LF: Re: G7NKS now txing on WSPR 137.5

["James Moritz" <james.moritz@btopenworld.com>]

Dear Steve, LF Group,

The software assumes you will be using a transceiver in USB mode. By 
default, WSPR generates/decodes audio at 1500Hz +/- 100Hz. The "Dial 
frequency" is the USB carrier frequency, so is offset 1.5kHz below the 
centre frequency of the WSPR "band" in use. So in this case, WSPR is being 
transmitted at 137.5kHz +/-100Hz, the receiver should be set to 136.0kHz 
USB, and the value of dial frequency entered to the software should be 
0.1360MHz. For transmission, you enter the actual transmit centre frequency 
in the "Tx" box, which in this example can be anywhere in the range 
0.13740MHz to 0.13760MHz.
Especially for 136k WSPR reception, you may want to use a receiver in CW 
mode in order to use narrow filters. In this case, the receive frequency 
would be set to the centre of the WSPR band. To get audio output centred on 
1.5kHz, the RX BFO pitch needs to be set to 1.5kHz, or alternatively the "RX 
BFO" option in the Setup/Advanced menu in WSPR needs to be set to the actual 
BFO pitch in the receiver. The Dial frequency value then needs to be (WSPR 
frequency) - (BFO pitch). So if the BFO pitch were actually 650Hz,  the 
receiver would be set to 137.5kHz, and Dial Frequency to (137.5kHz - 650Hz), 
i.e 0.13685MHz
Cheers, Jim Moritz
73 de M0BMU

----- Original Message ----- 
From: "Steve Sykes" <steve@ecsykes.com>
To: <rsgb_lf_group@blacksheep.org>
Sent: Saturday, January 29, 2011 7:04 PM
Subject: Re: LF: Re: G7NKS now txing on WSPR 137.5


> Roger,
> I have my receiver set at 137.5, but to display the correct frequency on
> the WSPERnet map, I need to set the program to 136.0.  Is this correct?