K2 VCO alignment trouble

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

K2 VCO alignment trouble

Jeff Kinzli
Ok, I'm at VCO alignment now :)

Problem is that moving L30's slug around doesn't change the reading on R30, it stays at 8V. My T5 *looks* good to me. The manual says refer to troubleshooting but I didn't see anything there that would get me in the ballpark.

I've checked solder joints in the vicinity and don't see anything obvious. I've searched through the archives and the only hit I see is someone who had a bad solder joint that would cause the voltage on R30 to be at the 8V rail.

Any more ideas?

Thanks,

-J
_______________________________________________
Elecraft mailing list
Post to: [hidden email]
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

Reply | Threaded
Open this post in threaded view
|

Re: K2 VCO alignment trouble

Jeff Kinzli
A little more investigating...turns out the voltage on R30 is much lower (4V, +/-) on other bands except 80M. On 80M, it's still at the 8v rail no matter where L30 is adjusted...

I've verified and reverified that T5 is good, and moved the coils around with no change on 80M and R30's voltage.

Anything else to check?

-J

On Tue, Jan 16, 2007 at 09:36:41PM -0500, Jeff Kinzli wrote:

> Ok, I'm at VCO alignment now :)
>
> Problem is that moving L30's slug around doesn't change the reading on R30, it stays at 8V. My T5 *looks* good to me. The manual says refer to troubleshooting but I didn't see anything there that would get me in the ballpark.
>
> I've checked solder joints in the vicinity and don't see anything obvious. I've searched through the archives and the only hit I see is someone who had a bad solder joint that would cause the voltage on R30 to be at the 8V rail.
>
> Any more ideas?
>
> Thanks,
>
> -J
_______________________________________________
Elecraft mailing list
Post to: [hidden email]
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

Reply | Threaded
Open this post in threaded view
|

Re: K2 VCO alignment trouble

Jeff Kinzli
17 turns on T5 might do it ;)

I found that if I tuned down to around 3800 then it was within range, which prompted me to recount the turns on T5 and I found one extra turn under the secondary winding. I'll pull that one out but I bet that's it.

There I go again, airing my dirty laundry :)

Cheers,

-J

On Tue, Jan 16, 2007 at 11:07:22PM -0500, Jeff Kinzli wrote:

> A little more investigating...turns out the voltage on R30 is much lower (4V, +/-) on other bands except 80M. On 80M, it's still at the 8v rail no matter where L30 is adjusted...
>
> I've verified and reverified that T5 is good, and moved the coils around with no change on 80M and R30's voltage.
>
> Anything else to check?
>
> -J
>
> On Tue, Jan 16, 2007 at 09:36:41PM -0500, Jeff Kinzli wrote:
> > Ok, I'm at VCO alignment now :)
> >
> > Problem is that moving L30's slug around doesn't change the reading on R30, it stays at 8V. My T5 *looks* good to me. The manual says refer to troubleshooting but I didn't see anything there that would get me in the ballpark.
> >
> > I've checked solder joints in the vicinity and don't see anything obvious. I've searched through the archives and the only hit I see is someone who had a bad solder joint that would cause the voltage on R30 to be at the 8V rail.
> >
> > Any more ideas?
> >
> > Thanks,
> >
> > -J
_______________________________________________
Elecraft mailing list
Post to: [hidden email]
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

Reply | Threaded
Open this post in threaded view
|

RE: Re: K2 VCO alignment trouble

Don Wilhelm-3
In reply to this post by Jeff Kinzli
Jeff,

Count the number of turns on T5 - it sounds like you may have one too many -
if not spread the turns out as much as possible and see if the voltage
drops.  When counting toroid turns, count the number of times the wire
passes through the center of the core - counting on the outside may lead to
one too many turns (proof is left to the reader <G>).

73,
Don W3FPR

> -----Original Message-----
>
> A little more investigating...turns out the voltage on R30 is
> much lower (4V, +/-) on other bands except 80M. On 80M, it's
> still at the 8v rail no matter where L30 is adjusted...
>
> I've verified and reverified that T5 is good, and moved the coils
> around with no change on 80M and R30's voltage.
>
>
--
No virus found in this outgoing message.
Checked by AVG Free Edition.
Version: 7.5.432 / Virus Database: 268.16.12/628 - Release Date: 1/15/2007
11:04 AM

_______________________________________________
Elecraft mailing list
Post to: [hidden email]
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