Contest stations operating in SO2R and multi-operator configurations will frequently have dedicated antenna systems for each HF contesting band. Installing Series XL bandpass filters in the antenna line after the linear amplifier and antenna switch means the right filter will always be in circuit on the band/antenna combination in use and the operator will never have to worry about switching filters between transceiver and linear amplifier.
"With the 4O3A filters our station to station and site to site interaction was negligible across 83,300+ QSO's. We ran six stations 24/7, and I don't recall ever seeing a station not manned. The only time anything was heard was on the exact harmonic and just tuning 5 kHz off that frequency to set the split allowed operation to continue with no impact." - Jay, W2IJ, T33A DXpedition team
"It is indeed a good feeling when you transmit on one band and can listen even to the weakest signals on the other band, without getting annoyed by the interference." - Ivo, 5B4ADA
4O3A BPFs made the trip to T33A, were used on the highly successful FT5ZM DXpedition, and were on board for the recent TX3X and VP8STI / VP8SGI operations. Some of the well-known contesters and DXers who are using 4O3A Signature gear include 5B4ADA, 5B4AGD, 9A1A, 9A1P, 9A5MT, A71CO, AA7XT, CR2X, CX6VM, DJ5MW, DJ6ZM, DK5QN, DL2ARD, DL4NER, DL8ZAW, DR1A, E73A, EA2AFL, EA5FX, EA7AEY, ED1R, EF8M, EI2FG, EI7M, ES5TV, HA1TJ, HA5JI, HB9BJL, JA1BPA, JE1CKA, JF2QNM, JK1MZT, K3LR, K3WW, LA6FJA, LP1H, LU8EOT, LX2A, LZ2BE, LZ9W, N6PEQ, OH2BH, OH6RX, OH8X, ON4AMX, ON4HIL, OZ5E, P49X, PI4DX, PJ2T, PY2ADR, PY5EG, S50A, S50K, S51TA, S52X, S53M, UA3AB, W0YK, WW4LL, WX3B, YO3JR, YU1EXY, YU1EW, YU5R, and many more.