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K2 front panel LCD soldering

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Conway Yee

K2 front panel LCD soldering

On page 27, right column of the current K2 construction manual, the
revised instructions tell me to place the spacers beside the LCD leads and
remove the spacers after soldering. The original instructions tell me to
place the LCD leads THROUGH the holes in the spacer. Presumably these
spacers are the LCD spacers broken from the RF probe/switch spacer at the
beginning of the construction.

Why did they change the instructions? What is the advantage?

Not knowing the benefits of the new instructions, it would appear that the
old instructions make more sense. The new method leaves the LCD supported
by only the leads. The spacers add support.

tnx.
Conway Yee, N2JWQ

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Don Wilhelm-4

Re: K2 front panel LCD soldering

Conrad,

The support is not the only issue (although it may make the LCD
backlight mounting more sturdy).
The problem was that for a period of time, the leads on the backlight
assembly from the vendor were too short, and those backlight assemblies
with short leads must use the instructions on the errata page this
situation has since been corrected with the vendor. If your backlight
assembly has leads of a sufficient length to use the spacers and still
allow soldering on the solder side of the board, then yes, you can
ignore the errata and use the original instructions. In other words,
look at the lead length you have with your K2 kit and do "what is
right". The one thing that is important is to get the backlight
assembly LEDs adequately soldered to the pads on the Front Panel board,
and spaced up so the backlight assembly fits nicely below the LCD
display module.

73,
Don W3FPR

Conway Yee wrote:

> On page 27, right column of the current K2 construction manual, the
> revised instructions tell me to place the spacers beside the LCD leads and
> remove the spacers after soldering. The original instructions tell me to
> place the LCD leads THROUGH the holes in the spacer. Presumably these
> spacers are the LCD spacers broken from the RF probe/switch spacer at the
> beginning of the construction.
>
> Why did they change the instructions? What is the advantage?
>
> Not knowing the benefits of the new instructions, it would appear that the
> old instructions make more sense. The new method leaves the LCD supported
> by only the leads. The spacers add support.
>
> tnx.
> Conway Yee, N2JWQ
>
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Conway Yee

Re: K2 front panel LCD soldering

KA9UCP writes:
>One point they did make, be sure the IC under the LCD is checked for
>proper soldering as any corrections after the LCD is installed is a
>"bear".

W3FPR writes:
>The problem was that for a period of time, the leads on the backlight
>assembly from the vendor were too short, and those backlight assemblies
>with short leads must use the instructions on the errata page

Gentlemen,
Your recommendations are appreciated. I checked the IC joints VERY
carefully for cold joints and bridges. I reflowed all joints as well.
My leads are long as well.

I have a followup question. The instructions specifically say NOT to
remove the backing on either side. My LCD backlight assembly has white
diffusers on both sides (so far so good). There is, however a SECOND
thin plastic translucent (not white) film as well on top of the assembly
which seems to be removable. Can I remove this second film?

tnx.
Conway Yee, N2JWQ

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Don Wilhelm-4

Re: K2 front panel LCD soldering

Conway,

You may (should) leave that film in place.

73,
Don W3FPR

Conway Yee wrote:

> Gentlemen,
> Your recommendations are appreciated. I checked the IC joints VERY
> carefully for cold joints and bridges. I reflowed all joints as well.
> My leads are long as well.
>
> I have a followup question. The instructions specifically say NOT to
> remove the backing on either side. My LCD backlight assembly has white
> diffusers on both sides (so far so good). There is, however a SECOND
> thin plastic translucent (not white) film as well on top of the assembly
> which seems to be removable. Can I remove this second film?
>
> tnx.
> Conway Yee, N2JWQ
>
>

Conway Yee

securing K2 RF board

I typically secure PC boards with a Panavise. With the K2 RF board, the
FIRST step is to place the standoffs and 2D spacer (which go to the
edge of the board! This makes the Panavise pretty much useless.

Other than leaving the board loose and elevating the board with spacers
as suggested by W3FPR and GM4ESD on February 28, 2005 what are my
options?

tnx.
Conway Yee, N2JWQ

BTW, I am having a blast building the K2. Kudos to N6KR and WA6HHQ.
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Don Wilhelm-4

Re: securing K2 RF board

Conway,

Just my way of working, I HATE things like the Panavise, it is more of
an encumbrance than a help IMHO.
However, you may elect to delay mounting the 2D connectors until you
need to mount the side panels - that will allow you to use your Panavise
if that is your preference.

With or without the 2D connectors, do not use the panavise until after
you have mounted the relays - use the procedure in the manual to hold
the relays in place with a book (or board or other hard surface) to
allow you to flip the board over with the relays in place prior to
soldering.

73,
Don W3FPR

Conway Yee wrote:

> I typically secure PC boards with a Panavise. With the K2 RF board, the
> FIRST step is to place the standoffs and 2D spacer (which go to the
> edge of the board! This makes the Panavise pretty much useless.
>
> Other than leaving the board loose and elevating the board with spacers
> as suggested by W3FPR and GM4ESD on February 28, 2005 what are my
> options?
>
> tnx.
> Conway Yee, N2JWQ
>
>

srife

Re: securing K2 RF board

I used the Panavise circuit board holder (large) even after
installing the 2D connectors. Just adjust it for a light hold and it will
stay in the vise ok. Even some of the components mounted REALLY close to the
edge of the board had the same affect as the 2D connectors, as far as using
the Panavise. Just have to adjust the clamping action to hold it lightly but
securely. The springs in the jaws will allow the jaws to hold on to the
board out at the end of the jaw, while touching the 2D connectors at the
other end.

Don I don't know how you did it without some kind of a vise. But I
guess everybody has their own technique. Personally I like all the
conveniences and gadgets that are available for this kind of work.

The K2 was my first major assembly project. I had never done
anything nearly that complex before. Not bragging but everything checked out
ok the first time everytime, and I did it in about 6 days if I remember
correctly. Of course that was 12 or so hours a day not counting the breaks
that I had to take. I had a weeks vacation scheduled just for building the
K2. That's probably not a major feat for some of the guys that built K2s,
but it was a personal first and best for me as a rank beginner.

Stan Rife
W5EWA

-----Original Message-----
From: [hidden email]
[mailto:[hidden email]] On Behalf Of Don Wilhelm
Sent: Monday, December 28, 2009 12:10 AM
To: Conway Yee
Cc: [hidden email]
Subject: Re: [Elecraft] securing K2 RF board

Conway,

Just my way of working, I HATE things like the Panavise, it is more of
an encumbrance than a help IMHO.
However, you may elect to delay mounting the 2D connectors until you
need to mount the side panels - that will allow you to use your Panavise
if that is your preference.

With or without the 2D connectors, do not use the panavise until after
you have mounted the relays - use the procedure in the manual to hold
the relays in place with a book (or board or other hard surface) to
allow you to flip the board over with the relays in place prior to
soldering.

73,
Don W3FPR

Conway Yee wrote:

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Phillip Heller

Re: securing K2 RF board

In reply to this post by Don Wilhelm-4

You can also install the chassis screws into the 2D connectors, which provide something narrow enough for the Panavise PCB holder to latch on to. That's how I did it, and it worked reasonably well.

--phil

On Dec 28, 2009, at 1:09 AM, Don Wilhelm wrote:

> Conway,
>
> Just my way of working, I HATE things like the Panavise, it is more of
> an encumbrance than a help IMHO.
> However, you may elect to delay mounting the 2D connectors until you
> need to mount the side panels - that will allow you to use your Panavise
> if that is your preference.

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