+++++++++++++++++
Message: 12
Date: Mon, 13 Jan 2003 07:31:56 +0000
To: Terry Bassett <mutabut at net66.com>
Cc: elecraft at mailman.qth.net
From: David Pratt <david at kippax.demon.co.uk>
Subject: Re: [Elecraft] K2 VCO Alignment not going well...

Terry -
A suggested mod (by Holger DL4LX on 18/7/02) is to remove C70 (4.7pF) 
completely and to fit a 10pF across C72 under the PCB.  Tests have found 
that this arrangement gives a more suitable range of VCO voltages across 
the bands.  Too high a VCO voltage will result in a chirpy note on CW.

73

David G4DMP

In a recent message, Terry Bassett <mutabut at net66.com> said....
>Hello All,
>
>       I am at the VCO Alignment stage. Two bands give high readings and I have
>checked parts identities and placement. I have pulled out T5 and T7 and redid
>them.
>
>
>here are my readings:
>
>80M 3500  2.03     4000    6.00
>40M 7000  1.64     7300    3.23
>30M 10000   2.81   10150    3.34
>20M 14000  2.45    15000   4.10
>17M  18000   8.44   18200   8.44
>15M  21000   2.36    21450   3.52
>12M   24800   4.05    25000   4.43
>10M   28000 8.44     28800    8.44
>
>       As you can see 17M and 10M are the problem.  I can see normal readings
>flashing on the LCD as I tune betweem the low end and high end of each of
>these bands.  But when I stop moving the tuning dial it goes back to 8.44v.
>       Also if if press the AGC buttom several times it will stay at an in-range
>reading and I can spin the tuning knob and the voltages will stay in range.
>If I press Band+ or Band- and then come back to the same band, the voltage
>will settle at 8.44.
>
>       I checked things over and over and am about out of things to look at.
>Do any of you have a fresh idea of what or where I should look?

+++++++++++++++++
From: "Steve Hull" <ag4l at conninc.com>
To: <elecraft at mailman.qth.net>
Date: Mon, 13 Jan 2003 16:32:24 -0500
Subject: [Elecraft] RE: k2 Alignment not going well

Hello Terry
I had the same problem with my unit except the=20
8.4 volts was on the high end of 40 and 80 meters..
So after talking with Gary and tried several things I=20
finally had to rewind T5 with only 15 turn and seperated
the windings over 90% of the core..
Now it mignt be different on 17m band
Good luck
Steve / AG4L

+++++++++++++++++++
From: Terry Bassett <mutabut at net66.com>
To: elecraft at mailman.qth.net
Subject: Re: [Elecraft] RE: k2 Alignment not going well (resolved)
Date: Mon, 13 Jan 2003 19:21:02 -0600

Hello,
=09It is resolved now. Peter Rosenberg AC7SB emailed me and mentioned the=
 RFC 15=20
mod on the errata sheet.  I checked mine out and re-heated the solder joi=
nts=20
there and re-tested and the VCO voltages are right now.
=09Many thanks Peter, somehow I had not double-checked the mod from the e=
rrata=20
sheet.=20
=09Now I am signal tracing the BFO, C174 doesnt have a signal on both sid=
es of=20
it. I am in contact with Scott at Elecraft and hope to get this radio goi=
ng=20
soon.

73 All,

Terry  KA9TXE  in East Central Illinois

+++++++++++++++++
From: "Don Brown" <DolfinDon at msn.com>
To: "Jibeji" <f8dql at radioamateur.org>, <elecraft at mailman.qth.net>
Subject: Re: [Elecraft] [K2] VCO Alignment problem
Date: Tue, 4 Mar 2003 14:21:03 -0600

Hi

I had this problem with a >3000 K2 a few days ago. After quite a bit of head
scratching I rewound T5 and added two turns. This solved the problem and all
of the voltages fell into place. You may want to give this a try.

Add two turns to the red winding. 18 turns rather than 16 turns

Don Brown
KD5NDB


----- Original Message -----
From: "Jibeji" <f8dql at radioamateur.org>
To: <elecraft at mailman.qth.net>
Sent: Tuesday, March 04, 2003 12:39 PM
Subject: [Elecraft] [K2] VCO Alignment problem


Hello.
I have a problem on page 58, VCO Aligment.
The voltage on R30 should be 6.0V but I have 4.85V max when I turn L30 CW.
C72 is 271, L30 is T1005, T5 is a yellow toroid, 16 turns of red wire (pads
1&2), 4 turns of green (3&4)
Any idea ?
Thanks
--
F8DQL
UFT 1116

+++++++++++++++++++++
From: "Don Brown" <DolfinDon at msn.com>
To: "Jibeji" <f8dql at radioamateur.org>, <elecraft at mailman.qth.net>
Subject: Re: [Elecraft] [K2] VCO Alignment problem
Date: Tue, 4 Mar 2003 15:05:57 -0600

Hi

Add two turns to the red winding. 18 turns rather than 16 turns

Don


----- Original Message ----- 
From: "Jibeji" <f8dql at radioamateur.org>
To: <elecraft at mailman.qth.net>
Sent: Tuesday, March 04, 2003 2:27 PM
Subject: Re: [Elecraft] [K2] VCO Alignment problem


> My K2 is S/N 3249
> Two turns with red or green wire ?
> Thank you Dan.
> --
> F8DQL
> UFT 1116

++++++++++++++++++++
From: "Jibeji" <f8dql at radioamateur.org>
To: <elecraft at mailman.qth.net>
Subject: Re: [Elecraft] [K2] VCO Alignment problem
Date: Tue, 4 Mar 2003 22:33:09 +0100

I have tried to compress the turns without success so I have add a turn =
to T5 and it works fine now.
Thank you very much for your answers.
--
F8DQL
UFT 1116

+++++++++++++++++++++
Date: Sat, 12 Apr 2003 22:59:27 -0800
From: "Thomas D.Simes" <simestd at netexpress.com>
To: elecraft at mailman.qth.net
Subject: Re: [Elecraft] Low R30 voltage also  - K2 #3378
Organization: NetExpress


First, I would like to thank everyone who responded with suggestions - what a great group of folks
this list is!!  Second, I would like to contribute back to the list that I rewound T5 with 17
turns on the 1-2 windings as Don had mentioned and was able to easily obtain 6V. R30 durning the
VCO alignment and the rest of the stage II tests were within limits :-)

Onward and upward with #3378!

On Fri, 11 Apr 2003 07:58:17 -0800
"Thomas D.Simes" <simestd at netexpress.com> wrote:

> 
> Unfortunately I seem to be in this boat as well.  Up to this point #3378 has checked out 100%
with no rework, but in the VCO alignment I cannot get more than 3.6 - 3.8 volts. R30.  
> 
> Input voltage measures 12.1 - 12.0V under load (battery)
> I have verified that C72 is marked "271"
> I have verified that L30 is marked "1005"
> T5 1-2 windings (red) pass through the core 16 times
> T5 3-4 windings (green) pass through the core 4 times
> T5 core verified as 1/2" yellow
> 
> The windings are evenly spaced and the 3-4 windings are exactly (by winding count) opposite the
1-2 leads on the core.  Looks just like figure 6-16 except smaller and 6-16 only shows 14 1-2
windings.
> 
> Given my respect for Don's postings on the list, I am inclined to follow his lead and rewind T5
with 17 turns on 1-2.  I am curious though as to why this might be necessary though since the rest
of the kit has gone so smoothly.
> 
> Also, is there enough wire in the kit to cover rewinding this guy or should I order some extra
now from Elecraft?
> 
> Thanks!
> 
> On Mon, 7 Apr 2003 14:41:02 -0500
> "Don Brown" <DolfinDon at msn.com> wrote:
> 
> > Hi
> > 
> > The signal at 4.000 mhz is the MPU clock but it is outside the ham bands so
> > is 14.36.
> > 
> > The last several K2's I have built had the low R30 voltage I rewound T5 with
> > 17 turns (one more turn) and the problem was corrected. Squeezing the turns
> > is also ok to get the voltage up.
> > 
> > Don Brown
> > KD5NDB
> > 
> > 
> > ----- Original Message -----
> > From: "Charles Esch" <cesch at nwhealth.edu>
> > To: <elecraft at mailman.qth.net>
> > Sent: Monday, April 07, 2003 2:01 PM
> > Subject: [Elecraft] K2 signal at 14,361.4 khz
> > 
> > 
> > > Hi,
> > >
> > > I have an almost completed #3315 K2 and I just installed SB board.
> > >
> > > All has gone quite well in building except for a few problems.
> > >
> > > 1. I have a strong signal ocurring at 14.36140 mhz that is about S1-2.
> > > As I tune down in frequency a few hundered cycles, in any mode, the
> > > signal drops off abruptly.
> > >
> > > I also have a less strong signal at 4.000 mhz that does not have this
> > > abrupt drop in the signal.
> > >
> > > I don't know if this was present before I installed the sideband board
> > > as I am not sure if I have listened at these frequency before.
> > >
> > > 2. The only other problem I have had was with VCO alignment.
> > > I was not able to get the voltage at R30 up to the 6 volt point with the
> > > L30 inductor adjustment.
> > > I found that if I compress the windings on T5 I was able to get there.
> > > The only problem, if it is a problem, is that the windings cover about
> > > 65% of the core rather than the 85% required. Rechecked components
> > > related, but did not find any problems.
> > >
> > > Thanks for any suggestions you have.
> > >
> > > Chuck W0KZM

++++++++++++++++++
From: "Don Brown" <DolfinDon at msn.com>
To: "John R. Lonigro" <johnlon at earthlink.net>,
        "Elecraft" <elecraft at mailman.qth.net>
Subject: Re: [Elecraft] K2 VCO Alignment Problem
Date: Wed, 7 May 2003 06:46:26 -0500

Hi

This is a common problem on <3000 S/N K2's. Just rewind T5 with 17 turns and
it will be fine. I had to do this on several K2's including the one I built
for Eric. Before rewinding T5 try squeezing the turns as close together as
possible, that may get the voltage up enough with 16 turns.

Don Brown
KD5NDB


----- Original Message -----
From: "John R. Lonigro" <johnlon at earthlink.net>
To: "Elecraft" <elecraft at mailman.qth.net>
Sent: Wednesday, May 07, 2003 6:45 AM
Subject: [Elecraft] K2 VCO Alignment Problem


> Everyone:
>
> I've finally reached the "Alignment and Test - Phase II" of my K2
> (#3401) assembly.  I was unable to adjust L30 sufficiently to get the
> voltage at R30 up to 6.0 volts at 4000 kHz.  On 80 Meters, the range is
> 1.42v (3500 kHz) to 4.19v (4000 kHz).  I can get 6.0 volts at 4176 kHz.
>  If I increase the frequency up to 4312 kHz, the reading makes it all
> the way to 8.35 volts.  On all the other ham bands, the voltage ranges
> from a low of 3.02 (15M low) to 5.80 (40M high).
>
> The hint says I probably wound the VCO inductor (T5) wrong or installed
> the wrong value at L30 or C72, but I used the right color toroid
> (yellow), the right number of turns (16 and 4) wound in the right
> direction, and the values at L30 and C72 are correct.
>
> Any ideas??
>
> John AA0VE

++++++++++++++++
Date: Wed, 7 May 2003 06:07:00 -0800
From: "Thomas D.Simes" <simestd at netexpress.com>
To: elecraft at mailman.qth.net
Subject: Re: [Elecraft] K2 VCO Alignment Problem
Organization: NetExpress



I can second that - following Don's advice with SN 3378, I rewound T5 with 17 turns and everything
else checked out 100%.  By the way, at least in my kit I had more than enough wire to rewind a
couple of the toroids which initially didn't turn out as well as I would have liked.

On Wed, 7 May 2003 06:46:26 -0500
"Don Brown" <DolfinDon at msn.com> wrote:

> Hi
> 
> This is a common problem on <3000 S/N K2's. Just rewind T5 with 17 turns and
> it will be fine. 

-- snip --

+++++++++++++++++++
From: "Don Brown" <DolfinDon at msn.com>
To: "Eddy Avila" <k6sdw at hotmail.com>, <simestd at netexpress.com>,
        <elecraft at mailman.qth.net>
Subject: Re: [Elecraft] K2 VCO Alignment Problem
Date: Wed, 7 May 2003 10:50:32 -0500

Hi

No if it makes 6 volts with 16 turns then it is fine. This is most likely a
build up of tolerances in the L's and C's that requires just a little more
inductance to make it work. As the manual states the voltage should not go
below 1.5 volts or above 7.5 volts. If you are in that range the PLL is
where it needs to be.

Don Brown
KD5NDB


----- Original Message -----
From: "Eddy Avila" <k6sdw at hotmail.com>
To: <simestd at netexpress.com>; <elecraft at mailman.qth.net>;
<DolfinDon at msn.com>
Sent: Wednesday, May 07, 2003 9:30 AM
Subject: Re: [Elecraft] K2 VCO Alignment Problem


> You guys making me curious now!! I had no problem getting the correct
> voltage from L30.....but, now wondeirng if there's any advantage to
> rewinding T5 to 17 turns for more voltage headroom? I wonder if the manual
> should be changed to 17 turns?
>
> tnx and 73....ed

++++++++++++++
Date: Wed, 07 May 2003 17:11:09 -0500
From: "John R. Lonigro" <johnlon at earthlink.net>
To: Elecraft <elecraft at mailman.qth.net>
Subject: [Elecraft] VCO Alignment Problem

Thanks to all for the "squeeze the T5 windings together" suggestion. 
 I'm now able to easily get 6.00 volts at 4000 kHz.  It sure is easy, 
once you know the trick.  Back to my alignment...

John AA0VE

+++++++++++++++++
From: "Don Brown" <DolfinDon at msn.com>
To: <elecraft at mailman.qth.net>, <wo7t at juno.com>
Subject: Re: [Elecraft] K2 #1059 VCO Alignment to 6.0V
Date: Mon, 19 May 2003 08:12:08 -0500

Hi

Double check T5. The winding sense is critical on this transformer. Make
sure the windings start and finish exactly like the picture in the manual
and the winding direction is correct. Check for poorly tinned toroid leads
(PTTL) on T5. Check all the varactor diodes to be sure they are the correct
type and installed correctly. D19 and D20 should NOT be installed and the
menu setting for D19 should be set to "N" the default.

Don Brown
KD5NDB


----- Original Message -----
From: <wo7t at juno.com>
To: <elecraft at mailman.qth.net>
Sent: Sunday, May 18, 2003 11:36 PM
Subject: [Elecraft] K2 #1059 VCO Alignment to 6.0V


>
>
>
> Hello All:
>
> I have a problem VCO Aligment.
>
> The voltage on R30 should be 6.0V but I have 8.35V, and no
> amount of turning L30 changes it from 8.35V. It's steady
> at that voltage.
>
> C72 is 271, L30 is T1005, T5 is a yellow toroid, 16 turns of red wire
(pads 1&2), 4 turns of green (3&4)
>
> I judge from some other postings that removing a primary winding might
> move my voltage reading down, but why no variablity even at current point?
>
> Any help most appreciated.......
>
> 72,
> Mark
>

+++++++++++++++
Date: Wed, 21 May 2003 06:05:31 -0700 (PDT)
From: Harry Yingst <ab2pn at yahoo.com>
Subject: Re: [Elecraft] [Remedy] K2 #1059 VCO Alignment to 6.0V
To: wo7t at juno.com, elecraft at mailman.qth.net

I had to squeeze the turns on T5 together a little bit to get it to
come up to 6.0 v.

K2 sn 3458






--- wo7t at juno.com wrote:
> 
> Hi All:
> 
> Just wanted to document the resolution to what's been my only
> issue to date on my K2 build up.
> 
> I guess on some of the earlier K2's I missed recommendations
> to drop back to 15 primary windings on T5 vs. the manual instruction
> to 16. Once I did this, I had variablity with L30, and could hit 
> the 6.0V level.
> 
> Many thanks to Carl Morris, who led me down this path. I was somehow
> believing at the higher voltage I would still see variability with 
> tuning L30. Not so. If starting voltage here is too high, take off 
> a primary turn.
> 
> 
> 72
> Mark
> 
> >
> >
> >
> > Hello All:
> >
> > I have a problem VCO Aligment.
> >
> > The voltage on R30 should be 6.0V but I have 8.35V, and no
> > amount of turning L30 changes it from 8.35V. It's steady
> > at that voltage.
> >
> > C72 is 271, L30 is T1005, T5 is a yellow toroid, 16 turns of red
> wire
> (pads 1&2), 4 turns of green (3&4)
> >
> > I judge from some other postings that removing a primary winding
> might
> > move my voltage reading down, but why no variablity even at current
>  point?
> >
> > Any help most appreciated.......
> >
> > 72,
> > Mark
> 

++++++++++++++++