K1 Filter Board Questions

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K1 Filter Board Questions

Ron Ricketts
I have obtained a K1 and have a couple of questions regarding the KFL1-4
board. Is there any reason it can't be constructed with 80 - 40 - 30 - 20
meters? If you purchase a new one it comes with 40 - 30 - 20 - 17/15 meters.
Considering the state of the solar cycle I'd prefer a board with lower
frequency capability. So is it possible to build a board with 80 - 40 - 30 -
20?

Second question has to do with 60 Meters. Is it technically feasible to have
60 meter receive cavility on a K1, assuming the toroids and other components
aer appropriate to the frequency?

The K1 is a super little rig and I'ce already become very fond of it. It
would be perfect if I could get my preferred band selection on one filter
board.

73,
Ron WA5VFA



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Re: K1 Filter Board Questions

Tom Hammond-3
Hi Ron:

At 10:34 PM 9/2/04, you wrote:

>I have obtained a K1 and have a couple of questions regarding the KFL1-4
>board. Is there any reason it can't be constructed with 80 - 40 - 30 - 20
>meters? If you purchase a new one it comes with 40 - 30 - 20 - 17/15 meters.
>
>Considering the state of the solar cycle I'd prefer a board with lower
>frequency capability. So is it possible to build a board with 80 - 40 - 30
>- 20?
>
>Second question has to do with 60 Meters. Is it technically feasible to
>have 60 meter receive cavility on a K1, assuming the toroids and other
>components aer appropriate to the frequency?
>
>The K1 is a super little rig and I'ce already become very fond of it. It
>would be perfect if I could get my preferred band selection on one filter
>board.

The K1 4-band board CAN be constructed for 80M, BUT then you'll have to
give up 40M!!! Here's why...

The two 2-band filters in the KFL1-4 are designed so that the upper
frequency cutoff of each filter is above the higher of the two frequencies,
BUT LOWER THAN the 2nd harmonic of the lower frequency.

In other words, the 40M/30M filter cuts off above 10MHz, and BELOW 14MHz.
If you were to build the first filter for 80/40 meters, then the filter
would have to be able to pass both 3.5 and 7.0 MHz energy, thus allowing
any potential 80M 2nd harmonic energy through to the antenna... this comes
under the heading of "Bad things will happen". So, in order for the KFL1-4
to be built to accommodate 80M, it's have to cut off at a frequency lower
than 40M, which means that you'd have 80M, but not 40M.

Sorry pal.  Good try though...

73,

Tom Hammond    N0SS


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Re: K1 Filter Board Questions

Don Wilhelm-2
In reply to this post by Ron Ricketts
Ron,

The 4 band board will not work well with 80 meters (it becomes a '3 band
board' due to the low pass filter sharing), but may I suggest that you build
the 4 band board and then add a 2 band board with 80 meters as one band -
the other band can be 17 or 15 meters (the one that is missing on your 4
band board), or I cna provide instructions on request for adding the parts
for 160 meter band coverage.

60 meter receive may be possible, but will not be quite so easy since 60
meters is USB only, and the K1 IF filters are intended for CW rather than
SSB.

73,
Don W3FPR

----- Original Message -----

>I have obtained a K1 and have a couple of questions regarding the KFL1-4
> board. Is there any reason it can't be constructed with 80 - 40 - 30 - 20
> meters? If you purchase a new one it comes with 40 - 30 - 20 - 17/15
> meters.
> Considering the state of the solar cycle I'd prefer a board with lower
> frequency capability. So is it possible to build a board with 80 - 40 -
> 30 -
> 20?
>
> Second question has to do with 60 Meters. Is it technically feasible to
> have
> 60 meter receive cavility on a K1, assuming the toroids and other
> components
> aer appropriate to the frequency?
>
> The K1 is a super little rig and I'ce already become very fond of it. It
> would be perfect if I could get my preferred band selection on one filter
> board.
>
> 73,
> Ron WA5VFA
>
>
>
> _______________________________________________
> Elecraft mailing list
> Post to: [hidden email]
> You must be a subscriber to post to the list.
> Subscriber Info (Addr. Change, sub, unsub etc.):
> http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/subscribers.htm
> Elecraft web page: http://www.elecraft.com
>
>


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Re: K1 Filter Board Questions

Daniel Reynolds-2
In reply to this post by Tom Hammond-3
But - if you consider that he also wants to receive on 60m (although I don't
know enough about tuning bandwidth considerations for the K1, and whether or
not the SSB would be normal or inverted), maybe the filter could be constructed
so that he has 80/60 and 40/30?

- Daniel / AA0NI

--- Tom Hammond <[hidden email]> wrote:

> Hi Ron:
>
> At 10:34 PM 9/2/04, you wrote:
> >I have obtained a K1 and have a couple of questions regarding the KFL1-4
> >board. Is there any reason it can't be constructed with 80 - 40 - 30 - 20
> >meters? If you purchase a new one it comes with 40 - 30 - 20 - 17/15 meters.
> >
> >Considering the state of the solar cycle I'd prefer a board with lower
> >frequency capability. So is it possible to build a board with 80 - 40 - 30
> >- 20?
> >
> >Second question has to do with 60 Meters. Is it technically feasible to
> >have 60 meter receive cavility on a K1, assuming the toroids and other
> >components aer appropriate to the frequency?
> >
> >The K1 is a super little rig and I'ce already become very fond of it. It
> >would be perfect if I could get my preferred band selection on one filter
> >board.
>
> The K1 4-band board CAN be constructed for 80M, BUT then you'll have to
> give up 40M!!! Here's why...
>
> The two 2-band filters in the KFL1-4 are designed so that the upper
> frequency cutoff of each filter is above the higher of the two frequencies,
> BUT LOWER THAN the 2nd harmonic of the lower frequency.
>
> In other words, the 40M/30M filter cuts off above 10MHz, and BELOW 14MHz.
> If you were to build the first filter for 80/40 meters, then the filter
> would have to be able to pass both 3.5 and 7.0 MHz energy, thus allowing
> any potential 80M 2nd harmonic energy through to the antenna... this comes
> under the heading of "Bad things will happen". So, in order for the KFL1-4
> to be built to accommodate 80M, it's have to cut off at a frequency lower
> than 40M, which means that you'd have 80M, but not 40M.
>
> Sorry pal.  Good try though...
>
> 73,
>
> Tom Hammond    N0SS
>
>
> _______________________________________________
> Elecraft mailing list
> Post to: [hidden email]
> You must be a subscriber to post to the list.
> Subscriber Info (Addr. Change, sub, unsub etc.):
> http://mailman.qth.net/mailman/listinfo/elecraft   
> Help: http://mailman.qth.net/subscribers.htm
> Elecraft web page: http://www.elecraft.com
>

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Re: K1 Filter Board Questions

Mike Morrow-3
In reply to this post by Ron Ricketts
Don wrote:

>I suggest that you build the 4 band board and then add a 2 band board
> with 80 meters as one band - the other band can be 17 or 15

I think that's the best and *only* practical approach.  That's what I did
with my old two-band filter board after the the four-band board came out.

>60 meter receive may be possible, but will not be quite so easy since 60
>meters is USB only, and the K1 IF filters are intended for CW rather than
>SSB.


That's a good point, not only because of the narrow bandpass of the K1 IF
filtering, but also because the K1 receiver functions in LSB mode on all
bands.  One would have to swap the product detector BFO frequency from below
the IF to above the IF to get USB.  I've not heard of anyone reporting
they've tried that on the K1, although it was discussed here a few months
ago.

>From what I've heard on it, 60m seems to be pretty much a wasteland.

73,
Mike / KK5F

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Re: K1 Filter Board Questions

Tom Hammond-3
In reply to this post by Daniel Reynolds-2
Hi Daniel:

Well, he MIGHT be able to come up with a filter to cover 80/60, but I'm not
certain about the signal inversion on that band... might not permit USB
reception... can't believe the FCC mandated USB in a (larger) band segment
which typically ALWAYS defaults to LSB, due to mixing 'standards'.

73,

Tom

At 08:14 AM 9/3/04, Daniel Reynolds wrote:

>But - if you consider that he also wants to receive on 60m (although I don't
>know enough about tuning bandwidth considerations for the K1, and whether or
>not the SSB would be normal or inverted), maybe the filter could be
>constructed
>so that he has 80/60 and 40/30?
>
>- Daniel / AA0NI
>
>--- Tom Hammond <[hidden email]> wrote:
>
> > Hi Ron:
> >
> > At 10:34 PM 9/2/04, you wrote:
> > >I have obtained a K1 and have a couple of questions regarding the KFL1-4
> > >board. Is there any reason it can't be constructed with 80 - 40 - 30 - 20
> > >meters? If you purchase a new one it comes with 40 - 30 - 20 - 17/15
> meters.
> > >
> > >Considering the state of the solar cycle I'd prefer a board with lower
> > >frequency capability. So is it possible to build a board with 80 - 40
> - 30
> > >- 20?
> > >
> > >Second question has to do with 60 Meters. Is it technically feasible to
> > >have 60 meter receive cavility on a K1, assuming the toroids and other
> > >components aer appropriate to the frequency?
> > >
> > >The K1 is a super little rig and I'ce already become very fond of it. It
> > >would be perfect if I could get my preferred band selection on one filter
> > >board.
> >
> > The K1 4-band board CAN be constructed for 80M, BUT then you'll have to
> > give up 40M!!! Here's why...
> >
> > The two 2-band filters in the KFL1-4 are designed so that the upper
> > frequency cutoff of each filter is above the higher of the two
> frequencies,
> > BUT LOWER THAN the 2nd harmonic of the lower frequency.
> >
> > In other words, the 40M/30M filter cuts off above 10MHz, and BELOW 14MHz.
> > If you were to build the first filter for 80/40 meters, then the filter
> > would have to be able to pass both 3.5 and 7.0 MHz energy, thus allowing
> > any potential 80M 2nd harmonic energy through to the antenna... this comes
> > under the heading of "Bad things will happen". So, in order for the KFL1-4
> > to be built to accommodate 80M, it's have to cut off at a frequency lower
> > than 40M, which means that you'd have 80M, but not 40M.
> >
> > Sorry pal.  Good try though...
> >
> > 73,
> >
> > Tom Hammond    N0SS
> >
> >
> > _______________________________________________
> > Elecraft mailing list
> > Post to: [hidden email]
> > You must be a subscriber to post to the list.
> > Subscriber Info (Addr. Change, sub, unsub etc.):
> > http://mailman.qth.net/mailman/listinfo/elecraft
> > Help: http://mailman.qth.net/subscribers.htm
> > Elecraft web page: http://www.elecraft.com
> >

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Re: K1 Filter Board Questions

George,  W5YR
Tom, I believe that the government, military, et al have mandated USB for
"everything."

73, George W5YR
Fairview, TX
[hidden email]
http://www.w5yr.com


----- Original Message -----
From: "Tom Hammond" <[hidden email]>
To: <[hidden email]>; "Ron Ricketts" <[hidden email]>;
<[hidden email]>
Sent: Friday, September 03, 2004 9:48 AM
Subject: Re: [Elecraft] K1 Filter Board Questions


> Hi Daniel:
>
> Well, he MIGHT be able to come up with a filter to cover 80/60, but I'm
not

> certain about the signal inversion on that band... might not permit USB
> reception... can't believe the FCC mandated USB in a (larger) band segment
> which typically ALWAYS defaults to LSB, due to mixing 'standards'.
>
> 73,
>
> Tom
>
> At 08:14 AM 9/3/04, Daniel Reynolds wrote:
> >But - if you consider that he also wants to receive on 60m (although I
don't
> >know enough about tuning bandwidth considerations for the K1, and whether
or

> >not the SSB would be normal or inverted), maybe the filter could be
> >constructed
> >so that he has 80/60 and 40/30?
> >
> >- Daniel / AA0NI
> >
> >--- Tom Hammond <[hidden email]> wrote:
> >
> > > Hi Ron:
> > >
> > > At 10:34 PM 9/2/04, you wrote:
> > > >I have obtained a K1 and have a couple of questions regarding the
KFL1-4
> > > >board. Is there any reason it can't be constructed with 80 - 40 -
30 - 20
> > > >meters? If you purchase a new one it comes with 40 - 30 - 20 - 17/15
> > meters.
> > > >
> > > >Considering the state of the solar cycle I'd prefer a board with
lower
> > > >frequency capability. So is it possible to build a board with 80 - 40
> > - 30
> > > >- 20?
> > > >
> > > >Second question has to do with 60 Meters. Is it technically feasible
to
> > > >have 60 meter receive cavility on a K1, assuming the toroids and
other
> > > >components aer appropriate to the frequency?
> > > >
> > > >The K1 is a super little rig and I'ce already become very fond of it.
It
> > > >would be perfect if I could get my preferred band selection on one
filter
> > > >board.
> > >
> > > The K1 4-band board CAN be constructed for 80M, BUT then you'll have
to
> > > give up 40M!!! Here's why...
> > >
> > > The two 2-band filters in the KFL1-4 are designed so that the upper
> > > frequency cutoff of each filter is above the higher of the two
> > frequencies,
> > > BUT LOWER THAN the 2nd harmonic of the lower frequency.
> > >
> > > In other words, the 40M/30M filter cuts off above 10MHz, and BELOW
14MHz.
> > > If you were to build the first filter for 80/40 meters, then the
filter
> > > would have to be able to pass both 3.5 and 7.0 MHz energy, thus
allowing
> > > any potential 80M 2nd harmonic energy through to the antenna... this
comes
> > > under the heading of "Bad things will happen". So, in order for the
KFL1-4
> > > to be built to accommodate 80M, it's have to cut off at a frequency
lower

> > > than 40M, which means that you'd have 80M, but not 40M.
> > >
> > > Sorry pal.  Good try though...
> > >
> > > 73,
> > >
> > > Tom Hammond    N0SS
> > >
> > >
> > > _______________________________________________
> > > Elecraft mailing list
> > > Post to: [hidden email]
> > > You must be a subscriber to post to the list.
> > > Subscriber Info (Addr. Change, sub, unsub etc.):
> > > http://mailman.qth.net/mailman/listinfo/elecraft
> > > Help: http://mailman.qth.net/subscribers.htm
> > > Elecraft web page: http://www.elecraft.com
> > >
>
> _______________________________________________
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Re: K1 Filter Board Questions

Sandy W5TVW
In reply to this post by Ron Ricketts

----- Original Message -----
From: "Ron Ricketts" <[hidden email]>
To: <[hidden email]>
Sent: Thursday, September 02, 2004 10:34 PM
Subject: [Elecraft] K1 Filter Board Questions


| I have obtained a K1 and have a couple of questions regarding the KFL1-4
| board. Is there any reason it can't be constructed with 80 - 40 - 30 - 20
| meters? If you purchase a new one it comes with 40 - 30 - 20 - 17/15 meters.
| Considering the state of the solar cycle I'd prefer a board with lower
| frequency capability. So is it possible to build a board with 80 - 40 - 30 -
| 20?
|

NO!  Not without a complete redesign.  It is setup so that more than one band uses
the same set of inductors.  It probably "could" be done, but not without
some problem solving. Best solutuin is to build an 80/17 2 band board.....
OR...As I will soon do, build an 80/160 board.  The 160 meter values have
been worked out, but it's a "do it yourself" project at present until/if
the Elecraft guys make 160 a band option for 2 band board.

| Second question has to do with 60 Meters. Is it technically feasible to have
| 60 meter receive cavility on a K1, assuming the toroids and other components
| aer appropriate to the frequency?

    No, Not even with a 2 band board owing to the filter frequencies used.
If you did it, what would be the point?  No CW operation is legal at
the moment on 60 meters.

73,
Sandy W5TVW
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Re: K1 Filter Board Questions

Mike Morrow-3
In reply to this post by Ron Ricketts
Martin wrote:

>...I built a 4-band board for 40/30/20/15 and a two band board
>for 80/40m

Hi Martin,

Is your frequency of operation on 40m accurately shown on the LCD for *both*
filter boards?

The problem with having the same band on two different filter boards is that
the K1 front panel MCU can only store *one* display calibration constant for
each HF ham band (as set using the OPF function).  The calibration constant
is not stored in the filter board MCU.  Unless the hetrodyne crystal
oscillators for that duplicated band on both filter boards operate at the
same frequency, the LCD frequency display for that band will be inaccurate
for the filter board which was not installed at the time of the OPF
frequency display calibration.  Judging by three Elecraft 40m hetrodyne
crystals I've tried, the variation between crystals can be several kHz.

The effects of hetrodyne oscillator frequency variations do *not*
automatically show up on the K1 LCD frequency display.  The LCD display is
driven by a frequency counter program in the front panel MCU that senses
*only* the raw output of the VFO before it is mixed with any other
oscillators in the K1.

73,
Mike / KK5F


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