in fig1 is set forth the prior art approach for compensating for cable loss between the receiver 10 and the converter 20 . the receiver 10 is typically located in the house or building of the user whereas the down converter 20 is typically located at the site of the satellite antenna . the down converter 20 is connected to the lna 30 over lines 40 . the lna 30 receives power , v 1 , over lines 40 from the down converter 20 which in turn receives power , v 2 , over lines 50 from source v p . in a typical embodiment , 150 mamp of current are delivered into the lna 30 and 100 mamp of current are delivered into the down converter 20 . these wires have a resistance loss of r t1 and r t2 of about approximately 10 ohms per thousand foot . the cable 60 is coaxial cable having a center conductor 62 and a ground shield 64 . both the ground shield 64 and the center conductor 62 have a resistance loss of approximately 17 ohms per thousand foot which is designated r c for the center conductor 52 and r s for the shield 54 . the ground shield 64 is connected to ground gnd 1 at the down converter 20 and also to ground gnd 2 at the receiver 10 . it is to be expressly understood that those circuit portions designated v 1 , v 2 , and v p contained in the lna 30 , the down converter 20 , and the receiver 10 , respectively , are all conventional and known in the art . in one prior art approach , the receiver 10 and down converter 20 are sold by winegard company , 3000 kirkwood street , burlington , ia 52601 as models sc - 7035 and sc - 7035s . and , the lna 30 is sold by winegard as model sc - 8101 . the coax wires 60 , as mentioned , interconnect the receiver 10 with the down converter 20 . the coax 60 interconnects a tuning voltage source v t to an oscillator , osc , in the down converter 20 . not shown in this circuit is the conventional circuitry for delivering the received signal ( usually 70 mhz ) from the down converter 20 to the receiver 10 . the voltage source , v t , provides tuning to the down converter in a conventional fashion . one of the problems in the prior art approach shown in fig1 is the variation of the resistances of r t , r s , and r c which variations are caused by changes in the temperature , changes in the length of the cables 50 and 60 , and deterioration of the cables 50 and 60 . furthermore , the use of different lnas 30 and different down converters 20 can cause varying currents to flow through cables 50 and 60 . such changes in the resistance or electrical current will cause the tuning voltage , v t , to be adversely affected and to cause the down converter 20 to tune in at different frequencies than those set at the receiver 10 . two prior art techniques , as mentioned , are available to correct such voltage changes . the first is a compensation control 70 which is a potentiometer that is adjusted by the installer of the system when the installer interconnects the cables 50 and 60 from the receiver to the down converter and installs the lna 30 . this is accomplished by adjusting the potentiometer 70 in the direction of arrow 72 usually with an insulated screwdriver to center the fine tuning range . this control is labeled comp in the aforesaid models sc - 7035 and sc - 7035s . a second correctional circuit is the fine tune circuit 80 which is adjusted by the user of the receiver 10 by turning a potentiometer in the direction of arrow 82 . in this fashion , the user of the system can fine tune the receiver 10 and , in part , compensate for the losses in cables 50 and 60 . the fine tune control 80 is usually used in conjunction with a signal strength meter . unfortunately , should significant changes in resistances r t , r s , and r c occur the fine tune 80 is insufficient to fully rectify the deficiency . in fig2 is set forth the prior art circuitry of fig1 modified by the present invention . at the outset , it is to be noted that the present invention as shown in fig2 eliminates the need for the compensation control 70 and the fine tune circuit 80 in conventional prior art receivers 10 . furthermore , it is to be also noted that no additional wires or cables are required between the receiver 10 and the down converter 20 as set forth in the prior art approach of fig1 . hence , the present invention achieves an automatic compensation control for the varying line losses r t , r s , and r c without additional interconnecting cable and through the elimination of the conventional fine tune circuit 80 and the compensation potentiometer 70 . at this point , reference back to fig1 is necessary . in fig1 the voltage difference between gnd2 and gnd1 is designated v l . v l is equal to the product of the parallel combination of r s and r t1 and the sum of the lna and down converter current . it is this voltage v l that combines with v t to deliver a resultant signal , v t minus v l , to the oscillator osc . under the teachings of the present invention , and as shown in fig2 connection of wire 54 is changed so that it does not connect to ground gnd2 in the receiver , as shown in fig1 but rather to the positive input of operational amplifier 200 located in receiver 10 . the negative input of operational amplifier 200 is delivered over line 202 through resistor 204 to ground gnd2 and through resistor 206 to the output 208 of the operational amplifier 200 . the output 208 is delivered through resistor 210 to the center conductor 62 of cable 60 . resistors 204 and 206 are adjusted to provide unity gain to amplifier 200 so that the input voltage , v l , is delivered to the output on line 208 . hence , a voltage , v l , is automatically added to the tuning voltage v t . the resultant voltage delivered to the oscillator osc is as follows : hence , the resulting voltage delivered to the oscillator osc at the down converter 20 is precisely v t and any voltage drop , v l , which may occur for any of the reasons discussed above over cables 50 and 60 is automatically and immediately compensated for under the teachings of the present invention . this not only results in savings in the circuitry of the receiver 10 by the elimination of the fine tune circuit 80 and the compensation control 70 , but it also saves in time and labor in having the installer adjust the compensation control 70 and the inconvenience to the user in having to adjust the fine tune control 80 . in addition to these benefits , the automatic compensation control of the present invention provides for more accurate tuning without the addition of any extra cables or wires between the down converter 20 and the receiver 10 . in the preferred embodiments , the operational amplifier is manufactured by motorola as model no . mc - 1741 . while the present invention has been presented with a particularly degree of specificity it is to be expressly understood that changes and modifications can be made thereto without departing from the spirit and scope of the claims that follow .