K2 40 meter IF band pass alignment

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K2 40 meter IF band pass alignment

Matt Osborn
PLL Reference oscillator range test is OK.
VCO alignment is OK (L30 adjusted to 6.00v at R30)

VCO voltage readings are all within range.

The 40 m readings are 1.91V @ 7000kz and 7300 reads 3.74V

All other bands are above 2V @ low freq and 3V or higher at high freq.

The BFO high is 4917.1; low is 4912.6
for a range of 4.5

CAL FIL all set to recommended levels
VFO Linearization passed

L34 adjusted for best signal approx 1.5 turns in from top.

Adjusting L1 and L2, however,  continues to improve the signal level
until the slug is bottomed out.  This doesn't seem right.

I don't have a signal generator, so I'm picking up signals using 15ft
of solid core hookup wire at around 7130kz.

Any ideas of where I should look?
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RE: K2 40 meter IF band pass alignment

Don Wilhelm-3
Matt,

If tuning L1 and L2 do not procuce peaks within about 3 turns from the top
there is something wrong.  The most probable thing is that the capacitors in
the bandpass circuit are the wrong value.  Check C5 and C7 (100 pf - 101),
C4 and C8 (820 pf - 821) and C6 (4.7 pf).  My first guess is that you may
have the 82 pf (marked 820) capacitors in the C4 and C8 positions.

73,
Don W3FPR

> -----Original Message-----

>
> Adjusting L1 and L2, however,  continues to improve the signal level
> until the slug is bottomed out.  This doesn't seem right.
>
> I don't have a signal generator, so I'm picking up signals using 15ft
> of solid core hookup wire at around 7130kz.
>
> Any ideas of where I should look?
>
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Re: K2 40 meter IF band pass alignment

Matt Osborn
Thanks, Don.  I've checked the capacitors and they are all correct
(doesn't mean I didn't cook one though).

I've ordered the N-Gen noise generator and the XG-1 oscillator from
Elecraft.  Looks like I'll get a chance to work with Spectrogram and
see what the signals look like.

The Marines trained me as a ground radio repairman back in '65, then
sent me off to an artillery outfit where I mostly drove a truck.  So
I'm afraid that I know enough to be dangerous, but it's a real blast
getting back into this stuff after 40 years.

Well, back to the schematics...


On Fri, 17 Jun 2005 09:04:01 -0400, "W3FPR - Don Wilhelm"
<[hidden email]> wrote:

>Matt,
>
>If tuning L1 and L2 do not procuce peaks within about 3 turns from the top
>there is something wrong.  The most probable thing is that the capacitors in
>the bandpass circuit are the wrong value.  Check C5 and C7 (100 pf - 101),
>C4 and C8 (820 pf - 821) and C6 (4.7 pf).  My first guess is that you may
>have the 82 pf (marked 820) capacitors in the C4 and C8 positions.
>
>73,
>Don W3FPR
>
>> -----Original Message-----
>
>>
>> Adjusting L1 and L2, however,  continues to improve the signal level
>> until the slug is bottomed out.  This doesn't seem right.
>>
>> I don't have a signal generator, so I'm picking up signals using 15ft
>> of solid core hookup wire at around 7130kz.
>>
>> Any ideas of where I should look?
>>

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