I recently got a Matchmaster 4 element phased array model MDU36 or L3087. At one stage had a perfect picture with all channels and thought it was fine so mounted it in desired position only to find no signal at all!.
Checked all leads eventually back to aerial where the input measured o/c.
Rang up Matchmaster to confirm what output impedance should be approx and they did not know whether it should be low or o/c but said they'd send a replacement balun in any case.
Anyway I have pulled the aerial down, and opened the balun which is just a PCB with connections to the F connector all correct. Very odd layout where both feeds of the phased array are shorted out on PCB, but the F connector goes to open circuit connections. The only possible way for the 'balun' to work would be through capacitive effect.
Does anybody know about these beasts and if so can you confirm the balun should be o/c output with both phased array feeds joined by pcb track?