CU4/G3TXF was active from Graciosa for three days in February 2004. The trip coincided with the FOC Marathon (an annual QSO-party among the 500 members of this CW operators' club).

Graciosa (CU4) is the second smallest of the nine main islands of the Azores archipelago. Corvo (CU9) is the smallest. Graciosa is one of the five islands that make up the central group [EU-175] in the Azores. The other islands in EU-175 are Terceira (CU3), San Jorge (CU5), Pico (CU6) and Faial (CU7).

Graciosa was chosen as the destination for two reasons. Firstly G3TXF has never worked any CU4 (or CU5) station from home, although he has confirmed CW QSOs with each of the other Azores prefixes. This suggested CU4 was rare. Secondly CU4 is described as being much flatter than other islands in the group. Most of the Azores are characterised by high peaks and sheer cliffs into the ocean. For all-round coverage flatter locations are usually to be preferred.

Checking the OH2BUA DX-Cluster Database revealed that there had been no significant activity from CU4 during the past five years, and absolutely no activity at all on CW. So CU4 it was to be.

There are only three small guest-houses on Graciosa (CU4), and on an initial inspection, none of them seemed suitable for radio. They are all within the main town (Santa Cruz) and none has any open space for antennas.

However a chance E-mail to Gabriel CU3AN on Terceira (who sometimes operates as CU4AP from Graciosa) resulted in an invitation to stay at his holiday house on CU4. This was a nice surprise. Gabriel's house is located in Fontes about one mile from the main town, and is located on the side of a hill with a clear view from the north-west through north to the south-east. This is an ideal take-off from CU4 for both the USA and Europe.

CU3AN's house is located in the middle of the village and although it has a superb view, the amount of space for antennas is restricted. However installing a vertical on the roof patio was simple enough.

John G4IRN had kindly lent me his SteppIR 40m-6m vertical [which John had used successfully on S79 and FH]. The SteppIR vertical has the major attraction of being a true quarter-wave on each band, without the necessary comprise and losses caused by using traps. The SteppIR vertical worked well. Only four radials were used. Others would have been added had the stay on CU4 been longer. John G4IRN's SteppIR vertical provided fast and easy access to the seven bands from 40m to 10m. However the greater challenge were the LF antennas for 80m and 160m.

There was no space to put out a horizontal 80m dipole (let alone a 160m dipole). Also the presence of over-head power cables close to the roof of the house further restricted the scope for LF antennas. Fortunately a 33ft portable fibre-glass pole had been taken along "just in case" and it turned out to be most useful. Initially an inverted-L antenna was installed for 80m, with about 33ft of vertical wire and 33ft horizontal. The vertical was "tuned" against the other half of an 80m dipole just dangling over the roof down to the ground in the garden next door. The 80m vertical antenna worked surprisingly well with some 500 QSOs being made. The greater challenge however was 160m.

After using the 80m antenna for just two nights, on the third night an extra 66ft of wire was added to the inverted-L. The antenna wire was then literally wrapped around the building. The lower end of the dipole was just "wound up" into a ball of wire until it resonated (vaguely!). During the last hour of the FOC Marathon, much to my surprise, some 19 UK stations were worked on 160m.

The CU4/G3TXF operation lasted just over three days and netted 3,600 CW QSOs. 600 QSOs were in the FOC Marathon and 3,000 were general CW QSOs, mainly on the WARC-bands. Following CU4 a few days were spent visiting CU3 and CU2, but this time there was no radio! The Azores (CU) are by no means rare as a country, and even the central group (EU-175) is not uncommon, but hopefully this short operation will have at least provided a few with a useful new prefix on CW for WPX : CU4.