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need some roofing filter advice?

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callen1155

need some roofing filter advice?

Sorry to do this to you guys but .....

I need some roofing filter advice:)

Currently I only have the stock 2.7K filter and it has worked fine for casual rag chewing and some dx'ing.
I've been operating my K3 for over a year and it seems I don't have any strong signals near me creating problems.

Over time my interests have changed and now I'm pursuing primarily cw dx'ing on 160 and 80 (lots of weak signals).

I'm attempting to fill out my 'elecraft cart' to purchase the second receiver and am stuck on the filter choices.

I can't afford lots of roofing filters so I'm thinking of going with one cw filter on both main and sub (for diversity receive capability).

It seems the 250 or 200 may be too limited in application so given the above would you suggest the 400 Hz 8 pole or the matching 500 Hz 5 pole filters?

thanks for any advice.
chuck
af4xk

Matt Zilmer

Re: need some roofing filter advice?

Chuck,

I'd go with the 250 Hz 8-pole. It's fine for PSK31 as well as CW and
keeps the in-band blocking to almost nothing.

I have one in both receivers, and it's really surprising what one can
do with it.

73,
matt W6NIA

On Wed, 13 Jul 2011 17:01:44 -0700 (PDT), you wrote:

>
>Sorry to do this to you guys but .....
>
>I need some roofing filter advice:)
>
>Currently I only have the stock 2.7K filter and it has worked fine for
>casual rag chewing and some dx'ing.
>I've been operating my K3 for over a year and it seems I don't have any
>strong signals near me creating problems.
>
>Over time my interests have changed and now I'm pursuing primarily cw dx'ing
>on 160 and 80 (lots of weak signals).
>
>I'm attempting to fill out my 'elecraft cart' to purchase the second
>receiver and am stuck on the filter choices.
>
>I can't afford lots of roofing filters so I'm thinking of going with one cw
>filter on both main and sub (for diversity receive capability).
>
>It seems the 250 or 200 may be too limited in application so given the above
>would you suggest the 400 Hz 8 pole or the matching 500 Hz 5 pole filters?
>
>thanks for any advice.
>chuck
>af4xk

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Jim Brown-10

Re: need some roofing filter advice?

In reply to this post by callen1155

On 7/13/2011 5:01 PM, callen1155 wrote:
> I need some roofing filter advice:)

Since your interest is weak signal CW but not contesting and you don't
have neighbors blowing away your radio, a roofing filter is not a
particularly high priority for you. Instead, I would concentrate on the
best RX antenna(s) you can rig, and buy the sub-RX when you can so that
you can use it in diversity mode.

If you DO decide to buy a roofer for CW, I'd go with the 250 Hz filter,
because you can cascade it with the IF filter when the going gets rough.

73, Jim K9YC
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Barry N1EU

Re: need some roofing filter advice?

In reply to this post by callen1155

callen1155 wrote

It seems the 250 or 200 may be too limited in application so given the above would you suggest the 400 Hz 8 pole or the matching 500 Hz 5 pole filters?

I disagree. I have switched to full-time use of 200hz 5-pole filters in both receivers for cw, configured as 300hz bandwidth in CONFIG menu. My width is typically set at 300hz. For contesting (running and S&P) and 160M dx'ing, this works exceptionally well for me and I feel no need for a wider cw roofing filter.

73, Barry N1EU

Nr4c

Re: need some roofing filter advice?

In reply to this post by callen1155

Chuck,

I'm certainly no expert. But, I was facing the same delema, which
filters to buy. I have my main rec filled with 6, 2.8, 1.8,400 and 200
filters. When I recently added the sub-rec, I only bought the 2.8 and
200. So far, I've been pleased.

Good luck, you'll get a lot of comments on this one.

...bill nr4c

On Wed, 13 Jul 2011 17:01:44 -0700 (PDT), callen1155 wrote:

> Sorry to do this to you guys but .....
>
> I need some roofing filter advice:)
>
> Currently I only have the stock 2.7K filter and it has worked fine
> for
> casual rag chewing and some dx'ing.
> I've been operating my K3 for over a year and it seems I don't have
> any
> strong signals near me creating problems.
>
>>
> I'm attempting to fill out my 'elecraft cart' to purchase the second
> receiver and am stuck on the filter choices.
>
> I can't afford lots of roofing filters so I'm thinking of going with
> one cw
> filter on both main and sub (for diversity receive capability).
>
> It seems the 250 or 200 may be too limited in application so given
> the above
> would you suggest the 400 Hz 8 pole or the matching 500 Hz 5 pole
> filters?
>
> thanks for any advice.
> chuck
> af4xk
>

Bill W4ZV

Re: need some roofing filter advice?

In reply to this post by Barry N1EU

callen1155 wrote

It seems the 250 or 200 may be too limited in application so given the above would you suggest the 400 Hz 8 pole or the matching 500 Hz 5 pole filters?

Barry N1EU wrote

I disagree. I have switched to full-time use of 200hz 5-pole filters in both receivers for cw, configured as 300hz bandwidth in CONFIG menu. My width is typically set at 300hz. For contesting (running and S&P) and 160M dx'ing, this works exceptionally well for me and I feel no need for a wider cw roofing filter.

Yes and no. Perhaps in extremely crowded contests but maybe not for more casual operating or on sparsely populated bands.

However, when used in conjunction with an accurate waterfall (e.g. Skimmer's decoder dots), even <200 Hz BW would work. Skimmer can be calibrated to automatically jump the K3 within 10 Hz of any signal with no additional tuning needed. This is why I suggested yesterday for my pileup macro to add some XIT to the K3 so that you don't zero beat everyone else calling. :-)

Notice how close the tones are as I automatically jump up the band with the mouse wheel in the video below. This allows using very narrow filters in the K3, even when tuning a sparsely populated band. The P3 should also work for this but it will depend on how accurately you can manually place the "QSY" cursor on the signal of interest.

http://www.youtube.com/watch?v=uZDXuOgUQJ0

73, Bill

Barry N1EU

Re: need some roofing filter advice?

Bill W4ZV wrote

Barry N1EU wrote

I disagree. I have switched to full-time use of 200hz 5-pole filters in both receivers for cw, configured as 300hz bandwidth in CONFIG menu. My width is typically set at 300hz. For contesting (running and S&P) and 160M dx'ing, this works exceptionally well for me and I feel no need for a wider cw roofing filter.

Yes and no. Perhaps in extremely crowded contests but maybe not for more casual operating or on sparsely populated bands.

For more casual operating or on sparsely populated bands, the 1.8Khz filters do just fine for me. After all, it's 95% dsp.

I find the advantages of the narrow roofing filter greatly outweigh any minor advantage of having a wider cw passband in contests. When running, they protect me from offending neighbors who would have otherwise ran me off my run freq, which occurs a few times in EVERY contest - far outweighs the one or two off frequency callers I might have missed. And in S&P, the narrow filters allow me to hear that weak signal right next to that s9+ running station and give me those dx mults in 160M contests.

I removed the 500hz filter pair that I used to also have installed.

Different strokes . . . .

73, Barry N1EU

Joe Subich, W4TV-4

Re: need some roofing filter advice?

> I removed the 500hz filter pair that I used to also have installed.

1.8 KHz and 200 Hz may be fine if you don't do any RTTY. However, for
either RTTY DX or contesting, you will want 500 Hz, "400 Hz" or "250
Hz" (370 Hz) filters.

73,

... Joe, W4TV

On 7/14/2011 9:29 AM, Barry N1EU wrote:

>
> Bill W4ZV wrote:
>>
>>
>> Barry N1EU wrote:
>>>
>>> I disagree. I have switched to full-time use of 200hz 5-pole filters in
>>> both receivers for cw, configured as 300hz bandwidth in CONFIG menu. My
>>> width is typically set at 300hz. For contesting (running and S&P) and
>>> 160M dx'ing, this works exceptionally well for me and I feel no need for
>>> a wider cw roofing filter.
>>>
>> Yes and no. Perhaps in extremely crowded contests but maybe not for more
>> casual operating or on sparsely populated bands.
>>
>
> For more casual operating or on sparsely populated bands, the 1.8Khz filters
> do just fine for me. After all, it's 95% dsp.
>
> I find the advantages of the narrow roofing filter greatly outweigh any
> minor advantage of having a wider cw passband in contests. When running,
> they protect me from offending neighbors who would have otherwise ran me off
> my run freq, which occurs a few times in EVERY contest - far outweighs the
> one or two off frequency callers I might have missed. And in S&P, the
> narrow filters allow me to hear that weak signal right next to that s9+
> running station and give me those dx mults in 160M contests.
>
> I removed the 500hz filter pair that I used to also have installed.
>
> Different strokes . . . .
>
> 73, Barry N1EU
>
> --
> View this message in context: http://elecraft.365791.n2.nabble.com/need-some-roofing-filter-advice-tp6581353p6583241.html
> Sent from the Elecraft mailing list archive at Nabble.com.
> ______________________________________________________________
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callen1155

Re: need some roofing filter advice?

This post was updated on .

CONTENTS DELETED

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callen1155

Re: need some roofing filter advice?

This post was updated on .

Thanks for all the comments gentlemen.

Regarding the RX antenna, I've been reading lots lately on the subject trying to figure what will work given my pathetic QTH space limitations and HOA restrictions.
Quite a challenge indeed. In fact, more of a challenge than I'd like. I may have to be content with WAS on 80m rather than true dx'ing on 160. Time will tell.

Regarding contesting, as I reflect on my antenna situation I may have to take contesting more seriously and participate just to get some decent contacts and increase the qso count on 80/160. Odds are probably greater that I'll snag some real dx during those events. Living rear Raleigh, I'd be surprised if some big signal guys aren't near me that are contesters. So maybe a narrower filter is the way to go?

And as far as roofing filters, it would be nice if there was a questionnaire with 50 questions that would just spit out the recommended configuration based on the answers. But that's dreaming. I might just have to flip a three sided coin.

But I do appreciate all the feedback.

73.
chuck
AF4XK

Robby.VY2SS

Re: need some roofing filter advice?

In reply to this post by callen1155

Hi Chuck,

I was faced with the same questions last winter when I added the second RX.

There was some concern that diversity reception would suffer if the two recievers were not filtered exactly the same. Since I considered diversity reception to be a bit of a gimmick I went with just two filters. The 2.7 5-pole that is included and an 8-pole 400hz filter. My main RX has 2.7, 1.8, 500 and 250 filters, all 8 pole except the 2.7.

A few months later I discovered that I had been wrong about diversity reception. It is actually amazing and it works great with my filter combination.

If you are working CW DX, you will be listening on the subRX and I find it useful to open the subRX up as much as 600 or 700 hz on some pileups so I hear more in the right ear and the narrow filter on the DX in my left ear. Team that up with the P3 and you are gonna be happy.

I got my 8-pole 500hz filter directly from INRad.

73,

-Robby
VY2SS

wa9fvp

Re: need some roofing filter advice?

In reply to this post by callen1155

I owned 5 transceivers in my lifetime and I purchased a narrow (1.8) SSB filter for only one. It was a total wast of money. For me the filter was too narrow for voice communications and if a nearby station was too close the splatter and the narrow passband made the situation worse. When I ordered my K3 I kept the stock 2.7/5 pole filter. I ordered the 250, 500, 6KHz and 13KHz (FM) filters.

Jack WA9FVP

Sent from my home-brew I5 Core PC

Frederick Atchley

Re: need some roofing filter advice?

In reply to this post by callen1155

Jack wrote: I owned 5 transceivers in my lifetime and I purchased a narrow
(1.8) SSB

filter for only one. It was a total wast of money. For me the filter was

too narrow for voice communications and if a nearby station was too close

the splatter and the narrow passband made the situation worse.

<END SNIP>

I have both the 2.1 and the 1.8 filters. They make the difference when there
is a big contest underway.

The secret is to use the "LO --- HI" adjustments together to "fit" the best
audio within the envelope. Its awesome how you can increase the
intelligibility while at the same time minimize unwanted adjacent signals.
Of course, there is nothing you can do about a strong signal right on you
frequency but that's not the fault of the 1.8 filter bandwidth.

73, Fred

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Ed Muns, W0YK

Re: need some roofing filter advice?

In reply to this post by wa9fvp

The K3 is entirely different. I've been operating SSB with a 1.5 kHz
bandwidth for three years now and it is perfectly intelligible. On prior
radios, though, I couldn't even get a 2.1 kHz filter to sound intelligible
enough to be useful. I think the difference is where the filter is located
relative to the signal. In the K3, narrow filtering on SSB sounds best if
you simply reduce the HI CUT to get the desired bandwidth. If you first
reduce the WIDTH, then you have to also adjust SHIFT to optimize
intelligibility. (Note the word "intelligibility", not "high fidelity", the
emphasis being on communication and the ability to copy.)

You don't need to buy a crystal filter to try narrow SSB bandwidths. Just
use the DSP HI CUT control. If you find a narrow SSB bandwidth you like to
use regularly, AND also you need to protect the IF from very strong nearby
signals, then consider a crystal filter of the appropriate bandwidth, ahead
of the DSP.

Ed - W0YK

Jack, WA9FVP, wrote:

> I owned 5 transceivers in my lifetime and I purchased a
> narrow (1.8) SSB
> filter for only one. It was a total wast of money. For me
> the filter was
> too narrow for voice communications and if a nearby station
> was too close
> the splatter and the narrow passband made the situation
> worse. When I
> ordered my K3 I kept the stock 2.7/5 pole filter. I ordered
> the 250, 500, 6KHz and 13KHz (FM) filters.

Don Wilhelm-4

Re: need some roofing filter advice?

Ed is entirely correct.
Those who attempt to manipulate the shift and width to obtain an
intelligible response on SSB are creating more trouble than it is worth.

For maximum voice intelligibility, the low frequency corner of the
filter must remain at 300 Hz (or slightly lower). The high frequency
end can be cut drastically and the signal will still be intelligible.

Try it - set the Lo Cut to 250 or 300 Hz, and then reduce the HI-Cut to
narrow the bandwidth. You can achieve a very narrow bandwidth and still
maintain intelligibility.

I have been setting K2 SSB filters to achieve that same result for a
very long time. Cut the highs, but leave the lows in place, and you can
use a filter as narrow as 1500 Hz (or less) with excellent results.

73,
Don W3FPR

On 7/19/2011 9:51 PM, Ed Muns wrote:

> The K3 is entirely different. I've been operating SSB with a 1.5 kHz
> bandwidth for three years now and it is perfectly intelligible. On prior
> radios, though, I couldn't even get a 2.1 kHz filter to sound intelligible
> enough to be useful. I think the difference is where the filter is located
> relative to the signal. In the K3, narrow filtering on SSB sounds best if
> you simply reduce the HI CUT to get the desired bandwidth. If you first
> reduce the WIDTH, then you have to also adjust SHIFT to optimize
> intelligibility. (Note the word "intelligibility", not "high fidelity", the
> emphasis being on communication and the ability to copy.)
>
> You don't need to buy a crystal filter to try narrow SSB bandwidths. Just
> use the DSP HI CUT control. If you find a narrow SSB bandwidth you like to
> use regularly, AND also you need to protect the IF from very strong nearby
> signals, then consider a crystal filter of the appropriate bandwidth, ahead
> of the DSP.
>
> Ed - W0YK
>

Bill W4ZV

Re: need some roofing filter advice?

In reply to this post by Ed Muns, W0YK

Ed Muns, W0YK wrote

The K3 is entirely different. I've been operating SSB with a 1.5 kHz
bandwidth for three years now and it is perfectly intelligible. On prior
radios, though, I couldn't even get a 2.1 kHz filter to sound intelligible
enough to be useful. I think the difference is where the filter is located
relative to the signal.

The K3 is not actually different or it would be violating the laws of physics. To make ANY radio work using narrow bandwidths on SSB is simply a matter of optimizing the placement of the filter passband in the voice spectrum (as Ed states above). The FT-1000MP, K2, Orion and many others can be made to work with narrow filters. I first discovered this on an MP I used in the late 90s:

http://www.va3cr.net/va3cr2.net/markv/Troubleshooting/Filters.htm

73, Bill

Ed Muns, W0YK

Re: need some roofing filter advice?

What's "different" about the K3 is its outstanding usability. With a single
front panel control, HI CUT, any SSB bandwidth can be quickly dialed in,
maintaining optimum intelligibility. With the few prior generation radios I
tried narrow SSB filtering on, there were obscure menu settings and/or IF
controls that were much more complicated to set for the same result. Some
users never figured out the appropriate settings and thus concluded it
didn't work.

Ed - W0YK

Bill, W4ZV, wrote:
> The K3 is not actually different or it would be violating the
> laws of physics. To make ANY radio work using narrow
> bandwidths on SSB is simply a matter of optimizing the
> placement of the filter passband in the voice spectrum (as Ed
> states above). The FT-1000MP, K2, Orion and many others can
> be made to work with narrow filters. I first discovered this
> on an MP I used in the late 90s:
>
> http://www.va3cr.net/va3cr2.net/markv/Troubleshooting/Filters.htm

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Iain MacDonnell - N6ML-2

Re: need some roofing filter advice?

Personally, I leave mine set at 1800 width, 1050 shift (the net effect
of dialing the HI-cut down until the the width is 1800) all the time,
and SSB sounds fine to me. I haven't touched those controls in SSB
mode in a long time. I may be missing out on some benefit of fiddling
with it. I generally only use SSB for DXing and some contesting, so
"fidelity" isn't an issue!

73,

~iain / N6ML

On Wed, Jul 20, 2011 at 4:44 PM, Ed Muns <[hidden email]> wrote:

> What's "different" about the K3 is its outstanding usability. With a single
> front panel control, HI CUT, any SSB bandwidth can be quickly dialed in,
> maintaining optimum intelligibility. With the few prior generation radios I
> tried narrow SSB filtering on, there were obscure menu settings and/or IF
> controls that were much more complicated to set for the same result. Some
> users never figured out the appropriate settings and thus concluded it
> didn't work.
>
> Ed - W0YK
>
> Bill, W4ZV, wrote:
>> The K3 is not actually different or it would be violating the
>> laws of physics. To make ANY radio work using narrow
>> bandwidths on SSB is simply a matter of optimizing the
>> placement of the filter passband in the voice spectrum (as Ed
>> states above). The FT-1000MP, K2, Orion and many others can
>> be made to work with narrow filters. I first discovered this
>> on an MP I used in the late 90s:
>>
>> http://www.va3cr.net/va3cr2.net/markv/Troubleshooting/Filters.htm
>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
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> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>

Ed Muns, W0YK

Re: need some roofing filter advice?

I "fiddled" with HI CUT a lot at first, to determine how narrow I could go
and still maintain excellent intelligibility. Once I settled on 1500 Hz, I
asked INRAD to make some 1500 Hz roofing filters (actually about 1600 Hz)
for contest work. Like you, my SSB bandwidth (DSP: 1500 Hz, crystal filter:
1600 Hz) hasn't been touched for three years.

Ed - W0YK

Iain, N6ML, commented:
> Personally, I leave mine set at 1800 width, 1050 shift (the
> net effect of dialing the HI-cut down until the the width is
> 1800) all the time, and SSB sounds fine to me. I haven't
> touched those controls in SSB mode in a long time. I may be
> missing out on some benefit of fiddling with it. I generally
> only use SSB for DXing and some contesting, so "fidelity"
> isn't an issue!

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Bill W4ZV

Re: need some roofing filter advice?

In reply to this post by Ed Muns, W0YK

Ed Muns, W0YK wrote

What's "different" about the K3 is its outstanding usability. With a single
front panel control, HI CUT, any SSB bandwidth can be quickly dialed in,
maintaining optimum intelligibility. With the few prior generation radios I
tried narrow SSB filtering on, there were obscure menu settings and/or IF
controls that were much more complicated to set for the same result. Some
users never figured out the appropriate settings and thus concluded it
didn't work.

Ten-Tec's Orion had exactly the same setup (HI/LO CUT and SHIFT/WIDTH) over 4 years before the K3 was introduced, but I don't think Ten-Tec was the first with this idea. In fact my ~30 year old TS-930S had something very similar (HI/LO CUT and VBT for CW...but no SHIFT). Nothing wrong with duplicating a good idea it's definitely not unique to the K3.

73, Bill