[K1] RF Board Resistance Checks

[Bob Molloy]

Hi,

 

I'm up to page 29 in the manual and doing the first resistance checks on the
RF board. I have problems with these 4 test points:

 

P1 pin 16

P1 pin 17

U4 pin 6

U4 pin 7

 

My DMM sometimes shows resistance on these points, then it climbs until it
indicates an open. Sometimes it just shows infinity. I've checked for solder
bridges, unsoldered pins, etc. Actually took pictures of the top and bottom
of the board so I could look at them full-screen on the PC. (The pictures
are here: http://www.kd2uj.com/Telegraphy2/default.html)

 

The other 9 test points seem to be OK.

 

The meter is an "Equus 3320 Auto-Ranging Digital Multimeter." Bought it on
Amazon.

 

Can anyone help?

 

Thanks,

Bob

KD2UJ

 

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html

[Don Wilhelm-4]

Bob,

I don't think you have any problem if the resistance read is high and
climbs in value (even to infinity).
The ">" symbol means "greater than" so anything greater than the
indicated value is good and passes the test.

The resistance climbing is due to electrolytic capacitors charging up to
the voltage used by your DMM.
If you have resistance readings lower than the value indicated, then
that is a problem that needs to be found.

73,
Don W3FPR

On 7/26/2012 3:28 PM, Bob Molloy wrote:

> Hi,
>
>  
>
> I'm up to page 29 in the manual and doing the first resistance checks on the
> RF board. I have problems with these 4 test points:
>
>  
>
> P1 pin 16
>
> P1 pin 17
>
> U4 pin 6
>
> U4 pin 7
>
>  
>
> My DMM sometimes shows resistance on these points, then it climbs until it
> indicates an open. Sometimes it just shows infinity. I've checked for solder
> bridges, unsoldered pins, etc. Actually took pictures of the top and bottom
> of the board so I could look at them full-screen on the PC. (The pictures
> are here: http://www.kd2uj.com/Telegraphy2/default.html)
>
>

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html

["Hjalmar Duklæt"]

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html

[Bob Molloy]

Hjalmar & Don,

 

Thanks very much. I’m sure that’s the right answer. It must be, it’s the one
I was hoping for.

 

73,

Bob

KD2UJ

 

 

From: "Hjalmar Duklæt" [mailto:[hidden email]]
Sent: Thursday, July 26, 2012 16:07
To: Bob Molloy; [hidden email]
Subject: Re: [Elecraft] [K1] RF Board Resistance Checks

 

I remember when I built my K1. The manual said > 1K ohm meaning infinite, or
< 5ohms meaning 0 ohm or shorted connections. Made me confused. I think as
long as it confirms to what the manual says it's ok.

73 de Hal

LA4XX

K1 #2929

 

 

On 12-07-26, Bob Molloy <[hidden email] <mailto:[hidden email]>
> wrote:

Hi,

 

I'm up to page 29 in the manual and doing the first resistance checks on the
RF board. I have problems with these 4 test points:

 

P1 pin 16

P1 pin 17

U4 pin 6

U4 pin 7

 

My DMM sometimes shows resistance on these points, then it climbs until it
indicates an open. Sometimes it just shows infinity. I've checked for solder
bridges, unsoldered pins, etc. Actually took pictures of the top and bottom
of the board so I could look at them full-screen on the PC. (The pictures
are here: http://www.kd2uj.com/Telegraphy2/default.html)

 

The other 9 test points seem to be OK.

 

The meter is an "Equus 3320 Auto-Ranging Digital Multimeter." Bought it on
Amazon.

 

Can anyone help?

 

Thanks,

Bob

KD2UJ

 

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email] <[hidden email]
<mailto:[hidden email]> >

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html