Last weekend, the 18th annual meeting of the Military Radio Collectors Group was held in San Luis Obispo, California, at Camp San Luis Obispo’s NCO club. The event included equipment displays, presentations, field operations and a swap meet. I had a great time, and nearly every other comment I heard about this year’s meet was positive. I’m already looking forward to next year’s annual meeting, as well as the occasional field events we’ll probably have throughout the year.
KSM + MRCG Joint Crypto Operation
This year, we conducted a joint crypto operation with radio station KSM. KSM transmitted two different messages, one by CW and one by RTTY, both enciphered with an M-209 cipher machine. KSM is licensed under commercial rules, and thus is not limited by the no-ciphers restriction of ham radio stations.
Tim Sammons N6CC and Tom Horsfall WA6OPE copied the CW message despite less than favorable signal conditions. After they copied it, I successfully deciphered it with my M-209-B. Tim used his GRC-109, but I don’t know what rig Tom used. The original message is one that was received by Merrill’s Marauders in Burma around 1944.
I received an email from Steve Hobensack N8YE, who reported that he received the message at his home station and successfully deciphered it.
John Castorina WB6AZP set up his AN/GRC-46 system to receive the RTTY message. Unfortunately, signal fades took out both the beginning and end of the ciphertext message. Those fades eliminated the message indicators which are necessary to decipher the message, so the plaintext was not recoverable at SLO.
However, Eric Volpe AG6EB successfully received the RTTY message in San Fransisco, and both printed and punched it on his Model 19 teletype. Tim Sammons N6CC provided the original message which was enciphered for the RTTY transmission.
Ralph Simpson gave a presentation about military cryptology through the ages. He provided an overview of military cryptosystems from Roman times up through the mechanical cipher machines of the first half of the 20th century. Along with his presentation, he displayed a number of machines from his large collection, including:
- Reproduction of Civil War era cipher disc.
- M-94 cipher device.
- Hagelin C-38, which was the machine that Boris Hagelin presented to the US government which led to the production of the nearly identical M-209 cipher machine.
- Dynamotor + keying discs from SCR-515/ABA IFF system.
- Transvertex HC-9 cipher machine.
- Hagelin CX-52 with B-52 keyboard.
- Vietnam War era “Whiz Wheel”.
- Demilitarized KY-57 voice encryption device.
- AT&T TSD-6300 “Clipper Chip” telephone security device.
Bjorn Forsburg SM5UR talked about the USSR R-354 “Schmel” (Bumblebee) HF transceiver with integrated CW burst encoder. His presentation included an over-the-air demonstration of what the CW burst transmissions sound like. He offered the R-354 for sale during the swap meet, but I don’t know if it found a new home.
Steve Hudson gave a detailed presentation about radio propagation.
A highlight of every annual MRCG meet is the swap meet on Saturday morning. Lots of neat equipment changes hands, despite the selection being smaller than it was in the pre-eBay days.
Bjorn Forsburg SM5UR has all sorts of exotic toys, and now he’s selling off much of his WW2 and later gear in order to focus more on WW1 equipment. This year, I became the happy new owner of his Russian R-107M transceiver, which provides FM and CW operation on the 10m band and the lower half of the 6m band.
I bought a GP-7 transmitter with a full set of plug-ins (plus two spares) from Chuck McClurg. Now I need to come up with a way to feed it with 120VAC 800Hz, and I’m looking for an ARB receiver to pair it up with. I also bought an LM frequency meter with matching power supply, which I’ll pair up with this set.
I saved a pair of Mite teleprinter parts units from the dumpster, and later did some swapping with another MRCG member who couldn’t make it to the meet. After all was done, we each have a “hopefully close to working” Mite and a parts unit.