Broadcast Writer

By Vicki W. Kipp
Society of Broadcast Engineers (SBE) Chapter 24 Newsletter 
April 1, 2003

When a day off comes, what’s a broadcast engineer to do?

Here’s an idea: marvel at the equipment used by the broadcast engineers, TV viewers, and radio listeners of decades past.

The Pavek Museum of Broadcasting is only a road trip away. The museum (Figure 1) is located at 3515 Raleigh Avenue in St. Louis Park, Minnesota, a Minneapolis suburb. Take a look at the Pavek Museum online at http://www.pavekmuseum.org or phone Pavek at (952) 926-8198. The museum is open 10:00 a.m. to 6:00 p.m. on Tuesday – Friday, and 9:00 a.m. to 5:00 p.m. on Saturday for guided tours.

The mission of the Pavek Museum of Broadcasting can be summarized in three tenets: to educate the community at large on how electronic communications impacted the evolution of society; to stimulate young people to explore science and communication arts; and to preserve historically significant items relating to the development of electronic communications.

Joseph R. Pavek began his famous broadcast equipment collection in 1946 while teaching electronics at Dunwoody Institute in downtown Minneapolis. Students routinely dismantled radios to learn about the circuits. Pavek was troubled to see the elaborately crafted radios destroyed, and decided to take one home for preservation. Thus began his lifelong collecting hobby.

After retiring from decades of teaching, Joseph Pavek created his own venture, Twin City Nut and Bolt Company. While traveling through North and South Dakota, Minnesota, Iowa, and Wisconsin selling nuts, bolts, and paint, Joseph Pavek also acquired old broadcast equipment. He stored his broadcast collection at his business site.

The Museum’s Wurlitzer P-10 Jukebox, the first model manufactured by the Rudolph Wurlitzer Company, was aptly nick-named the “Debutante”. This early mechanical jukebox lifts up the record when it is finished playing and drops it into a depository below (Figure 3).

The recording lathe (Figure 4) contained in the Mullin Collection was used to cut the Vitaphone discs for the first talking movies.

During the seventies, Joseph Pavek sought a sponsor to acquire, shelter, staff, and exhibit his collection to the public. Unsuccessful in finding a benefactor for his equipment, Pavek resigned himself to selling the entire collection at auction.

When Pavek’s dream seemed most elusive, hope appeared in the form of Earl Bakken. Bakken, the co-founder of Medtronic and inventor of the wearable pacemaker, shared Pavek’s fondness for old radios. Earl Bakken had funded his college education by repairing radios and televisions. Bakken envision the educational opportunities which Pavek’s collection could provide.

Joseph Pavek, Earl Bakken, and Paul Hedberg of the Minnesota Broadcasters Association banded together to create a non-profit organization to fund the museum.

The museum opened on October 29, 1988, with Pavek’s collection of transmitters, radios, and televisions which dated from 1900 to 1950. Joseph Pavek passed away in June 1989 at age 81 after having realized his life’s ambition to create a broadcast history museum.

Joseph Pavek Collection

The Pavek Collection features a working 1912 rotary spark-gap transmitter (Figure 2). Historically, telegraph operators were called “sparks” because a spark was generated when the operator keyed a character on the transmitter. This set cost about $88 in 1912. The spark-gap transmitter was popular from 1900 to 1920 when it was superceded by the vacuum tube oscillator. Pavek’s collection also includes early-Twenties crystal radios, and a chronologically organized vacuum tube display.

Pavek Ham Shack

Devoted amateur radio operator Joseph Pavek went by the call sign W0OEP. When Pavek died, the Pavek Museum convinced the FCC to reassign his call sign to the museum’s club station. The Pavek club station W0OEP (“Old Empty Pockets”) is set up for communication on the 20-, 15-, 10-, and 2-meter Bands. A 60-foot crank up tower holds a tri-band HF antenna and a VHF antenna. QSOs are usually made using W0OEP’s 100-watt Kenwood 440 transmitter, although a 600-watt Collins KWM2 transmitter is also available.

Jack Mullin Collection

The Jack Mullin Collection covers 125 years of audio recording technology spanning from phonograph to television to magnetic recording.

Figure 1. Pavek Musuem is in the St. Louis Park suburb of Minneapolis.

Figure 2. Sending an S-O-S on a sparkgap transmitter.

Figure 3. Wurlitzer P-10 “Debutante” Jukebox.

Figure 4. Vitaphone disc record lathe.

The cone speakers on display – adorned with wood cutouts of flowers, ships, and castles – were both functional and artistic (Figure 5).

Figure 5. These 1920’s cone speakers originally sold for about $10 each.

At the end of World War II, Jack Mullin brought two AEG Magnetophon tape records from a German radio station to the United States. Mullin introduced tape recording technology to America. The first recorded radio program in US history occurred when Bing Crosby hired Mullin to record Crosby’s radio show.

In 1952, Emory Cook introduced the “Binaural” Disc. Binaural records contain two separate tracks to be played simultaneously by a single arm with two pickup needles (Figure 6). Cook’s product was doomed once the mono groove stereophonic disc arrived in 1958.

Charles Bradley Collection

The Charles Bradley Collection kept in the Minnesota Room features more than 60 radio and television manufacturers who had operations in the Twin Cities area.

Other Exhibits

One of the first Theremins made by RCA is on display (Figure 7). Russian physicist Leon Theremin invented this unusual instrument in 1919. The Theremin is played by moving one’s hands near the vertical pitch antenna and horizontal volume antenna without actually touching the antennas. Theremins create an eerie sound effect typical of outer-space movies.

One exhibit that particularly impressed me was a Philco radio model 39-116 with a wireless remote control called “Mystery Control” (Figure 8). Philco released this innovative product in June 1938. The Mystery Control resembled an old rotary dial telephone without the handset (Figure 9).

By dialing one of the ten dial finger holes to the finger stop, listeners could remotely switch to any of eight preset stations. To raise or lower volume, the listener dialed from the loud or soft finger hole to the finger stop, and then held down the finger stop until the desired volume was reached. A pulsing mechanism connected to the dial times the return of the dial when it is released. Inside the wooden remote control case is a battery operated oscillator which is normally off and only turned on during dialing operations. Using control frequencies ranging from 350 to 400 Kilocycles, the Mystery Control transmits RF pulses to a receiver in the radio cabinet. To adjust volume, the control box sends a continuous RF signal. The Mystery Control cannot remotely power on the Philco radio because the control frequency receiver in the radio is turned off until the radio is powered on.

Another memorable exhibit was the 1949 Stewart-Warner Wonder Window television (Figure 10). When you want to watch a show, you lift the hinged lid containing a “Photo-Mirror” screen to a 45-degree angle above the cathode ray picture tube. The mirror displayed a reflected, magnified image of the picture on the CRT screen.

Figure 6. Binaural Disc was an early method of stereo audio.

Figure 7. Theremin is played by moving hands near the antennas without touching them.

Figure 8. Philco radio model 39-116 with a wireless remote control called “Mystery Control” sold for $198 new.

Figure 9. When dialed to finger stop and released, the 6 by 8 by 4 inch remote control causes the 39-116 receiver to retune itself to the selected station within 15 seconds.

Figure 10. 1949 Stewart-Warner AVC1 Wonder Window “New Yorker” television,.

Interactive

Groups can create their own radio broadcasts from the Pavek Museum’s 1950s era studio KPAV-AM 1200 kHz broadcast station.

The Pavek Museum conducts 6,000 tours per year for schoolchildren. The children’s tour includes visitor participation in a television quiz show.

Children in fourth, fifth, or sixth grade can enroll in Pavek’s Saturday morning ‘Magnets to Megacycles’ class about basic electricity.

Electronics savvy volunteers teach ‘Magnets to Megacycles’. The class involves lectures, problem solving, and hands-on construction.

Adults may enroll in Pavek’s ‘Historical Perspectives’ or ‘Vintage Radio Service’ classes. ‘Historical Perspectives’ is for post-secondary students preparing for a career in broadcasting or mass communications. The course studies the history and development of the broadcast industry. The ‘Vintage Radio Repair Service’ class is for broadcast equipment collectors and hobbyists who would rather fix old equipment than throw it out. This class runs for seven Saturday mornings.

Those who choose to sponsor the Pavek Museum of Broadcasting receive free admission, the bimonthly newsletter, priority invitations to museum special events, a discount at the museum gift shop, use of museum research library and archives, and use of museum equipment to transfer older recordings to newer formats. While the most popular dub request is transfer of wire recordings which were popular from 1946 to 1950 to cassette or compact disc, the Museum can dub just about any audio tape format including LPs up to 16-inches.

The Pavek Museum’s technical library features schematics for most consumer radios, televisions, and HI fidelity equipment up to 1970; 22 volumes of John F. Rider’s Perpetual Troubleshooter Manuals; Howard W. Sam’s PHOTOFACT Manuals 1-1200; many amateur radio schematics and operating manuals; RCA manuals; Western Electric manuals; every TVGuide from volume 1 through 1980; past issues of Radio Mirrors, Popular Radio, Radio News, QST, Radio, and CQ; and old catalogs.

The Museum’s Director, Steve Raymer, has a background in antique radio repair. When I visited the Museum’s Technical Shop, Steve was advising an old-radio enthusiast about replacing capacitors and resistors in his 1939 Emerson radio. The Technical Shop would draw out the treasure hunter in any engineer. This large room contains all kinds of retired equipment, some of it for sale to the public. The substantial assortment included Morse code keyers, vintage television sets, radios, and VTRs; rotary dial telephones; ham radio equipment; transmitters; a slow motion VTR ; books about ham radio and broadcast technology; and a vast collection of working vacuum tubes for older devices.

Today, broadcast equipment is highly-integrated. Mechanical parts have been replaced by hard drives. Minuscule circuits with VLSI make some boards almost impossible to service. In contrast, the Pavek Museum’s broadcast equipment has mechanical parts, discrete components, and spacious circuit boards which make for easier understanding of how the equipment works. Glamorous lighted signs promoting vacuum tubes for receivers made me ponder the days of user-serviceable appliances and TV repair people who made house calls. I also enjoyed the novelty of a broadcast environment constant enough that station call letters could be permanently labeled on receivers.

In conclusion, a day off exploring at the Pavek Museum of Broadcasting is a day well spent.

Acknowledgements: Stephen Raymer, Director of the Pavek Museum of Broadcasting; members.aol.com/philcomc/mcoper.htm by Chuck Schwark; tvhistory.tv