Topics

QCX 80 T1 Installed, checking for shorts #80m


Scott - N1ST
 

Hi Folks, just beginning my QCX.  I've installed T1 (I won't comment on how much fun this was for 80m), and I'm seeing 300k between pad #1 - #3, #4.   I'm thinking with such high resistance, they're likely meeting in one of the SMCs.  Your comments please.

BTW I'm also seeing 8M between #1-8, but with reversed probes, 0M, so I'm sure those are meeting in a SMC.

Thanks.


George Korper
 

I await other comments, but at those very high resistances, it may well just be
that you really should be careful to keep your fingers away from everything. I would
hold T1 down in a fixture and try to hold the probes with gloves! My DVM with ranging feature
can decide, and decide. Sometimes it show an open and sometimes a very high resistance
which goes away when I don't touch anything. 

On Sun, Apr 12, 2020 at 2:09 PM Scott via groups.io <n1st=yahoo.com@groups.io> wrote:
Hi Folks, just beginning my QCX.  I've installed T1 (I won't comment on how much fun this was for 80m), and I'm seeing 300k between pad #1 - #3, #4.   I'm thinking with such high resistance, they're likely meeting in one of the SMCs.  Your comments please.

BTW I'm also seeing 8M between #1-8, but with reversed probes, 0M, so I'm sure those are meeting in a SMC.

Thanks.


James Daldry W4JED
 

Hi, Scott

Methinks you have to yank T1 back out, remove the enamel from the leads, and stick it back in. Connections 1, 2, 3, and 4 should read zero ohms between the leads. While you are at it, connections 5, 6, 7, and 8 should have zero ohms in any combination and somewhere near open circuit to 1 thru 4.

73

Jim W4JED

On 4/12/20 1:52 PM, Scott via groups.io wrote:
Hi Folks, just beginning my QCX.  I've installed T1 (I won't comment on how much fun this was for 80m), and I'm seeing 300k between pad #1 - #3, #4.   I'm thinking with such high resistance, they're likely meeting in one of the SMCs.  Your comments please.

BTW I'm also seeing 8M between #1-8, but with reversed probes, 0M, so I'm sure those are meeting in a SMC.

Thanks.


Timothy East
 

You may leave the T1 in place and follow Hans' instructions for soldering the toroid using a generous amount of solder.  I have employed this technique very effectively on QCXs and other kits since reading about it in the QCX instructions.  I always check with a VOM and have rarely needed to repeat a solder.

Tim
K0EMP


From: QRPLabs@groups.io <QRPLabs@groups.io> on behalf of James Daldry W4JED <jim@...>
Sent: Sunday, April 12, 2020 3:23 PM
To: QRPLabs@groups.io <QRPLabs@groups.io>
Subject: Re: [QRPLabs] QCX 80 T1 Installed, checking for shorts #80m
 

Hi, Scott

Methinks you have to yank T1 back out, remove the enamel from the leads, and stick it back in. Connections 1, 2, 3, and 4 should read zero ohms between the leads. While you are at it, connections 5, 6, 7, and 8 should have zero ohms in any combination and somewhere near open circuit to 1 thru 4.

73

Jim W4JED

On 4/12/20 1:52 PM, Scott via groups.io wrote:
Hi Folks, just beginning my QCX.  I've installed T1 (I won't comment on how much fun this was for 80m), and I'm seeing 300k between pad #1 - #3, #4.   I'm thinking with such high resistance, they're likely meeting in one of the SMCs.  Your comments please.

BTW I'm also seeing 8M between #1-8, but with reversed probes, 0M, so I'm sure those are meeting in a SMC.

Thanks.


Mike Besemer - WM4B
 

I find that if you keep feeding solder to it, you end up with a solder blob on top of the board.  I’ve been soldering the lead, then removing the solder with a sucker and cleaning the hole with brake cleaner and a toothbrush.  I usually have to do this twice and the third time results in a nice, clean joint.  No issues with lifting traces using this method; Hans’ boards are first class.

 

Your mileage may vary.

Stay inside.

Wash your hands.

Don’t touch your face.

Happy Easter.

 

73,

 

Mike

WM4B

 

From: QRPLabs@groups.io [mailto:QRPLabs@groups.io] On Behalf Of Timothy East
Sent: Sunday, April 12, 2020 4:35 PM
To: QRPLabs@groups.io
Subject: Re: [QRPLabs] QCX 80 T1 Installed, checking for shorts #80m

 

You may leave the T1 in place and follow Hans' instructions for soldering the toroid using a generous amount of solder.  I have employed this technique very effectively on QCXs and other kits since reading about it in the QCX instructions.  I always check with a VOM and have rarely needed to repeat a solder.

 

Tim

K0EMP

 


From: QRPLabs@groups.io <QRPLabs@groups.io> on behalf of James Daldry W4JED <jim@...>
Sent: Sunday, April 12, 2020 3:23 PM
To: QRPLabs@groups.io <QRPLabs@groups.io>
Subject: Re: [QRPLabs] QCX 80 T1 Installed, checking for shorts #80m

 

Hi, Scott

Methinks you have to yank T1 back out, remove the enamel from the leads, and stick it back in. Connections 1, 2, 3, and 4 should read zero ohms between the leads. While you are at it, connections 5, 6, 7, and 8 should have zero ohms in any combination and somewhere near open circuit to 1 thru 4.

73

Jim W4JED

On 4/12/20 1:52 PM, Scott via groups.io wrote:

Hi Folks, just beginning my QCX.  I've installed T1 (I won't comment on how much fun this was for 80m), and I'm seeing 300k between pad #1 - #3, #4.   I'm thinking with such high resistance, they're likely meeting in one of the SMCs.  Your comments please.

BTW I'm also seeing 8M between #1-8, but with reversed probes, 0M, so I'm sure those are meeting in a SMC.

Thanks.


Scott - N1ST
 

Thanks for the suggestion.  All is well,  (user error). 
Another question about T1.  Because all of the wire is the same color and Pri, S1, and S2 overlay S3, I'm not at all sure that I haven't crossed 1 or more of the 5 turns of Pri, S1 and S2.  If I have, will this effect performance of T1?  If it will, I'll remove the 3 and use magic marker to color them before re-winding.
TIA,
Scott


Gregg Myers
 

Hi Scott,

Crossing any of the transformer sections will put wrong phases onto the transformer. This will indeed effect the performance (greatly). It might save a lot of grief to be sure of the phases as detailed in the manual.

Good luck,
Gregg

On Sun, Apr 12, 2020 at 6:22 PM Scott via groups.io <n1st=yahoo.com@groups.io> wrote:
Thanks for the suggestion.  All is well,  (user error). 
Another question about T1.  Because all of the wire is the same color and Pri, S1, and S2 overlay S3, I'm not at all sure that I haven't crossed 1 or more of the 5 turns of Pri, S1 and S2.  If I have, will this effect performance of T1?  If it will, I'll remove the 3 and use magic marker to color them before re-winding.
TIA,
Scott


George Korper
 

No. Read the note by Hans about this in the manual in red at the T1 winding section. 


On Sun, Apr 12, 2020, 7:22 PM Scott via groups.io <n1st=yahoo.com@groups.io> wrote:
Thanks for the suggestion.  All is well,  (user error). 
Another question about T1.  Because all of the wire is the same color and Pri, S1, and S2 overlay S3, I'm not at all sure that I haven't crossed 1 or more of the 5 turns of Pri, S1 and S2.  If I have, will this effect performance of T1?  If it will, I'll remove the 3 and use magic marker to color them before re-winding.
TIA,
Scott


George Korper
 

You may have to add turns anyway...so I'd see if it works. 


On Sun, Apr 12, 2020, 9:35 PM George Korper via groups.io <georgekorper=gmail.com@groups.io> wrote:
No. Read the note by Hans about this in the manual in red at the T1 winding section. 

On Sun, Apr 12, 2020, 7:22 PM Scott via groups.io <n1st=yahoo.com@groups.io> wrote:
Thanks for the suggestion.  All is well,  (user error). 
Another question about T1.  Because all of the wire is the same color and Pri, S1, and S2 overlay S3, I'm not at all sure that I haven't crossed 1 or more of the 5 turns of Pri, S1 and S2.  If I have, will this effect performance of T1?  If it will, I'll remove the 3 and use magic marker to color them before re-winding.
TIA,
Scott