K2 kit build problem

classic Classic list List threaded Threaded
4 messages Options
Reply | Threaded
Open this post in threaded view
|

K2 kit build problem

Don Schroder
Greetings!

I am new to ham radio. I studied and passed the “extra” class. I am now building my first radio, a K2. This is my first post to the reflector, too.

I am on page 38 of my build (serial 7818) and just completed the resistance checks. Two of the test points have a lower resistance value than suggested.

U1 pin 4 measured 15.06K, should be > 20K
U1 pin 28 measured 5.06K, should be > 20K

I’m heading for the schematics to debug. Any suggestions on where to look would be greatly appreciated!
Thanks!

Don, KE0PVQ
(a 75 year old career Marine, retired & disabled)

Sent from Mail<https://go.microsoft.com/fwlink/?LinkId=550986> for Windows 10

______________________________________________________________
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
Message delivered to [hidden email]
Reply | Threaded
Open this post in threaded view
|

Re: K2 kit build problem

Don Schroder
Ok, I’m confused. But I have an excuse (I’m old). I remeasured and both pins were > 20K! Problem solved it’s self.

I should have known that touching the probe tips would change the resistance, because I have a lot of resistance especially
When the wife “tells me” tp do something! I also played taps at gravesites for three years while in high school.

Thank you all for your kind words. I’m excited. A great radio (K2), a great reflector, and great friends a-coming!

So, no problem so far (Yea !!!!).

Don, KE0PVQ

Sent from Mail<https://go.microsoft.com/fwlink/?LinkId=550986> for Windows 10

From: Dave Sublette<mailto:[hidden email]>
Sent: Monday, June 25, 2018 5:18 PM
To: [hidden email]<mailto:[hidden email]>
Subject: Re: [Elecraft] K2 kit build problem

Hello Don,

Welcome to ham radio and to the Elecraft Family.  I am not an official or employee of Elecraft.  Watch for an answer from Don, W3FPR.  He is an official Elecraft repair guy and he knows what he is doing.

I don't want to insult your intelligence or experience, but I have to ask that you make sure you are not touching the metal parts of the probe tips when you make these measurements. Your body resistance will lower the readings, especially if they are supposed to be more than 20K.  Also, look for solder bridges or splashes that aren't supposed to be there.

This is a great reflector and someone will have the answer.  I built a K2 in 2004 and it is a great rig.

I am 76 and an retired Electronics Engineer.  I was in the Navy from 61-65 as a CT M brancher.

I am associated with the local chapter of the Marine Corps League as I play TAPS for the military honors at graveside services for veterans.

Sempre Fi!

Dave, K4TO

On Mon, Jun 25, 2018 at 5:57 PM Don Schroder <[hidden email]<mailto:[hidden email]>> wrote:
Greetings!

I am new to ham radio. I studied and passed the “extra” class. I am now building my first radio, a K2. This is my first post to the reflector, too.

I am on page 38 of my build (serial 7818) and just completed the resistance checks. Two of the test points have a lower resistance value than suggested.

U1 pin 4 measured 15.06K, should be > 20K
U1 pin 28 measured 5.06K, should be > 20K

I’m heading for the schematics to debug. Any suggestions on where to look would be greatly appreciated!
Thanks!

Don, KE0PVQ
(a 75 year old career Marine, retired & disabled)

Sent from Mail<https://go.microsoft.com/fwlink/?LinkId=550986<https://nam01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgo.microsoft.com%2Ffwlink%2F%3FLinkId%3D550986&data=02%7C01%7C%7C3edf6ae56ea14e384d0c08d5dae985e1%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C636655618866411955&sdata=iM%2BtZMTcCYPTPhpljEx0ekNvd2AZnQNBNSLhhN6dTJM%3D&reserved=0>> for Windows 10

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft<https://nam01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fmailman.qth.net%2Fmailman%2Flistinfo%2Felecraft&data=02%7C01%7C%7C3edf6ae56ea14e384d0c08d5dae985e1%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C636655618866411955&sdata=MNclwtdnKJ6Qy%2BjtnGCjP8Bzx146rGy5dNm0RSrJJlQ%3D&reserved=0>
Help: http://mailman.qth.net/mmfaq.htm<https://nam01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fmailman.qth.net%2Fmmfaq.htm&data=02%7C01%7C%7C3edf6ae56ea14e384d0c08d5dae985e1%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C636655618866411955&sdata=VpIpFphXoZEalDlWT4DxAR1MtSKk9b%2FJDGaLRevyRMw%3D&reserved=0>
Post: mailto:[hidden email]<mailto:[hidden email]>

This list hosted by: http://www.qsl.net<https://nam01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.qsl.net&data=02%7C01%7C%7C3edf6ae56ea14e384d0c08d5dae985e1%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C636655618866411955&sdata=L1Ky4voTPLq4N0w416Z2TZo%2FuUiAh6jU2WyHetT6%2BpA%3D&reserved=0>
Please help support this email list: http://www.qsl.net/donate.html<https://nam01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.qsl.net%2Fdonate.html&data=02%7C01%7C%7C3edf6ae56ea14e384d0c08d5dae985e1%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C636655618866411955&sdata=inRPhnssiUgy67Xp7D0SaMb6OwgIz5Sh%2BU3sNFPg0%2BQ%3D&reserved=0>
Message delivered to [hidden email]<mailto:[hidden email]>

______________________________________________________________
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
Message delivered to [hidden email]
Reply | Threaded
Open this post in threaded view
|

Re: K2 kit build problem

Don Wilhelm
Don,

I am glad to hear that you solved your problem.
Some DMMs (but very few) reverse the polarity of the red and black probes.

I trust you were using a modern DMM as opposed to an older VTVM or VOM.
Those older meters have voltages when measuring resistance that will
turn on semiconductor junctions.
If that is what you are using, get a proper DMM for the K2 and any other
semiconductor project.  The inexpensive (or free with a coupon) DMMs
offered by Harbor Freight are adequate for your measurements on a K2.  I
have 4 of them in various places for when I need a quick reading.  If I
need real accuracy coupled with speed of response, I use my expensive Fluke.

73,
Don W3FPR

On 6/25/2018 8:07 PM, Don Schroder wrote:

> Ok, I’m confused. But I have an excuse (I’m old). I remeasured and both pins were > 20K! Problem solved it’s self.
>
> I should have known that touching the probe tips would change the resistance, because I have a lot of resistance especially
> When the wife “tells me” tp do something! I also played taps at gravesites for three years while in high school.
>
> Thank you all for your kind words. I’m excited. A great radio (K2), a great reflector, and great friends a-coming!
>
> So, no problem so far (Yea !!!!).
>
> Don, KE0PVQ
>
> Sent from Mail<https://go.microsoft.com/fwlink/?LinkId=550986> for Windows 10
>
> From: Dave Sublette<mailto:[hidden email]>
> Sent: Monday, June 25, 2018 5:18 PM
> To: [hidden email]<mailto:[hidden email]>
> Subject: Re: [Elecraft] K2 kit build problem
>
> Hello Don,
>
> Welcome to ham radio and to the Elecraft Family.  I am not an official or employee of Elecraft.  Watch for an answer from Don, W3FPR.  He is an official Elecraft repair guy and he knows what he is doing.
>
> I don't want to insult your intelligence or experience, but I have to ask that you make sure you are not touching the metal parts of the probe tips when you make these measurements. Your body resistance will lower the readings, especially if they are supposed to be more than 20K.  Also, look for solder bridges or splashes that aren't supposed to be there.
>
> This is a great reflector and someone will have the answer.  I built a K2 in 2004 and it is a great rig.
>
> I am 76 and an retired Electronics Engineer.  I was in the Navy from 61-65 as a CT M brancher.
>
> I am associated with the local chapter of the Marine Corps League as I play TAPS for the military honors at graveside services for veterans.
>
> Sempre Fi!
>
> Dave, K4TO
>
> On Mon, Jun 25, 2018 at 5:57 PM Don Schroder <[hidden email]<mailto:[hidden email]>> wrote:
> Greetings!
>
> I am new to ham radio. I studied and passed the “extra” class. I am now building my first radio, a K2. This is my first post to the reflector, too.
>
> I am on page 38 of my build (serial 7818) and just completed the resistance checks. Two of the test points have a lower resistance value than suggested.
>
> U1 pin 4 measured 15.06K, should be > 20K
> U1 pin 28 measured 5.06K, should be > 20K
>
> I’m heading for the schematics to debug. Any suggestions on where to look would be greatly appreciated!
> Thanks!
>
> Don, KE0PVQ
> (a 75 year old career Marine, retired & disabled)
>
> Sent from Mail<https://go.microsoft.com/fwlink/?LinkId=550986<https://nam01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgo.microsoft.com%2Ffwlink%2F%3FLinkId%3D550986&data=02%7C01%7C%7C3edf6ae56ea14e384d0c08d5dae985e1%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C636655618866411955&sdata=iM%2BtZMTcCYPTPhpljEx0ekNvd2AZnQNBNSLhhN6dTJM%3D&reserved=0>> for Windows 10
>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft<https://nam01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fmailman.qth.net%2Fmailman%2Flistinfo%2Felecraft&data=02%7C01%7C%7C3edf6ae56ea14e384d0c08d5dae985e1%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C636655618866411955&sdata=MNclwtdnKJ6Qy%2BjtnGCjP8Bzx146rGy5dNm0RSrJJlQ%3D&reserved=0>
> Help: http://mailman.qth.net/mmfaq.htm<https://nam01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fmailman.qth.net%2Fmmfaq.htm&data=02%7C01%7C%7C3edf6ae56ea14e384d0c08d5dae985e1%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C636655618866411955&sdata=VpIpFphXoZEalDlWT4DxAR1MtSKk9b%2FJDGaLRevyRMw%3D&reserved=0>
> Post: mailto:[hidden email]<mailto:[hidden email]>
>
> This list hosted by: http://www.qsl.net<https://nam01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.qsl.net&data=02%7C01%7C%7C3edf6ae56ea14e384d0c08d5dae985e1%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C636655618866411955&sdata=L1Ky4voTPLq4N0w416Z2TZo%2FuUiAh6jU2WyHetT6%2BpA%3D&reserved=0>
> Please help support this email list: http://www.qsl.net/donate.html<https://nam01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.qsl.net%2Fdonate.html&data=02%7C01%7C%7C3edf6ae56ea14e384d0c08d5dae985e1%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C636655618866411955&sdata=inRPhnssiUgy67Xp7D0SaMb6OwgIz5Sh%2BU3sNFPg0%2BQ%3D&reserved=0>
> Message delivered to [hidden email]<mailto:[hidden email]>
>
> ______________________________________________________________
> 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
> Message delivered to [hidden email]
>
______________________________________________________________
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
Message delivered to [hidden email]
Reply | Threaded
Open this post in threaded view
|

Re: K2 kit build problem

ab2tc
Hi Don,

I know this is OT, I apologize. I have at least three of the bright yellow
meters from Harbor Freight and I love them. I have checked them all against
NIST certified meters at work and they are all accurate to all digits shown.
Not bad for a 3 to 6 dollars (or 0 as you indicate) instrument. In general I
am skeptical about most of Harbor Freight's offerings, but this one is a
winner.

AB2TC - Knut


Don,

I am glad to hear that you solved your problem.
Some DMMs (but very few) reverse the polarity of the red and black probes.

I trust you were using a modern DMM as opposed to an older VTVM or VOM.
Those older meters have voltages when measuring resistance that will
turn on semiconductor junctions.
If that is what you are using, get a proper DMM for the K2 and any other
semiconductor project.  The inexpensive (or free with a coupon) DMMs
offered by Harbor Freight are adequate for your measurements on a K2.  I
have 4 of them in various places for when I need a quick reading.  If I
need real accuracy coupled with speed of response, I use my expensive Fluke.

73,
Don W3FPR

<snip>



--
Sent from: http://elecraft.365791.n2.nabble.com/
______________________________________________________________
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
Message delivered to [hidden email]