+++++++++++++++ From: "Don Brown" To: "Bozidar Benc" , "Elecraft" Subject: Re: Ground jumpers (Was: RE: [Elecraft] Electronics & radio questions: Don't be shy--go ahead and ask!) Date: Wed, 21 May 2003 07:42:27 -0500 Hi If Wayne doesn't mind I will answer this one. The ground jumpers are a convenient place to connect the ground for your meter or scope when making measurements or calibrating the radio. The 6 mm is not critical but must be high enough to get a clip lead on to the test point. I have worked on a few radios where the ground jumpers were so close to the board that it was impossible to use them. I also like to use the clipped leads from 1N4007 diodes for the jumpers because they are larger and less fragile when used as a test point like this. It is the little things like this that shows the thought that went into the design of the K2 and K1. Don Brown KD5NDB ----- Original Message ----- From: "Bozidar Benc" To: "Elecraft" Sent: Wednesday, May 21, 2003 3:34 AM Subject: Ground jumpers (Was: RE: [Elecraft] Electronics & radio questions: Don't be shy--go ahead and ask!) > Wayne, > > Here is the first one. :-) > > I've built K1 and K2 with almost all options (my KAT100 didn't arrive yet). > Almost every PCB has two, or more, 6 mm high, "U" shaped ground jumpers. > All around those jumpers is ground so for DC they are not needed. > > My question is, why they are needed? Why they must be loops 6 mm high? > Is there anything special in their positions on PCBs? > > TiA > > Bole, 9A3RR ++++++++++++++++++ Date: Wed, 21 May 2003 11:02:01 -0500 To: elecraft at mailman.qth.net From: Tom Hammond Subject: Re: Ground jumpers (Was: RE: [Elecraft] Electronics & radio questions: Don't be shy--go ahead and ask!) Hi Bole: >I've built K1 and K2 with almost all options (my KAT100 didn't arrive yet). >Almost every PCB has two, or more, 6 mm high, "U" shaped ground jumpers. >All around those jumpers is ground so for DC they are not needed. > >My question is, why they are needed? Why they must be loops 6 mm high? >Is there anything special in their positions on PCBs? The 'jumpers' are merely there to provide convenient access points for the GND lead of test equipment! Nothing more. The height is NOT critical, but should be high enough to allow an alligator clip to be readily (and securely) attached). By the way, I always try to use the largest diameter wire I have available when I make my grounding loops. Heavier wire withstands more abuse. THe clipped leads of 1n400x diodes are great for this purpose. >PS. Unrelated question: Do you know if there any other K1/K2 owners in 9A >land? SRI OM, someone else will have to respond to this one. 73, Tom Hammond N0SS ++++++++++++++++