Elecraft

Filter Recommendations

Classic

List

Threaded

18 messages Options

Elecraft mailing list

Filter Recommendations

I am looking to upgrade my K3S with filters and am using the DX version of the radio as a guide. What is the advantage of the 2.8 KHz filter over the stock 2.7? What does the 2.1 KHz filter do for you?
______________________________________________________________
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
Message delivered to [hidden email]

Bill Frantz

Re: Filter Recommendations

I find the 2.1 KHz filter useful for SSB contesting when the
band is crowded. At other times it also seems to reduce band
noise when it is engaged. (The other filter that will be engaged
in my radio is a 5 pole 2.7 KHz filter.)

If you set a low cutoff of 350 Hz then the 2.1 KHz filter will
pass audio up to 2.45 KHz, which makes SSB voice quite intelligible.

73 Bill AE6JV

On 8/26/18 at 5:45 AM, [hidden email] (Lee Murrah via
Elecraft) wrote:

>What does the 2.1 KHz filter do for you?

-------------------------------------------------------------------------
Bill Frantz | Re: Hardware Management Modes: | Periwinkle
(408)356-8506 | If there's a mode, there's a | 16345
Englewood Ave
www.pwpconsult.com | failure mode. - Jerry Leichter | Los Gatos,
CA 95032

______________________________________________________________
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
Message delivered to [hidden email]

Elecraft mailing list

Re: Filter Recommendations

In reply to this post by Elecraft mailing list

That is a really good question Lee and the answer can be very complicated. It depends is probably the best answer.

An everyday experience is what I used in my determination to purchase neither was:

When in my daily 3710 LSB group QSO there would regularly be an interfering station on 3713 who was a bit wide. The rest of the 3713 group was not an issue, only this one station. Since he was jus above us and we were on LSB none of the filters would really offer much relief.

At other times there would be stations on 3707 that had somewhat poor IMD resulting in some power in what would be their USB. This would interfere and depending on how wide the IMD was a sharper filter might help, but maybe not.

What it all boiled down to, for me, was how much strong interference was I experiencing and was the bulk of it in the narrow gap between the filter differences. Since the filters only serve to protect the DSP from overload I have not found compelling reasons to purchase one. When I do purchase one it will be the 2.1 as it offers the most promise with nearby interference and overload.

That was just where I wound up:)

Very 73 - Mike - K9JRI

> On Aug 26, 2018, at 8:45 AM, Lee Murrah via Elecraft <[hidden email]> wrote:
>
> I am looking to upgrade my K3S with filters and am using the DX version of the radio as a guide. What is the advantage of the 2.8 KHz filter over the stock 2.7? What does the 2.1 KHz filter do for you?
> ______________________________________________________________
> 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
> Message delivered to [hidden email]

Bob McGraw - K4TAX

Re: Filter Recommendations

In reply to this post by Elecraft mailing list

Although I have the standard 2.7 kHz filter in my K3S, the 2.8 is
reported to give a little bit better SSB sounding audio. From
experience with another radio, opening up the SSB BW 100 Hz gives a wee
bit better sounding audio. Emphasis on "wee" bit. As to the 2.1 kHz, I
opted for a 1.8 kHz as a 2nd filter and I've found it good for SSB
reception in heavy QRM. A 500 Hz is the third filter for CW and Digital
work. These are roofing filters and it is the DSP engine which gives
the receiver selectivity.

Everyone has their preferences and these are mine in both of the
stations on the desk.

73

Bob, K4TAX

On 8/26/2018 7:45 AM, Lee Murrah via Elecraft wrote:

> I am looking to upgrade my K3S with filters and am using the DX version of the radio as a guide. What is the advantage of the 2.8 KHz filter over the stock 2.7? What does the 2.1 KHz filter do for you?
> ______________________________________________________________
> 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
> Message delivered to [hidden email]
>

Nate Bargmann

Re: Filter Recommendations

In reply to this post by Elecraft mailing list

* On 2018 26 Aug 07:46 -0500, Lee Murrah via Elecraft wrote:
> I am looking to upgrade my K3S with filters and am using the DX
> version of the radio as a guide. What is the advantage of the 2.8 KHz
> filter over the stock 2.7? What does the 2.1 KHz filter do for you?

I have the 2.7 and 2.1 filters for SSB work. I'm often on a 75m net with a
group that is 2 kHz below the net frequency. With the 2.1 kHz filter I
can dial the Hi Cut down to 2.05 kHz and I don't hear them at all while
still having excellent intelligibility of the net. For the QSO Party
this weekend, I can dial the width down to just where the 2.1 kHz is
switched in and operate without a lot of squeaks and squawks.

In years past I bought a TS-850S fitted with a 1.8 kHz Kenwood filter
which was next to useless as the speech was not intelligible. I sold it
and bought a pair of INRAD 2.1 kHz filters (one for each IF) which
really made that radio work very well until it had other issues. I've
been a fan of the INRAD 2.1 kHz filter for narrow SSB work ever since.

The K3[S] with the choice of Hi/Lo Cut or Width and shift, allows one to
make maximum use of the filtering depending on the need. ++++

73, Nate, N0NB

--

"The optimist proclaims that we live in the best of all
possible worlds. The pessimist fears this is true."

Web: http://www.n0nb.us GPG key: D55A8819 GitHub: N0NB
______________________________________________________________
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
Message delivered to [hidden email]

Wes Stewart-2

Re: Filter Recommendations

In reply to this post by Elecraft mailing list

The 2.8 has better symmetry and no frequency offset. Personally, I have no use
for a 2.1. If you are a CW or RTTY man get a 400 Hz.

Wes N7WS

On 8/26/2018 5:45 AM, Lee Murrah via Elecraft wrote:
> I am looking to upgrade my K3S with filters and am using the DX version of the radio as a guide. What is the advantage of the 2.8 KHz filter over the stock 2.7? What does the 2.1 KHz filter do for you?

______________________________________________________________
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
Message delivered to [hidden email]

Don Wilhelm

Re: Filter Recommendations

In reply to this post by Elecraft mailing list

Lee,

The 2.8kHz filter has a flatter passband and steeper skirts than the 2.7kHz.

But remember that this is a roofing filter, the DSP provides the actual
filtering for the K3/K3S.
The purpose of the roofing filter is to keep strong adjacent signals
from overloading the Hardware AGC and the ADC at the input to the DSP
circuits. A strong signal that is inside the passband of the roofing
filter, but outside the passband of the DSP filter (you may not hear
that signal since it is outside the DSP filter) can cause receiver AGC
"pumping" and in extreme cases can overload the ADC causing severe
"information garbling".

73,
Don W3FPR

On 8/26/2018 8:45 AM, Lee Murrah via Elecraft wrote:

Bob McGraw - K4TAX

Re: Filter Recommendations

In reply to this post by Wes Stewart-2

In regard to filters, see http://www.elecraft.com/K3/Roofing_Filters.htm
for the explanation and justification and application of various
filters. Wayne and Eric have provided excellent real world advice in
this regard.

73

Bob, K4TAX

______________________________________________________________
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
Message delivered to [hidden email]

Peter W2IRT

Re: Filter Recommendations

In reply to this post by Elecraft mailing list

For SSB, I tricked my K3s out with a pair of matched 2.8s (needed for diversity
reception) and a 2.1 that frankly doesn't make much of a difference. I also have
the 13 kHz filter in for wideband RX and 10m FM (and if I ever wanted ESSB
audio, which I don't). On the CW side, I have a matched pair of 400 Hz filters
(again, for diversity reception), and a 250 -- and only because at the time I
ordered, the 200 wasn't available.

I'm very pleased with that combination, and the only change I'd make if I had to
do it again would be a 1.8 instead of a 2.1 for SSB.

- pjd

-----Original Message-----
From: [hidden email] [mailto:[hidden email]]
On Behalf Of Lee Murrah via Elecraft
Sent: Sunday, August 26, 2018 8:45 AM
To: Elecraft Mail List
Subject: [Elecraft] Filter Recommendations

I am looking to upgrade my K3S with filters and am using the DX version of the
radio as a guide. What is the advantage of the 2.8 KHz filter over the stock
2.7? What does the 2.1 KHz filter do for you?
______________________________________________________________
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
Message delivered to [hidden email]

______________________________________________________________
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
Message delivered to [hidden email]

Lovin' my K3S (S/N 10023)
73, Peter W2IRT

Jim Brown-10

Re: Filter Recommendations

In reply to this post by Don Wilhelm

On 8/26/2018 6:50 AM, Don Wilhelm wrote:
> The 2.8kHz filter has a flatter passband and steeper skirts than the
> 2.7kHz.

Yes. I use 2.8 kHz filters in all three of my main receivers, and 2.7
kHz in my Sub Receivers. The better flatness of the 2.8 kHz filter
reduces incidental AM when transmitting RTTY. I don't bother matching
the 2.8 and 2.7 filters because I don't use them when set for diversity
reception -- rather, I'm trying to dig weak CW signals out of the noise.

I do SSB contesting, so first bought 1.8 kHz filters, which I find too
narrow. I've settled on 2.1 kHz.

For RTTY and some CW I use 400 Hz filters, and 250 Hz for CW most of the
time.

As Don as observed, it's important to understand that these are roofing
filters, and that the K3 IF is in DSP, and is variable from 50 Hz to >4
kHZ. The settings of the DSP IF are what mainly set the RX bandwidth. In
addition to protecting the DSP IF from overload and the AGC from signals
outside the set bandwidth, the roofing filters also CASCADE with the DSP
IF. That is, when the DSP IF is set to about the same bandwidth as the
selected roofing filter, the two filters combine to provide much steeper
"skirts," so that very close signals are more deeply rejected. This is
what helps N0NB copy his net with QRM only 2 kHz below them.

73, Jim K9YC

______________________________________________________________
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
Message delivered to [hidden email]

Elecraft mailing list

Re: Filter Recommendations

In reply to this post by Don Wilhelm

I opted for a 2.1 ssb filter hoping to be able to enjoy phone contesting just a little bit more but so far I haven't found the magic elixir for phone.I only replied to the post after seeing "information garbling" from Don. That is exactly what happens to me with whatever filter or passbandsetting I have tried in my K3 during a phone contest. Btw, that is during major DX contests, I can handle the smaller ones but normally don't, hi.

BillK3WJV
On Sunday, August 26, 2018, 9:53:41 AM EDT, Don Wilhelm <[hidden email]> wrote:

Lee,

The 2.8kHz filter has a flatter passband and steeper skirts than the 2.7kHz.

But remember that this is a roofing filter, the DSP provides the actual
filtering for the K3/K3S.
The purpose of the roofing filter is to keep strong adjacent signals
from overloading the Hardware AGC and the ADC at the input to the DSP
circuits. A strong signal that is inside the passband of the roofing
filter, but outside the passband of the DSP filter (you may not hear
that signal since it is outside the DSP filter) can cause receiver AGC
"pumping" and in extreme cases can overload the ADC causing severe
"information garbling".

73,
Don W3FPR

On 8/26/2018 8:45 AM, Lee Murrah via Elecraft wrote:

Peter W2IRT

Re: Filter Recommendations

I find the best thing for phone contesting is a ton of attenuation and judicious use of RF Gain, combined with narrow bandwidth. No way to get rid of the low-frequency rumble from within the passband, but the combination of the roofing filter, DSP high cut and shift/width will get rid of the high-pitched adjacent noise enough to be reasonably efficient. I still don't like SSB contests, but they're far more survivable with a loaded K3s than they were with previous radios!

---------------------------------------------
GO FRC!
Peter, W2IRT

www.facebook.com/W2IRT

-----Original Message-----
From: [hidden email] [mailto:[hidden email]] On Behalf Of Bill Stravinsky via Elecraft
Sent: Monday, August 27, 2018 1:35 AM
To: Elecraft Reflector
Subject: Re: [Elecraft] Filter Recommendations

I opted for a 2.1 ssb filter hoping to be able to enjoy phone contesting just a little bit more but so far I haven't found the magic elixir for phone.I only replied to the post after seeing "information garbling" from Don. That is exactly what happens to me with whatever filter or passbandsetting I have tried in my K3 during a phone contest. Btw, that is during major DX contests, I can handle the smaller ones but normally don't, hi.

BillK3WJV
On Sunday, August 26, 2018, 9:53:41 AM EDT, Don Wilhelm <[hidden email]> wrote:

Lee,

The 2.8kHz filter has a flatter passband and steeper skirts than the 2.7kHz.

But remember that this is a roofing filter, the DSP provides the actual
filtering for the K3/K3S.
The purpose of the roofing filter is to keep strong adjacent signals
from overloading the Hardware AGC and the ADC at the input to the DSP
circuits. A strong signal that is inside the passband of the roofing
filter, but outside the passband of the DSP filter (you may not hear
that signal since it is outside the DSP filter) can cause receiver AGC
"pumping" and in extreme cases can overload the ADC causing severe
"information garbling".

73,
Don W3FPR

On 8/26/2018 8:45 AM, Lee Murrah via Elecraft wrote:

______________________________________________________________
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
Message delivered to [hidden email]

______________________________________________________________
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
Message delivered to [hidden email]

______________________________________________________________
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
Message delivered to [hidden email]

Lovin' my K3S (S/N 10023)
73, Peter W2IRT

Bob McGraw - K4TAX

Re: Filter Recommendations

I agree with Peter in that many hams use too much RX RF Gain and too
little attenuation.    Per one authority on receiver performance, the
optimum receiver performance occurs when the no signal band noise is
about 10 dB above the receiver noise floor. Since we can't adjust the
receiver noise floor, we can adjust the overall signal coming into the
receiver by using attenuation and RF gain reduction. Typically, 160M -
40M one should expect to run 15 dB to 10 dB attenuation unless you are
in a super low noise receiving environment. For higher frequency bands,
less attenuation and more RF gain is found to be desired.   Still
maintaining the 10 dB practice regardless of band and antenna and band
noise.

As example; if your no signal band noise is S-5 or -97 dBm and the
receiver noise floor is -130 dBm, thus a difference of 33 dB, then the
optimum performance will occur with about 15 dB attenuation and 6 to 8
dB of RF gain reduction. Or use 10 dB of attenuation and 12 to 13 dB
of RF gain reduction. It will vary from band to band and antenna to
antenna but will generally be stable across the band for a short period
of time, i.e. several hours considering atmospheric activity. Once
applied, you will find signals will pop out of the noise.    Many hams
believe attenuation is used solely to prevent receiver overload.
Attenuation can be utilized for a more effective means as well.

73

Bob, K4TAX

On 8/27/2018 9:55 AM, Peter W2IRT wrote:
> I find the best thing for phone contesting is a ton of attenuation and judicious use of RF Gain, combined with narrow bandwidth. No way to get rid of the low-frequency rumble from within the passband, but the combination of the roofing filter, DSP high cut and shift/width will get rid of the high-pitched adjacent noise enough to be reasonably efficient. I still don't like SSB contests, but they're far more survivable with a loaded K3s than they were with previous radios!
>
> ---------------------------------------------
> GO FRC!
> Peter, W2IRT
>
> www.facebook.com/W2IRT
>
>

______________________________________________________________
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
Message delivered to [hidden email]

Don Wilhelm

Re: Filter Recommendations

Many hams equate no signal band noise to receiver sensitivity. Nothing
could be further from the truth. Bob has pointed out some very good
guidelines.

For those who do not want to play with the RF Gain to simplify things,
the attenuation and preamp settings will still do a great deal to help.

Listen to a no-signal spot on the band. Listening to the noise level,
try attenuation first - if you can still hear the band noise, leave it
there.
On bands where the receiver seems silent, first turn off attenuation,
and if you do not hear band noise at a low level, turn on some
preamplification.

When you can just barely hear the no-signal band noise, signals will
tend to pop out of the noise.

Just a note - the KX2 and KX3 design point is to always have the preamp
on for the best front end "out of passband" protection. SDR receivers
are different animals and may change our habits with using the receiver
controls in the future. Attenuation is still effective.

73,
Don W3FPR

On 8/27/2018 1:01 PM, Bob McGraw K4TAX wrote:

> I agree with Peter in that many hams use too much RX RF Gain and too
> little attenuation.    Per one authority on receiver performance, the
> optimum receiver performance occurs when the no signal band noise is
> about 10 dB above the receiver noise floor. Since we can't adjust the
> receiver noise floor, we can adjust the overall signal coming into the
> receiver by using attenuation and RF gain reduction. Typically, 160M -
> 40M one should expect to run 15 dB to 10 dB attenuation unless you are
> in a super low noise receiving environment. For higher frequency bands,
> less attenuation and more RF gain is found to be desired.   Still
> maintaining the 10 dB practice regardless of band and antenna and band
> noise.
>
> As example; if your no signal band noise is S-5 or -97 dBm and the
> receiver noise floor is -130 dBm, thus a difference of 33 dB, then the
> optimum performance will occur with about 15 dB attenuation and 6 to 8
> dB of RF gain reduction. Or use 10 dB of attenuation and 12 to 13 dB
> of RF gain reduction. It will vary from band to band and antenna to
> antenna but will generally be stable across the band for a short period
> of time, i.e. several hours considering atmospheric activity. Once
> applied, you will find signals will pop out of the noise.    Many hams
> believe attenuation is used solely to prevent receiver overload.
> Attenuation can be utilized for a more effective means as well.

Jim Brown-10

Re: Filter Recommendations

In reply to this post by Bob McGraw - K4TAX

On 8/27/2018 10:01 AM, Bob McGraw K4TAX wrote:
> Per one authority on receiver performance, the optimum receiver
> performance occurs when the no signal band noise is about 10 dB above
> the receiver noise floor.

Not quite -- when the noise from the antenna is 10 dB above the receiver
noise, the combined noise is fractional dB greater than the antenna
noise alone. As the ratio increases (13 dB from the antenna, for
example), that fractional dB becomes even smaller.

A common misunderstanding is that 1 dB is the smallest change in
loudness that average listeners can hear, but the ear is FAR more
sensitive to differences between signal and noise at low signal to noise
ratios, so fractional dB improvements can make the difference between no
copy and just enough to get the rare DX in the log. :)

Another manifestation of this is mixing multiple mics that pick up the
various parts of a band or orchestra. Anyone who's done much live mixing
will tell you that when the balance relative to the rest of the band of
a vocal or instrument is not quite right, the volume slider for the mic
in question rarely needs to move more than a dB or two. In other words,
the ear-brain is far more sensitive to differences between sounds than
to absolute loudness of the combination of the sounds it hears.

73, Jim K9YC

______________________________________________________________
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
Message delivered to [hidden email]

Bill K9YEQ

Re: Filter Recommendations

In reply to this post by Don Wilhelm

Don, Great reminder. I follow your suggestions, to a fault. In the long past not so much but the quality of the Elecraft equipment changed my practices going back to the K2.

73,
Bill
K9YEQ

https://wrj-tech.com/

-----Original Message-----
From: [hidden email] <[hidden email]> On Behalf Of Don Wilhelm
Sent: Monday, August 27, 2018 10:02 PM
To: [hidden email]
Subject: Re: [Elecraft] Filter Recommendations

Many hams equate no signal band noise to receiver sensitivity. Nothing could be further from the truth. Bob has pointed out some very good guidelines.

For those who do not want to play with the RF Gain to simplify things, the attenuation and preamp settings will still do a great deal to help.

Listen to a no-signal spot on the band. Listening to the noise level, try attenuation first - if you can still hear the band noise, leave it there.
On bands where the receiver seems silent, first turn off attenuation, and if you do not hear band noise at a low level, turn on some preamplification.

When you can just barely hear the no-signal band noise, signals will tend to pop out of the noise.

Just a note - the KX2 and KX3 design point is to always have the preamp on for the best front end "out of passband" protection. SDR receivers are different animals and may change our habits with using the receiver controls in the future. Attenuation is still effective.

73,
Don W3FPR

On 8/27/2018 1:01 PM, Bob McGraw K4TAX wrote:

> I agree with Peter in that many hams use too much RX RF Gain and too
> little attenuation.    Per one authority on receiver performance, the
> optimum receiver performance occurs when the no signal band noise is
> about 10 dB above the receiver noise floor. Since we can't adjust the
> receiver noise floor, we can adjust the overall signal coming into the
> receiver by using attenuation and RF gain reduction. Typically, 160M
> - 40M one should expect to run 15 dB to 10 dB attenuation unless you
> are in a super low noise receiving environment. For higher frequency
> bands, less attenuation and more RF gain is found to be desired.
> Still maintaining the 10 dB practice regardless of band and antenna
> and band noise.
>
> As example; if your no signal band noise is S-5 or -97 dBm and the
> receiver noise floor is -130 dBm, thus a difference of 33 dB, then
> the optimum performance will occur with about 15 dB attenuation and 6
> to 8 dB of RF gain reduction. Or use 10 dB of attenuation and 12 to
> 13 dB of RF gain reduction. It will vary from band to band and
> antenna to antenna but will generally be stable across the band for a
> short period of time, i.e. several hours considering atmospheric
> activity. Once applied, you will find signals will pop out of the
> noise.    Many hams believe attenuation is used solely to prevent receiver overload.
> Attenuation can be utilized for a more effective means as well.

Wes Stewart-2

Re: Filter Recommendations

In reply to this post by Don Wilhelm

I've been at this for 60 years now and the only time I've ever heard signals
"pop out of the noise" was when I was working 2-meter meteor scatter. Where
have I gone wrong?

Wes N7WS

On 8/27/2018 8:02 PM, Don Wilhelm wrote:
> When you can just barely hear the no-signal band noise, signals will tend to
> pop out of the noise.

______________________________________________________________
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
Message delivered to [hidden email]

Elecraft mailing list

Re: Filter Recommendations

The only time I can make signals pop out is when I put in enough ATT to make noises floor S0. Then it is like a FM channel when signal come in. BUT the incoming signal needs to be several S units above the quiet noise floor to truly open the gate so to speak. Weak signals near the noise floor do not open the gate.

Mel, K6KBE

From: Wes Stewart <[hidden email]>
To: [hidden email]
Sent: Tuesday, August 28, 2018 1:15 PM
Subject: Re: [Elecraft] Filter Recommendations

I've been at this for 60 years now and the only time I've ever heard signals
"pop out of the noise" was when I was working 2-meter meteor scatter. Where
have I gone wrong?

Wes N7WS

On 8/27/2018 8:02 PM, Don Wilhelm wrote:
> When you can just barely hear the no-signal band noise, signals will tend to
> pop out of the noise.

______________________________________________________________
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
Message delivered to [hidden email]

______________________________________________________________
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
Message delivered to [hidden email]