\begin{table}%t8
\caption {\label{tab:spr}Spectral response test results. }             % title of Table
%\centering
                          % used for centering table
\begin{tabular}{l l r r r r}        % centered columns (4 columns)
\hline\hline                 % inserts double horizontal lines
\par
  & & \multicolumn{4}{c}{SPR B\sc{andwidth and central frequency }}\\
 & & M-00 & M-01 & S-10 & S-11 \\    % table heading 
\hline                        % inserts single horizontal line
{\tt RCA18}  
& $\beta_{\rm spr}$ &12.40 &11.14	&	10.84&10.25 \\
%& $\nu_0$       & & &&  \\
{\tt RCA19}  
& $\beta_{\rm spr}$ &10.45 &10.74	&8.00	& 9.91\\
%& $\nu_0$       & & & & \\
{\tt RCA20}  
& $\beta_{\rm spr}$ & 11.19&12.21	&	12.57&10.82 \\
%& $\nu_0$       & & & & \\
{\tt RCA21}  
& $\beta_{\rm spr}$ & 11.19&	12.21&	12.57& 10.82\\
%& $\nu_0$       & & & & \\
{\tt RCA22}  
& $\beta_{\rm spr}$ &11.49 &10.38	&	11.11&10.44 \\
%& $\nu_0$       & & & & \\
{\tt RCA23}  
& $\beta_{\rm spr}$ & 10.35&11.52	&	11.62& 11.44\\
%& $\nu_0$       & & & & \\
{\tt RCA24}  
& $\beta_{\rm spr}$ &5.15 &	4.08&5.26	&5.82 \\
& $\nu_0$       &45.75 & 42.4& 45.6& 45.3\\
{\tt RCA25}  
& $\beta_{\rm spr}$ & 4.42&4.49	&4.17	&5.91 \\
& $\nu_0$       &45.75 &45.25&45.85 &44.90 \\
{\tt RCA26}  
& $\beta_{\rm spr}$ &6.10 &4.86	&4.26	&5.48 \\
& $\nu_0$       &44.35 &44.85 &44.90 & 44.20\\
{\tt RCA27}  
& $\beta_{\rm spr}$ & --&--	&	3.89& 3.71 \\
& $\nu_0$       & --& --& 30.45& 30.70\\
{\tt RCA28}  
& $\beta_{\rm spr}$ &4.94 &5.12	&--	& --\\
& $\nu_0$       &31.4& 31.35 &--  & --  \\
\hline
\end{tabular}
\tablefoot {The numbers are bandwidth values, $\beta_{\rm spr}$ and central frequency, $\nu_0$, both in~GHz.}
\end{table}