Hi I agree but remember the K1, K2 and most other Elecraft products have a self resetting fuse in series with the power line. This fuse will limit the current draw to about 3 amps if there any shorts on the circuit board. It would still be a good idea to limit the power supply or fuse it to a low value for initial tests in case in the unlikely event you had a short on the connector or somewhere between the connector and the fuse. I use a bench supply with a current limit adjustment when testing a new radio or when working on a radio.
As to D19 the reason it is there is to protect the PA transistor in case you transmit into an open circuit or mis-matched antenna. All Elecraft radios have very conservatively rated finals with appropriate protection. Although I don't recommend transmitting into high SWR conditions it is nice to know the radio will take a lot of abuse with no damage. Don Brown KD5NDB ----- Original Message ----- From: Mike Morrow<mailto:[EMAIL PROTECTED]> To: [EMAIL PROTECTED]<mailto:[EMAIL PROTECTED]> ; [email protected]<mailto:[email protected]> Sent: Friday, July 23, 2004 11:52 PM Subject: Re: [Elecraft] K1 Manual Errata Sheet - add these? Jeff wrote: > Page 30, column 2, box 2: Add "Do NOT use a power supply over [3?] > amps as any short on the board could vaporize a trace. A wise man would always use a fused DC power lead, not just for initial testing but also for normal operation. If you ever develope a DC power short, such as a shorted D19 (zener across the final PA) due to transmitting without an appropriate antenna, you'll wish you had that fuse. <SNIP> _______________________________________________ Elecraft mailing list Post to: [email protected] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
