Re: [Elecraft] KFL3C-400 offset?

[Bob McGraw K4TAX]

Grant et al;

I can agree that many hams do not understand the application of 
"filters" in a radio, specially today with the advancements in DSP 
technology.  I find today that many many hams rely on "old school 
methodology" to justify what they do.  They, for the most part, seem to 
shy away from learning and understanding how things work today.   Times 
have changed.   In fact I see more and more the adage of  "what someone 
said" taking precedence.


The roofing filter concept protects the AGC, just as the DSP provides 
the selectivity.    For strong signal operations one should have both.  
But in many cases in our normal QTH environments, little is to be gained 
with added roofing filters.


This is a slide presentation from Sherwood Engineering on FILTERS, why 
and why not. http://www.sherweng.com/documents/Barc2008.pdf



I'll take his word for it.   It is well worth the read.

73

Bob, K4TAX


On 2/27/2019 12:22 PM, Grant Youngman wrote:

Just an opine.  Since these are ROOFING filters, and not the means of 
determining the radio’s ultimate selectivity, you may not notice a substantial 
performance improvement of the radio with 8-pole vs 6-pole filters.

I have my flame suit on, just in case — (it can be almost guaranteed to be 
needed around here).  :-)

Grant NQ5T
K3 #2091 KX3 #8342
.qsl.net/donate.html

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Re: [Elecraft] KFL3C-400 offset?

[Grant Youngman]

Just an opine.  Since these are ROOFING filters, and not the means of 
determining the radio’s ultimate selectivity, you may not notice a substantial 
performance improvement of the radio with 8-pole vs 6-pole filters.

I have my flame suit on, just in case — (it can be almost guaranteed to be 
needed around here).  :-)

Grant NQ5T
K3 #2091 KX3 #8342

> On Feb 27, 2019, at 12:33 PM, Carl Jón Denbow  wrote:
> 
> To put a wrapper on this thread: I ended up ordering two 400Hz filter direct 
> from Inrad.  They had them clearly marked as eight pole and said they were 
> mount-compatible with the K3.   I had email exchanges with K3 support, most 
> of which were helpful, but the question about a KFL3C-400 eight-pole filter 
> went unanswered.  They seem to have a problem in this area.  Not exactly sure 
> why.  Uncharacteristic.   So, I have two 6-pole 400Hz filters for sale!  You 
> can find an ad for them on qth.com: 
> https://swap.qth.com/search-results.php?keywords=n8vz=call
> 

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Re: [Elecraft] KFL3C-400 offset?

[Carl Jón Denbow]

To put a wrapper on this thread: I ended up ordering two 400Hz filter direct 
from Inrad.  They had them clearly marked as eight pole and said they were 
mount-compatible with the K3.   I had email exchanges with K3 support, most of 
which were helpful, but the question about a KFL3C-400 eight-pole filter went 
unanswered.  They seem to have a problem in this area.  Not exactly sure why.  
Uncharacteristic.   So, I have two 6-pole 400Hz filters for sale!  You can find 
an ad for them on qth.com: 
https://swap.qth.com/search-results.php?keywords=n8vz=call

73,

Carl
N8VZ

-- Original Message --
From: "Carl Jón Denbow" 
To: j...@kk9a.com
Cc: elecraft@mailman.qth.net
Sent: 2/23/2019 7:39:03 PM
Subject: Re: [Elecraft] KFL3C-400 offset?

> Thanks, I’ll check that out also.
>  
> Sent from my iPhone
> ===
> Carl Jón Denbow, N8VZ
> 17 Coventry Lane
> Athens, Ohio 45701-3718
>  
> c...@n8vz.com
> www.n8vz.com
> EM89wh
>  
> IRLP 4533 Echolink 116070
>  
> PSK and JT65 Forever!
> ===
>  
>> On Feb 23, 2019, at 6:10 PM,   wrote:
>>  
>> I have noticed that also. Luckily I remember which filters are 8 pole but
>> the website really should specify.
>>  
>> N8VZ may also try contacting Inrad. Scott may answer on weekends?
>>  
>> John KK9A
>>  
>>  
>>  
>> Dave WW2R wrote
>>  
>>  
>> The "previous" web site used to implicitly say which filters were 5 pole and
>> which were 8 pole on the ordering page. The new "improved?" website omits
>> this information. Looking to answer the same question recently I had to
>> resort to looking elsewhere on the web!
>>  
>> Dave
>> Ww2r
>>  
>> __
>> Elecraft mailing list
>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
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>  
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Re: [Elecraft] KFL3C-400 offset?

[Nr4c]

I think Elecraft altered their filter array recently ( maybe 1-2 years) and 
maybe the order page hasn’t caught up. I believe they discontinued some and 
added some 6-pole filters. I think that is what you have. 

Sent from my iPhone
...nr4c. bill


> On Feb 23, 2019, at 3:36 PM, Carl Jón Denbow  wrote:
> 
> Bill, 
> 
> Thanks for your response.  This filter, unlike the others, is exposed and 
> there are six crystal cans.  Does this mean it’s a five-pole?  I was sure I 
> ordered an eight-pole filter?  When I do a search on the KFL3C-400 everything 
> I see indicates it’s an eight-pole filter.  Are there two types of KFL3C-400 
> filters?  As you can see I’m still confused.
> 
> 73,  
> 
> Carl
> 
> Sent from my iPhone
> ===
> Carl Jón Denbow, N8VZ
> 17 Coventry Lane
> Athens, Ohio 45701-3718
>  
> c...@n8vz.com
> www.n8vz.com
> EM89wh
>  
> IRLP 4533   Echolink 116070
>  
> PSK and JT65 Forever!
> ===
> 
>> On Feb 23, 2019, at 2:41 PM, Nr4c  wrote:
>> 
>> Is your filter in a metal can. Eight pole filters used to be in a can. Five 
>> pole filters were exposed parts. If the later, count the crystal cans. 
>> Should be 5, 6, or 8. 
>> 
>> Sent from my iPhone
>> ...nr4c. bill
>> 
>> 
>>> On Feb 23, 2019, at 1:44 PM, Carl-N8VZ  wrote:
>>> 
>>> I’m assembling a KRX3 second receiver for my K3.  One of the filters I’m
>>> installing is a KFL3C-400.  When I ordered it, the order form said it was an
>>> 8-pole filter.  I purposely only ordered 8-pole filters.  It was my
>>> understanding that 8-pole filters have no offsets to worry about.  Why,
>>> then, does the KFL3C-400 have an offset (-0.79) listed on the filter when
>>> the others do not?  I’m confused.  Can someone clarify this for me?  73 de
>>> Carl N8VZ
>>> 
>>> 
>>> 
>>> --
>>> Sent from: http://elecraft.365791.n2.nabble.com/
>>> __
>>> Elecraft mailing list
>>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
>>> Help: http://mailman.qth.net/mmfaq.htm
>>> Post: mailto:Elecraft@mailman.qth.net
>>> 
>>> This list hosted by: http://www.qsl.net
>>> Please help support this email list: http://www.qsl.net/donate.html
>> 
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Re: [Elecraft] KFL3C-400 offset?

[Carl Jón Denbow]

Thanks, I’ll check that out also. 

Sent from my iPhone
===
Carl Jón Denbow, N8VZ
17 Coventry Lane
Athens, Ohio 45701-3718
 
c...@n8vz.com
www.n8vz.com
EM89wh
 
IRLP 4533   Echolink 116070
 
PSK and JT65 Forever!
===

> On Feb 23, 2019, at 6:10 PM,   wrote:
> 
> I have noticed that also. Luckily I remember which filters are 8 pole but
> the website really should specify.
> 
> N8VZ may also try contacting Inrad. Scott may answer on weekends?
> 
> John KK9A
> 
> 
> 
> Dave WW2R wrote
> 
> 
> The "previous" web site used to implicitly say which filters were 5 pole and
> which were 8 pole on the ordering page. The new "improved?" website omits
> this information. Looking to answer the same question recently I had to
> resort to looking elsewhere on the web!
> 
> Dave
> Ww2r
> 
> __
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
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Re: [Elecraft] KFL3C-400 offset?

[Carl Jón Denbow]

Good advice, Mark.  I’ll do that on Monday.  I’m happy to see that I’m not the 
only one confused by this. I really only want to use eight-pole filters in both 
main and sub receivers.  73 de Carl

Sent from my iPhone
===
Carl Jón Denbow, N8VZ
17 Coventry Lane
Athens, Ohio 45701-3718
 
c...@n8vz.com
www.n8vz.com
EM89wh
 
IRLP 4533   Echolink 116070
 
PSK and JT65 Forever!
===

> On Feb 23, 2019, at 5:31 PM, Mark Musick  wrote:
> 
> Something is definitely amiss.
> The only six pole filter (which has six crystals) that I know of that 
> Elecraft sells is the 200 Hz filter. The 200 Hz filter does have an offset 
> and is an open frame filter like the one you have shown me in the attachment.
> My 400 Hz filters are 8 pole with the 8 crystals and assembly installed in a 
> can and has no offset.
> The 400 Hz is suppose to be a 8 pole filter. By the way, there is one crystal 
> for each pole. Hence a 8 pole filter would have 8 crystals.
> If it were me, I would call Elecraft support, not sales, and ask them what is 
> going on with the 400 Hz filter.
> The tag on the filter definitely describes a s 400 Hz filter with an offset. 
> Maybe they can’t get 8 pole 400 Hz filters anymore and substituted a 6 pole 
> which would have an offset.
>  
> Mark, WB9CIF
>  
> From: Carl Jón Denbow  
> Sent: Saturday, February 23, 2019 22:18
> To: Mark Musick 
> Subject: Re: [Elecraft] KFL3C-400 offset?
>  
> Mark,
> 
> Here’s a photo. You think they put the wrong label on the filter?
> 
> 73 de Carl
> 
> 
> 
> 
> Sent from my iPhone
> ===
> Carl Jón Denbow, N8VZ
> 17 Coventry Lane
> Athens, Ohio 45701-3718
>  
> c...@n8vz.com
> www.n8vz.com
> EM89wh
>  
> IRLP 4533   Echolink 116070
>  
> PSK and JT65 Forever!
> ===
> 
> > On Feb 23, 2019, at 5:07 PM, Mark Musick  wrote:
> > 
> > Carl,
> > It is a six pole filter. 
> > It sounds like you got the 200 Hz filter in lieu of a 400 Hz filter.
> > I think a call to Elecraft Sales is in order.
> > 
> > 73,
> > Mark, WB9CIF
> > 
> > -----Original Message-----
> > From: elecraft-boun...@mailman.qth.net  
> > On Behalf Of Carl Jón Denbow
> > Sent: Saturday, February 23, 2019 20:36
> > To: Nr4c 
> > Cc: elecraft@mailman.qth.net
> > Subject: Re: [Elecraft] KFL3C-400 offset?
> > 
> > Bill, 
> > 
> > Thanks for your response.  This filter, unlike the others, is exposed and 
> > there are six crystal cans.  Does this mean it’s a five-pole?  I was sure I 
> > ordered an eight-pole filter?  When I do a search on the KFL3C-400 
> > everything I see indicates it’s an eight-pole filter.  Are there two types 
> > of KFL3C-400 filters?  As you can see I’m still confused.
> > 
> > 73,  
> > 
> > Carl
> > 
> > Sent from my iPhone
> > ===
> > Carl Jón Denbow, N8VZ
> > 17 Coventry Lane
> > Athens, Ohio 45701-3718
> > 
> > c...@n8vz.com
> > www.n8vz.com
> > EM89wh
> > 
> > IRLP 4533   Echolink 116070
> > 
> > PSK and JT65 Forever!
> > ===
> > 
> >> On Feb 23, 2019, at 2:41 PM, Nr4c  wrote:
> >> 
> >> Is your filter in a metal can. Eight pole filters used to be in a can. 
> >> Five pole filters were exposed parts. If the later, count the crystal 
> >> cans. Should be 5, 6, or 8. 
> >> 
> >> Sent from my iPhone
> >> ...nr4c. bill
> >> 
> >> 
> >>> On Feb 23, 2019, at 1:44 PM, Carl-N8VZ  wrote:
> >>> 
> >>> I’m assembling a KRX3 second receiver for my K3.  One of the filters 
> >>> I’m installing is a KFL3C-400.  When I ordered it, the order form 
> >>> said it was an 8-pole filter.  I purposely only ordered 8-pole 
> >>> filters.  It was my understanding that 8-pole filters have no offsets 
> >>> to worry about.  Why, then, does the KFL3C-400 have an offset (-0.79) 
> >>> listed on the filter when the others do not?  I’m confused.  Can 
> >>> someone clarify this for me?  73 de Carl N8VZ
> >>> 
> >>> 
> >>> 
> >>> --
> >>> Sent from: http://elecraft.365791.n2.nabble.com/
> >>> __
> >>> Elecraft mailing list
> >>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> >>> Help: http://mailman.qth.net/mmfaq.htm
> >>> Post: mailto:Elecraft@mailman.qth.net
> >>> 
> >>

Re: [Elecraft] KFL3C-400 offset?

[elecraft]

The "previous" web site used to implicitly say which filters were 5 pole and
which were 8 pole on the ordering page. The new "improved?" website omits
this information. Looking to answer the same question recently I had to
resort to looking elsewhere on the web!

Dave
Ww2r


>Bill, 

>Thanks for your response.  This filter, unlike the others, is exposed and
there are six crystal cans.  Does this mean it?s a five-pole?  I was >sure I
ordered an eight-pole filter?  When I do a search on the KFL3C-400
everything I see indicates it?s an eight-pole filter.  Are there >two types
of KFL3C-400 filters?  As you can see I?m still confused.

>73,  

>Carl

Sent from my iPhone
===
Carl J?n Denbow, N8VZ
17 Coventry Lane
Athens, Ohio 45701-3718
 
c...@n8vz.com
www.n8vz.com
EM89wh


---
This email has been checked for viruses by AVG.
https://www.avg.com

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Re: [Elecraft] KFL3C-400 offset?

[Mark Musick]

Carl,
It is a six pole filter. 
It sounds like you got the 200 Hz filter in lieu of a 400 Hz filter.
I think a call to Elecraft Sales is in order.

73,
Mark, WB9CIF

-Original Message-
From: elecraft-boun...@mailman.qth.net  On 
Behalf Of Carl Jón Denbow
Sent: Saturday, February 23, 2019 20:36
To: Nr4c 
Cc: elecraft@mailman.qth.net
Subject: Re: [Elecraft] KFL3C-400 offset?

Bill, 

Thanks for your response.  This filter, unlike the others, is exposed and there 
are six crystal cans.  Does this mean it’s a five-pole?  I was sure I ordered 
an eight-pole filter?  When I do a search on the KFL3C-400 everything I see 
indicates it’s an eight-pole filter.  Are there two types of KFL3C-400 filters? 
 As you can see I’m still confused.

73,  

Carl

Sent from my iPhone
===
Carl Jón Denbow, N8VZ
17 Coventry Lane
Athens, Ohio 45701-3718
 
c...@n8vz.com
www.n8vz.com
EM89wh
 
IRLP 4533   Echolink 116070
 
PSK and JT65 Forever!
===

> On Feb 23, 2019, at 2:41 PM, Nr4c  wrote:
> 
> Is your filter in a metal can. Eight pole filters used to be in a can. Five 
> pole filters were exposed parts. If the later, count the crystal cans. Should 
> be 5, 6, or 8. 
> 
> Sent from my iPhone
> ...nr4c. bill
> 
> 
>> On Feb 23, 2019, at 1:44 PM, Carl-N8VZ  wrote:
>> 
>> I’m assembling a KRX3 second receiver for my K3.  One of the filters 
>> I’m installing is a KFL3C-400.  When I ordered it, the order form 
>> said it was an 8-pole filter.  I purposely only ordered 8-pole 
>> filters.  It was my understanding that 8-pole filters have no offsets 
>> to worry about.  Why, then, does the KFL3C-400 have an offset (-0.79) 
>> listed on the filter when the others do not?  I’m confused.  Can 
>> someone clarify this for me?  73 de Carl N8VZ
>> 
>> 
>> 
>> --
>> Sent from: http://elecraft.365791.n2.nabble.com/
>> __
>> Elecraft mailing list
>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
>> Help: http://mailman.qth.net/mmfaq.htm
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>> 
>> This list hosted by: http://www.qsl.net Please help support this 
>> email list: http://www.qsl.net/donate.html
> 
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Re: [Elecraft] KFL3C-400 offset?

[Carl Jón Denbow]

Bill, 

Thanks for your response.  This filter, unlike the others, is exposed and there 
are six crystal cans.  Does this mean it’s a five-pole?  I was sure I ordered 
an eight-pole filter?  When I do a search on the KFL3C-400 everything I see 
indicates it’s an eight-pole filter.  Are there two types of KFL3C-400 filters? 
 As you can see I’m still confused.

73,  

Carl

Sent from my iPhone
===
Carl Jón Denbow, N8VZ
17 Coventry Lane
Athens, Ohio 45701-3718
 
c...@n8vz.com
www.n8vz.com
EM89wh
 
IRLP 4533   Echolink 116070
 
PSK and JT65 Forever!
===

> On Feb 23, 2019, at 2:41 PM, Nr4c  wrote:
> 
> Is your filter in a metal can. Eight pole filters used to be in a can. Five 
> pole filters were exposed parts. If the later, count the crystal cans. Should 
> be 5, 6, or 8. 
> 
> Sent from my iPhone
> ...nr4c. bill
> 
> 
>> On Feb 23, 2019, at 1:44 PM, Carl-N8VZ  wrote:
>> 
>> I’m assembling a KRX3 second receiver for my K3.  One of the filters I’m
>> installing is a KFL3C-400.  When I ordered it, the order form said it was an
>> 8-pole filter.  I purposely only ordered 8-pole filters.  It was my
>> understanding that 8-pole filters have no offsets to worry about.  Why,
>> then, does the KFL3C-400 have an offset (-0.79) listed on the filter when
>> the others do not?  I’m confused.  Can someone clarify this for me?  73 de
>> Carl N8VZ
>> 
>> 
>> 
>> --
>> Sent from: http://elecraft.365791.n2.nabble.com/
>> __
>> Elecraft mailing list
>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
>> Help: http://mailman.qth.net/mmfaq.htm
>> Post: mailto:Elecraft@mailman.qth.net
>> 
>> This list hosted by: http://www.qsl.net
>> Please help support this email list: http://www.qsl.net/donate.html
> 
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Re: [Elecraft] KFL3C-400 offset?

[Nr4c]

Is your filter in a metal can. Eight pole filters used to be in a can. Five 
pole filters were exposed parts. If the later, count the crystal cans. Should 
be 5, 6, or 8. 

Sent from my iPhone
...nr4c. bill


> On Feb 23, 2019, at 1:44 PM, Carl-N8VZ  wrote:
> 
> I’m assembling a KRX3 second receiver for my K3.  One of the filters I’m
> installing is a KFL3C-400.  When I ordered it, the order form said it was an
> 8-pole filter.  I purposely only ordered 8-pole filters.  It was my
> understanding that 8-pole filters have no offsets to worry about.  Why,
> then, does the KFL3C-400 have an offset (-0.79) listed on the filter when
> the others do not?  I’m confused.  Can someone clarify this for me?  73 de
> Carl N8VZ
> 
> 
> 
> --
> Sent from: http://elecraft.365791.n2.nabble.com/
> __
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
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> 
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