[Elecraft] K1 VFO frequency does not change

[John Reed, W8DE]

Don,
thanks so much for your advice.  The board traces in that area all check out good.  I'll email a request to elecraft for a new D3.

If it really is bad, it makes me wonder about the 1SV149 diodes in the crystal filter circuit.  I don't know how I would tell if those are functioning correctly.

73,
John W8DE

On Feb 24, 2013, at 4:25 PM, "Don Wilhelm-4 [via Elecraft]" <ml-node+s365791n7570316h63 at n2.nabble.com> wrote:

> John, 
> 
> Yes, that would strongly indicate that D3 is faulty.  It is good that 
> you confirmed RIT does change the frequency. 
> I don't think you will find one locally, but an email to 
> [hidden email] should bring you one quickly in the mail. 
> 
> Since a bad D3 is a rarity, you might also want to check for board 
> continuity with your DMM.  Check to see that you have the same voltage 
> variation on one lead of C2 - that will confirm that D3 is connected to 
> C2.  The other lead of C2 cannot be tested with voltage, so use your 
> ohmmeter to check for continuity between the other lead of C2 and L1. 
> Should you find the board has an open trace (also a real rarity), repair 
> it with a wire.  Elecraft would send you a new board, but you already 
> have enough work in that board to warrant repairing it with a wire. 
> 
> 73, 
> Don W3FPR 
> 
> On 2/24/2013 3:27 PM, John Reed, W8DE wrote: 
> > Don, 
> > C2 and D3 look to be properly installed.  I confirmed orientation from a 1SV149 data sheet just in case I mis-read the instructions. 
> > 
> > I can adjust receive frequency with RIT, so it looks like the D4 control is working. 
> > 
> > Since the D3 voltage is varying from 0v to 5.888v with the tuning pot, but there is no change in frequency, I'm starting to suspect a bad D3.  I don't know of anyway to check it in circuit -- at least with the tools I have.  I'll see if I can pick up a 1SV149 locally.  I considered swapping it with D6, but I don't think I can remove it without damaging it. 
> > 
> >




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