Some poppycock has been written in the yachting press about this.

These observations are written to help the hopeful amateur who may decide to ‘have a go’ at doing this conversion, and to give other users some idea of the work involved to do the job properly and produce a receiver with a performance as good as or better than that of models costing many times as much.

In a small boat, you just cannot mess about with a rotating aerial and hand-bearing compass: furthermore, such aerials are readily subject to damage, and the compass is too easily laid aside hurriedly where it may be stepped or sat on.

The receiver, therefore, is installed in line fore-and-aft. The boat itself is swung until a null is obtained, and the bearing of the boat’s compass then noted.

Unlike the ‘swinging’ of a compass in order to compile a deviation table, once the R.D.F. set is aligned on one station it is true for all other stations in any direction.

Wire rigging, etc., may affect the true alignment of the receiver, but provided this rigging, etc., is not altered in position at a later date, the original alignment of the receiver will remain constant.

If ‘homing’ on a station, an error of some ten degrees will not greatly affect your course: in fact, with an error of nearly ninety degrees you will still reach your landfall, but by a circuitous route. An unmodified transistor radio is not much use.

Modifications include :-

disconnecting the AGC and substituting a manual gain control. Otherwise, on a strong close station, you just will not get a null

fitting a BFO, or similar device, to convert the mere background ‘mush’ of CW stations into a whistle

enclosing the receiver (and the speaker) so as to exclude damp.

Talbot Kirk, Sloop Pat FH25, c/o P.O. Helford, Cornwall, is selling R.D.F. sets at £22 and will advise any members trying to convert radios.