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K1: No output on 18MHz

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Stephen Prior

K1: No output on 18MHz

I get full power output with the four band board on 40/30/20, but not a
thing on 17m. The receiver is also dead on 17m. I have pulled out the KAT1
and the four band board beneath and checked visually - all looks neat.
Plugged the boards back in, still the same.

I have only had the radio a few days and haven't had much time to check it
out so I cannot remember whether it was like it when I received it.
Unfortunately I didn't build it, so diving into the manual 2/3 of the way in
is tricky, but I have read the appropriate bits and I am no further forward.

I'd be very grateful for any advice please,

73, Stephen G4SJP

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Stephen Prior

Re: K1: No output on 18MHz

All sorted, although I'm not 100% sure whether the problem was a mixer
oscillator not oscillating of a bad connection somewhere. A few taps with
a screwdriver on the can of the crystal and re-assembly (for about the
fifth time!) brought 18MHz back to life. Thanks to Dave, AB9CA/4 for the
pointer.

73 Stephen G4SJP

On 24/09/2011 17:20, "Stephen Prior" <[hidden email]> wrote:

>
>I get full power output with the four band board on 40/30/20, but not a
>thing on 17m. The receiver is also dead on 17m. I have pulled out the
>KAT1
>and the four band board beneath and checked visually - all looks neat.
>Plugged the boards back in, still the same.
>
>I have only had the radio a few days and haven't had much time to check it
>out so I cannot remember whether it was like it when I received it.
>Unfortunately I didn't build it, so diving into the manual 2/3 of the way
>in
>is tricky, but I have read the appropriate bits and I am no further
>forward.
>
>I'd be very grateful for any advice please,
>
>73, Stephen G4SJP
>
>
>
>
>______________________________________________________________
>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
>

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Don Wilhelm-4

Re: K1: No output on 18MHz

In reply to this post by Stephen Prior

Stephen,

Refer to the manual for the 4 band board rather than the K1 manual - the
K1 manual covers only the tuning of a two band board. On the 4 band
board, 17 (or 15) meters must be tuned before 20 meters. I suspect
either that is the problem, or the crystal for 17 meters has quit. Not
relevant right now, but do know that 30 meters must be aligned before 40
meters. Do the initial 4 steps on page 19 of the KFL1-4 manual -
remove the tuner if present, and install the jumper between pins 2 and
10 of J2. If you have a recent K1, change the jumper near the right
rear corner to the K1 position. If you have an older K1 without the 3
pin header and jumper, AND you removed the tuner, you will have to
remove the bottom cover and re-solder R36.

Initially set trimmers C1, C2, C3 and C4 and CA, CB, CC and CD so the
slots are parallel with the long side of the filter board

The use of a 'scope makes tuning the Pre-Mixer bandpass filters very
easy, and I recommend it over the tuning method in the manual.
You can use the 'scope to check for oscillation of the crystal first -
you should have at least 200 mV peak to peak at P1 pin 4 on the filter
board. After checking that, put the probe on P1 pin 6 and tune C1 and
C2 for maximum RF voltage.
Now connect a dummy load.
If you got that far, place the probe on P2 pin 8 and do a TUNE. Adjust
CA and CB for maximum RF - you will have to go back and adjust C1 and C2
a small amount. As a final step, set the OUT menu parameter for 1.5
watts and re-adjust CA and CB slightly while monitoring the RF voltage
at the output.

Then switch to 20 meters and repeat, but adjusting C3, C4, CC, and CD.

If you do not have a 'scope, you will need a strong signal (generator or
another transmitter running into a dummy load) that you can tune to 17
meters and make the adjustments in receive - Tune the 17 meter trimmers
first until the received signal is as strong as you can detect - do the
same on 20 meters.
Then change to a dummy load and follow the instructions in the KFL1-4
manual for the 18 MHz and 14 MHz bands (in that order).

All done? Don't forget to put the jumper on the 3 pin header on the
right pins (or remove one end of R36 from the bottom of the board) when
you re-install the tuner.

73,
Don W3FPR

On 9/24/2011 12:20 PM, Stephen Prior wrote:

> I get full power output with the four band board on 40/30/20, but not a
> thing on 17m. The receiver is also dead on 17m. I have pulled out the KAT1
> and the four band board beneath and checked visually - all looks neat.
> Plugged the boards back in, still the same.
>
> I have only had the radio a few days and haven't had much time to check it
> out so I cannot remember whether it was like it when I received it.
> Unfortunately I didn't build it, so diving into the manual 2/3 of the way in
> is tricky, but I have read the appropriate bits and I am no further forward.
>
> I'd be very grateful for any advice please,
>
> 73, Stephen G4SJP
>
>
>
>
> ______________________________________________________________
> 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
>