[Elecraft] K2 VCO trouble and fix

[Roger Marrotte]

I too had RFC15 go open and I also was very careful and didn't think I did
anything to break it.  I was even more careful with the replacement and it
works fine.

I'm not sure if bending the leads made it go open circuit or heat from the
soldering process.  I didn't yank on the leads but you sure have to bend
them a lot to make it fit.  I also didn't over heat the device.  One of the
two processes apparently broke it.  It must be really fragile.

73,  Roger, W1EM

-----Original Message-----
From: Stewart Baker
Sent: Wednesday, October 05, 2005 4:22 AM
To: HSHERRIFF at sc.rr.com; elecraft at mailman.qth.net
Subject: Re: [Elecraft] K2 VCO trouble and fix


On Tue, 04 Oct 2005 21:33:17 -0400, HSHERRIFF at sc.rr.com wrote:
> I e-mail Gary at Elecraft (3:01pm)
> Get a reply from Gary (4:33pm)
>
> He gave me a PAGE worth of "might be"... one being to check RCF15. He 
> said if it was open it can cause all sorts of odd problems.
>
> Well, it WAS open... I must have bent the leads to much or heated it 
> too much, or whatever. Anyway, I bridged across it momentarily to see 
> what effect it would have.
> Guess what?   ALL VCO voltages were well within limits...including 10m
> high freq. Without even touching L30. So, I ordered a new choke and 
> thanked Gary for a quick and accurate response.

Glad that with Gary's help you found the problem. A search of the reflector 
shows that there is a high incidence of RFC15 going open circuit. It is such
a fragile device (probably too fragile),  and I believe that Elecraft 
should change it for one that is more robust. When assembling my K2, knowing

this to be a potential problem, I took particular care in soldering the RFC,

only to find that it too had gone open circuit.

73
Stewart G3RXQ