\typeout{------- telescope --------}

\subsection{The Telescope}


This section gives all the technical details of observations with the
30m telescope that the typical user will have to know. A concise
summary of telescope characteristics is published on the
\htmladdnormallink{IRAM web pages}
{\wwwes/mainWiki/TelescopeSystemSummary}.

\subsubsection {Pointing and Focusing}

With the systematic use of inclinometers the telescope pointing became
much more stable. Pointing sessions are now scheduled at larger intervals.
%Pointing sessions are normally scheduled twice per week; at present,
The fitted pointing parameters typically yield an absolute rms
pointing accuracy of better than $3''$ \cite{pointing}. However,
larger deviations can occur around sunset or sunrise, in which case we
recommend more frequent pointings (every 1 or 2 hours, depending on
the beam size). An effort is made that receivers are closely 
(usually $\simlt2''$) aligned.
%, however, alignment can be lost occasionally).
Checking the pointing, focus, and receiver alignment is the
responsibility of the observers (use a planet for alignment checks).
Systematic (up to 0.4 mm) differences between the foci of various receivers
%were noted in the past and may well persist, even with the new
%generation receivers.
can occasionally occur.
In such a case the foci should be carefully monitored and a compromise value
be chosen.  Not doing so may result in broadened and
distorted beams (\cite{R2}).

%\begin{table}
%\caption[]{Summary of 30m telescope characteristics}
%\label{summ}
%\begin{tabular}{|c|}\hline
%supplied by Wolfgang\\ \hline
%\end{tabular}
%\end{table}

\subsubsection {Wobbling Secondary}

\begin{itemize}
\item Beam--throw is $\le 240''$ depending on wobbling frequency.
      At 2 Hz, the maximum throw is $90''$
\item Standard phase duration: 2 sec for spectral line observations, 0.25 sec
for continuum observations.
\end{itemize}

Unnecessarily large wobbler throws should be avoided, since they introduce
a loss of gain, particularly at the higher frequencies, and imply a loss
of observing efficiency (more dead time).


\subsubsection{Beam and Efficiencies}

See the \href{http://www.iram.es/IRAMES/mainWiki/TelescopeSystemSummary}
{summary of telescope parameters} for the current efficiencies between 
70 and 270~GHz, and the predictions for the 345~GHz (0.8~mm) band.

