Вытащить данные с сайта

string de_call = "UT7DU";
string dx_call = "C8X";
int frequency = 7090;
string info = "up 3";
 
using (WebClient web = new WebClient())
{
    string json = string.Format(
        "{{\"de_call\":\"{0}\",\"dx_call\":\"{1}\",\"frequency\":\"{2}\",\"info\":\"{3}\"}}",
        de_call, dx_call, frequency, info);
    byte[] postData = Encoding.UTF8.GetBytes(json);
 
    web.Headers.Add("Referer", "http://www.dxsummit.fi/");
    web.Headers.Add("Content-Type", "application/json;charset=utf-8");
    web.Headers.Add("User-Agent", ".NET Application");
    string jsonResponse = Encoding.UTF8.GetString(web.UploadData("http://www.dxsummit.fi/api/v1/spots", postData));
    if (jsonResponse == "{\"status\": \"ok\"}")
    {
        // Spot добавлен
    }
    else
    {
        // Ошибка
    }
}

string de_call = SpotCallsign.Text; //MainForm.DataSpot.de_call; //"UT7DU";
string dx_call = MainCallsign.Text; //MainForm.DataSpot.dx_call;
 
string frequency = "3605"; //SpotBand.Text;  //Convert.ToInt32(MainForm.DataSpot.frequency);
string info = SpotInfo.Text;

string json = string.Format(
"{{\"de_call\":\"{0}\",\"dx_call\":\"{1}\",\"frequency\":\"{2}\",\"info\":\"{3}\"}}",
de_call, dx_call, frequency, info);

if (MainForm.DataSpot.frequency.Length == 9) { SpotBand.Text = MainForm.DataSpot.frequency.Replace(".", "").Remove(5); SpotBand.Text= SpotBand.Text.Insert(4,","); }
 
if (MainForm.DataSpot.frequency.Length == 10) { SpotBand.Text = MainForm.DataSpot.frequency.Replace(".", "").Remove(6); SpotBand.Text = SpotBand.Text.Insert(5, ","); }

string dx_call = SpotCallsign.Text; ; 
string de_call = MainCallsign.Text; 
string frequency = SpotBand.Text;  
string info = SpotInfo.Text;