EME219 2m VHF X-POL Switch
The EME219 2m VHF X-POL switch replaces the EME218 VHF and has been designed to be used with two 145MHz yagi antennas mounted in a X configuration for use with the LEO Satellites. The switch allows the antennas to be switched between Vertical, Horizontal, Right Hand Circular and Left Hand Circular Polarization. Depending on the bandwidth of the antennas used, the switch will work between 144 and 148MHz for both terrestrial horizontal SSB, and vertical FM polarization.
This product has been fully tested over time and can easily handle the full 100W output power from an IC-9700 into correctly matched Antennas over the 2m band. Each Relay only has to handle half the RF power as it is split, but the power rating of the Relays is also dependent on the return loss from the Antennas being low in each polarization mode. It is highly recommended that the return loss is fully tested on the frequencies and different polarization modes that are required of the Antenna system before using full power.
the rating also depend on the return loss of the antennas and being able to fully test the return loss in each polarization mode. Said this the switch will easily handle full power from an IC-9700 into correctly matched antennas across the band.
The switch has been designed to be easy to construct, but does require experienced skills to fabricate the coaxial cable phasing lines. . BUY THIS PRODUCT
Top view of the EME219-2M Polarization Switch
Bottom View of the EME219-2M Polarization Switch
Side view of the EME219-2M showing how the phasing lines are routed
Side view of the EME219-2M showing how the phasing lines are routed
Side view of the EME219-2M showing how the phasing lines are routed and soldered to the board before the relays are fitted.
Side view of the EME219-2M showing how the phasing lines are routed and soldered to the board before the relays are fitted.
The Tests below show the through loss, return loss and the phase of the signals from the TRX to Antenna connectors for Vertical, Horizontal, Right Hand and Left Hand Circular polarization. The phasing lines were optimized using a DG8SAQ VNA with a 50ohm BNC termination on the unused antenna port. The phasing line lengths are slightly different than calculated and include the strip lines and relays that all affect the optimized lengths. The results indicate that the phases between the antenna connectors for the various polarizations are within a couple of degrees. Vertical is -271.85 degrees, LHCP is 1.22 degrees, Horizontal is -91.51 degrees, RHCP is 181.6 degrees.
EME219-2M TRX to ANT1 ( RL1 Off RL2 Off Vertical )
EME219-2M TRX to ANT2 ( RL1 Off RL2 Off Vertical )
EME219-2M TRX to ANT1 ( RL1 On RL2 Off LHCP )
EME219-2M TRX to ANT2 ( RL1 On RL2 Off LHCP )
EME219-2M TRX to ANT1 ( RL1 Off RL2 On Horizontal )
EME219-2M TRX to ANT2 ( RL1 Off RL2 On Horizontal )
EME219-2M TRX to ANT1 ( RL1 On RL2 On RHCP )
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EME219-2M TRX to ANT2 ( RL1 On RL2 On RHCP )
The GME Masthead enclosure will accept cables up to around 8mm in diameter. Therefore larger cables like RG8/213 cannot be used. Larger cables would also place too much strain on the BNC sockets on the pre-amplifier board. To connect the Antenna feed line to the pre-amplifier, and pre-amplifier output to the main feed line, we recommend the use of CNT®240 ( 240 Type ) cable with crimped BNC connectors. CNT®240 is double shielded and has losses similar to RG213 cable, but has a much smaller 6mm diameter. Use the website search box and search for 240 series cable and connectors.
The EME219 board mounted in a GME Masthead Enclosure
The Enclosure has a locking Tab that holds the board firmly
