MacKay Radio and Telegraph 128 AW
Manufactured by Federal Telephone and Radio Corp. VLF regenerative receiver used in the merchant marine and the U.S. Coastguard vintage WWII. Coverage is 15 to 650 KHz in four bands. Can be operated from 120 volts AC or DC or directly from 6 volts DC and a 90 volt "B" battery. I'm told the Coast Guard also designated the 128-AY version made by Federal as the RC-123. A good portion of the Liberty ships built from September 1941 to 1945 used a Federal Mackay console which included one or more variations of these receivers. Like most marine receivers of the period, the AC-DC design was not to save money but stemmed from the use of 120 volts DC on many ships and the ability to use the batteries for backup power source. If you used one of these before, during, or after WW II or much later, send me a note about your experiences.
Notes from users of the Mackay.
I'm told that there's still a very small amount of CW on the MF band, mostly in Asia and the Indian Ocean. Wherever 500khz is still used, I'd bet these receivers are still working. They are very sensitive and offer reasonable stability but are susceptable to overload from nearby broadcast transmitters. Plus they were fun to use.
P.S. in 1997 or so, MARAD went into a panic when Burgess (or whoever) announced that they weren't going to build the "B" batteries anymore."
Alex sent copies of the DDD SOS that he received in November 1994 from the Achille Lauro on 500 kHz while serving as Master Radio Electronics Officer (ARA) onboard the Leslie Lykes, callsign WHTU. According to Alex, the exact QTH for his ship was around 900 miles southeast of the disaster site. He adds,"Unfortunately, we were too far to be of any useful assistance, as deemed by the OM."
I gave the mate the code challenge and he, with his pen light and the code book, gave me the correct response for that date. I sent it and we weren't blown out of the water fortunately. After my eyes began to adjust to the darkness, I borrowed the mate's binoculars and scanned the horrizon in the direction the challenge came from. I could see what looked like a monster battlewagon! I'll never forget that!!"
In 1993 I answered an ad for a marine electronics tech with a radiotelegraph license posted by the MacKay office in Berkeley, California. They had lost their staff to sea duty for the big money offered during Gulf War I and were rather desperate for guys licensed to work on CW consoles in port. I had used my telegraph license for aircraft years before but had never worked on ships.
When I visited the MacKay office, the manager there pointed to the bench where a 128 was sitting and asked me what it was. I looked at it. Obviously it was a LF receiver, but I was astonished to see it had a regeneration control.
"Don't tell me they are still using regenerative receivers on ships?" I asked.
"You're hired!" the manager bellowed. "Of all the guys coming in here looking for the job, you are the first one to recognize a regen when he saw one!"
Some months later I overhauled one for a vessel visiting the port of Oakland - an old Lykes 'tramp' if I recall correctly. When I returned it to the ship and installed it, Sparky was watching closely as I turned it on. Since we were in the enclosed San Francisco Bay ringed with high powered broadcast stations in all directions - some only a fraction of a mile from us - we were greeted with a cacophony of racket by signals overloading the sensitive detector no matter how far I advanced the regeneration control.
"It wont do that at sea. You'll be able to hear a lot more." I commented.
Sparky, an old sea dog with years of experience who had been pulled out of retirement by the radio officer shortage created by Gulf War I, cast a baleful eye on me, pulled on his beard and said, "Sonny, if this tub's a'sinking and I'm reduced to the emergency set and someone is close enough to overload the receiver like that, he's exactly the vessel I WANT to talk to!"
Enough said. It was a very good receiver. Love to have one today.""