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This paper presents an extensive overview of known and proposed RR Lyraestars in binaries. The aim is to revise and extend the list with new Galacticfield systems. We utilized maxima timings for eleven RRab type stars withsuspicious behaviour from the GEOS database, and determined maxima timings fromdata of sky surveys and our own observations. This significantly extended thenumber of suitable maxima timings. We modelled the proposed Light Time Effect(LiTE) in O-C diagrams to determine orbital parameters for these systems. Incontrast to recent studies, our analysis focused on decades-long periodsinstead of periods in the order of years. Secondary components were found to bepredominantly low-mass objects. However, for RZ Cet and AT Ser the mass of thesuspected companion of more than one solar mass suggests that it is a massivewhite dwarf, a neutron star or even a black hole. We found that the semi-majoraxes of the proposed orbits are between 1 and 20 au. Because the studied starsbelong to the closest RR Lyraes, maximal angular distances between componentsduring orbit should at least be between 1 and 13 mas and this improves thechance to detect both stars using current telescopes. However, ourinterpretation of the O-C diagrams as a consequence of the LiTE should beconsidered as preliminary without reliable spectroscopic measurements. On theother hand our models give a prediction of the period and radial velocityevolution which should be sufficient for plausible proof of binarity.

Cyclic variations in O-C diagrams of field RR Lyrae stars as a result of LiTE