[600MRG] Receiver bandwidth for WSPR

[jrusgrove at comcast.net]

Brian

This has been a 'known issue' for a couple years now. You can verify this for yourself by receiving 
a stable locally generated weak WSPR signal and observe the s/n change with ssb and narrower 
receiver bandwidths. I don't know how Joe is making the calculation but I can tell you that 
bandwidth size does matter.

Jay


----- Original Message ----- 
From: "Brian Pease" <bpease2 at myfairpoint.net>
To: <600mrg at w7ekb.com>
Sent: Friday, March 21, 2014 9:24 AM
Subject: Re: [600MRG] Receiver bandwidth for WSPR


> But is WSPR really looking at noise outside the 200Hz WSPR band?  I have assumed that the software 
> just looks at noise over a small bandwidth very close to each signal's frequency, then simply 
> converts it to what it would be at 2500 Hz.  If it averaged the whole 2500Hz I.F. bandwidth then 
> the 400Hz BW s/n numbers would be about 8dB better since the noise drops towards zero outside +/- 
> 200Hz.
> On 3/21/2014 9:08 AM, jrusgrove at comcast.net wrote:
>> WSPR s/n measurements will be incorrect if the receiver bandwidth is set to less than the 
>> expected SSB bandwidth.
>>
>> Jay W1VD  WD2XNS  WE2XGR/2
>>
>>
>>
>> ----- Original Message ----- From: "Brian Pease" <bpease2 at myfairpoint.net>
>> To: <600MRG at w7ekb.com>
>> Sent: Friday, March 21, 2014 8:48 AM
>> Subject: [600MRG] Receiver bandwidth for WSPR
>>
>>
>>> I have found that my WSPR reception seems slightly better using the wide 3100Hz bandwidth on my 
>>> HP3586C receiver compared to 400Hz. Have others tested this? My theory is that the static bursts 
>>> reach the sound card sharp and crisp without the ringing from the narrow physical filter.  There 
>>> should be no effect on the desired signals. The extra noise on other audio frequencies may not 
>>> matter.  Of course it could be related to my particular man made 
>>> noise.................................
>>>
>>> _______________________________________________
>>> 600MRG mailing list
>>> 600MRG at w7ekb.com
>>> http://w7ekb.com/mailman/listinfo/600mrg_w7ekb.com
>>
>>
>> _______________________________________________
>> 600MRG mailing list
>> 600MRG at w7ekb.com
>> http://w7ekb.com/mailman/listinfo/600mrg_w7ekb.com
>>
>
>
> _______________________________________________
> 600MRG mailing list
> 600MRG at w7ekb.com
> http://w7ekb.com/mailman/listinfo/600mrg_w7ekb.com