A system for providing transvascular retrograde access in a central blood vessel of a patient. Therefore, in the seal portion heating apparatus for a resinous tube, the end portion of the resinous tube serving as the sealed portion is heated uniformly to obtain excellent sealing and achieve excellent appearance. A layer of cushioned material is preferably disposed between the inner and outer layers to provide the case with a soft feel. The cell and the peripheral trenches have sidewalls. Additional embodiments include the use of a supplemental voltage provider that is able to further boost or hold the isolated word line at the needed voltage level. The transceiver also comprises a transmitter having a closed power control loop, and a harmonic rejection modulator, the use thereof made possible by a frequency plan designed to allow the synthesizer to develop the transmit and receive LO signals without a frequency multiplier.