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K1 band pass filter alignment

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ki4bbl

K1 band pass filter alignment

I love this rig already! My wife was sure I was having an affair last
night when I came in from my man cave just smiling ear to ear because
my led backlight lit up, and I was able to play with the controls. I
was most notably giddy when I aligned the VFO by manipulating the L1
toroidal....I love electricity, but I digress. I am on page 40 doing
the band-pass filter alignment. What does it mean to peak the
inductors? I am not sure what I am looking for there. Thanks so much.

Greg Doughty
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Greg
ki4bbl

David Herring-2

Re: K1 band pass filter alignment

Congrats on passing your test!

What you need is a USB to serial adapter. Several have been
recommended on this reflector recently. Refer back to the archives.
Elecraft even has one on their web site.

Good luck and welcome!

Dave
K6DCH

Sent from my iPhone

On May 26, 2010, at 1:35 PM, [hidden email] wrote:

> I love this rig already! My wife was sure I was having an affair last
> night when I came in from my man cave just smiling ear to ear because
> my led backlight lit up, and I was able to play with the controls. I
> was most notably giddy when I aligned the VFO by manipulating the L1
> toroidal....I love electricity, but I digress. I am on page 40 doing
> the band-pass filter alignment. What does it mean to peak the
> inductors? I am not sure what I am looking for there. Thanks so
> much.
>
> Greg Doughty
> ______________________________________________________________
> 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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Help: http://mailman.qth.net/mmfaq.htm
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David Herring-2

Re: K1 band pass filter alignment

In reply to this post by ki4bbl

Whoops. Replied to the wrong email.

My reply was intended for Mike the new technician.

Sorry about that!

Dave
K6DCH

Sent from my iPhone

On May 26, 2010, at 1:35 PM, [hidden email] wrote:

ki4bbl

Re: K1 band pass filter alignment

Thanks, I thought something was up with that response!

Greg Doughty

On May 26, 2010, at 7:47 PM, "David Herring, K6DCH" <[hidden email]>
wrote:

> Whoops. Replied to the wrong email.
>
> My reply was intended for Mike the new technician.
>
> Sorry about that!
>
> Dave
> K6DCH
>
> Sent from my iPhone
>
> On May 26, 2010, at 1:35 PM, [hidden email] wrote:
>
>> I love this rig already! My wife was sure I was having an affair
>> last
>> night when I came in from my man cave just smiling ear to ear because
>> my led backlight lit up, and I was able to play with the controls. I
>> was most notably giddy when I aligned the VFO by manipulating the L1
>> toroidal....I love electricity, but I digress. I am on page 40 doing
>> the band-pass filter alignment. What does it mean to peak the
>> inductors? I am not sure what I am looking for there. Thanks so
>> much.
>>
>> Greg Doughty
>> ______________________________________________________________
>> 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

Greg
ki4bbl

Don Wilhelm-4

Re: K1 band pass filter alignment

In reply to this post by ki4bbl

Greg,

You will "peak the inductors" two times - first in receive to get then
into the approximate correct position, and then in transmit for the
final setting.
NOTE WELL - you will peak the inductors if you have the 2 band board,
but if you have the 4 band board, you will be peaking the capacitive
trimmers instead - and for the 4 band board, follow the band order - 30
meters must be peaked before 40 meters and 15/17 meters must be peaked
before 20 meters.

OK, what does "peaking" mean - for receive, you will simply adjust for
maximum signal (or band noise if you cannot hear any signals) You can
use another QRP transmitter running into a dummy load as a signal
source, or if you have a signal generator, that is ideal - listen to the
signal and adjust the inductors (or capacitors for the 4 band board) to
achieve the strongest received signal

On transmit, things are a bit easier - you have already pre-set the
tuning during receive, so this is just a matter of refining the tuning -
in other words, you should not have to move the adjustment very far.
Set the power (menu OUT parameter) to about 1.5 watts, and then adjust
for the maximum power output. Problem - if the power output rises to
more than 5 watts, the peak will "hide". and you will reach the power
output capability of the transistors rather than finding the peak, so
exit TUNE and re-enter (or in the case of the K1, often repetitively
tapping the WPM- button will reduce the power) keep the power level low
so you can discern the peak. You will find a point where the power
output increases, and then decreases as you adjust the inductor (or
capacitor). The point in between where the power is maximum is the peak
that you are searching for.

73,
Don W3FPR

[hidden email] wrote:

> I love this rig already! My wife was sure I was having an affair last
> night when I came in from my man cave just smiling ear to ear because
> my led backlight lit up, and I was able to play with the controls. I
> was most notably giddy when I aligned the VFO by manipulating the L1
> toroidal....I love electricity, but I digress. I am on page 40 doing
> the band-pass filter alignment. What does it mean to peak the
> inductors? I am not sure what I am looking for there. Thanks so much.
>
> Greg Doughty
> ______________________________________________________________
> 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
>
>

Alexey Kats

Re: K1 band pass filter alignment

Greg,

You can use XG2 kit from Elecraft as a signal source for K1 on 80m,
40m and 20m bands (it'll also give you a chance to adjust S-meter as
well). 80m might be a little problematic if you selected 80kHz tuning
range because it is close to the upper end of the band, but you should
still be able to use it unless your VFO is misaligned.

Or you could use N-gen kit too, but be careful with it - it's easy to
adjust all filters on receive so it will look like you reached the
peak, while in reality your IF will not align properly with center
frequency of crystal filters. This is because it produces relatively
strong noise signal. If that happens (the giveaway is that you can
hear noise generator, but nothing from the antenna) - move all
adjustments for the problematic band to their neutral positions and
start over.

But the easiest method is to use another QRP rig or a signal generator
as a signal source.

On Wed, May 26, 2010 at 5:19 PM, Don Wilhelm <[hidden email]> wrote:

> Greg,
>
> You will "peak the inductors" two times - first in receive to get then
> into the approximate correct position, and then in transmit for the
> final setting.
> NOTE WELL - you will peak the inductors if you have the 2 band board,
> but if you have the 4 band board, you will be peaking the capacitive
> trimmers instead - and for the 4 band board, follow the band order - 30
> meters must be peaked before 40 meters and 15/17 meters must be peaked
> before 20 meters.
>
> OK, what does "peaking" mean - for receive, you will simply adjust for
> maximum signal (or band noise if you cannot hear any signals) You can
> use another QRP transmitter running into a dummy load as a signal
> source, or if you have a signal generator, that is ideal - listen to the
> signal and adjust the inductors (or capacitors for the 4 band board) to
> achieve the strongest received signal
>
> On transmit, things are a bit easier - you have already pre-set the
> tuning during receive, so this is just a matter of refining the tuning -
> in other words, you should not have to move the adjustment very far.
> Set the power (menu OUT parameter) to about 1.5 watts, and then adjust
> for the maximum power output. Problem - if the power output rises to
> more than 5 watts, the peak will "hide". and you will reach the power
> output capability of the transistors rather than finding the peak, so
> exit TUNE and re-enter (or in the case of the K1, often repetitively
> tapping the WPM- button will reduce the power) keep the power level low
> so you can discern the peak. You will find a point where the power
> output increases, and then decreases as you adjust the inductor (or
> capacitor). The point in between where the power is maximum is the peak
> that you are searching for.
>
> 73,
> Don W3FPR
>
> [hidden email] wrote:
>> I love this rig already! My wife was sure I was having an affair last
>> night when I came in from my man cave just smiling ear to ear because
>> my led backlight lit up, and I was able to play with the controls. I
>> was most notably giddy when I aligned the VFO by manipulating the L1
>> toroidal....I love electricity, but I digress. I am on page 40 doing
>> the band-pass filter alignment. What does it mean to peak the
>> inductors? I am not sure what I am looking for there. Thanks so much.
>>
>> Greg Doughty

--
Alexey Kats (neko)
______________________________________________________________
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

Don Wilhelm-4

Re: K1 band pass filter alignment

Alexey,

Using the noise source or "dead band noise" with the K1-4 is problematic
for the 15/17 meter and 20 meter bands.
The real world situation is that it is possible to tune the 15/17 meter
Pre-Mixer bandpass trimmers to the region of 29 MHz rather than 23 MHz.
The usual result is that 20 meters cannot be tuned properly (and the
frequency that 15/17 meters is tuned to is incorrect).

The way to avoid that situation is to use a known signal source when
tuning 15/17 meters.

The manual states that the initial position for the Trimmer capacitors
is to be with the slots parallel with the long side of the board. The
final adjustment ot the trimmers will be no further than 20 degrees away
from that position. If the 'peak' occurs further away from that range,
it is at the wrong point.

Using a signal source of a known frequency will avoid this problem, but
using a wideband noise source can certainly produce this false response.

Note that this condition does not occur as readily with the 2 band board.

73,
Don W3FPR

Alexey Kats wrote:

> Greg,
>
> You can use XG2 kit from Elecraft as a signal source for K1 on 80m,
> 40m and 20m bands (it'll also give you a chance to adjust S-meter as
> well). 80m might be a little problematic if you selected 80kHz tuning
> range because it is close to the upper end of the band, but you should
> still be able to use it unless your VFO is misaligned.
>
> Or you could use N-gen kit too, but be careful with it - it's easy to
> adjust all filters on receive so it will look like you reached the
> peak, while in reality your IF will not align properly with center
> frequency of crystal filters. This is because it produces relatively
> strong noise signal. If that happens (the giveaway is that you can
> hear noise generator, but nothing from the antenna) - move all
> adjustments for the problematic band to their neutral positions and
> start over.
>
> But the easiest method is to use another QRP rig or a signal generator
> as a signal source.
>
>
>

Alexey Kats

Re: K1 band pass filter alignment

Don,

You are absolutely right - the biggest trouble I had with my K1-4 was
on 17m band. With 20m I used XG2, but for 17m I ended up tuning it
after transmitter was fully built - I first tuned it roughly on low
power transmit with dummy load and watt meter, then using noise
generator on receive (with attenuator on), then again with watt meter
on transmit. And as a result I had to re-tune 20m again.

On Wed, May 26, 2010 at 6:04 PM, Don Wilhelm <[hidden email]> wrote:

> Alexey,
>
> Using the noise source or "dead band noise" with the K1-4 is problematic for
> the 15/17 meter and 20 meter bands.
> The real world situation is that it is possible to tune the 15/17 meter
> Pre-Mixer bandpass trimmers to the region of 29 MHz rather than 23 MHz. The
> usual result is that 20 meters cannot be tuned properly (and the frequency
> that 15/17 meters is tuned to is incorrect).
>
> The way to avoid that situation is to use a known signal source when tuning
> 15/17 meters.
>
> The manual states that the initial position for the Trimmer capacitors is to
> be with the slots parallel with the long side of the board. The final
> adjustment ot the trimmers will be no further than 20 degrees away from that
> position. If the 'peak' occurs further away from that range, it is at the
> wrong point.
>
> Using a signal source of a known frequency will avoid this problem, but
> using a wideband noise source can certainly produce this false response.
>
> Note that this condition does not occur as readily with the 2 band board.
>
> 73,
> Don W3FPR
>
> Alexey Kats wrote:
>>
>> Greg,
>>
>> You can use XG2 kit from Elecraft as a signal source for K1 on 80m,
>> 40m and 20m bands (it'll also give you a chance to adjust S-meter as
>> well). 80m might be a little problematic if you selected 80kHz tuning
>> range because it is close to the upper end of the band, but you should
>> still be able to use it unless your VFO is misaligned.
>>
>> Or you could use N-gen kit too, but be careful with it - it's easy to
>> adjust all filters on receive so it will look like you reached the
>> peak, while in reality your IF will not align properly with center
>> frequency of crystal filters. This is because it produces relatively
>> strong noise signal. If that happens (the giveaway is that you can
>> hear noise generator, but nothing from the antenna) - move all
>> adjustments for the problematic band to their neutral positions and
>> start over.
>>
>> But the easiest method is to use another QRP rig or a signal generator
>> as a signal source.
>>
>>
>

Don Wilhelm-4

Re: K1 band pass filter alignment

If we were in a period of higher sunspot activity, we would not have
this problem. If there were good signals on the 17/15 meter bands, we
could use those to adjust the K1-4 to the correct band. Unfortunately,
we are in a time when solar activity does not produce a lot of signals
on the 17/15 meter bands, so the use of a known frequency signal source
is almost mandatory. Yes, there are 'workarounds', but those should be
used wtth a degree of awareness for the consequences.

73,
Don W3FPR

Alexey Kats wrote:

> Don,
>
> You are absolutely right - the biggest trouble I had with my K1-4 was
> on 17m band. With 20m I used XG2, but for 17m I ended up tuning it
> after transmitter was fully built - I first tuned it roughly on low
> power transmit with dummy load and watt meter, then using noise
> generator on receive (with attenuator on), then again with watt meter
> on transmit. And as a result I had to re-tune 20m again.
>
> On Wed, May 26, 2010 at 6:04 PM, Don Wilhelm <[hidden email]> wrote:
>
>> Alexey,
>>
>> Using the noise source or "dead band noise" with the K1-4 is problematic for
>> the 15/17 meter and 20 meter bands.
>> The real world situation is that it is possible to tune the 15/17 meter
>> Pre-Mixer bandpass trimmers to the region of 29 MHz rather than 23 MHz. The
>> usual result is that 20 meters cannot be tuned properly (and the frequency
>> that 15/17 meters is tuned to is incorrect).
>>
>> The way to avoid that situation is to use a known signal source when tuning
>> 15/17 meters.
>>
>> The manual states that the initial position for the Trimmer capacitors is to
>> be with the slots parallel with the long side of the board. The final
>> adjustment ot the trimmers will be no further than 20 degrees away from that
>> position. If the 'peak' occurs further away from that range, it is at the
>> wrong point.
>>
>> Using a signal source of a known frequency will avoid this problem, but
>> using a wideband noise source can certainly produce this false response.
>>
>> Note that this condition does not occur as readily with the 2 band board.
>>
>> 73,
>> Don W3FPR
>>
>> Alexey Kats wrote:
>>
>>> Greg,
>>>
>>> You can use XG2 kit from Elecraft as a signal source for K1 on 80m,
>>> 40m and 20m bands (it'll also give you a chance to adjust S-meter as
>>> well). 80m might be a little problematic if you selected 80kHz tuning
>>> range because it is close to the upper end of the band, but you should
>>> still be able to use it unless your VFO is misaligned.
>>>
>>> Or you could use N-gen kit too, but be careful with it - it's easy to
>>> adjust all filters on receive so it will look like you reached the
>>> peak, while in reality your IF will not align properly with center
>>> frequency of crystal filters. This is because it produces relatively
>>> strong noise signal. If that happens (the giveaway is that you can
>>> hear noise generator, but nothing from the antenna) - move all
>>> adjustments for the problematic band to their neutral positions and
>>> start over.
>>>
>>> But the easiest method is to use another QRP rig or a signal generator
>>> as a signal source.
>>>
>>>
>>>
>
>
>
>

ki4bbl

Re: K1 band pass filter alignment

Thanks so much to you both. I wasn't sure if I could use the xg2 I
built, but we solved that, so I plugged that in, and I noticed the
difference in noise with very slight adjustment. I am now building
the tx side.

Greg Doughty

On May 26, 2010, at 9:25 PM, Don Wilhelm <[hidden email]> wrote:

> If we were in a period of higher sunspot activity, we would not have
> this problem. If there were good signals on the 17/15 meter bands, we
> could use those to adjust the K1-4 to the correct band. Unfortunately,
> we are in a time when solar activity does not produce a lot of signals
> on the 17/15 meter bands, so the use of a known frequency signal
> source
> is almost mandatory. Yes, there are 'workarounds', but those should
> be
> used wtth a degree of awareness for the consequences.
>
> 73,
> Don W3FPR
>
>

Greg
ki4bbl