Prior to World War One, Frank Conrad had operated experimental radio station 8XK from the detatched garage at his home in Wilkinsburg, Pennsylvania. During the war he continued to operate a station, under a special authorization for conducting research. After the war he returned to the civilian airwaves, apparently at first under an informal authorization, as 8XK would not be issued a new licence until January 21, 1920.
The Radio Amateur, A Department for Wireless News, By C. E. Urban

Pittsburgh Gazette Times, October 26, 1919, Sixth section, page 13: (Full column at Google newspapers)

Wireless  Telephone  Here.
    What is believed to have been the first wireless telephone heard in Pittsburgh since the lifting of amateur restrictions made its debut Friday evening, October 17. The station making the tests is in Wilkinsburg and is owned by Mr. Frank Conrad, a research engineer with the Westinghouse Electric and Manufacturing Company. On the evening referred to Mr. Conrad gave a wireless concert which lasted about two hours, and was greatly enjoyed by a large number of the local amateurs who were listening in. A phonograph was used to produce the music and between records Mr. Conrad would announce their titles. Grand opera, popular music, jazz bands, orchestral and various other numbers were among the selections.
    Quite a little applause from the large and widely-scattered audience marked the close of each piece played. This applause was registered in the dots and dashes of wireless telegraphy. When Mr. Conrad finally announced that he had no more records to play and would have to quit for the evening there were many regrets. One amusing incident in connection with the wireless concert occurred when, during a catchy melody, a peal of merry, feminine laughter was heard in the receivers of the attentive audience. Mr. Conrad informed the listeners that it was Mrs. Conrad, who had just then stepped into the room where the telephone was and had laughed at some pun of his. The laughter was startling in its clearness. In fact, both the music and speech transmitted by the wireless telephone were very clear and distinct; the humming, buzzing and other induction noises so common to the ordinary telephone being entirely absent.

Telephone  Downtown  Soon.
    Mr. Conrad used four VT bulbs in this test: two for sending and two as modulators. The high voltage current was furnished by a motor-driven generator.
December 7, 1919, Fifth section, page 14: (Full column at Google newspapers.)

    A meeting of the Radio Engineering Society of Pittsburgh was held in the club rooms at Smithfleld street and Second avenue November 29.

    The principal feature, however, was a practical demonstration of audion amplification used in receiving radio messages, both telegraph and telephone, by E. W. Zinsmaster of the East End, who used a "Grebe" short-wave, two-step amplifier, audion receiving set. A line was run into the meeting hall from the society's operating room adjoining, and each member "cut in" his own pair of headphones. Local amateur stations in this vicinity that happened to be transmitting at the time were tuned in by Mr. Zinsmaster, as well as numerous ship and land commercial stations and the wireless telephone station of Mr. Conrad, located in Wilkinsburg. This latter proved to be the most interesting part of the entertainment as Mr. Conrad was rendering a concert by radiophone, using a phonograph.

    A letter received from a radio enthusiast of Monongahela, Pa., should prove interesting. It follows in part:
    For the past month or so I have been reading your department in the Sunday Gazette Times with much interest.
    I am pleased to state that the radio inspector has assigned me the call "8DS", which you may add in the list in your next issue.
    The amateurs of this district, as in all others, are very much interested in the wireless telephone messages being sent out from your city. On the night of November 22 I had the pleasure to listen to an hour's entertainment of phonograph music, presumably sent out by Mr. Conrad. I suppose it is very common for the amateurs situated within the city to hear this music, but being located 30 miles distant it is not heard as easily.
    Among the list of calls published in your last issue, the station "USB" is heard here louder than any other. I would suggest you publish, if possible, the hours and days at which the radiophones operate. Also a preferred hookup for the reception of radiophone signals, published in one of your forthcoming issues. I am sure would be appreciated by al the amateurs.
    For the information of Mr. Underwood, and others interested, we would advise that, up to the present time, the wireless phone concerts have been given by Mr. Conrad on Saturday evenings, usually commencing about 8 o'clock and ending shortly before 10.
February 29, 1920, Sixth section, page 10: (Full column at Google newspapers.)

CONCERTS by wireless have become more popular than ever within the past few weeks. On Saturday evening, February 21, Frank Conrad of Wilkinsburg rendered an excellent radio concert, which was enjoyed by amateurs near and far. This is the first time in several weeks that Mr. Conrad has given a concert from his station, but everyone who heard it pronounced it superior in volume and clarity to his former concerts, although they were excellent in quality. From this it would seem that the time during which these concerts were discontinued has been utilized by Mr. Conrad to improve his radiophone apparatus. Radio amateurs of this vicinity are very much pleased that Mr. Conrad is again giving wireless concerts.
April 4, 1920, Fifth section, page 12: (Full column at Google newspapers.)

    We predict that during the summer season this year there will be an unprecedented amount of experimentation by amateurs on radiotelephony. The radiophone concerts given by Frank Conrad of Wilkinsburg, Doubleday-Hill Company, and one or two of our local radio fraternity who are the possessors of radiophone sets, has furnished such a demonstration of the practicability of this apparatus that an ambition has been inspired in many radio men of this vicinity to construct radiophones of their own.
April 18, 1920, Sixth section, page 2: (Full column at Google newspapers.)

On Saturday night, April 10, four different radio-phones took turns in rendering a selection of music which made one of the finest wireless concerts of the season. These phones were at the stations of Frank Conrad, John E. Coleman, Carnegie Tech and Grove City College.
May 2, 1920, Sixth section, page 4: (Full column at Google newspapers.)

    The last two radio concerts given by Mr. Conrad of Wilkinsburg were exceptionally fine. The usual repertoire was changed to include piano selections rendered by Mr. Conrad's son Francis, who is an accomplished pianist. A special line was installed for this purpose which led from the laboratory and experimental station several hundred feet to the music room in the Conrad residence, where a telephone transmitter was used to catch the sounds and transfer them back to the laboratory to be sent out into the ether by the radiophone apparatus located there. The diversion met with much favor and was greatly enjoyed by hundreds of listeners. Biddle Arthurs, a popular amateur of this city, who is somewhat of an artist on the saxaphone, has been scheduled to assist at some of Mr. Conrad's concerts.
May 9, 1920, Fourth section, page 1: (Full column at Google newspapers.)

    Finishing up the week, Frank Conrad of Wilkinsburg gave the usual wireless concert, but with additions to his repertoire which made it the best concert of the season.
The  Radio  Piano.
    The Radio Piano, demonstrated by Dr. Thomas at Mr. Conrad's station in Wilkinsburg, as a part of the last two wireless concerts, is a wonderful instrument. It is called a "Radio Piano" by its inventor at this time, for want of a better name, but it really produces with great fidelity the tones of the violin, violin-cello, flute, clarinet and oboe.
July 4, 1920, Second section, page 5: (Full column at Google newspapers.)

    Through the co-operation of Frank Conrad of Wilkinsburg, whose wireless concerts have often delighted the local radiographers, and Paul F. Shuey, who is connected with the Tuberculosis League Hospital at Bedford and Wandless avenues, the patients at the hospital were enabled on June 26 to enjoy one of Mr. Conrad's most delightful programs.
    Mr. Shuey, who has been interested in radio for a number of years, was formerly a patient in the hospital and even while undergoing treatment, did not lose interest in this fascinating art. Some of the "old-timers" in amateur wireless here may remember seeing an article about Mr. Shuey in the papers several years ago, accompanied by a photograph showing him propped up in bed at the hospital with a pair of receivers on his ears and a receiving set along side of the bed, listening to radio messages travelling through the ether. It remained for Mr. Shuey, with the memory of the diversion which communication with the outside world afforded him when he was confined to his bed in the hospital, to bring to the present patients in the hospital a radio entertainment which far surpassed any which he was able to enjoy during his illness.
    A single wire aerial, about 400 feet long, was stretched from the top of the hospital to a telegraph pole near the gate at the entrance to the hospital grounds. A lead-in was brought down to a portable receiving set which was installed on the lawn in front of the hospital facing the sleeping porches. The honeycomb three-coil tickler circuit, recently described in this column, with the addition of a two-step amplifier and a magnavox (the latter instrument being furnished by Mr. Conrad for the occasion) was used for receiving and reproducing the concert. The music was originally produced by a victrola at Mr. Conrad's experimental studio laboratory in Wilkinsburg and transmitted by wireless telephone. It was received at the hospital and reproduced with such volume that every patient on the porches there was able to enjoy the concert and hear Mr. Conrad's voice. The entertainment, needless to say, was much appreciated.
September 26, 1920, Fifth section, page 10: (Full column at Google newspapers.)

    Those who remember the Saturday night radiophone concerts given last winter by Frank Conrad (Radio 8XK) will be much pleased to learn that Mr. Conrad has decided to resume these entertainments this winter. The first concert of the season was given last night and was much enjoyed by the many persons who heard it.
October 17, 1920, Eighth section, page 8: (Full column at Google newspapers.)

    In connection with the subject of radio telephony, many amateurs who heard Frank Conrad of Wilkinsburg (Radio 8XK) using his radiophone to talk to stations at a great distance from Pittsburgh, have wondered just what system was being employed, due to the pronounced 60-cycle hum present. This has only been noticeable lately.
    Last Saturday Mr. Conrad talked, via radiophone, to L. A. Benson at St. Louis. (Radio 9KV), and John Clayton, at Little Rock, Ark. (Radio 5ZL). We are informed by Mr. Conrad that at the time he made these records he was using a method involving stepped up alternating current and doing away with a motor-generator to supply direct current to the plate. In this way he was able to get six amperes radiation in the aerial, resulting in a carrying wave of exceptional capacity. The modulation was also of very good quality.
Concert  Given.
    Previous to these radiophone long-distance tests Mr. Conrad gave a concert by radiophone, which was somewhat out of the ordinary and surpassed any concert that has been given so far. By means of a separate transmitter in the music room at his residence, Mr. Conrad was able to entertain his large audience of listeners stationed at their instruments within a wide radius of Pittsburgh, with a repertoire of selections, including piano solos, duets, songs accompanied by the piano, etc., all being rendered by talented artists from among his large circle of friends, those persons having volunteered their services for the occasion.
    The fact that the musicale was given directly on the piano and by the singers in person, instead of by means of a phonograph, as has been usually the case, added considerable interest to the performance. In between pieces the cross talk of the gathering in the room where the concert was being given could be distinctly heard, as well the applause which followed each piece of music played. Everything considered the concert was heartily enjoyed by everyone who heard it, and it is hoped that we may again be favored in this manner. The last concert, Saturday night, October 16, was also very fine and much appreciated by the radio listeners of this vicinity.
October 24, 1920, Sixth Section, page 4: (Full column at Google newspapers.)

The plans made by the Westinghouse company are the reason for the change in the A. R. R. L. program whereby Mr. Williams, at station 8ZD, will broadcast the returns from Pittsburg instead of Mr. Conrad, at Station 8XK, as Mr. Conrad, who is employed at the Westinghouse plant, will be needed there on that night to assist in their radio work.