounded to the same bus.  Use RG174 coax for the key line from 
the interface to the radio, and make sure that its shield is connected to 
chassis as well as signal grounds.  Garden variety snap-on  ferrite cores 
may not provide enough inductance at 80m.


73, Pete N4ZR
2671 calls now in the
World HF Contest Station Database
at www.pvrc.org/wcsd/wcsdsearch.htm