Back in the 70s I bought some IMTS GE Progress Line radios from the Western Electric depot near Cleveland Ohio. They were being offered to Hams due to an upgrade. I asked the tech what the letters meant and he told me they were channel designators, one for the receive channel and the other for the transmit channel. I don't recall which came first, the TX or RX.
One of the high band radios was not fully populated and two channels were marked MT. He said even though that looked like a valid TX-RX pair it really stood for Empty or no crystal oven installed. FWIW Eric KH6CQ --- On Wed, 8/26/09, Eric Lemmon <[email protected]> wrote: From: Eric Lemmon <[email protected]> Subject: RE: [Repeater-Builder] IMTS Channel Designators To: [email protected] Date: Wednesday, August 26, 2009, 3:31 PM Jesse, Actually, those are MTS channel designations; the IMTS came several years after MTS was deployed. The eleven "Y" and "J" channels were in the 152-158 MHz VHF band, while there were also ten "Z" channels in the 35-43 MHz Low band, and six "Q" channels in the 454-459 MHz UHF band. The low-band channels had an 8 MHz split, VHF channels had a 5.26 MHz split, and UHF channels had a 5 MHz split. The oddball VHF channels were later used for taxicabs. I am currently using two of those VHF channels in commercial repeater service, taking advantage of the small additional separation. Back in 1968, I put a two-channel GE Pacer (gasp!) with a Secode mechanical selector attached, in MTS service back in Rantoul, Illinois. Not too many folks in that part of Illinois had mobile telephones back then, and even fewer had a kluge like a Pacer. Despite its appearance, it worked quite well, and I learned to anticipate when the phone would ring by counting the clicks as the Secode unit stepped. I, too, would like to know the origin of the two-letter channel designators. 73, Eric Lemmon WB6FLY -----Original Message----- From: Repeater-Builder@ yahoogroups. com [mailto:Repeater-Builder@ yahoogroups. com] On Behalf Of Jesse Lloyd Sent: Wednesday, August 26, 2009 5:32 PM To: Repeater-Builder@ yahoogroups. com Subject: [Repeater-Builder] IMTS Channel Designators Hey All, I was having a discussion with a fellow tech and the topic of IMTS came up. Does anyone here remember the reason for the strange channel designators? JL YL JP YP YJ YK JS YS YR JK KR ? Why YL... why not channel B or Ch 2, they must mean something... Jesse
