Dr. A. Hoyt Taylor: "Eifel Tower Communication"

Communication to Eifel Tower and first direct exchange with Rome by President Wilson

The German transmitter stations at Tuckerton and Sayville had been operated with high frequency alternating current generators which, I believe, were of the Goldschmidt type. We never did get the one at Tuckerton to operate satisfactorily. By the time I arrived on the scene, we had re-placed it with a 60 K.W. Poulsen arc. This operated into an umbrella-like antenna whose center support was an insulated steel tower 800 feet high. The ribs of the umbrella were supported by a circle of smaller towers. The station was located on what was practically marsh land, a few miles back from the ocean. Warrant Officer (Radio Gunner) Hessler was in charge of the Tuckerton station. Very good ground connection was obtainable at Tuckerton but at Sayville, L. I., the dry sand under the antenna presented so high a resistance that the Germans had erected an extensive counterpoise, about twenty feet high, underneath the antenna; this was used in place of a ground connection.

We operated the alternator at Sayville for some time but had a great deal of trouble with it, largely on account of variations in transmis-sion line voltage of the sixty cycle supply system of the station. This alternator operated at about 11,000 cycles or 11 K.C. It was a reflection type alternator, with a complicated system of very carefully tuned low-loss circuits, creating a strong third harmonic at 33 K.C. which was approximately the frequency used in the antenna. It was impossible to keep these reflection circuits properly tuned if the speed of the drive motors varied even a small amount, due to the supply voltage variations. We therefore finally installed a 350 K.W. Poulsen arc.

Mr. Haraden Pratt, who is now one of the leading men in the Inter-national Telegraph and Telephone Company, was, at that time, Expert Radio Aide for the Navy and our specialist on Poulsen Arcs. He certainly was one of the most competent civilian engineers that the Navy ever had in the Service. I have always had the greatest respect for him, both as an indi-vidual and as an engineer. I well remember visiting the Sayville Station after receiving notice that they were about to turn the power on the Poulsen arc; this was probably some time in the late fall of 1917.

The usual method of installing the Poulsen arc was to connect the water cooled terminal to the copper strip leading to ground, since the cir-culating water more or less grounded this terminal in any case. The other terminal was then connected, through suitable tuning coils of very large cross section, to the antenna. The adjustment of these tuning coils deter-mined the wavelength, or frequency, of the emitted wave. We found it impossible to get more than about 20 amperes into the antenna, in spite of the fact that we had connected the counterpoise to the ground terminal. Since we knew we should have more than 300 amperes, considering the power available, it was evident that something was radically wrong.

Fortunately before I went up to Sayville I had taken the trouble to study the use of the counterpoise in connection with antennae. I told the engineers that it would be necessary to tune the counterpoise as well as the antenna. This required a tuning coil that would carry very large current, but need have only a very small inductance. We had no such coil, but found a copper strip about 3/4" in thickness and 3" wide. We hurriedly built this strip into a spiral by simply nailing it to a couple of planks in the form of a cross, in order to hold it in shape. We didntt need any better insulation, since the voltage of the counterpoise would be Very low, although it might rise to well over 100,000 volts on the antenna.

After soldering the heavy leads from the counterpoise to one end of this strip, we fixed up a heavy flexible lead to the arc terminal, with a large copper clip which could be slipped along our spiral, thus permitting a crude, but very effective, form of tuning.

Starting the arc at low power, we adjusted this clip until we found the resonance point. I then ordered the power pushed up to the maximum. The current in the antenna went up to 400 amperes, which was more than any one had seen in an antenna at that time. I am sure that Mr. Pratt will remember this incident, and how astonished our helpers were when we had finished adjusting this crude contrivance.

I knew about counterpoise action because of my experience at New Brunswick. New Brunswick had originally been equipped for the American Marconi Company with a huge 300 K.W. rotary spark gap installation. I wish I might have seen this installation in operation; it must have been quite a sight, provided you had plenty of cotton in your ears to shut out the noise.
Page updated December 30, 2003  page created September 02, 2000