Topics

K3s 400 Hz filter differences...

Clay Autery
 

The 400Hz filter on my Main RX is an Elecraft (by INRAD) 8-pole filter in a Faraday cage and no offset.
The 400Hz filter I just received for my SubRX  is an Elecraft (by Vibroplex?) that is a 6-pole filter with no Farady cage AND it has a -0.71 kHz offset.

I called support when I saw the obvious differences, and they said, "Don't worry about it.  Enter the SubRX offset exactly as on the crystal (no averaging with the [supposed] 0.00 offset on the 8-pole filter), and let the new Synthesizers do the heavy lifting." or words to that effect.

I hear what was said, and I don't want to come off like I don't trust what I was told....  But something simply is not sitting right with me on this.... a 6-pole "matched" with an 8-pole?  No offset averaging?  What about the difference in the skirts between a 6-pole and an 8-pole.... Aren't the cutoffs and cutoff rates different?  I realize that things change, and that perhaps the instructions for averaging the offsets is not applicable here... (though I don't yet understand why)

Can someone clear this up for me so even I can understand it.

Seems to me that I either need to get a matching INRAD-made 8-pole, or buy another of these new parts and try to get it matched.

Want to move on this, because IF I am going to have a hope in getting a "matching" 6-pole (new stock) 400 Hz filter, I need to try and do so from within the same batch that the one I just bought came from.
The prospect of finding an "by INRAD" 8-pole available on the market seems much less likely...

Obviously, I am operating on a number of assumptions here... which is why I am asking...


73

______________________
Clay Autery, KY5G
(318) 518-1389

Everett N4CY
 

Vibroplex bought INRAD, that is why it now has the Vibroplex name.

On Jan 14, 2020, at 6:15 AM, Clay Autery <KY5G@...> wrote:

Vibroplex

Bill Maddock
 

Clay,

As far as diversity receive, the 2 different filters should work fine. The offset on 6 pole will guaranty that both signals are on same frequency and have same tone. As far as one being  8 pole and the other 6 pole, yes the curve on the filter will be different. I doubt very seriously that it will hurt the diversity recieve.

73 Bill WW5M 




On Tuesday, January 14, 2020, 6:26 AM, Everett N4CY via Groups.Io <everettsharp@...> wrote:

Vibroplex bought INRAD, that is why it now has the Vibroplex name.

> On Jan 14, 2020, at 6:15 AM, Clay Autery <KY5G@...> wrote:
>
> Vibroplex



Clay Autery
 

Yes, I discovered that about 2 minutes ago while looking at INRAD.net to see if the 8-pole 400Hz was still available...  It is, BTW...

Wonder why the switch from 8-pole to 6-pole?

Cheaper to make? New synths don't "need" them?  Less need for higher gain compensation?

73,

______________________
Clay Autery, KY5G
(318) 518-1389
On 01/14/20 06:26, Everett N4CY via Groups.Io wrote:

Vibroplex bought INRAD, that is why it now has the Vibroplex name. 

On Jan 14, 2020, at 6:15 AM, Clay Autery <KY5G@...> wrote:

Vibroplex


Clay Autery
 

Probably not something I will ever notice EVEN IF/WHEN I finally get set up for diversity receive... But it really bothers me that they are "different" in a fundamental way.
The curse of borderline OCD...  <wink>

73, and thanks for the response!

______________________
Clay Autery, KY5G
(318) 518-1389
On 01/14/20 06:32, Bill Maddock via Groups.Io wrote:

Clay,

As far as diversity receive, the 2 different filters should work fine. The offset on 6 pole will guaranty that both signals are on same frequency and have same tone. As far as one being  8 pole and the other 6 pole, yes the curve on the filter will be different. I doubt very seriously that it will hurt the diversity recieve.

73 Bill WW5M 




On Tuesday, January 14, 2020, 6:26 AM, Everett N4CY via Groups.Io <everettsharp@...> wrote:

Vibroplex bought INRAD, that is why it now has the Vibroplex name.

> On Jan 14, 2020, at 6:15 AM, Clay Autery <KY5G@...> wrote:
>
> Vibroplex



Bill Maddock
 

Yeah probably cost savings , doubt there’s a lot  of difference if any that you would notice. Several years ago I switched out my 200 hz filters in both my K3’s. They had the standard 5 pole filters and I upgraded to 6 pole. I couldn’t really tell difference on recieve. I compared had one 5 pole and other 6 pole and couldn’t tell difference. Probably wasted the money . I still have original 5 pole- hope to sell them one day lol

73 de Bill WW5M 




On Tuesday, January 14, 2020, 6:46 AM, Clay Autery <KY5G@...> wrote:

Probably not something I will ever notice EVEN IF/WHEN I finally get set up for diversity receive... But it really bothers me that they are "different" in a fundamental way.
The curse of borderline OCD...  <wink>

73, and thanks for the response!

______________________
Clay Autery, KY5G
(318) 518-1389
On 01/14/20 06:32, Bill Maddock via Groups.Io wrote:
Clay,

As far as diversity receive, the 2 different filters should work fine. The offset on 6 pole will guaranty that both signals are on same frequency and have same tone. As far as one being  8 pole and the other 6 pole, yes the curve on the filter will be different. I doubt very seriously that it will hurt the diversity recieve.

73 Bill WW5M 




On Tuesday, January 14, 2020, 6:26 AM, Everett N4CY via Groups.Io <everettsharp@...> wrote:

Vibroplex bought INRAD, that is why it now has the Vibroplex name.

> On Jan 14, 2020, at 6:15 AM, Clay Autery <KY5G@...> wrote:
>
> Vibroplex



Joe Subich, W4TV
 

The 6 pole filters are made "in house" by Elecraft. The 8 pole
filters are an Inrad/Vibroplex product (made in Asia).

This is no different than the original 500 Hz/5 pole filters for
the K3.

73,

... Joe, W4TV

On 2020-01-14 7:44 AM, Clay Autery wrote:
Yes, I discovered that about 2 minutes ago while looking at INRAD.net to see if the 8-pole 400Hz was still available...  It is, BTW...
Wonder why the switch from 8-pole to 6-pole?
Cheaper to make? New synths don't "need" them?  Less need for higher gain compensation?
73,
______________________
Clay Autery, KY5G
(318) 518-1389
On 01/14/20 06:26, Everett N4CY via Groups.Io wrote:
Vibroplex bought INRAD, that is why it now has the Vibroplex name.

On Jan 14, 2020, at 6:15 AM, Clay Autery <KY5G@...> wrote:

Vibroplex

Rob Sherwood
 

The reason for the 6-pole filter vs. the 5-pole filter was for much better (less) passive IMD in the roofing filter.  Some 5-pole filters limited the close-in dynamic range of the K3 to the mid 80 dB instead of better than 100 dB.  Passive IMD can occur in many components, including crystals.   My testing prompted the new filter. Rob, NC0B


On Jan 14, 2020, at 6:16 AM, Bill Maddock via Groups.Io <n4zi96@...> wrote:

 Yeah probably cost savings , doubt there’s a lot  of difference if any that you would notice. Several years ago I switched out my 200 hz filters in both my K3’s. They had the standard 5 pole filters and I upgraded to 6 pole. I couldn’t really tell difference on recieve. I compared had one 5 pole and other 6 pole and couldn’t tell difference. Probably wasted the money . I still have original 5 pole- hope to sell them one day lol

73 de Bill WW5M 




On Tuesday, January 14, 2020, 6:46 AM, Clay Autery <KY5G@...> wrote:

Probably not something I will ever notice EVEN IF/WHEN I finally get set up for diversity receive... But it really bothers me that they are "different" in a fundamental way.
The curse of borderline OCD...  <wink>

73, and thanks for the response!

______________________
Clay Autery, KY5G
(318) 518-1389
On 01/14/20 06:32, Bill Maddock via Groups.Io wrote:
Clay,

As far as diversity receive, the 2 different filters should work fine. The offset on 6 pole will guaranty that both signals are on same frequency and have same tone. As far as one being  8 pole and the other 6 pole, yes the curve on the filter will be different. I doubt very seriously that it will hurt the diversity recieve.

73 Bill WW5M 




On Tuesday, January 14, 2020, 6:26 AM, Everett N4CY via Groups.Io <everettsharp@...> wrote:

Vibroplex bought INRAD, that is why it now has the Vibroplex name.

> On Jan 14, 2020, at 6:15 AM, Clay Autery <KY5G@...> wrote:
>
> Vibroplex



Clay Autery
 

Really?  In house?

So if you ad to pick one or the other to create a matching pair, would you use the 6-pole Elecraft BY Elecraft, or dual INRAD 8-poles?

Thanks... you helped!

______________________
Clay Autery, KY5G
(318) 518-1389
On 01/14/20 08:22, Joe Subich, W4TV wrote:


The 6 pole filters are made "in house" by Elecraft.  The 8 pole
filters are an Inrad/Vibroplex product (made in Asia).

This is no different than the original 500 Hz/5 pole filters for
the K3.

73,

   ... Joe, W4TV


On 2020-01-14 7:44 AM, Clay Autery wrote:
Yes, I discovered that about 2 minutes ago while looking at INRAD.net to see if the 8-pole 400Hz was still available...  It is, BTW...

Wonder why the switch from 8-pole to 6-pole?

Cheaper to make? New synths don't "need" them?  Less need for higher gain compensation?

73,

______________________
Clay Autery, KY5G
(318) 518-1389

On 01/14/20 06:26, Everett N4CY via Groups.Io wrote:
Vibroplex bought INRAD, that is why it now has the Vibroplex name.

On Jan 14, 2020, at 6:15 AM, Clay Autery <KY5G@...> wrote:

Vibroplex









Clay Autery
 

Thanks for the response Mr. Sherwood!
 But I am inquiring as to why Elecraft decided to make the 6-pole 400Hz part rather than stay with the INRAD 8-pole filters?  Like the Elecraft branded "by INRAD" 8-pole 400Hz filter I bought with my K3s in 2016....  Appears to be a co-branded version of INRAD's #701.

73,

______________________
Clay Autery, KY5G
(318) 518-1389
On 01/14/20 09:15, Rob Sherwood wrote:

The reason for the 6-pole filter vs. the 5-pole filter was for much better (less) passive IMD in the roofing filter.  Some 5-pole filters limited the close-in dynamic range of the K3 to the mid 80 dB instead of better than 100 dB.  Passive IMD can occur in many components, including crystals.   My testing prompted the new filter. Rob, NC0B


On Jan 14, 2020, at 6:16 AM, Bill Maddock via Groups.Io <n4zi96@...> wrote:

 Yeah probably cost savings , doubt there’s a lot  of difference if any that you would notice. Several years ago I switched out my 200 hz filters in both my K3’s. They had the standard 5 pole filters and I upgraded to 6 pole. I couldn’t really tell difference on recieve. I compared had one 5 pole and other 6 pole and couldn’t tell difference. Probably wasted the money . I still have original 5 pole- hope to sell them one day lol

73 de Bill WW5M 




On Tuesday, January 14, 2020, 6:46 AM, Clay Autery <KY5G@...> wrote:

Probably not something I will ever notice EVEN IF/WHEN I finally get set up for diversity receive... But it really bothers me that they are "different" in a fundamental way.
The curse of borderline OCD...  <wink>

73, and thanks for the response!

______________________
Clay Autery, KY5G
(318) 518-1389
On 01/14/20 06:32, Bill Maddock via Groups.Io wrote:
Clay,

As far as diversity receive, the 2 different filters should work fine. The offset on 6 pole will guaranty that both signals are on same frequency and have same tone. As far as one being  8 pole and the other 6 pole, yes the curve on the filter will be different. I doubt very seriously that it will hurt the diversity recieve.

73 Bill WW5M 




On Tuesday, January 14, 2020, 6:26 AM, Everett N4CY via Groups.Io <everettsharp@...> wrote:

Vibroplex bought INRAD, that is why it now has the Vibroplex name.

> On Jan 14, 2020, at 6:15 AM, Clay Autery <KY5G@...> wrote:
>
> Vibroplex



redarlington
 

Because they can sell you the buck in parts for $100 or more without paying a middle man.  Just a hunch.

-Bob

On Tue, Jan 14, 2020 at 9:45 AM Clay Autery <KY5G@...> wrote:

Thanks for the response Mr. Sherwood!
 But I am inquiring as to why Elecraft decided to make the 6-pole 400Hz part rather than stay with the INRAD 8-pole filters?  Like the Elecraft branded "by INRAD" 8-pole 400Hz filter I bought with my K3s in 2016....  Appears to be a co-branded version of INRAD's #701.

73,

______________________
Clay Autery, KY5G
(318) 518-1389
On 01/14/20 09:15, Rob Sherwood wrote:
The reason for the 6-pole filter vs. the 5-pole filter was for much better (less) passive IMD in the roofing filter.  Some 5-pole filters limited the close-in dynamic range of the K3 to the mid 80 dB instead of better than 100 dB.  Passive IMD can occur in many components, including crystals.   My testing prompted the new filter. Rob, NC0B


On Jan 14, 2020, at 6:16 AM, Bill Maddock via Groups.Io <n4zi96@...> wrote:

 Yeah probably cost savings , doubt there’s a lot  of difference if any that you would notice. Several years ago I switched out my 200 hz filters in both my K3’s. They had the standard 5 pole filters and I upgraded to 6 pole. I couldn’t really tell difference on recieve. I compared had one 5 pole and other 6 pole and couldn’t tell difference. Probably wasted the money . I still have original 5 pole- hope to sell them one day lol

73 de Bill WW5M 




On Tuesday, January 14, 2020, 6:46 AM, Clay Autery <KY5G@...> wrote:

Probably not something I will ever notice EVEN IF/WHEN I finally get set up for diversity receive... But it really bothers me that they are "different" in a fundamental way.
The curse of borderline OCD...  <wink>

73, and thanks for the response!

______________________
Clay Autery, KY5G
(318) 518-1389
On 01/14/20 06:32, Bill Maddock via Groups.Io wrote:
Clay,

As far as diversity receive, the 2 different filters should work fine. The offset on 6 pole will guaranty that both signals are on same frequency and have same tone. As far as one being  8 pole and the other 6 pole, yes the curve on the filter will be different. I doubt very seriously that it will hurt the diversity recieve.

73 Bill WW5M 




On Tuesday, January 14, 2020, 6:26 AM, Everett N4CY via Groups.Io <everettsharp@...> wrote:

Vibroplex bought INRAD, that is why it now has the Vibroplex name.

> On Jan 14, 2020, at 6:15 AM, Clay Autery <KY5G@...> wrote:
>
> Vibroplex



Rob Sherwood
 

Wayne will have to answer that. Rob, NC0B


On Jan 14, 2020, at 9:45 AM, Clay Autery <KY5G@...> wrote:



Thanks for the response Mr. Sherwood!
 But I am inquiring as to why Elecraft decided to make the 6-pole 400Hz part rather than stay with the INRAD 8-pole filters?  Like the Elecraft branded "by INRAD" 8-pole 400Hz filter I bought with my K3s in 2016....  Appears to be a co-branded version of INRAD's #701.

73,

______________________
Clay Autery, KY5G
(318) 518-1389
On 01/14/20 09:15, Rob Sherwood wrote:
The reason for the 6-pole filter vs. the 5-pole filter was for much better (less) passive IMD in the roofing filter.  Some 5-pole filters limited the close-in dynamic range of the K3 to the mid 80 dB instead of better than 100 dB.  Passive IMD can occur in many components, including crystals.   My testing prompted the new filter. Rob, NC0B


On Jan 14, 2020, at 6:16 AM, Bill Maddock via Groups.Io <n4zi96@...> wrote:

 Yeah probably cost savings , doubt there’s a lot  of difference if any that you would notice. Several years ago I switched out my 200 hz filters in both my K3’s. They had the standard 5 pole filters and I upgraded to 6 pole. I couldn’t really tell difference on recieve. I compared had one 5 pole and other 6 pole and couldn’t tell difference. Probably wasted the money . I still have original 5 pole- hope to sell them one day lol

73 de Bill WW5M 




On Tuesday, January 14, 2020, 6:46 AM, Clay Autery <KY5G@...> wrote:

Probably not something I will ever notice EVEN IF/WHEN I finally get set up for diversity receive... But it really bothers me that they are "different" in a fundamental way.
The curse of borderline OCD...  <wink>

73, and thanks for the response!

______________________
Clay Autery, KY5G
(318) 518-1389
On 01/14/20 06:32, Bill Maddock via Groups.Io wrote:
Clay,

As far as diversity receive, the 2 different filters should work fine. The offset on 6 pole will guaranty that both signals are on same frequency and have same tone. As far as one being  8 pole and the other 6 pole, yes the curve on the filter will be different. I doubt very seriously that it will hurt the diversity recieve.

73 Bill WW5M 




On Tuesday, January 14, 2020, 6:26 AM, Everett N4CY via Groups.Io <everettsharp@...> wrote:

Vibroplex bought INRAD, that is why it now has the Vibroplex name.

> On Jan 14, 2020, at 6:15 AM, Clay Autery <KY5G@...> wrote:
>
> Vibroplex