Your CR70A Receiver is capable of world wide reception under
normal atmospheric conditions. It will give excellent
results under adverse conditions and good reception can be
obtained with simple indoor aerial systems.
However, for consistent long distance reception and improved
signal/noise ratio, an outdoor aerial is far superior. The
actual length for general coverage is not critical but it
should be as high as possible and kept clear of buildings
etc. Space limitations determine the total length that can
be erected, but if possible an aerial about 30 feet long
will give excellent results. Avoid making joints in aerial
wire unless soldered as eventual corrision will cause
crackling and intermittent signals. Insulators should be
used at each end.
Where space is a limiting factor, vertical aerials are
capable of excellent results. The vertical wire can be
installed from upper and lower windows, but should be spaced
away from the wall with stand-off lengths of wood or
plastic. One advantage of vertical aerials is that they are
less directional than the horizontal type, although the
pick-up pattern can be effected by local buildings.
A good earth can improve results on all bands and will
assist in reducing local interference. If a seperate earth
to a water pipe or metal pipe driven into the ground is not
available, the third pin (the largest earth pin) on the
mains plug should be used.
Short Wave reception varies on the different bands according
to the time of day, period of the year and atmospheric
conditions. It will be found that reception on one
particular band may be excellent in the morning or afternoon
and fade out as darkness approaches. At the same time
reception on another band will steadily improve. Sunspot
activity and electrical storms will also effect reception