KX3 2m Install

[Bruce Nourish]

Hi folks,

Last night I installed and configured a KX3 2m module following the current
instructions on the website (Rev C). My KX3 is a recent factory build.
Everything seems to be working fine; I haven't actually tried it on-air yet
(need to finish my 2m Moxon), but at least I didn't blow my rig up.

I encountered one difference with the instructions: When installing the LO
coax on J4, I could not find any capacitor C120 to avoid. My KX3 simply
doesn't have C120 or R81 on that PCB. Has something changed in recent KX3s?

The only hard part was the final installation, specifically clamping the
heatsink lug properly with retainer TO-220. It seems like the clamping
arrangement unavoidably puts the nylon bottom screw at a weird angle. I
double-checked the orientation of TO-220 and redid these steps over several
times, and couldn't figure out any other way to make it work. Is this right? If
so, a clarification in the instructions would help.

Bruce
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[Bruce Nourish]

Yes, sorry, C180, not C120. Not that I'm complaining, its absence made
assembly easier.

Re: TO-220. If you look at Fig 24 (bottom of p28) in the instructions,
you'll see TO-220 "leaning back" inwards from the side of the case, loosely
held by the nylon screw. My TO-220 looked like that before I inserted the
module -- so far so good.

When I inserted the module, the transistor heat sink went into the gap
between the top of TO-220 and the case. I wiggled it a bit until the hole
in the heat sink, and the top hole of TO-220 approximately lined up. I was
able to screw in the metal Phillips screw fine, so the heat sink should
have a good connection to the case. But TO-220 was still "leaning back",
meaning that the bottom hole of TO-220 was still at an angle. I tried
unscrewing both screws, but the heatsink had wedged TO-220 firmly at that
angle.

Bruce

On Mon, Apr 25, 2016 at 8:17 PM Ron D'Eau Claire <[hidden email]> wrote:

> Hi Bruce:
>
> Are talking about C180 near J4? I'll check into it. It won't be the first
> time the engineers made a change and didn't realize it impacted the
> assembly
> instructions (I'm 600 miles from Watsonville, but only milliseconds by
> voice
> and e-mail. Still that can be "light years" at times, Hi!)
>
> I'm not sure what could put the TO-220 screw at an angle. The TO-220 heat
> sink simply slips in between the retainer, which is then pulled tightly
> against the TO-220 heat sink and the side of the case. That's the critical
> part - good mechanical and thermal contact between the TO-220 heat sink and
> the side of the case.
>
> Have you tried loosening both screws and then re-tightening them? What
> comes
> to mind is that in tightening the top screw, the retainer might have turned
> slightly, misaligning the bottom screw in the hole. With everything in
> place. Loosen both screws a bit, then retighten the bottom (nylon) screw to
> hold the retainer, then tighten the top screw and see if things line up
> better.
>
> I'd appreciate hearing if that works either at my address on this message
> or
> [hidden email].
>
> 73. Ron AC7AC
>
> -----Original Message-----
> From: Elecraft [mailto:[hidden email]] On Behalf Of
> Bruce
> Nourish
> Sent: Monday, April 25, 2016 5:37 PM
> To: Elecraft Reflector
> Subject: [Elecraft] KX3 2m Install
>
> Hi folks,
>
> Last night I installed and configured a KX3 2m module following the current
> instructions on the website (Rev C). My KX3 is a recent factory build.
> Everything seems to be working fine; I haven't actually tried it on-air yet
> (need to finish my 2m Moxon), but at least I didn't blow my rig up.
>
> I encountered one difference with the instructions: When installing the LO
> coax on J4, I could not find any capacitor C120 to avoid. My KX3 simply
> doesn't have C120 or R81 on that PCB. Has something changed in recent KX3s?
>
> The only hard part was the final installation, specifically clamping the
> heatsink lug properly with retainer TO-220. It seems like the clamping
> arrangement unavoidably puts the nylon bottom screw at a weird angle. I
> double-checked the orientation of TO-220 and redid these steps over several
> times, and couldn't figure out any other way to make it work. Is this
> right?
> If so, a clarification in the instructions would help.
>
> Bruce
> ______________________________________________________________
> 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
> Message
> delivered to [hidden email]
>
>

______________________________________________________________
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Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

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Please help support this email list: http://www.qsl.net/donate.html
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