[WriteLog] More Sloppy Keying

[Jim Brown]

On Tue, 22 Jun 2004 03:17:56 -0000, arholub wrote:

>Was just thinking about the keying levels out of a laptop as compared to a 
desktop.  

I've specifically looked at the keying levels on two of my IBM laptops with a DC 
coupled scope. One has a built-in serial port (T22) and the other, a T41, uses a 
B&B Electronics PCMCIA dual serial port card.  Both put out more than enough to 
very solidly key the NPN interverter (sometimes called a level shifter) that needs to 
sit between the computer and the radio's keying line.  I have several inverters built 
up, all identical, that use a 2N4123 transistor that I had a lot of in my junk box. So 
far, I have used it to key a TS850, Omni V, K2, and TS790A. 

Jim K9YC