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Radio Daze

A radio boyhood leads to a lifelong passion

Mark Leavitt
In 1960s, Grand Tour, Radio Daze

Wireless Wizardry

1960-1963

The Attractions of Amateur Radio

We moved to a different house in 1960, where the prior owner had left a short-wave antenna on the roof with a wire dangling into the dining room. Intrigued, I begged my Mom to buy a crystal radio kit I’d seen in a store window. Connecting to the antenna, I could hear local radio stations.

Then a neighbor across the street erected an enormous antenna on his roof, and I started picking up a much louder signal which I realized was coming from him. I shyly knocked on his door and showed him my crystal set. After a thoughtful puff on his pipe, he invited me in to see his own radio equipment. He let me spin the glowing receiver dial and I heard voices from all over the world. Then he activated his transmitter, made a contact, and handed me the microphone so I could say hello to someone far away. I was instantly spellbound by this wireless wizardry (and admittedly, I still am).

I’d found my first mentor, Fred Mey, K7JFY. He explained how I’d have to learn Morse Code and radio theory to get a license, and off we went. Here I am in July 1960 proudly displaying my novice class call sign, KN7OLZ (aka the Old Lonesome Zombie):

School was not nearly as interesting to me as radio, and I was ravenous to gain more technical knowledge. Luckily, I could reach the Tucson Public Library downtown on my bicycle, and they had a complete collection of the amateur radio magazine, QST, in their stacks. I had the librarian bring me a few years of issues at a time, starting around 1930. So I learned radio technology in the same chronologic sequence that it had been developed. I also practiced Morse Code to gain speed. By the time I was 13, I had gained sufficient technical knowledge and code-reading speed to pass the test for the highest amateur license level, called Extra Class.
Mark Leavitt
In 1960s, Grand Tour, Radio Daze, The Sound of Music

World’s Youngest Jewish Spanish DJ

1965-1970

After achieving the most advanced Amateur Radio license at age 13, I studied two more years to pass the FCC First Class Commercial Radio license exam. With this in hand, I applied to local radio stations for a job as a transmitter engineer.

Tucson’s rock station KTKT was my first choice, but they hesitated since I was only 15 and it might violate child labor laws. I kept trying until I reached KXEW-AM, a 100% Spanish-language station. My Dad had to take me there to apply, since I was too still too young for a driver’s license. The intrigued station manager, Ernesto Portillo, said he could overlook that issue if I’d take $1/hour to cover weekends (I had to be in school during the weekdays). I had my first job!

I stuck to the transmitter room initially, but the Spanish-language immersion and the party atmosphere at the station (after all, it was called Radio Fiesta) was infectious. I observed how the announcers operated the studio console to seamlessly mix music, commercials, and patter into an engaging program. One Sunday morning I turned on the transmitter but the DJ didn’t show up. I played some records while I called Ernesto and asked what to do. He said, “well, start announcing, muchacho!” So I did! Later I got my own teenage Spanish rock-and-roll show. It didn’t last long, but I still claim the Guinness record for having been the “World’s Youngest Jewish Spanish DJ“.

Mark Leavitt
In 1960s, Grand Tour, Modeling and Making, Radio Daze, The Sound of Music

Adventures in Audio and Engineering

1967-1971

From ’67 to ’71 I was attending the University of Arizona toward a BS in Electrical Engineering. My interest in ham radio had faded, replaced by a fascination with sound and audio engineering, and somehow I found time to work several side jobs while still in college.

KXEW-AM had landed an FCC license to add an FM signal. They promoted me to Chief Engineer and had me supervise the purchase and installation of a 5 kW FM transmitter and a second broadcasting studio. This was great fun for an 18-year-old nerd! To avoid the expense of adding a second full-time DJ, we installed one of the early “automated” radio studios, with reel-to-reel tape recorders and robotic drums of tape cartridges. With PCs not yet developed, this ran on banks of telephone stepping relays and was programmed with a telephone dial. You can probably guess that this Rube Goldberg contraption did not survive for long.

It was around this time that ICs (integrated circuits, or “silicon chips” to the layman) became available to hobbyists and experimenters. I wanted to try building a circuit with both analog and digital ICs, so I designed and built a compact automated studio console for KXEW’s remote broadcasts. This was my first “professional” electronic project. Operational amplifier ICs served to mix audio from a microphone, two turntables, and two cassette playback decks. Digital logic ICs automatically started and stopped the turntables and decks when you pushed a single button.

To protect the setup in mobile use, I also built a custom, padded “roadie” case from plywood. Now I can see that this project was the precursor of two of my lifelong hobbies, electronics and woodworking.

Around this time, I learned that a new recording studio had opened up in Tucson. I dropped in on a whim to see if they had any openings. Forster Cayce, owner of Copper State Recording Studios, was always looking for technical help, so he graciously gave me the grand tour. His studio had a brush with greatness, doing early sessions with Alyce Cooper and Linda Ronstadt, but I never met anyone famous. I mainly cleaned and aligned the massive Ampex multitrack recorders, and occasionally helped with roadie duties. But I eagerly absorbed lots of new knowledge about sound and recording. And I took advantage of their commercial discounts to customize my home stereo with massive studio-quality Altec speakers. As I entered my final year of college, I thought I was headed for a career in audio engineering. I was wrong.

Mark Leavitt
In 1970s, Grand Tour, Modeling and Making, Radio Daze

The Seventies in Silicon Valley

1971-1977

In Spring 1971, companies visited the U of A campus in search of new EE grads. With Vietnam and the Cold War raging on, it was defense companies making the most attractive offers. I was about to accept an offer from MIT’s Lincoln Laboratory, but a boutique Silicon Valley defense contractor — Electromagnetic Systems Laboratories (ESL) — outbid them by throwing in full tuition for grad school at Stanford including time off with pay when attending!

After graduation, I arrived in Sunnyvale with my worldly possessions in a U-Haul behind my VW beetle. The photo shows me and my first wife, Susie, in front of a condo we’d just purchased in the crazy Bay Area housing market. In 1975 we had to camp outside a development sales office for 7 days and nights to buy our first tract home.

Finding a direction in direction-finding

At ESL I started work in the Antenna Department, designing antenna systems for radio direction-finding systems on reconnaissance aircraft. First, an accurate scale model of the aircraft was built from aluminum. Then, we fabricated working scale models of the antennas, often an inch or less in size, and mounted them. The finished model with antenna arrays was tested in an anechoic chamber to measure the radiation pattern and other characteristics of the antennas.

In case an engineer might be needed onboard during testing, I and a few other engineers went through hypobaric/rapid-decompression training. That was an unforgettable experience, fortunately never subsequently needed. I’m surprised that almost 50 years later, a version of this reconnaissance plane is still being flown by the Air Force.

Graduate studies at Stanford

While playing with model airplanes was fun at ESL, I was also engaged in the serious task of completing an M.S., and then a Ph.D., at nearby Stanford University. The STAR (Space, Telecommunications, and Radioscience) lab attracted me, and it was an enormous privilege to have Prof. Ronald N. Bracewell as an initial advisor, and later Prof. Robert Helliwell as I focused on my dissertation.

My dissertation covered the development of a specialized receiver for tracking and performing direction-finding on VLF (very low frequency) radio signals called whistlers. Fans of technologic history can find out more in Don Carpenter’s epic memoir here: The Early History of Very Low Frequency (VLF) Research at Stanford

I thought life would be simpler once I completed my Ph.D. work. And once again, I could not have been more wrong…

Mark Leavitt
In 1980s, Doctor, Doctor!, Grand Tour, Health Informatics, Inventions and Patents, Radio Daze

A Medical Residency in Portland

1979-1982

How I learned to hate paper medical charts…

I chose Oregon Health & Science University for my residency. Susie’s health was declining so we chose Portland to be near her family.

A few weeks into internship at the Portland VA, I was summoned at 2 AM to “pronounce” a patient. Being my first time, I was very careful to check for vital signs and confirm the chart matched the patient bracelet before signing the certificate. Paged again at 3 AM, I was told it was also my responsibility to call the family. Trudging back to the ward, I took the chart handed to me and called the number on the next-of-kin form. The daughter was shocked, but I did my best to console her. After another fitful hour of sleep, I was paged again to find the daughter had arrived and now confronted me with her declaration that “my father’s not dead!” My own heart stopped — had I missed a faint heartbeat? She led me to a different patient room, where a father wondered why his daughter seemed so surprised to see him.

At my 3 AM call, I’d been handed the wrong chart, with the same, common last name. The daughter was so happy to find her Dad alive, she didn’t lodge a complaint, but I was deeply mortified. I already disliked the messiness of paper medical charts, but this took my aversion to a new level. It probably set the stage for my 30-year career endeavor to bring medical charts into the computer age.

 

A novel form of doctor/patient communication

In my senior residency year, we had a patient in the VA ICU with Guillain-Barre Syndrome, a rapidly progressive paralysis that ascends from the legs upward through the body. With meticulous care there can be a full recovery over many weeks, but the “locked-in” phase of complete paralysis can be psychological torture. We could only guess at what he wanted or needed and his suffering was undeniable.

When his family visited, I asked them about his experience as a WW II veteran. When they reported he was a submarine radio operator, a light bulb blinked on in my brain. I asked him if he knew Morse code, and he blinked once for yes, but trying to blink his eyes in Morse code quickly exhausted him. So I examined him to see what other muscle strength he had left, and found he could still clench his jaw slightly. I donned a glove, put one finger between his teeth, and asked him to try sending Morse code that way. Immediately he squeezed out HOW DO YOU DO. THANK YOU !

I built a crude Morse code key using tongue depressor sticks, a switch, and buzzer. With this he could send clean Morse code, and became quite chatty with me! A Morse code chart over the bed helped the nurses understand him, though he had to send very slowly. Finally able to express his needs, he made it through the locked-in phase to a full recovery.

Mark Leavitt
In 2020s, Grand Tour, Radio Daze, The Sound of Music

Rewinding by Half a Century

Restoring a 1971 vintage Teac A-4070 tape deck

2023

On the NextDoor social network, I found a post by Stephen Atkins looking for a nearby tape deck technician. There was a special meaning behind his request: Steve’s father, being blind, had preserved his memoirs and family events on reel-to-reel audio tape, not in photographs. When Steve’s Dad passed away 30 years ago, his recorder and tapes became lost in storage until recently.

From his online bio, I realized Steve himself was quite an expert with a long career in audio production. Still, he wisely decided not to just plug in the recorder, but to seek help. My own experience — side jobs during the ’60s in high school and college, at radio stations and a recording studio — was antiquated but relevant. With both the tape deck and me being relics from the same era, I thought we might be compatible.

The photo above shows the deck as it appeared when Steve brought it over, after 30 years of storage in its original shipping carton. The tape head cover had fallen off and its internal shield had come unglued, but otherwise things looked OK until I removed the case and began moving the mechanical parts by hand. The reel brakes were extremely tight and squeaky, the tape tension arms were frozen,  the level controls were nearly impossible to rotate, and some pushbutton switches were stuck. Inside, the drive belt had stretched with age and fallen completely off its pulleys.

Was I up for performing an operation on Steve’s prized, sentimental possession? I wasn’t quite sure until I found a scanned service manual for a later, but similar, model online. Having a schematic and assembly drawing, now I could understand the anatomy before undertaking surgery, so with the informed consent of the patient (actually the patient’s guardian) I went ahead.

Deck interior from behind

Thick steel chassis, cast frame, 3 motors, 6 relays: SOLID, baby!

Drive belt comparison

Old belt has stretched > 1 inch

Tape head base lifted on block

Access to install belt and lube capstan flywheel thrust bearing

Tape tension arm side view

Pulley must be levered down to gain access to bushing for lubrication

New drive belt installed

Note: guide only used to switch 60/50 Hz power

The solid construction of the deck was reassuring. Weighing 50 pounds, it had a thick steel chassis, a cast aluminum frame, three big motors, a power transformer, and half a dozen printed circuit boards bristling with relays and solenoids. I opted not to power up the deck — which could damage irreplaceable components if there were short circuits — and to tackle the purely mechanical issues first.

The four tape heads and capstan/flywheel were supported by a thick steel plate. Since I didn’t want to unsolder the connections to the heads, I just detached the plate from the chassis and tilted it up, supported in on a wood block. That allowed enough access to disassemble and lubricate the tape tension arms, lubricate the capstan bearing, and mount the new drive belt. So far so good.

Reel motor capacitor 5 pin

Daunting challenge to desolder all at once

Reel motor capacitor side view

Luckily, original cap not seated well, allowing access to clip some tabs

Chassis-mounted capacitor replacements

Mounting bases for new caps are 3-D printed

Audio PCB

Access for desoldering/soldering replacement parts

Audio PCB

Deck on side to allow access to top and bottom of PCB

Relay PCBs

Electrolytic capacitors have been replaced

The electronic components most affected by aging — even worse when sitting unused — are electrolytic capacitors. Some restorers replace them all preemptively, while others just cross their fingers and turn on the power. Faced with more than 60 of them, I decided to start by replacing the two dozen most vulnerable ones — power supply filtering and motor capacitors — that could damage other parts if they failed.

The reel motor capacitor had 4 elements, housed in a can with its 5 tabs soldered to a PCB, and I was nervous about heating all those tabs at once while pulling the capacitor off. But fate smiled! Despite the otherwise stellar quality of the deck, the factory had failed to seat the capacitor fully onto the board. I was able to get needle nose pliers and diagonal cutters in to snip some of the tabs loose before desoldering.

The three capacitors housed in chassis-mounted cans were replaced with modern, smaller cylindrical capacitors. So I had some fun designing and 3-D printing plastic mounting brackets to adapt them to the original chassis mounting holes.

The remaining electrolytic capacitors were just a matter of patiently desoldering and replacing them on their respective printed circuit boards. I appreciated that the deck was obviously designed for repairability — by turning it to various positions, I could reach the bottom and top of most of the boards. Before reassembling, I cleaned all of the switches and level controls with spray-in contact cleaner, then re-lubed them until everything worked smoothly.

Reel hub brake

Note band adjustment already at loosest position

Calibration Setup

Inputs/outputs patched to signal generator and oscilloscope

Calibration tape

Magnetic Reference Laboratory tape with test tones

Calibration Tape Response

Close to achieving factory specifications

It was time for the Moment of Truth: power up — cautiously. A Variac was used, gradually increasing the line voltage while watching for any signs of overheating or smoke. Everything looked good, so it was time for mechanical and electrical alignment.

Mechanical alignment consisted of checking and adjusting the torque from the reel motors and brakes. The reel brakes were very tight and squeaky, even adjusted to their loosest setting. I solved this by “exercising” the brake springs, which had apparently stiffened in their old age (like people do). The motor torques were measured using spring scales, pulling on a string wrapped around the hub of a tape reel. Luckily, I was able to get everything within factory specs, and the deck demonstrated its rewinding, fast forwarding, reversing, and stopping prowess without snapping or spilling any tape.

Before performing electronic alignment, I cleaned and demagnetized the heads and guides. An oscilloscope was connected to the outputs, and a signal generator fed to the inputs.

A reference calibration tape was mounted, and the playback levels of prerecorded test tones on the tape were measured on the scope. Only minor adjustments had to be made to the playback head azimuth to peak the high-frequency response, and to bring left and right channels into phase match. A response plot showed the deck was achieving close to factory spec.

Since the primary intended use of the deck was to play back Steve’s archival tapes, didn’t attempt a full alignment for recording, but confirmed that recording does work.

Restoration complete, here’s the rejuvenated Teac A-4070 playing the #1 hit song of 1971!