KX1 - Power Amplifier Q6 Installation Question

[Chuck Guenther]

Hi Barry,

As you recall, I ran into the same thing when I completed s/n 2512, and
that this was
reported to the Reflector March 29, 2011.  I hope that the Elecraft
folks have noted the
problem with the standoff.

I also omitted the bottom lockwasher, and worried about the nylon screw
bottoming out.
(It didn't).

I also worried about damaging the nylon screw during soldering, so I
used a metal one
just during soldering.  (My kit contained two nylon screws, and I used a
magnet to separate
the metal ones).

73,
Chuck Guenther
KX1 s/n 2512




Barry, K8QI, wrote:

"Figure 24 shows the installation of the standoff using 2 split washers, One
below and one on top of the board.   I am not able to get the threads to
catch using the 2 washers.    So I only used the one on the top of the board
to maintain the correct heigth of the standoff.   I am a little concerned
that the threads from the 3/16 Pan head and the Nylon 1/4 Flat Head may
contact inside the standoff and result in the Power Amplifier Q6 being loose
and not making good contact with the Thermal Pad.  Did anyone else have this
problem?   What was your solution?

During the solder process for the Power Transistor Q6, the instructions
state to "Temporarily secure Q6 with a 4-40 flat head screw....."     My
question is should I use the nylon flat head or the metal flat head for this
solder step.   Any possibility of deforming the nylon flat head during the
soldering process due to heat transfer?   My thought is no, use the nylon.
Thought I would ask, since I already have the question above."



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[Chuck Guenther]

Chuck, it doesn't say "both washers" in my manual.  Here's the exact quote:
"*The split washer under the standoff is important to reach the proper
height
so Q6 will come in contact with the cover.*"

The lockwasher under the board has nothing to do with the height of Q6's
collector.

73,
Chuck Guenther, NI0C
KX1 s/n 2512


Chuck, K4QS, wrote:

"There is a warning in bold letters stating that both washers
  need to be in place or Q6 will not lay flat against the heat sink pad."



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[K8QI]

I am currently building Serial # 2520.    Going well with no problems found during the testing of Phase #1 or #2.   Thanks to all for the great suggestions to a new kit builder.

Figure 24 shows the installation of the standoff using 2 split washers, One below and one on top of the board.   I am not able to get the threads to catch using the 2 washers.    So I only used the one on the top of the board to maintain the correct heigth of the standoff.   I am a little concerned that the threads from the 3/16 Pan head and the Nylon 1/4 Flat Head may contact inside the standoff and result in the Power Amplifier Q6 being loose and not making good contact with the Thermal Pad.  Did anyone else have this problem?   What was your solution?  

During the solder process for the Power Transistor Q6, the instructions state to "Temporarily secure Q6 with a 4-40 flat head screw....."     My question is should I use the nylon flat head or the metal flat head for this solder step.   Any possibility of deforming the nylon flat head during the soldering process due to heat transfer?   My thought is no, use the nylon.    Thought I would ask, since I already have the question above.

If all goes well, I hope to have my new KX1 on the air on 20 and 40 meters this weekend.

Thanks and 73,

Barry K8QI

[Chuck Stover]

There is a warning in bold letters stating that both washers need to be in place or Q6 will not lay flat against the heat sink pad.

I had difficulty getting the threads started too.  It took several attempts.  I wonder if maybe compressing the split washers in a vise will take enough "spring" out of them to give you the gap needed to get the threads started.

I used the nylon flathead screw to temporarily hold Q6 in place while it was soldered in place.  It survived.  It doesn't have to be real tight.

Chuck K4QS  KX1#2509
--- On Thu, 4/7/11, K8QI <[hidden email]> wrote:

> From: K8QI <[hidden email]>
> Subject: [Elecraft] KX1 - Power Amplifier Q6 Installation Question
> To: [hidden email]
> Date: Thursday, April 7, 2011, 7:52 AM
> I am currently building Serial #
> 2520.    Going well with no problems found
> during the testing of Phase #1 or
> #2.   Thanks to all for the great
> suggestions to a new kit builder.
>
> Figure 24 shows the installation of the standoff using 2
> split washers, One
> below and one on top of the board.   I am
> not able to get the threads to
> catch using the 2 washers.    So I only used the
> one on the top of the board
> to maintain the correct heigth of the
> standoff.   I am a little concerned
> that the threads from the 3/16 Pan head and the Nylon 1/4
> Flat Head may
> contact inside the standoff and result in the Power
> Amplifier Q6 being loose
> and not making good contact with the Thermal Pad.  Did
> anyone else have this
> problem?   What was your
> solution?   
>
> During the solder process for the Power Transistor Q6, the
> instructions
> state to "Temporarily secure Q6 with a 4-40 flat head
> screw....."     My
> question is should I use the nylon flat head or the metal
> flat head for this
> solder step.   Any possibility of deforming
> the nylon flat head during the
> soldering process due to heat transfer?   My
> thought is no, use the nylon.   
> Thought I would ask, since I already have the question
> above.
>
> If all goes well, I hope to have my new KX1 on the air on
> 20 and 40 meters
> this weekend.
>
> Thanks and 73,
>
> Barry K8QI
>
> --
> View this message in context: http://elecraft.365791.n2.nabble.com/KX1-Power-Amplifier-Q6-Installation-Question-tp6249642p6249642.html
> Sent from the Elecraft mailing list archive at Nabble.com.
> ______________________________________________________________
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>

     
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[Chuck Stover]

Chuck,

I didn't have access to my manual when I first responded and was relying on memory.  Good catch on your part.

I finished #2509 over the weekend with the 8030 band adapter and ATU.  I dabbled with it in the QRPARCI event and made contacts all over the US and into Europe.  I was suffering from a head cold, so didn't feel up to a major effort.

It's a very capable rig and will ride well in my SOTA backpack.  I can't wait to fire it up from a mountain top.

Chuck K4QS

--- On Thu, 4/7/11, Chuck Guenther <[hidden email]> wrote:

> From: Chuck Guenther <[hidden email]>
> Subject: Re: [Elecraft]  KX1 - Power Amplifier Q6 Installation Question
> To: "Chuck Stover" <[hidden email]>
> Date: Thursday, April 7, 2011, 11:24 AM
> No problem, Chuck.  Thanks for
> your entry into this conversation.  I was
> surprised to learn from your message that you had actually
> been able to
> capture some threads in the standoff with both lockwashers
> in place.  I
> suppose that pre-compressing the lock washers in a vise
> might have
> worked (my fingers weren't strong enough).
>
> 73 & good wishes for DX and QRP radio fun to you!
>
> Chuck  NI0C
>
>
> On 4/7/2011 10:10 AM, Chuck Stover wrote:
> > Yup.  Your right.  I just dug out the manual
> and re-read that part.  I stand corrected.
> >
> > Chuck K4QS
> >
> > --- On Thu, 4/7/11, Chuck Guenther<[hidden email]> 
> wrote:
> >
> >> From: Chuck Guenther<[hidden email]>
> >> Subject: [Elecraft]  KX1 - Power Amplifier Q6
> Installation Question
> >> To: [hidden email]
> >> Date: Thursday, April 7, 2011, 9:40 AM
> >> Chuck, it doesn't say "both washers"
> >> in my manual.  Here's the exact quote:
> >> "*The split washer under the standoff is important
> to reach
> >> the proper
> >> height
> >> so Q6 will come in contact with the cover.*"
> >>
> >> The lockwasher under the board has nothing to do
> with the
> >> height of Q6's
> >> collector.
> >>
> >> 73,
> >> Chuck Guenther, NI0C
> >> KX1 s/n 2512
> >>
> >>
> >> Chuck, K4QS, wrote:
> >>
> >> "There is a warning in bold letters stating that
> both
> >> washers
> >>    need to be in place or Q6 will not
> lay flat against
> >> the heat sink pad."
> >>
> >>
> >>
> >>
> ______________________________________________________________
> >> 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
> >>
> >
> >
> >
> >
>
>
>

     
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[K8QI]

Thanks for the suggestions.    I was able to compress 2 split washers using a pair of vise grips.    After doing that, I was able to install the standoff with a washer on top of the board and a washer on the bottom of the board.    Now moving on with the building of the kit

73,
Barry K8QI

[Don Wilhelm-4]

  Barry,

Yes, this is sometimes a problem - in all cases, the lockwasher between
the spacer and the board must be present to make the standoff the
correct height.  I have omitted the second lockwasher in some cases, and
in others, I have used already compressed lockwashers that have been
laying on my workbench.  Your technique of squashing the lockwashers
with vise-grips was a good one  I am glad you were ultimately successful.

73,
Don W3FPR

On 4/7/2011 7:52 AM, K8QI wrote:

> I am currently building Serial # 2520.    Going well with no problems found
> during the testing of Phase #1 or #2.   Thanks to all for the great
> suggestions to a new kit builder.
>
> Figure 24 shows the installation of the standoff using 2 split washers, One
> below and one on top of the board.   I am not able to get the threads to
> catch using the 2 washers.    So I only used the one on the top of the board
> to maintain the correct heigth of the standoff.   I am a little concerned
> that the threads from the 3/16 Pan head and the Nylon 1/4 Flat Head may
> contact inside the standoff and result in the Power Amplifier Q6 being loose
> and not making good contact with the Thermal Pad.  Did anyone else have this
> problem?   What was your solution?
>
> During the solder process for the Power Transistor Q6, the instructions
> state to "Temporarily secure Q6 with a 4-40 flat head screw....."     My
> question is should I use the nylon flat head or the metal flat head for this
> solder step.   Any possibility of deforming the nylon flat head during the
> soldering process due to heat transfer?   My thought is no, use the nylon.
> Thought I would ask, since I already have the question above.
>
> If all goes well, I hope to have my new KX1 on the air on 20 and 40 meters
> this weekend.
>
> Thanks and 73,
>
> Barry K8QI
>

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