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Filters for K3

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KARL MARDERIAN

Filters for K3

N6XVT Karl
Here is my two cents. A ragchewer. I have: 13, 6 , 2.8 , 2.1 , 500/8
pole.
The DSP does the rest. Just run the K3 with the 2.8 and figure out
want you want.

Sent from my iPhone
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Martin-2

Re: Filters for K3

Elecrafters, thanks for all the input.
I had many replies, personal mail or via the reflector.

To sum it up:

Matched filters are important for diversity.

8 votes for the 1.8khz, 4 for the 2.1 ssb filter for contesting.
Some use the 1.8khz ssb filter for cw, with the dsp set to narrower
bandwith. I think i will order one of those, it makes sense to use it
for cw-operation on a quiet band and in ssb contests when things get rough.

The 200hz and 250hz cw filters got an equal number of votes, you left me
alone on this ;-)

The expense on 2 matched 5 pole or 2 8-pole filters is about the same,
so the criteria here is performance.

May i call for a run-off?

Thanks to all es HNY

Martin

--

73, DM4iM
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Dunc Carter - W5DC

Re: Filters for K3

Just to add further confusion to the cw opinions, I currently have the
250 Hz 8 pole, which I like as it allows me to work very close to strong
locals including those with key clicks, and I plan the purchase the 8
pole 500 Hz Inrad filter on New Years Day. Some of the responders have
commented that the -6dB width of the 250 Hz filter is not that much
smaller than the 250 Hz filter width, which is true. The problem is
that the response on either side of the peak of the 250 Hz filter isn't
symmetrical, at least mine isn't, I assume the result of working with
real, physical, hardware.. One side matches well with the 250 Hz dsp
filter width but the other side is wider and sets most of the overall -6
dB with if the dsp filter is set to a wider bandwidth.

Dunc, W5DC

DM4iM wrote:

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Dunc Carter - W5DC

Re: Filters for K3

Ooops, typos are us.

Some of the responders have
commented that the -6dB width of the 250 Hz filter is not that much
smaller than the 400 Hz filter width, which is true. T

Duncan Carter wrote:

> Just to add further confusion to the cw opinions, I currently have the
> 250 Hz 8 pole, which I like as it allows me to work very close to strong
> locals including those with key clicks, and I plan the purchase the 8
> pole 500 Hz Inrad filter on New Years Day. Some of the responders have
> commented that the -6dB width of the 250 Hz filter is not that much
> smaller than the 400 Hz filter width, which is true. The problem is
> that the response on either side of the peak of the 250 Hz filter isn't
> symmetrical, at least mine isn't, I assume the result of working with
> real, physical, hardware.. One side matches well with the 250 Hz dsp
> filter width but the other side is wider and sets most of the overall -6
> dB with if the dsp filter is set to a wider bandwidth.
>
> Dunc, W5DC
>
>
> DM4iM wrote:
>
>> Elecrafters, thanks for all the input.
>> I had many replies, personal mail or via the reflector.
>>
>> To sum it up:
>>
>> Matched filters are important for diversity.
>>
>> 8 votes for the 1.8khz, 4 for the 2.1 ssb filter for contesting.
>> Some use the 1.8khz ssb filter for cw, with the dsp set to narrower
>> bandwith. I think i will order one of those, it makes sense to use it
>> for cw-operation on a quiet band and in ssb contests when things get rough.
>>
>> The 200hz and 250hz cw filters got an equal number of votes, you left me
>> alone on this ;-)
>>
>> The expense on 2 matched 5 pole or 2 8-pole filters is about the same,
>> so the criteria here is performance.
>>
>> May i call for a run-off?
>>
>> Thanks to all es HNY
>>
>> Martin
>>
>>
>>
>
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>

Joe Subich, W4TV-4

Re: Filters for K3

In reply to this post by Martin-2

>
> The 200hz and 250hz cw filters got an equal number of votes,
> you left me alone on this ;-)

The filter curves on the Elecraft web site for the 250 Hz show
the filter to be more than 350 Hz wide (at best) which does
not provide a significant improvement over the 400 Hz filter.

On the other hand, the 200 Hz filters regularly measure 190 to
210 Hz wide at -6dB and when plotted against the "250 Hz" filter
are consistently "tighter" all the way down in spite of the
larger shape factor.

In my opinion, one is wasting money to have both the 400 Hz and
250 Hz filters ... use 500/200 or 400/200 or 1000/250 depending
on your needs.

I also don't know that I would use 250 or 200 Hz filter in the
sub-receiver. If one has 500/200 in the main, I would order
the 200 "matched" to the 500 Hz pair ... or I would simply
accept the slight mismatch between 200 in the main and a 400
Hz 8-pole in the sub receiver.

73,

... Joe, W4TV

> -----Original Message-----
> From: [hidden email]
> [mailto:[hidden email]] On Behalf Of DM4iM
> Sent: Monday, December 28, 2009 3:25 PM
> To: [hidden email]
> Subject: Re: [Elecraft] Filters for K3
>
>
> Elecrafters, thanks for all the input.
> I had many replies, personal mail or via the reflector.
>
> To sum it up:
>
> Matched filters are important for diversity.
>
> 8 votes for the 1.8khz, 4 for the 2.1 ssb filter for
> contesting. Some use the 1.8khz ssb filter for cw, with the
> dsp set to narrower bandwith. I think i will order one of
> those, it makes sense to use it for cw-operation on a quiet
> band and in ssb contests when things get rough.
>
> The 200hz and 250hz cw filters got an equal number of votes,
> you left me alone on this ;-)
>
> The expense on 2 matched 5 pole or 2 8-pole filters is about
> the same, so the criteria here is performance.
>
> May i call for a run-off?
>
> Thanks to all es HNY
>
> Martin
>
> --
>
> 73, DM4iM
> ______________________________________________________________
> 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

hf4me

Re: Filters for K3

In reply to this post by Martin-2

There is a big difference between the 200 (actually 224) and the 250
(actually 370) and very little diffference between the 250 and the 400
(actually 435). My selection was for the 250 and I am very happy with it
and actually see the 200 as being RARELY used if at all. It is narrow
enough that if the responding cw station is off frequency, you will NOT hear
them at all. I intend to add the 500 filter (actually 565) next.

Before you buy the 1.8, set your DSP to 1.8 and spend some time listening at
that width to see if you like it compared to the DSP setting of 2.1 to
decide between those two filters.

2.7, 1.8, 500, 250 and someday may also add a 1.0 filter. I may also have
to swap out my 1.8 for a 2.1 because of my damaged hearing.

73, de JIm KG0KP

----- Original Message -----
From: "DM4iM" <[hidden email]>
To: <[hidden email]>
Sent: Monday, December 28, 2009 2:24 PM
Subject: Re: [Elecraft] Filters for K3

> Elecrafters, thanks for all the input.
> I had many replies, personal mail or via the reflector.
>
> To sum it up:
>
> Matched filters are important for diversity.
>
> 8 votes for the 1.8khz, 4 for the 2.1 ssb filter for contesting.
> Some use the 1.8khz ssb filter for cw, with the dsp set to narrower
> bandwith. I think i will order one of those, it makes sense to use it
> for cw-operation on a quiet band and in ssb contests when things get
> rough.
>
> The 200hz and 250hz cw filters got an equal number of votes, you left me
> alone on this ;-)
>
> The expense on 2 matched 5 pole or 2 8-pole filters is about the same,
> so the criteria here is performance.
>
> May i call for a run-off?
>
> Thanks to all es HNY
>
> Martin
>
> --
>
> 73, DM4iM
> ______________________________________________________________
> 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
>

Arie Kleingeld PA3A-2

Re: Filters for K3

In reply to this post by Martin-2

Martin,

About the 2.7 filters and matching.

I have two of those and they do not match. I set the offset between the two
and they are now both 50 Hz off or so :-) . No need to worry about this. In
SSB you cannot hear any difference. (It will be a problem with the low
bandwidths so if you plan 200Hz 5-poles, then they MUST match. But we are
talking about the 2.7s now)

I think that you should choose on the filter characteristics, not on the
price. The price difference between two 2.8s and two 2.7s (matched or
unmatched) is peanuts compared to the K3-rigprice.

My choice were the 2.7s because they are actually wider than the 2.8s so I
can well listen AM broadcast stations and wide SSB with it, without
sacrificing much roofing-effect.

In the end, it is your choice.

73
Arie PA3A

-------------------------------------

<Snip>

The expense on 2 matched 5 pole or 2 8-pole filters is about the same,
so the criteria here is performance.

May i call for a run-off?
<snip>

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Joe Subich, W4TV-4

Re: Filters for K3

> I think that you should choose on the filter characteristics,
> not on the price. The price difference between two 2.8s and
> two 2.7s (matched or unmatched) is peanuts compared to the
> K3-rigprice.

Think again about the difference between two 2.8 KHz filters
vs. matched 2.7 KHz filters. The upgrade price on the 2.8
KHz filters are $109.95 EACH. The cost to match the 2.7 KHz
filters is $30.95. The $179.95 difference almost pays for
the 500/200 Hz pair if one uses 5-pole filters.

Yes, it's small difference in comparison to the overall cost
of the transceiver but by using 5-pole filters instead of the
8-pole filters and buying as a kit, one could add the 100W
amplifier or possibly KRX3 for the price of the factory built
version with 8-pole filters.

73,

... Joe, W4TV

> -----Original Message-----
> From: [hidden email]
> [mailto:[hidden email]] On Behalf Of Arie
> Kleingeld PA3A
> Sent: Tuesday, December 29, 2009 5:04 AM
> To: 'DM4iM'; [hidden email]
> Subject: Re: [Elecraft] Filters for K3
>
>
> Martin,
>
> About the 2.7 filters and matching.
>
> I have two of those and they do not match. I set the offset
> between the two and they are now both 50 Hz off or so :-) .
> No need to worry about this. In SSB you cannot hear any
> difference. (It will be a problem with the low bandwidths so
> if you plan 200Hz 5-poles, then they MUST match. But we are
> talking about the 2.7s now)
>
> I think that you should choose on the filter characteristics,
> not on the price. The price difference between two 2.8s and
> two 2.7s (matched or
> unmatched) is peanuts compared to the K3-rigprice.
>
> My choice were the 2.7s because they are actually wider than
> the 2.8s so I can well listen AM broadcast stations and wide
> SSB with it, without sacrificing much roofing-effect.
>
> In the end, it is your choice.
>
> 73
> Arie PA3A
>
>
>
> -------------------------------------
>
> <Snip>
>
> The expense on 2 matched 5 pole or 2 8-pole filters is about
> the same, so the criteria here is performance.
>
> May i call for a run-off?
> <snip>
>
>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
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Jim Brown-10

Re: Filters for K3

In reply to this post by hf4me

On Tue, 29 Dec 2009 01:23:42 -0600, Jim Miller KG0KP wrote:

>My selection was for the 250 and I am very happy with it
>and actually see the 200 as being RARELY used if at all. It is narrow
>enough that if the responding cw station is off frequency, you will NOT hear
>them at all.

Let's clarify a few things about these very narrow roofing filters. First,
when you install any roofing filter, you tell the K3 what bandwidth it is,
what slot it's in, and how much passband attenuation it has (so that the K3
can add gain to correct for it).

Second, as you operate, contesting or otherwise, a good operator will
constantly be readjusting bandwidth and RIT to respond to callers. My CW
roofer is 400 Hz, and I usually operate with an IF bandwidth of 250-350 Hz in
CW mode, so it is virtually always engaged. When the going gets rough,
whether because he's weak or there's QRM, I'll quickly narrow up the IF to
pull him out of the mud.

The time you want that 200 Hz roofer is when there's strong QRM within a few
hundred Hz of your frequency. This is a "5% of the time" filter, not a
general purpose filter. It's for the guy who's a serious contester, his rig
is bought and paid for, and he's got a few bucks laying around. The 400 Hz
and 500 Hz filters are good general use CW filters. When I bought my K3s, I
put the 400 Hz filters in the next to the last filter slots, figuring that
someday I might want the 200 Hz filters. And someday I still might. I sure
did Sunday morning, trying to copy JT1CO within 200 Hz of a Seattle area
station during the 160M Stew Perry contest.

73,

Jim K9YC

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Dave Hachadorian

Re: Filters for K3

In reply to this post by hf4me

----- Original Message -----
From: "Jim Miller KG0KP" <[hidden email]>
To: "DM4iM" <[hidden email]>; <[hidden email]>
Sent: Tuesday, December 29, 2009 7:23 AM
Subject: Re: [Elecraft] Filters for K3

> Before you buy the 1.8, set your DSP to 1.8 and spend some time
> listening at
> that width to see if you like it
------------------------------

When you set BW=1.8, set the FC at about 1.05. That's where most
people agree that SSB sounds best at that narrow bandwidth.

In practice, the best way to get to that BW and FC is by
normalizing, then putting the DSP controls into SHIFT/WIDTH mode
and adjusting only HI CUT. Use only as much HI CUT as the QRM
conditions require. Thanks to W0YK for that valuable tip.

I use the 1.8 on SSB, but I told the K3 that it was a 2.1, so it
cuts in when the DSP BW is reduced to 2.1 (by using HI CUT). The
1.8 filter sounds great at DSP BW=2.1. DSP BW can be reduced as
far as 1.5 if necessary, and SSB remains intelligible.

Dave Hachadorian, K6LL
Yuma, AZ

.

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David Gilbert

Re: Filters for K3

I agree that shifting the FC is very important when using narrow filters
on SSB. For a while Inrad was selling 1.5 KHz 8-pole filters for really
narrow SSB and I bought a pair for my K3. They work great as long as I
drop the FC down to 1.05 KHz.

In extreme cases I've even narrowed the DSP filter down to as low as 1.1
Khz and shifted FC to about 0.95, but that only works for some voices.

Which brings up another observation I've made ... for any given WIDTH,
the optimum FC for best intelligibility will be different depending upon
the characteristics of the voice you are trying to copy. I can go an
entire contest without changing the WIDTH, but I often adjust the SHIFT
to dig out a difficult one.

73,
Dave AB7E

Dave Hachadorian wrote:

>> Before you buy the 1.8, set your DSP to 1.8 and spend some time
>> listening at
>> that width to see if you like it
>>
> ------------------------------
>
> When you set BW=1.8, set the FC at about 1.05. That's where most
> people agree that SSB sounds best at that narrow bandwidth.
>
> In practice, the best way to get to that BW and FC is by
> normalizing, then putting the DSP controls into SHIFT/WIDTH mode
> and adjusting only HI CUT. Use only as much HI CUT as the QRM
> conditions require. Thanks to W0YK for that valuable tip.
>
> I use the 1.8 on SSB, but I told the K3 that it was a 2.1, so it
> cuts in when the DSP BW is reduced to 2.1 (by using HI CUT). The
> 1.8 filter sounds great at DSP BW=2.1. DSP BW can be reduced as
> far as 1.5 if necessary, and SSB remains intelligible.
>
> Dave Hachadorian, K6LL
> Yuma, AZ
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
> .
>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
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>
>

alorona

Re: Filters for K3

> Which brings up another observation I've made ... for any given WIDTH,
> the optimum FC for best intelligibility will be different depending upon
> the characteristics of the voice you are trying to copy.

> 73,
> Dave AB7E

The way IF SHIFT controls have worked on radios for decades now has been that, as you turn in one direction away from the center knob position, you are both narrowing the bandwidth *and* shifting the apparent center frequency (what the K3 calls "FC"). Since the K3 has separate controls for WIDTH and SHIFT this is not easily done without having to adjust two controls.

A workaround (to return to the old way of thinking about IF SHIFT) is to set up macros that give you the desired WIDTH and FC with one button push. In this way you can emulate, for example, what the K2 does with its four pre-set filter settings per mode.

Al W6LX
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Don Wilhelm-4

Re: Filters for K3

In reply to this post by David Gilbert

Dave and all,

Your observation is exactly the reason I use HI and LO CUT for SSB.
Typically one only needs to decrease HI CUT and the center frequency
takes care of itself. When the HI CUT gets so low that intelligibility
is beginning to decay, a slight change upward in LO CUT can improve
things, but normally LO CUT is a "set and forget" control for SSB - mine
normally stays at 0.15, 0.20 or 0.25.
Try it and I would wager that most of you struggling with the WIDTH and
SHIFT for SSB will never go back.

73,
Don W3FPR

David Gilbert wrote:

> I agree that shifting the FC is very important when using narrow filters
> on SSB. For a while Inrad was selling 1.5 KHz 8-pole filters for really
> narrow SSB and I bought a pair for my K3. They work great as long as I
> drop the FC down to 1.05 KHz.
>
> In extreme cases I've even narrowed the DSP filter down to as low as 1.1
> Khz and shifted FC to about 0.95, but that only works for some voices.
>
> Which brings up another observation I've made ... for any given WIDTH,
> the optimum FC for best intelligibility will be different depending upon
> the characteristics of the voice you are trying to copy. I can go an
> entire contest without changing the WIDTH, but I often adjust the SHIFT
> to dig out a difficult one.
>
> 73,
> Dave AB7E
>
>

N2TK

Re: Filters for K3

In reply to this post by alorona

Why not use HI Cut for SSB and WIDTH for CW. This way I find I usually do
not need to do anything with SHIFT for SSB.

N2TK, Tony

-----Original Message-----
From: [hidden email]
[mailto:[hidden email]] On Behalf Of Al Lorona
Sent: Tuesday, December 29, 2009 5:07 PM
To: Elecraft Reflector
Subject: Re: [Elecraft] Filters for K3

> Which brings up another observation I've made ... for any given WIDTH,
> the optimum FC for best intelligibility will be different depending upon
> the characteristics of the voice you are trying to copy.

> 73,
> Dave AB7E

The way IF SHIFT controls have worked on radios for decades now has been
that, as you turn in one direction away from the center knob position, you
are both narrowing the bandwidth *and* shifting the apparent center
frequency (what the K3 calls "FC"). Since the K3 has separate controls for
WIDTH and SHIFT this is not easily done without having to adjust two
controls.

A workaround (to return to the old way of thinking about IF SHIFT) is to set
up macros that give you the desired WIDTH and FC with one button push. In
this way you can emulate, for example, what the K2 does with its four
pre-set filter settings per mode.

Al W6LX
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Joe Subich, W4TV-4

Re: Filters for K3

In reply to this post by alorona

> The way IF SHIFT controls have worked on radios for decades
> now has been that, as you turn in one direction away from the
> center knob position, you are both narrowing the bandwidth
> *and* shifting the apparent center frequency (what the K3
> calls "FC").

It depends entirely on which brand of radio you were using
and how the manufacturer implemented IF shift and/or width.
The better radios did not have any interaction between the
two controls (like Elecraft). Only the designs that tried
to eliminate one of the two filters or failed to make the
local oscillator and BFO track bye the same amount (in
opposite directions) had interaction between shift and width.

73,

... Joe, W4TV

> -----Original Message-----
> From: [hidden email]
> [mailto:[hidden email]] On Behalf Of Al Lorona
> Sent: Tuesday, December 29, 2009 5:07 PM
> To: Elecraft Reflector
> Subject: Re: [Elecraft] Filters for K3
>
>
>
> > Which brings up another observation I've made ... for any
> given WIDTH,
> > the optimum FC for best intelligibility will be different
> depending upon
> > the characteristics of the voice you are trying to copy.
>
> > 73,
> > Dave AB7E
>
> The way IF SHIFT controls have worked on radios for decades
> now has been that, as you turn in one direction away from the
> center knob position, you are both narrowing the bandwidth
> *and* shifting the apparent center frequency (what the K3
> calls "FC"). Since the K3 has separate controls for WIDTH and
> SHIFT this is not easily done without having to adjust two controls.
>
> A workaround (to return to the old way of thinking about IF
> SHIFT) is to set up macros that give you the desired WIDTH
> and FC with one button push. In this way you can emulate, for
> example, what the K2 does with its four pre-set filter
> settings per mode.
>
> Al W6LX ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
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alorona

Re: Filters for K3

> It depends entirely on which brand of radio you were using
> and how the manufacturer implemented IF shift and/or width.

Originally, IF shift was defined as moving one IF passband within another IF passband, making the resulting passband the intersection (not the union) of the two passbands.

When you do that, you effectively reduce the width *and* the center frequency of the IF passband... it has nothing to do with manufacturers failing to make it work correctly.

Take two pieces of paper and cut a square in each. Hold them up to a window, and slide one square horizontally across the other one, and note how the width *and* center of the opening shifts left or right. This is what I mean when I say, "IF shift". We might be talking about two different things.

Regards,

Al W6LX
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Don Wilhelm-4

Re: Filters for K3

Al,

As has been pointed out - the K3 does it a bit differently because you
can control both the width and the shift.
For the K3, the width remains constant (whatever you set it at), and the
shift moves that entire passband higher or lower.
In the K3 it is no as you describe, but for transceivers with fixed
width filters (and Pre-DSP filters), the way you described it is how
they work

73,
Don W3FPR

Al Lorona wrote:

>> It depends entirely on which brand of radio you were using
>> and how the manufacturer implemented IF shift and/or width.
>>
>
> Originally, IF shift was defined as moving one IF passband within another IF passband, making the resulting passband the intersection (not the union) of the two passbands.
>
> When you do that, you effectively reduce the width *and* the center frequency of the IF passband... it has nothing to do with manufacturers failing to make it work correctly.
>
> Take two pieces of paper and cut a square in each. Hold them up to a window, and slide one square horizontally across the other one, and note how the width *and* center of the opening shifts left or right. This is what I mean when I say, "IF shift". We might be talking about two different things.
>
> Regards,
>
> Al W6LX
>
>

Joe Subich, W4TV-4

Re: Filters for K3

In reply to this post by alorona

> Originally, IF shift was defined as moving one IF passband
> within another IF passband, making the resulting passband the
> intersection (not the union) of the two passbands.

Again, you are incorrect. Drake implemented a shift control long
before any of the Japanese imports and its shift moved the entire
passband without changing the width. Width was controlled
separately, in discrete steps.

Many of Yaesu's transceivers ... going back to the 1970's ...
also had independent shift and width controls. Even today
the FT-1000D, FT-1000MP, Mark V, FT-2000, FT-9000, etc. have
width and shift controls that are independent and behave
exactly like the K3 in Width/shift mode.

It was only when Kenwood eliminated the third filter and
failed to link the mixers that shift/width became effectively
a high cut or low cut filter.

Like so many other features of the radio, what you prefer
depends on what you first used. For me, the current Elecraft
design is the right way to do shift and width. Even better,
I can select independent shift and width for CW and digital
operation or high/low cut for SSB operation at the press of
the encoder (or if I select 10 Hz steps for shift the behavior
can change automatically as I change between voice and CW/data
modes).

73,

... Joe, W4TV

> -----Original Message-----
> From: [hidden email]
> [mailto:[hidden email]] On Behalf Of Al Lorona
> Sent: Tuesday, December 29, 2009 6:18 PM
> To: Elecraft Reflector
> Subject: Re: [Elecraft] Filters for K3
>
>
> > It depends entirely on which brand of radio you were using
> > and how the manufacturer implemented IF shift and/or width.
>
> Originally, IF shift was defined as moving one IF passband
> within another IF passband, making the resulting passband the
> intersection (not the union) of the two passbands.
>
> When you do that, you effectively reduce the width *and* the
> center frequency of the IF passband... it has nothing to do
> with manufacturers failing to make it work correctly.
>
> Take two pieces of paper and cut a square in each. Hold them
> up to a window, and slide one square horizontally across the
> other one, and note how the width *and* center of the opening
> shifts left or right. This is what I mean when I say, "IF
> shift". We might be talking about two different things.
>
> Regards,
>
> Al W6LX ______________________________________________________________
> 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

alorona

Re: Filters for K3

In reply to this post by Don Wilhelm-4

> Al,

> As has been pointed out - the K3 does it a bit differently because you can control both the width and the shift.

> 73,
> Don W3FPR

Hi, Don!

Right, this is what I've been trying to say, but saying it poorly, apparently!

K3's SHIFT and WIDTH controls, being separate controls, do *not* do what I have been calling "IF shift" as implemented in old radios.

That being the case, if what one wants is the old-style IF shift, or for example to use the controls as Dave AB7E described, one has to adjust two controls. In the heat of battle, you may find it advantageous to have a single control do both. That's all I'm saying.

Here is a possible macro to emulate the old-style IF shift:

SHIFTDN = BW0200;IS 1000;
or
SHIFTUP = BW0190;IS 1550;

This will narrow the bandwidth and do the shift, much like the old-style IF shift. These macros could be useful in a contest situation where you need to immediately change the passband to eliminate QRM while copying an exchange. The undo of these macros is something like:

UNSHIFT = BW0240;IS 9999;

Regards,

Al W6LX
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Merv Schweigert

Re: Filters for K3

In reply to this post by Joe Subich, W4TV-4

Drake?? What about Collins and the 75A4 that had a fine shift
control on the front panel, done mechanically/electrically but was
well before Drake had a radio.. Width was controlled by filters.
Merv KH7C

>> Originally, IF shift was defined as moving one IF passband
>> within another IF passband, making the resulting passband the
>> intersection (not the union) of the two passbands.
>>
>
> Again, you are incorrect. Drake implemented a shift control long
> before any of the Japanese imports and its shift moved the entire
> passband without changing the width. Width was controlled
> separately, in discrete steps.
>
> Many of Yaesu's transceivers ... going back to the 1970's ...
> also had independent shift and width controls. Even today
> the FT-1000D, FT-1000MP, Mark V, FT-2000, FT-9000, etc. have
> width and shift controls that are independent and behave
> exactly like the K3 in Width/shift mode.
>
> It was only when Kenwood eliminated the third filter and
> failed to link the mixers that shift/width became effectively
> a high cut or low cut filter.
>
> Like so many other features of the radio, what you prefer
> depends on what you first used. For me, the current Elecraft
> design is the right way to do shift and width. Even better,
> I can select independent shift and width for CW and digital
> operation or high/low cut for SSB operation at the press of
> the encoder (or if I select 10 Hz steps for shift the behavior
> can change automatically as I change between voice and CW/data
> modes).
>
> 73,
>
> ... Joe, W4TV
>
>
>
>
>
>> -----Original Message-----
>> From: [hidden email]
>> [mailto:[hidden email]] On Behalf Of Al Lorona
>> Sent: Tuesday, December 29, 2009 6:18 PM
>> To: Elecraft Reflector
>> Subject: Re: [Elecraft] Filters for K3
>>
>>
>>
>>> It depends entirely on which brand of radio you were using
>>> and how the manufacturer implemented IF shift and/or width.
>>>
>> Originally, IF shift was defined as moving one IF passband
>> within another IF passband, making the resulting passband the
>> intersection (not the union) of the two passbands.
>>
>> When you do that, you effectively reduce the width *and* the
>> center frequency of the IF passband... it has nothing to do
>> with manufacturers failing to make it work correctly.
>>
>> Take two pieces of paper and cut a square in each. Hold them
>> up to a window, and slide one square horizontally across the
>> other one, and note how the width *and* center of the opening
>> shifts left or right. This is what I mean when I say, "IF
>> shift". We might be talking about two different things.
>>
>> Regards,
>>
>> Al W6LX ______________________________________________________________
>> 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
>
>