Hi Rys,
Simply change the turns ratios of the reflection transformer and matching transformer to correspond to the approximate termination impedance and feed impedance. 4:1 transformers work well for a reversible BOG and a 9:1 transformers works well for an elevated Beverage. For a reversible Beverage, its very important that the unused coax be terminated in approximately a 75 ohm resistor. If you use a single coax feed, the switch box at the feedpoint must use a resistor to terminate the unused feed transformer. Its possible to optimize the termination resistor value to improve the front-to-back ratio, but the improvement is small especially in the case of a BOG. RG-174 has approximately 1 dB loss per 100 feet on 160 meters which is quite acceptable for a 220 foot BOG. You should use 6:1 transformers. 73 Frank W3LPL ----- Original Message ----- From: "Ryszard Tymkiewicz" <[email protected]> To: [email protected], [email protected] Sent: Wednesday, January 10, 2018 11:50:20 AM Subject: Re: Re: Topband: Supporting Ladder line Hi Frank..I understand in the case of BOG we should use both transformers T1 and T3 with 4:1 impedance ratio... ? I wonder if it is possible to use RG174 which unfortunately has quite big attenuation even on 160m? 73 Rys SP5EWY > A reversible Beverage or BOG can be constructed out of a single run > of RG-6, there's no need to form an open wire line out of two runs > of RG-6, > > > See ON4UN's Low Band DXing, Volume 5, page 7-88 and fig. 7-118 > > > 73 > Frank > W3LPL > > _________________ Topband Reflector Archives - http://www.contesting.com/_topband
