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K3 Filter Question

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Brett Howard

K3 Filter Question

Ok so I'm curious if I'll be able to do what I'd like. I'd like to
setup my K3 for maximum flexibility. At the moment I have these
filters.

2.8Khz
1.8Khz
1Khz
250Hz

These 4 filters are duplicated in the lower 4 slots of both receivers.
I'd like to have the ability to do AM and FM both TX and RX in this
radio. Can I add the AM filter and KBPF into the main RX and then put
the FM filter into the KRX3?

I'm hoping that I can then use the MainRX for broad frequency coverage
and AM broadcast receive. Then if I ever want to do FM work I simply
have to use the sub receiver to do so. Will TX through the FM filter
work with it in the sub RX... To the best of my knowledge it appears
that I can set the rig up in this fashion but that doesn't always mean
it will work how I expect it to.

Am I all wet here?

Thanks

~Brett

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Bob Cunnings NW8L

Re: K3 Filter Question

Manual, pg 74:

"Rule #1: If you plan to use a particular filter for both transmitting
and receiving (main receiver), you’ll need to
install it on the RF board. You can optionally install a filter of the
same or similar bandwidth on the sub
receiver for receive-only use. (This is recommended since it will keep
the receivers identical.)"

Bob NW8L

On Wed, Jul 8, 2009 at 11:31 PM, Brett Howard<[hidden email]> wrote:

> Ok so I'm curious if I'll be able to do what I'd like. I'd like to
> setup my K3 for maximum flexibility. At the moment I have these
> filters.
>
> 2.8Khz
> 1.8Khz
> 1Khz
> 250Hz
>
> These 4 filters are duplicated in the lower 4 slots of both receivers.
> I'd like to have the ability to do AM and FM both TX and RX in this
> radio. Can I add the AM filter and KBPF into the main RX and then put
> the FM filter into the KRX3?
>
> I'm hoping that I can then use the MainRX for broad frequency coverage
> and AM broadcast receive. Then if I ever want to do FM work I simply
> have to use the sub receiver to do so. Will TX through the FM filter
> work with it in the sub RX... To the best of my knowledge it appears
> that I can set the rig up in this fashion but that doesn't always mean
> it will work how I expect it to.
>
> Am I all wet here?
>
> Thanks
>
> ~Brett
>
> ______________________________________________________________
> 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
>

Brett Howard

Re: K3 Filter Question

I forgot to go back to that... I was thrown off by the comment on the
order page that said you only need one of each filter for transmit. I
know that doesn't fully say what I was hoping for though....

I wonder if there is any possibility of allowing AM TX and/or ESSB via
the FM filter... As I'd like to have maximum flexibility but only have
one slot left because of the way I have setup the radio for what I spend
most of my time doing.

Thanks for the assistance gentlemen.

~Brett

On Thu, 2009-07-09 at 00:13 -0600, Bob Cunnings wrote:

> Manual, pg 74:
>
> "Rule #1: If you plan to use a particular filter for both transmitting
> and receiving (main receiver), you’ll need to
> install it on the RF board. You can optionally install a filter of the
> same or similar bandwidth on the sub
> receiver for receive-only use. (This is recommended since it will keep
> the receivers identical.)"
>
> Bob NW8L
>
> On Wed, Jul 8, 2009 at 11:31 PM, Brett Howard<[hidden email]> wrote:
> > Ok so I'm curious if I'll be able to do what I'd like. I'd like to
> > setup my K3 for maximum flexibility. At the moment I have these
> > filters.
> >
> > 2.8Khz
> > 1.8Khz
> > 1Khz
> > 250Hz
> >
> > These 4 filters are duplicated in the lower 4 slots of both receivers.
> > I'd like to have the ability to do AM and FM both TX and RX in this
> > radio. Can I add the AM filter and KBPF into the main RX and then put
> > the FM filter into the KRX3?
> >
> > I'm hoping that I can then use the MainRX for broad frequency coverage
> > and AM broadcast receive. Then if I ever want to do FM work I simply
> > have to use the sub receiver to do so. Will TX through the FM filter
> > work with it in the sub RX... To the best of my knowledge it appears
> > that I can set the rig up in this fashion but that doesn't always mean
> > it will work how I expect it to.
> >
> > Am I all wet here?
> >
> > Thanks
> >
> > ~Brett
> >
> > ______________________________________________________________
> > 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
> >
> ______________________________________________________________
> 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

AD4C2009

Re: K3 Filter Question

In reply to this post by Brett Howard

Brett
I do have all the slots filled with roofers and the FL1 in my case its an 8 poles 6.0 Khz,with that I am able to TX and RX on AM but not on FM,if you want to be able to use either AM or FM RX/TX you will have to purchase the FM filter of 13Khz BW.Hope this answer your doubt.

AD4C
K3 # 2192

"The difference between genius and stupidity is that genius has its limits".. -- Albert Einstein

--- On Thu, 7/9/09, Brett Howard <[hidden email]> wrote:

From: Brett Howard <[hidden email]>
Subject: Re: [Elecraft] K3 Filter Question
To: "Bob Cunnings" <[hidden email]>
Cc: [hidden email]
Date: Thursday, July 9, 2009, 6:20 AM

I forgot to go back to that... I was thrown off by the comment on the
order page that said you only need one of each filter for transmit. I
know that doesn't fully say what I was hoping for though....

I wonder if there is any possibility of allowing AM TX and/or ESSB via
the FM filter... As I'd like to have maximum flexibility but only have
one slot left because of the way I have setup the radio for what I spend
most of my time doing.

Thanks for the assistance gentlemen.

~Brett

On Thu, 2009-07-09 at 00:13 -0600, Bob Cunnings wrote:

______________________________________________________________
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

______________________________________________________________
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

Joe Subich, W4TV-4

Re: K3 Filter Question

In reply to this post by Brett Howard

> I wonder if there is any possibility of allowing AM TX and/or
> ESSB via the FM filter...

It is theoretically possible to transmit AM and ESSB through
the FM filter but the K3 is currently configured to prohibit
AM and ESSB transmit unless the 6 KHz filter is used. I have
transmitted using the FM filter by setting the K3 as if the
FM filter was an AM filter but then I can not transmit FM
without resetting the filter set-up.

Elecraft will argue that the 6 KHz filter is necessary to
prevent transmitted images (the DSP IF is 15 KHz, the image
is 30 KHz away from the transmit frequency). However, I
can not measure any image - to -120 dB from the CW level -
when looking at the transmitter output with a directional
coupler using the SDR-IQ as a spectrum analyzer. This
is as expected since the FM filter should be at least -60
dB at +/-23 (2:1 shape factor) with an ultimate attenuation
of at least -100 dB.

It would certainly be nice if the "6 KHz" restriction was
removed.

73,

... Joe, W4TV

> -----Original Message-----
> From: [hidden email]
> [mailto:[hidden email]] On Behalf Of Brett Howard
> Sent: Thursday, July 09, 2009 2:21 AM
> To: Bob Cunnings
> Cc: [hidden email]
> Subject: Re: [Elecraft] K3 Filter Question
>
>
> I forgot to go back to that... I was thrown off by the
> comment on the order page that said you only need one of each
> filter for transmit. I know that doesn't fully say what I
> was hoping for though....
>
> I wonder if there is any possibility of allowing AM TX and/or
> ESSB via the FM filter... As I'd like to have maximum
> flexibility but only have one slot left because of the way I
> have setup the radio for what I spend most of my time doing.
>
> Thanks for the assistance gentlemen.
>
> ~Brett
>
> On Thu, 2009-07-09 at 00:13 -0600, Bob Cunnings wrote:
> > Manual, pg 74:
> >
> > "Rule #1: If you plan to use a particular filter for both
> transmitting
> > and receiving (main receiver), you’ll need to install it on the RF
> > board. You can optionally install a filter of the same or similar
> > bandwidth on the sub receiver for receive-only use. (This is
> > recommended since it will keep the receivers identical.)"
> >
> > Bob NW8L
> >
> > On Wed, Jul 8, 2009 at 11:31 PM, Brett
> Howard<[hidden email]>
> > wrote:
> > > Ok so I'm curious if I'll be able to do what I'd like.
> I'd like to
> > > setup my K3 for maximum flexibility. At the moment I have these
> > > filters.
> > >
> > > 2.8Khz
> > > 1.8Khz
> > > 1Khz
> > > 250Hz
> > >
> > > These 4 filters are duplicated in the lower 4 slots of both
> > > receivers. I'd like to have the ability to do AM and FM
> both TX and
> > > RX in this radio. Can I add the AM filter and KBPF into
> the main RX
> > > and then put the FM filter into the KRX3?
> > >
> > > I'm hoping that I can then use the MainRX for broad frequency
> > > coverage and AM broadcast receive. Then if I ever want to do FM
> > > work I simply have to use the sub receiver to do so. Will TX
> > > through the FM filter work with it in the sub RX... To
> the best of
> > > my knowledge it appears that I can set the rig up in this fashion
> > > but that doesn't always mean it will work how I expect it to.
> > >
> > > Am I all wet here?
> > >
> > > Thanks
> > >
> > > ~Brett
> > >
> > > ______________________________________________________________
> > > 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
> > >
> > ______________________________________________________________
> > 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
>
> ______________________________________________________________
> 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
>

Stewart Baker

Re: K3 Filter Question

I agree.
The cost of the K3 filters is now so high in the UK, that I want to
get away with the minimum number necessary.

73
Stewart G3RXQ
On Thu, 9 Jul 2009 10:00:42 -0400, Joe Subich, W4TV wrote:

>
>> I wonder if there is any possibility of allowing AM TX and/or
>> ESSB via the FM filter...
>
> It is theoretically possible to transmit AM and ESSB through
> the FM filter but the K3 is currently configured to prohibit
> AM and ESSB transmit unless the 6 KHz filter is used. I have
> transmitted using the FM filter by setting the K3 as if the
> FM filter was an AM filter but then I can not transmit FM
> without resetting the filter set-up.
>
> Elecraft will argue that the 6 KHz filter is necessary to
> prevent transmitted images (the DSP IF is 15 KHz, the image
> is 30 KHz away from the transmit frequency). However, I
> can not measure any image - to -120 dB from the CW level -
> when looking at the transmitter output with a directional
> coupler using the SDR-IQ as a spectrum analyzer. This
> is as expected since the FM filter should be at least -60
> dB at +/-23 (2:1 shape factor) with an ultimate attenuation
> of at least -100 dB.
>
> It would certainly be nice if the "6 KHz" restriction was
> removed.
>
> 73,
>
> ... Joe, W4TV
>
>
>> -----Original Message-----
>> From: [hidden email]
>> [mailto:[hidden email]] On Behalf Of Brett Howard
>> Sent: Thursday, July 09, 2009 2:21 AM
>> To: Bob Cunnings
>> Cc: [hidden email]
>> Subject: Re: [Elecraft] K3 Filter Question
>>
>>
>> I forgot to go back to that... I was thrown off by the
>> comment on the order page that said you only need one of each
>> filter for transmit. I know that doesn't fully say what I
>> was hoping for though....
>>
>> I wonder if there is any possibility of allowing AM TX and/or
>> ESSB via the FM filter... As I'd like to have maximum
>> flexibility but only have one slot left because of the way I
>> have setup the radio for what I spend most of my time doing.
>>
>> Thanks for the assistance gentlemen.
>>
>> ~Brett
>>
>> On Thu, 2009-07-09 at 00:13 -0600, Bob Cunnings wrote:
>> > Manual, pg 74:
>> >
>> > "Rule #1: If you plan to use a particular filter for both
>> transmitting
>> > and receiving (main receiver), you'll need to install it on the RF
>> > board. You can optionally install a filter of the same or similar
>> > bandwidth on the sub receiver for receive-only use. (This is
>> > recommended since it will keep the receivers identical.)"
>> >
>> > Bob NW8L
>> >
>> > On Wed, Jul 8, 2009 at 11:31 PM, Brett
>> Howard<[hidden email]>
>> > wrote:
>> > > Ok so I'm curious if I'll be able to do what I'd like.
>> I'd like to
>> > > setup my K3 for maximum flexibility. At the moment I have these
>> > > filters.
>> > >
>> > > 2.8Khz
>> > > 1.8Khz
>> > > 1Khz
>> > > 250Hz
>> > >
>> > > These 4 filters are duplicated in the lower 4 slots of both
>> > > receivers. I'd like to have the ability to do AM and FM
>> both TX and
>> > > RX in this radio. Can I add the AM filter and KBPF into
>> the main RX
>> > > and then put the FM filter into the KRX3?
>> > >
>> > > I'm hoping that I can then use the MainRX for broad frequency
>> > > coverage and AM broadcast receive. Then if I ever want to do FM
>> > > work I simply have to use the sub receiver to do so. Will TX
>> > > through the FM filter work with it in the sub RX... To
>> the best of
>> > > my knowledge it appears that I can set the rig up in this fashion
>> > > but that doesn't always mean it will work how I expect it to.
>> > >
>> > > Am I all wet here?
>> > >
>> > > Thanks
>> > >
>> > > ~Brett
>> > >
>> > > ______________________________________________________________
>> > > 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
>> > >
>> > ______________________________________________________________
>> > 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
>>
>> ______________________________________________________________
>> 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
>>
>
> ______________________________________________________________
> 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

Joe Subich, W4TV-4

Re: K3 Filter Question

> > This is as expected since the FM filter should be at least -60
> > dB at +/-23 (2:1 shape factor) with an ultimate attenuation
> > of at least -100 dB.

Correction ... +/- 26 KHz or a 2:1 shape factor. However
for comparison, Inrad's six pole front end filters for 40
meters are 15 KHz wide (+/- 7.5 KHz) at 1 dB and 32 KHz
(+/- 16 KHz) at - 60 dB or 20 KHz ((+/- 10 KHz) at -1 dB
and 45 KHz (+/- 22.5 KHz) at - 60 dB. Converting to a 6:60
framework makes the shape factor around 1.8:1.

73,

... Joe, W4TV

> -----Original Message-----
> From: Stewart Baker [mailto:[hidden email]]
> Sent: Thursday, July 09, 2009 10:35 AM
> To: [hidden email]; 'Brett Howard'; 'Bob Cunnings'
> Cc: [hidden email]
> Subject: Re: [Elecraft] K3 Filter Question
>
>
> I agree.
> The cost of the K3 filters is now so high in the UK, that I
> want to get away with the minimum number necessary.
>
> 73
> Stewart G3RXQ
> On Thu, 9 Jul 2009 10:00:42 -0400, Joe Subich, W4TV wrote:
> >
> >> I wonder if there is any possibility of allowing AM TX and/or ESSB
> >> via the FM filter...
> >
> > It is theoretically possible to transmit AM and ESSB through the FM
> > filter but the K3 is currently configured to prohibit AM and ESSB
> > transmit unless the 6 KHz filter is used. I have transmitted using
> > the FM filter by setting the K3 as if the FM filter was an
> AM filter
> > but then I can not transmit FM without resetting the filter set-up.
> >
> > Elecraft will argue that the 6 KHz filter is necessary to prevent
> > transmitted images (the DSP IF is 15 KHz, the image is 30 KHz away
> > from the transmit frequency). However, I can not measure
> any image -
> > to -120 dB from the CW level - when looking at the
> transmitter output
> > with a directional coupler using the SDR-IQ as a spectrum
> analyzer.
> > This is as expected since the FM filter should be at least -60
> > dB at +/-23 (2:1 shape factor) with an ultimate attenuation
> > of at least -100 dB.
> >
> > It would certainly be nice if the "6 KHz" restriction was removed.
> >
> > 73,
> >
> > ... Joe, W4TV
> >
> >
> >> -----Original Message-----
> >> From: [hidden email]
> >> [mailto:[hidden email]] On Behalf Of Brett Howard
> >> Sent: Thursday, July 09, 2009 2:21 AM
> >> To: Bob Cunnings
> >> Cc: [hidden email]
> >> Subject: Re: [Elecraft] K3 Filter Question
> >>
> >>
> >> I forgot to go back to that... I was thrown off by the comment on
> >> the order page that said you only need one of each filter for
> >> transmit. I know that doesn't fully say what I was hoping for
> >> though....
> >>
> >> I wonder if there is any possibility of allowing AM TX and/or ESSB
> >> via the FM filter... As I'd like to have maximum flexibility but
> >> only have one slot left because of the way I have setup
> the radio for
> >> what I spend most of my time doing.
> >>
> >> Thanks for the assistance gentlemen.
> >>
> >> ~Brett
> >>
> >> On Thu, 2009-07-09 at 00:13 -0600, Bob Cunnings wrote:
> >> > Manual, pg 74:
> >> >
> >> > "Rule #1: If you plan to use a particular filter for both
> >> transmitting
> >> > and receiving (main receiver), you'll need to install it
> on the RF
> >> > board. You can optionally install a filter of the same
> or similar
> >> > bandwidth on the sub receiver for receive-only use. (This is
> >> > recommended since it will keep the receivers identical.)"
> >> >
> >> > Bob NW8L
> >> >
> >> > On Wed, Jul 8, 2009 at 11:31 PM, Brett
> >> Howard<[hidden email]>
> >> > wrote:
> >> > > Ok so I'm curious if I'll be able to do what I'd like.
> >> I'd like to
> >> > > setup my K3 for maximum flexibility. At the moment I
> have these
> >> > > filters.
> >> > >
> >> > > 2.8Khz
> >> > > 1.8Khz
> >> > > 1Khz
> >> > > 250Hz
> >> > >
> >> > > These 4 filters are duplicated in the lower 4 slots of both
> >> > > receivers. I'd like to have the ability to do AM and FM
> >> both TX and
> >> > > RX in this radio. Can I add the AM filter and KBPF into
> >> the main RX
> >> > > and then put the FM filter into the KRX3?
> >> > >
> >> > > I'm hoping that I can then use the MainRX for broad frequency
> >> > > coverage and AM broadcast receive. Then if I ever
> want to do FM
> >> > > work I simply have to use the sub receiver to do so. Will TX
> >> > > through the FM filter work with it in the sub RX... To
> >> the best of
> >> > > my knowledge it appears that I can set the rig up in
> this fashion
> >> > > but that doesn't always mean it will work how I expect it to.
> >> > >
> >> > > Am I all wet here?
> >> > >
> >> > > Thanks
> >> > >
> >> > > ~Brett
> >> > >
> >> > > ______________________________________________________________
> >> > > 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
> >> > >
> >> > ______________________________________________________________
> >> > 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
> >>
> >> ______________________________________________________________
> >> 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
> >>
> >
> > ______________________________________________________________
> > 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
>
>

Brett Howard

Re: K3 Filter Question

Looks like buying the FM filter and lying to the rig gives me the
maximum flexibility with a minor inconvenience. Being that I won't be
TXing in those modes all that often I'm not too worred but I just want
to have a true All mode tranceiver.

~Brett

On Thu, 2009-07-09 at 11:35 -0400, Joe Subich, W4TV wrote:

>
> > > This is as expected since the FM filter should be at least -60
> > > dB at +/-23 (2:1 shape factor) with an ultimate attenuation
> > > of at least -100 dB.
>
> Correction ... +/- 26 KHz or a 2:1 shape factor. However
> for comparison, Inrad's six pole front end filters for 40
> meters are 15 KHz wide (+/- 7.5 KHz) at 1 dB and 32 KHz
> (+/- 16 KHz) at - 60 dB or 20 KHz ((+/- 10 KHz) at -1 dB
> and 45 KHz (+/- 22.5 KHz) at - 60 dB. Converting to a 6:60
> framework makes the shape factor around 1.8:1.
>
> 73,
>
> ... Joe, W4TV
>
>
>
>
> > -----Original Message-----
> > From: Stewart Baker [mailto:[hidden email]]
> > Sent: Thursday, July 09, 2009 10:35 AM
> > To: [hidden email]; 'Brett Howard'; 'Bob Cunnings'
> > Cc: [hidden email]
> > Subject: Re: [Elecraft] K3 Filter Question
> >
> >
> > I agree.
> > The cost of the K3 filters is now so high in the UK, that I
> > want to get away with the minimum number necessary.
> >
> > 73
> > Stewart G3RXQ
> > On Thu, 9 Jul 2009 10:00:42 -0400, Joe Subich, W4TV wrote:
> > >
> > >> I wonder if there is any possibility of allowing AM TX and/or ESSB
> > >> via the FM filter...
> > >
> > > It is theoretically possible to transmit AM and ESSB through the FM
> > > filter but the K3 is currently configured to prohibit AM and ESSB
> > > transmit unless the 6 KHz filter is used. I have transmitted using
> > > the FM filter by setting the K3 as if the FM filter was an
> > AM filter
> > > but then I can not transmit FM without resetting the filter set-up.
> > >
> > > Elecraft will argue that the 6 KHz filter is necessary to prevent
> > > transmitted images (the DSP IF is 15 KHz, the image is 30 KHz away
> > > from the transmit frequency). However, I can not measure
> > any image -
> > > to -120 dB from the CW level - when looking at the
> > transmitter output
> > > with a directional coupler using the SDR-IQ as a spectrum
> > analyzer.
> > > This is as expected since the FM filter should be at least -60
> > > dB at +/-23 (2:1 shape factor) with an ultimate attenuation
> > > of at least -100 dB.
> > >
> > > It would certainly be nice if the "6 KHz" restriction was removed.
> > >
> > > 73,
> > >
> > > ... Joe, W4TV
> > >
> > >
> > >> -----Original Message-----
> > >> From: [hidden email]
> > >> [mailto:[hidden email]] On Behalf Of Brett Howard
> > >> Sent: Thursday, July 09, 2009 2:21 AM
> > >> To: Bob Cunnings
> > >> Cc: [hidden email]
> > >> Subject: Re: [Elecraft] K3 Filter Question
> > >>
> > >>
> > >> I forgot to go back to that... I was thrown off by the comment on
> > >> the order page that said you only need one of each filter for
> > >> transmit. I know that doesn't fully say what I was hoping for
> > >> though....
> > >>
> > >> I wonder if there is any possibility of allowing AM TX and/or ESSB
> > >> via the FM filter... As I'd like to have maximum flexibility but
> > >> only have one slot left because of the way I have setup
> > the radio for
> > >> what I spend most of my time doing.
> > >>
> > >> Thanks for the assistance gentlemen.
> > >>
> > >> ~Brett
> > >>
> > >> On Thu, 2009-07-09 at 00:13 -0600, Bob Cunnings wrote:
> > >> > Manual, pg 74:
> > >> >
> > >> > "Rule #1: If you plan to use a particular filter for both
> > >> transmitting
> > >> > and receiving (main receiver), you'll need to install it
> > on the RF
> > >> > board. You can optionally install a filter of the same
> > or similar
> > >> > bandwidth on the sub receiver for receive-only use. (This is
> > >> > recommended since it will keep the receivers identical.)"
> > >> >
> > >> > Bob NW8L
> > >> >
> > >> > On Wed, Jul 8, 2009 at 11:31 PM, Brett
> > >> Howard<[hidden email]>
> > >> > wrote:
> > >> > > Ok so I'm curious if I'll be able to do what I'd like.
> > >> I'd like to
> > >> > > setup my K3 for maximum flexibility. At the moment I
> > have these
> > >> > > filters.
> > >> > >
> > >> > > 2.8Khz
> > >> > > 1.8Khz
> > >> > > 1Khz
> > >> > > 250Hz
> > >> > >
> > >> > > These 4 filters are duplicated in the lower 4 slots of both
> > >> > > receivers. I'd like to have the ability to do AM and FM
> > >> both TX and
> > >> > > RX in this radio. Can I add the AM filter and KBPF into
> > >> the main RX
> > >> > > and then put the FM filter into the KRX3?
> > >> > >
> > >> > > I'm hoping that I can then use the MainRX for broad frequency
> > >> > > coverage and AM broadcast receive. Then if I ever
> > want to do FM
> > >> > > work I simply have to use the sub receiver to do so. Will TX
> > >> > > through the FM filter work with it in the sub RX... To
> > >> the best of
> > >> > > my knowledge it appears that I can set the rig up in
> > this fashion
> > >> > > but that doesn't always mean it will work how I expect it to.
> > >> > >
> > >> > > Am I all wet here?
> > >> > >
> > >> > > Thanks
> > >> > >
> > >> > > ~Brett
> > >> > >
> > >> > > ______________________________________________________________
> > >> > > 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
> > >> > >
> > >> > ______________________________________________________________
> > >> > 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
> > >>
> > >> ______________________________________________________________
> > >> 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
> > >>
> > >
> > > ______________________________________________________________
> > > 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
> >
> >
>

K2QI

Re: K3 Filter Question

In reply to this post by Brett Howard

My setup is as follows:

Main: 13k, 6k, 2.7k, 500Hz
Sub: 13k, 2.7k, 500Hz

I also have the wide-receive module installed on the sub. This way the sub
receiver will have broad coverage while the main is strictly relegated to
the amateur bands. It works quite well as the 13k filter in the sub does
double duty for FM and AM receive.

73 de James K2QI

-----Original Message-----
From: [hidden email]
[mailto:[hidden email]] On Behalf Of Brett Howard
Sent: Thursday, July 09, 2009 1:31 AM
To: [hidden email]
Subject: [Elecraft] K3 Filter Question

Ok so I'm curious if I'll be able to do what I'd like. I'd like to
setup my K3 for maximum flexibility. At the moment I have these
filters.

2.8Khz
1.8Khz
1Khz
250Hz

These 4 filters are duplicated in the lower 4 slots of both receivers.
I'd like to have the ability to do AM and FM both TX and RX in this
radio. Can I add the AM filter and KBPF into the main RX and then put
the FM filter into the KRX3?

I'm hoping that I can then use the MainRX for broad frequency coverage
and AM broadcast receive. Then if I ever want to do FM work I simply
have to use the sub receiver to do so. Will TX through the FM filter
work with it in the sub RX... To the best of my knowledge it appears
that I can set the rig up in this fashion but that doesn't always mean
it will work how I expect it to.

Am I all wet here?

Thanks

~Brett

______________________________________________________________
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

______________________________________________________________
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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