Canmlwyddiant y darllediad radio cyntaf dros y dŵr
Cyfrwng: tsieni asgwrn
Maint: 72 x 102 x 94 mm
Derbyniwyd: 1997; Rhodd
Rhif Derbynoli: 1997.88
Print ar y cefn 'Guliemo Marconi & George Kemp / made the first radio transmission / across water on 13th May 1897. / between Lavernock Point, Vale of / Glamorgan, & Flatholm Island in / the Bristol Channel. / This event was re-enacted on 13th / May 1997 by members of the / Barry Radio Society.'