My Memories of Leonard Kahn, Engineer and Inventor


Leonard Kahn was a dear friend of mine. I met Leonard at WFIL-AM in 1978.  I was really impressed with his patents and ideas regarding Synchronous AM Transmission and Independent Sideband Transmission.

Over the years I would see Leonard at engineering conferences and technical meetings.   His comments were always of great interest to me.

I have always had a great love for AM Radio and the potential of long distance communications.  I also was quite interested in AM Stereo.

In 1996 I was hired by Network Broadcasting as Engineer in Charge at WBUX-AM and finished rebuilding the station.  A Kahn Power side unit had been installed in 1992 on the old Continental Five Kilowatt Transmitter.

We had removed a STR-84 from service because of a problem on the power amplifier module.  I was also concerned about connecting the unit to our new BE-5 transmitter.

Leonard phoned me at WBUX, and asked me if I was using his power side unit.  I explained to Leonard I did not want to complicate my transmission system with unneeded equipment.  The new transmitter had a CQUAM exciter built in to it and we were using an Orban Optimod 9100B-2.  The station was very loud and sound great.  Leonard asked me if we had any problem reception areas.   I knew of four areas that were in heavy reradiating environments where the modulation sounded really bad.  These areas were located six to eight miles from the transmitter site and the signal should have been fine.

Leonard requested that I send him all the cards from his exciter and he would repair and upgrade our system at NO CHARGE.  After the work on the unit was completed, Leonard gave me reinstallation instructions and  sent Ira Saltzman to the station to guide me with adjustments.  We completed the final connection and adjustments in about three hours.  I wired the remote Phase Modulator Kill connection to my Gentner VRC-2000, remote control and was able to A-B test the Power Side in the field.  The unit made a 60% improvement in our problem areas.  I was really impressed!

A few years later, Leonard called me to help him with regional station field adjustments.  In one station situation   (WTEL-AM) the antenna system had a very high Q.  The null off the rear and sides of the pattern caused severe sideband and carrier cancellation.  The power side was installed and tuned up fine.  The problem of carrier cancellation could not be corrected.

Even with the one sideband enhanced, if it was being cancelled, there was little or no improvement.  The client apparently removed the unit from service because of poor performance or no improvement in the nulls.  Obviously, Leonard was upset.  We talked about the situation and he finally conceded that the unit was not appropriate for WTEL.  Leonard sent me a check for my help, even though we were unsuccessful!  He was a real gentleman!

Over the years, I always enjoyed speaking with Leonard’s wife Ruth.  She would share with me Leonard’s frustration and disappointment that his “superior” system was not adopted by broadcasters or the FCC.  Leonard also felt that he had been taken advantage of by other manufacturers who had much more capital to spend on litigation!

Leonard and I had a falling out in November of 2003.  I did a job for Leonard on a non directional, in Maryland near Washington, DC.  The antenna system was combined with another station and the networks used were very high in “Q”.  The transmitter was an RCA BTA-1S.  I was not involved in the first attempt to connect the Power Side that apparently caused the transmitter to fail.  The drive was apparently injected where the crystal connected to a unijunction transistor.  The four watts of drive destroyed the oscillator transistor.

When I arrived, the RCA was not operational.  I connected the Power Side drive to the grid of the buffer tube through a .047 Ufd. capacitor and the rig powered up.  The power side performed as expected, even with moderate Incidental phase modulation.  I adjusted the IPM correction and was able to get about 22 db of separation.  I met with Mr. Owner and the station manager.  I don’t think they were happy with the performance.  Apparently the unit was returned, and Leonard felt that I was responsible for the loss of the sale.  Leonard was not pleased and would not return any of my phone calls.  I continued to speak with Ruth and continued to receive Leonard and Ruth’s Christmas cards.

Finally in November of 2005, I think, Leonard called me and asked me if I could help him with a project in Florida.  I had to decline because of other commitments.  We did have a very cordial conversation and Leonard advised me that Ruth was in stage four of pancreatic cancer.  He was still hopeful for a recovery or remission.  She was being treated apparently with radiation or chemotherapy.

Ruth passed away on Christmas day.  What a loss for Leonard and His state of mind.  Ruth was truly a blessing for Leonard and all of us that knew her.

After Ruth passed away it appeared to be “ALL Down Hill” for Leonard.   When I would call Leonard, I felt that I was bothering him.  He told me he was deeply involved with CAM-D.  I had a long pause in my communication with him.

I had little or no contact with Leonard until February of 2010.  He was glad to hear from me and said that he felt abandoned by some of his other friends.  He told me he had a nice big apartment at Fort Lauderdale, Florida.   We would have many long conversations about Thermo Electronics, and other interesting topics.

I sent Leonard a few pieces of test equipment, and a power supply, an eight ampere twelve volt storage battery, and a thermoelectric chip for him to experiment with.  I also sent him an IAM Radio Systems Part 15 AM Transmitter.  I was working on a special project for Radio Systems at the time and had acquired ten units as part of the project.

Leonard’s eyesight was really failing him.  He had trouble soldering and had a young lady he met helping him.  I think her name was Maria.  She would solder the red and black wires together and Leonard was pleased with the steam heater and / refrigerator we were able to build.  I sent him a steam engine I had put together for him.  He attached a thermoelectric chip hot side to the water tank of the steam engine and the cold side to a heat exchanger.  The engine ran fine and there was cold on the other side of the chips heat sink.  Leonard used this to experiment with his Peltier projects.

It was now May of 2010.  Leonard requested an analog Volt Ohm Ampere meter.  I had a few units left from a project.  I sent him two meters so he could measure current and voltage at the same time.  In June of 2010 Leonard requested a cigar lighter plug cable kit so he could conduct his experiments in a mobile environment.

Over the next month or so Leonard seemed to be getting more confused, and I could see a profound change in his personality.  He became very argumentative and was focusing on politics and how he hated to see what was happening to our great nation.   I would be able to distract his negativity by asking him questions about his patents.  I would ask him to explain synchronous am transmission improvements, and he did in great detail. I was able to learn a lot about his invention that fixed the MUSH ZONE when using two or more synchronized transmitters.  What an education.  When he would start in on the political stuff again, I would ask more questions about Independent Sideband Transmission and Diversity Reception.  Leonard had all this great stuff in his head and I am so glad he was willing to share his knowledge with me.

The time line is now August of 2010.  Leonard asked me to provide a few more electronic components for a resistive 12 volt heater he was using to

boil water for steam.  He gave me the values of what he wanted and I provided the parts.  I never heard if what he was building worked or failed.  Again, he seemed to be loosing interest in engineering and would get politically sidetracked.

We continued to communicate a few times a week.  I would normally call Leonard from my office at WNPV-AM.  I could talk with him and listen   while I prepared automation logs and did my normal engineering duties.

The time line is now December of 2010.  Leonard asked me for financial assistance on December 20, 2010, as he was being evicted from his Fort Lauderdale Apartment / Condo.  I sent him an overnight UPS Letter with enough cash to get him by. He waited outside of his former condo building at 511 SE Fifth Avenue Fort Lauderdale, Florida for the UPS delivery. Can you believe UPS messed up the delivery and he had to wait another day for his envelope?

I could see that things were really starting to get bad.  Leonard called me on December 24, 2010 and thanked me for the Christmas Gift!  He said, “David, I am not a poor man, I have quite a bit of GM stock and some other investments”.  It was really difficult for Leonard to ask for financial help.  I could hear the disappointment in his voice.  I suggested that he contact the Florida Department of Public Assistance.  He would have no part of that at this time. He then got a room at The Seaside Motel in Fort Lauderdale.  I asked him if there was any way I could help him.  I determined that he could use some new cloths and underwear.  I made a trip to Wal Mart and fulfilled the order.

Leonard said he could sue the condo association and management and get a big settlement because they evicted him.  I asked him who was going to represent him.  He said he could represent himself.  Conditions got worse over the next few months. A friend of Leonard’s called me on April 08, 2012, and gave me his new address at The Villa Rio Vista Assisted Living in Fort Lauderdale.

After a few weeks at this facility Leonard decided to leave (escape) and find another place to live.  He moved to the Fort Pierce Inn, Fort Pierce Florida. The motel management was kind to Leonard, but the room rent had to be paid.  Leonard was trying to get his social security sent to him at the Fort Pierce Inn.  He told me that The Villa Rio Vista Assisted Living had commandeered his Social Security.  I continued to encourage Leonard to apply for help with the DPA.  I know there were other people who came to Leonard’s aid, BIG TIME!  Finally Leonard could no longer stay at The Fort Pierce Inn.   He was given a chance to go to (or perhaps taken to) The Amore Memory Care Facility at Stuart, Florida and received the care he deserved.   He was now on a long term care agreement with the DPW and had a case worker who was looking out for him.

I would call Leonard every week or so and he was now very subdued.  I offered to send him an Analog Radio with real knobs that he could tune.  He declined and I noticed how quiet he had become.  One of the nice resident care aides told me he really enjoyed our conversations.  Leonard said he was well fed and well cared for.  However he said he felt restricted because he could not do what he wanted when he wanted to do it!

I spoke with Leonard about two weeks before he passed away He was quiet and spoke softly.  I was in the process of preparing to have my shoulder repaired.  I didn’t have the time to do much talking on the phone. I only wish I could have spoken to Leonard just one more time.  I had my rotator cuff and tendon fixed on June 15, 2012.  For the next week I was really restricted on my activity.

Early in July 2012 Carl Marcucci called me and told me of Leonard’s passing on June 03, 2012.  I was really taken back and saddened as I did not expect him to pass away so soon.   However I am really thankful for the many enlightening conversations that I was privileged to have had with such a brilliant engineer and inventor.  I will remember Leonard and always be thankful for his friendship.

–David C. McCrork

Engineer in charge (CE)

WNPV-AM Lansdale Pennsylvania

[email protected]