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Question about filters in USB as shown on a P3

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tomb18

Question about filters in USB as shown on a P3

Hi,

I have a question concerning what you see on the P3 when you tune in a USB signal.
The green band that represents the bandwidth is not quite at the tuned in frequency (center frequency) but is displaced slight higher in frequency. If you lower the bandwidth say using a 2.1 KHz filter it has shifted quite a bit up.
Can someone explain what is happening from the radio point of view please?

Thanks, Tom VA2FSQ
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Joe Subich, W4TV-4

Re: Question about filters in USB as shown on a P3

The P3 display shows the "carrier (dial) frequency" as a vertical line
and the audio (filter) bandwidth as the boarder bar. In USB/LSB the
filter bandwidth is typically something like 200 Hz to 2900 Hz (for
a 2.7 KHz "width").

If you have selected shift/width instead of Lo/Hi, adjusting "width"
will reduce the bandwidth equally above and below the center frequency
(typically 1500 Hz). Thus if you select "width" = 2.1 KHz the filter
will be 500 - 2600 Hz and you will see 500 Hz between the vertical
line (carrier/dial) and the actual filter response.

73,

... Joe, W4TV

On 11/2/2013 4:28 PM, [hidden email] wrote:

> Hi,
>
> I have a question concerning what you see on the P3 when you tune in a USB signal.
> The green band that represents the bandwidth is not quite at the tuned in frequency (center frequency) but is displaced slight higher in frequency. If you lower the bandwidth say using a 2.1 KHz filter it has shifted quite a bit up.
> Can someone explain what is happening from the radio point of view please?
>
> Thanks, Tom VA2FSQ
> ______________________________________________________________
> 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
>

tomb18

Re: Question about filters in USB as shown on a P3

In reply to this post by tomb18

Thanks, got it
73s Tom

-------- Original message --------
From: "Joe Subich, W4TV" <[hidden email]>
Date: 02/11/2013 16:42 (GMT-05:00)
To: [hidden email]
Subject: Re: [Elecraft] Question about filters in USB as shown on a P3

The P3 display shows the "carrier (dial) frequency" as a vertical line
and the audio (filter) bandwidth as the boarder bar. In USB/LSB the
filter bandwidth is typically something like 200 Hz to 2900 Hz (for
a 2.7 KHz "width").

If you have selected shift/width instead of Lo/Hi, adjusting "width"
will reduce the bandwidth equally above and below the center frequency
(typically 1500 Hz). Thus if you select "width" = 2.1 KHz the filter
will be 500 - 2600 Hz and you will see 500 Hz between the vertical
line (carrier/dial) and the actual filter response.

73,

... Joe, W4TV

On 11/2/2013 4:28 PM, [hidden email] wrote:

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tomb18

Re: Question about filters in USB as shown on a P3

In reply to this post by tomb18

Just when I thought I had it all together I had this observation:
For am, the bandwidth as shown on the k3 or kx3 says 3 with a shift of 1.5.
However when you look at the p3 the band is clearly centered on the carrier but the band you see is 6khz wide. Shouldn't the bandwidth be shown as 6khz with a center frequency of 0??
Does anyone. Have a an explanation?
73s Tom

-------- Original message --------
From: Tom <[hidden email]>
Date: 04/11/2013 18:24 (GMT-05:00)
To: bill conkling <[hidden email]>
Subject: Re: [Elecraft] Question about filters in USB as shown on a P3

Nope
Check it out today in detail. The filters are centered at the center frequency of the audio passband which for USB is above the carrier frequency and for LSB is below. Gets a bit more complex with all the data modes but its the same idea.
73s Tom

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Don Wilhelm-4

Re: Question about filters in USB as shown on a P3

Tom,

The P3 is showing you the IF bandwidth of the signal before any
filtering, but the K3 or KX3 is indicating the audio bandwidth (after
filtering and demodulation.

With AM, the IF bandwidth is double the AF bandwidth. A bit of study
into AM modulation may be helpful.

73,
Don W3FPR

On 11/5/2013 10:37 PM, Tom wrote:
> Just when I thought I had it all together I had this observation:
> For am, the bandwidth as shown on the k3 or kx3 says 3 with a shift of 1.5.
> However when you look at the p3 the band is clearly centered on the carrier but the band you see is 6khz wide. Shouldn't the bandwidth be shown as 6khz with a center frequency of 0??
> Does anyone. Have a an explanation?
> 73s Tom
>

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tomb18

Re: Question about filters in USB as shown on a P3

Thanks Don…,
I guess the upcoming snowy months up here are a perfect time to study for my advanced license. I’ve got to do something!
73’s

On Nov 5, 2013, at 11:05 PM, Don Wilhelm <[hidden email]> wrote:

> Tom,
>
> The P3 is showing you the IF bandwidth of the signal before any filtering, but the K3 or KX3 is indicating the audio bandwidth (after filtering and demodulation.
>
> With AM, the IF bandwidth is double the AF bandwidth. A bit of study into AM modulation may be helpful.
>
> 73,
> Don W3FPR
>
> On 11/5/2013 10:37 PM, Tom wrote:
>> Just when I thought I had it all together I had this observation:
>> For am, the bandwidth as shown on the k3 or kx3 says 3 with a shift of 1.5.
>> However when you look at the p3 the band is clearly centered on the carrier but the band you see is 6khz wide. Shouldn't the bandwidth be shown as 6khz with a center frequency of 0??
>> Does anyone. Have a an explanation?
>> 73s Tom
>>
>

Fred Smith-2

Re: Question about filters in USB as shown on a P3

No more Advanced licenses anymore, you're ready for the extra get the ARRL
study manual.....and good luck.

73,
Fred/N0AZZ
K3 Ser # 6730--KX3 # 5210--K2/100 # 6470-KAT100
P3/SVGA--KAT500--W2
Amps Elecraft KPA500 HF/6m--Alpha's 9500 HF--87A HF--Mirage B-5030-G
300+w--(2) B-5016-G's 165w 2m

-----Original Message-----
From: [hidden email]
[mailto:[hidden email]] On Behalf Of Tom Blahovici
Sent: Tuesday, November 05, 2013 11:33 PM
To: [hidden email]; [hidden email]
Subject: Re: [Elecraft] Question about filters in USB as shown on a P3

Thanks Don.,
I guess the upcoming snowy months up here are a perfect time to study for my
advanced license. I've got to do something!
73's

On Nov 5, 2013, at 11:05 PM, Don Wilhelm <[hidden email]> wrote:

> Tom,
>
> The P3 is showing you the IF bandwidth of the signal before any filtering,
but the K3 or KX3 is indicating the audio bandwidth (after filtering and
demodulation.
>
> With AM, the IF bandwidth is double the AF bandwidth. A bit of study into
AM modulation may be helpful.
>
> 73,
> Don W3FPR
>
> On 11/5/2013 10:37 PM, Tom wrote:
>> Just when I thought I had it all together I had this observation:
>> For am, the bandwidth as shown on the k3 or kx3 says 3 with a shift of
1.5.
>> However when you look at the p3 the band is clearly centered on the
carrier but the band you see is 6khz wide. Shouldn't the bandwidth be shown
as 6khz with a center frequency of 0??
>> Does anyone. Have a an explanation?
>> 73s Tom
>>
>

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-----
No virus found in this message.
Checked by AVG - www.avg.com
Version: 2013.0.3426 / Virus Database: 3222/6813 - Release Date: 11/06/13

______________________________________________________________
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vk2rq

Re: Question about filters in USB as shown on a P3

As far as I know, there's no such thing as an Extra class in Canada, I think the highest class there is Advanced.

73,
Matt VK2RQ

On 06/11/2013, at 8:40 PM, "Fred Smith" <[hidden email]> wrote:

> No more Advanced licenses anymore, you're ready for the extra get the ARRL
> study manual.....and good luck.
>
>
> 73,
> Fred/N0AZZ
> K3 Ser # 6730--KX3 # 5210--K2/100 # 6470-KAT100
> P3/SVGA--KAT500--W2
> Amps Elecraft KPA500 HF/6m--Alpha's 9500 HF--87A HF--Mirage B-5030-G
> 300+w--(2) B-5016-G's 165w 2m
>
>
>
> -----Original Message-----
> From: [hidden email]
> [mailto:[hidden email]] On Behalf Of Tom Blahovici
> Sent: Tuesday, November 05, 2013 11:33 PM
> To: [hidden email]; [hidden email]
> Subject: Re: [Elecraft] Question about filters in USB as shown on a P3
>
> Thanks Don.,
> I guess the upcoming snowy months up here are a perfect time to study for my
> advanced license. I've got to do something!
> 73's
>
> On Nov 5, 2013, at 11:05 PM, Don Wilhelm <[hidden email]> wrote:
>
>> Tom,
>>
>> The P3 is showing you the IF bandwidth of the signal before any filtering,
> but the K3 or KX3 is indicating the audio bandwidth (after filtering and
> demodulation.
>>
>> With AM, the IF bandwidth is double the AF bandwidth. A bit of study into
> AM modulation may be helpful.
>>
>> 73,
>> Don W3FPR
>>
>> On 11/5/2013 10:37 PM, Tom wrote:
>>> Just when I thought I had it all together I had this observation:
>>> For am, the bandwidth as shown on the k3 or kx3 says 3 with a shift of
> 1.5.
>>> However when you look at the p3 the band is clearly centered on the
> carrier but the band you see is 6khz wide. Shouldn't the bandwidth be shown
> as 6khz with a center frequency of 0??
>>> Does anyone. Have a an explanation?
>>> 73s Tom
>
> ______________________________________________________________
> 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
> -----
> No virus found in this message.
> Checked by AVG - www.avg.com
> Version: 2013.0.3426 / Virus Database: 3222/6813 - Release Date: 11/06/13
>
> ______________________________________________________________
> 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

tomb18

Re: Question about filters in USB as shown on a P3

In reply to this post by tomb18

In Canada we have the Basic, Basic with honors, and advanced. The advanced is like the US extra.

-------- Original message --------
From: Fred Smith <[hidden email]>
Date: 06/11/2013 07:40 (GMT-05:00)
To: 'Tom Blahovici' <[hidden email]>,[hidden email],[hidden email]
Subject: RE: [Elecraft] Question about filters in USB as shown on a P3

No more Advanced licenses anymore, you're ready for the extra get the ARRL
study manual.....and good luck.

73,
Fred/N0AZZ
K3 Ser # 6730--KX3 # 5210--K2/100 # 6470-KAT100
P3/SVGA--KAT500--W2
Amps Elecraft KPA500 HF/6m--Alpha's 9500 HF--87A HF--Mirage B-5030-G
300+w--(2) B-5016-G's 165w 2m

-----Original Message-----
From: [hidden email]
[mailto:[hidden email]] On Behalf Of Tom Blahovici
Sent: Tuesday, November 05, 2013 11:33 PM
To: [hidden email]; [hidden email]
Subject: Re: [Elecraft] Question about filters in USB as shown on a P3

Thanks Don.,
I guess the upcoming snowy months up here are a perfect time to study for my
advanced license. I've got to do something!
73's

On Nov 5, 2013, at 11:05 PM, Don Wilhelm <[hidden email]> wrote:

> Tom,
>
> The P3 is showing you the IF bandwidth of the signal before any filtering,
but the K3 or KX3 is indicating the audio bandwidth (after filtering and
demodulation.
>
> With AM, the IF bandwidth is double the AF bandwidth. A bit of study into
AM modulation may be helpful.
>
> 73,
> Don W3FPR
>
> On 11/5/2013 10:37 PM, Tom wrote:
>> Just when I thought I had it all together I had this observation:
>> For am, the bandwidth as shown on the k3 or kx3 says 3 with a shift of
1.5.
>> However when you look at the p3 the band is clearly centered on the
carrier but the band you see is 6khz wide. Shouldn't the bandwidth be shown
as 6khz with a center frequency of 0??
>> Does anyone. Have a an explanation?
>> 73s Tom
>>
>

______________________________________________________________
Elecraft mailing list
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Post: mailto:[hidden email]

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Please help support this email list: http://www.qsl.net/donate.html
-----
No virus found in this message.
Checked by AVG - www.avg.com
Version: 2013.0.3426 / Virus Database: 3222/6813 - Releas
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
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Post: mailto:[hidden email]

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