[Elecraft] K2 Assembly Question on LED diffuser

Sun Feb 17 02:40:07 EST 2008

DW:

First of all, I note from your serial number that Elecraft sold about  
22 K2's in roughly the week that separates our two purchases.   
Interesting bit of data.  I wish them well, and hope that they make  
lots of money selling us great radio designs for years to come!

Secondly, I feel your pain, since I went through the same thing with  
the diffuser last week.  I have to say that it has been the most head- 
scratchingly odd part of the build so far.  I'm just now heading into  
the PA section, with everything having gone perfectly so far, except  
for the 8-volt regulator on the control board only putting out a bit  
over 7.5 volts.  A replacement cured that (made setting the agc  
voltage high enough impossible).  I got a very accurate and quick  
diagnosis from Gary Surrency, and a quick offer to send a new  
regulator from the parts folks.  Great support!

I hope that Elecraft comes up with a better way of assembly for the  
diffuser, or changes it to one that has long enough leads for the  
LEDs.  The use of the four little pieces of pcb material as a gauge is  
also mechanically dicey compared with how they apparently used to fit  
over the LED wires.  Now, they are just free-stacked 2-and-2 on each  
side of the diffuser as you attempt to hold it and these little pieces  
in place for the soldering operation.  Their suggestion to hold the  
assembly with a rubber band proved mechanically impossible for me, but  
YMMV.

It reminds me of trying to build a stable house of cards!  Since these  
little pieces no longer go in the LED holes, they are simply stacked,  
cordwood style, to properly space and hold up the diffuser.  I had the  
assembly tumble several times before managing to get it properly  
soldered down.  Yes, I also found that my LED leads barely touched the  
pads, but it sounds like maybe mine were just a fraction longer than  
yours, as I'm reasonably happy with the slight metal-to-metal contact,  
but the leads are just barely touching the pads.  A little extra  
solder helps.

That said, I'm very, very pleased with my K2 build so far, and can't  
wait to get it up and running.

Lastly, does this count as Elecraft mojo or not?  I've made CW QSO's  
on 17m and 15m with VP6DX's great K3's while building my K2 about 5  
feet away from my operating position!  Those guys can really hear  
anything!  I was running 100 watts on an FT-847 into a small Pacific  
Antenna PAC-12 vertical (essentially a mobile antenna) stuck into the  
grass in my small back yard.  I was so impressed with the very light  
traffic they had on 17m Friday afternoon (about 2330Z) that I tried  
them again on 15m, but this time running only 10 watts--closer to "K2  
style."  They came back on the second call.  Outstanding!  I'm  
confirmed on their on-line log now for 2 bands, and all I had to do  
was have a partially-built Elecraft radio nearby!  I think that  
qualifies as Proximity Mojo...

73,

Dave K7DAA

http://www.k7daa.com

On Feb 16, 2008, at 7:29 PM, DW Holtman wrote:

> Ken,
>
> Thank you for the suggestion, sounds like it will work great.
>
> Best,
> DW Holtman
> WB7SSN
>
> ----- Original Message ----- From: "Ken, KA0W" <ars_ka0w at yahoo.com>
> To: "DW Holtman" <tubestuff at comcast.net>; <Elecraft at mailman.qth.net>
> Sent: Saturday, February 16, 2008 8:25 PM
> Subject: Re: [Elecraft] K2 Assembly Question
>
>
>> I put a short lead in each of the holes for the solder to slightly  
>> puddle around. Than centered the diffuser and heated each lead from  
>> bottom of board while adding slightly more solder. Than checked and  
>> it took well. Don't want too large of a puddle, but enuff so  
>> diffuser leads get soldered. I wouldn't solder right next to  
>> diffuser. I don't think it likes heat - "HI!"
>>
>> Have fun!
>>
>> Ken, KA0W
>>
>>
>>
>>
>>
>> ----- Original Message ----
>> From: DW Holtman <tubestuff at comcast.net>
>> To: Elecraft at mailman.qth.net
>> Sent: Saturday, February 16, 2008 9:00:40 PM
>> Subject: [Elecraft] K2 Assembly Question
>>
>> Hello,
>>
>> Last Sunday (10 Feb) I ordered a K2, the great people at Elecraft  
>> shipped it Monday. It arrived Wednesday (S/N 6412) and the assembly  
>> is under way.
>>
>> Everything went smooth with the control Board. Everything was going  
>> great with the Front Panel Board until I got to installing the  
>> Diffuser light for the LCD display.
>>
>> I posted the Errata sheet for page 28. The instructions are to  
>> install the Diffuser 1/8" off the circuit board using the spacers  
>> provided.
>>
>> The length of the leads from the LEDs in the Diffuser are 1/8", the  
>> same length as the spacers. They cannot go into the hole on the  
>> Front panel Circuit board. The new picture from the Errata sheet  
>> looks like it is just soldered without any physical connection.  
>> Just sort of lumping solder to attach the Leads to the pads on the  
>> Circuit board without going into the hole and soldering from the  
>> back side of the circuit board?
>>
>> Is this right? Trying to get a soldering iron under the diffuser to  
>> the pin on the top of the board to solder it looks tough to do with  
>> out burning the diffuser or the LED bar graph.
>>
>> Have I missed the boat on this?
>>
>> Any help would be greatly appreciated.
>>
>> Best,
>> DW Holtman
>> WB7SSN
>
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