You said: "In addition, when the DSP IF filters are set to about the same width
as the roofing filters, the two filters "cascade" -- the rejection of adjacent
signals is the sum of the rejection of the two filters. "
There is no requirement that the widths be about the same. They could be
On 4/1/2020 7:17 AM, Wes wrote:
Until you get down to the noise floor isn't it always the sum (in dB) of
the rejection?
Isn't that what I said? Perhaps I said it badly.
73, Jim
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Until you get down to the noise floor isn't it always the sum (in dB) of the
rejection?
Wes N7WS
On 3/31/2020 8:52 PM, Jim Brown wrote:
On 3/31/2020 8:36 PM, Don Wilhelm wrote:
What the roofing filters will do is keep the receiver from reducing the
hardware AGC for stations which are within
: elecraft-boun...@mailman.qth.net On
Behalf Of j...@kk9a.com
Sent: Wednesday, April 1, 2020 7:30 AM
To: elecraft@mailman.qth.net
Subject: Re: [Elecraft] K3 SSB Filters
I concur. I have 2.8, 2.1 and 1.8 KHz 8 pole roofing filters in my K3S. I
made over 8500 SSB QSOs last month and I used the 2.1 KHz
I concur. I have 2.8, 2.1 and 1.8 KHz 8 pole roofing filters in my
K3S. I made over 8500 SSB QSOs last month and I used the 2.1 KHz
roofing filter for all of them.
John KK9A
Jim Brown K9YC wrote:
I tried that and didn't like the result. I prefer 2.1 kHz 8 pole
73, Jim K9YC
No, the roofing filters aren't superfluous even with lower level
signals. If you set the bandwidths similarly as I do all of the time,
the rejection of the filter adds to the rejection from the DSP. I think
this should be pretty obvious.
Dave AB7E
On 3/31/2020 8:36 PM, Don Wilhelm
On 3/31/2020 8:36 PM, Don Wilhelm wrote:
What the roofing filters will do is keep the receiver from reducing the
hardware AGC for stations which are within the roofing filter passband.
In addition, when the DSP IF filters are set to about the same width as
the roofing filters, the two filters
Hopefully that we will remember that the DSP filter skirts are steeper
than the crystal filter skirts, so judicious use of the HiCut and LoCut
will provide us with a better passband than narrow roofing filters.
What the roofing filters will do is keep the receiver from reducing the
hardware
Remember, different brands of 2.1 or 1.8 filters are not necessarily equal.
One must realize the shape factor is more important than the published BW.
Just because one radio filter is 1.8 kHz does not mean another 1.8 kHz BW is
the same.
Bob, K4TAX
Sent from my iPhone
> On Mar 31, 2020,
I typically use Hi Cut the most, Lo Cut once in a while and almost never
use Width in SSB mode. For me the 2.1 kHz filter works swell in this
application.
In the late '90s I bought a TS-850s which was fitted with a 1.8 kHz
factory accessory filter. I couldn't get rid of it fast enough and
Having the 1.8 kHz in my K3S, I know what and how it works.
I work 2 SSB traffic LSB nets which both have LSB nets which are 2 kHZ above
my net frequency. That means at least 700 Hz to 1000 Hz of their primary
signal is in my receiver passband. The 1.8 kHz filter, the DSP at 1.8 kHz and
On 3/31/2020 3:18 PM, Buck wrote:
Why go halfway? I would go with the 1.8 as a roofing filter.
I tried that and didn't like the result. I prefer 2.1 kHz 8 pole
73, Jim K9YC
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Why go halfway? I would go with the 1.8 as a roofing filter. Crank the
DSP down to 1.6 and slew the passband to get the best readability.
Buck, k4ia
Honor Roll
8BDXCC
EasyWayHamBooks.com
On 3/31/2020 12:17 PM, John Simmons wrote:
David,
I'm looking to upgrade my filters for SSB. I have the
David,
I'm looking to upgrade my filters for SSB. I have the 2.8 filter
installed, which has steeper skirts than the 2.7. I'm wondering if the
2.1 would have a noticeable enough effect to justify the cost.
-de John NI0K
David Smith wrote on 3/31/2020 10:26 AM:
Been interesting reading the
Been interesting reading the comments on SSB contesting and filtering. As a
serious SSB contester from way back in the 80s, side rejection from other
contesters (especially where we are all bunched up on 40 meters and also when
the shortwave broadcast stations come on) has always been a topic
I have, in my K3S, the standard 2.7 kHz filter for transmit and often
use the 1.8 kHz filter for receive to deal with QRM. It is necessary to
adjust the SHIFT in order to improve copy when the 1.8 kHz filter is
active. Yes, this is perfectly normal, the 1.8 kHz filter is not going
to allow
Hi John,
There’s a nice writeup from Wayne and Eric here:
https://elecraft.com/pages/k3s-crystal-roofing-filters
Perhaps that will help. It certainly helped me.
73 de AG7TX
David Thompson, AG7TX
Jack of All Trades
Master of None
dbthomp...@me.com
> On Mar 31, 2020, at 08:00, John Simmons
With the recent experience in SSB contests, I'm thinking of upgrading
my SSB filter(s). Currently for SSB I have only the 2.8 filter. What are
thoughts about other SSB filters? I know when I narrow the bandwidth to
1.8 the intelligibility goes down.
-de John NI0K
I've been reading the FAQ and the list archives trying to find out
what SSB filters I could benefit from in my K3, which is due to come
any day now! :) I've read some references that seem to suggest the 1.0
filter for SSB might be a bit on the narrow side.
I'm a 95% cw op, so I got the 500 and
Since the filters are roofing filters, I'm thinking that you don't have
to overboard. My guess is the 2.7 is very good for contesting as it is.
For CW, it's wide, but for SSB, as a roofing filter, I'd actually call
it pretty narrow.
But then again, I'm a CW guy. What do I know :-)
- Keith
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