[Milsurplus] 618S preliminary manual publication date

[Mike Morrow]

Ray is correct.  The USN RT-311/ARC-38 is definitely NOT a 618S-1 "with SMO".  That's an old old ham-ster claim...made without checking ANY technical details apparently.

However, there was a USB/channelized VFO version of the 618S-1 known as the 618S-1/MC that uses a control box with alpha characters to select the frequency.  It has NO memory drum.  The USAF bought some.  This modification was engineered and performed by RCA.

And FWIW, the USB modification that created the USN RT-594/ARC-38A was engineered and performed by RCA.

And FWIW again, the USB modification of the USAF RT-128A/ARC-21 that created the RT-400/ARC-65 was by RCA...but the original AN/ARC-21 set was an RCA set.  It looks like RCA made a business of USB mods for Collins gear as well as their own.

Mike / KK5F

-----Original Message-----
>From: Ray Fantini <RAFANTINI at salisbury.edu>
>
>If you look at the stenciling on the chassis of the 618S you will find that it list the sections for the 144 channel crystal pack or the SMO version. At first I thought that this was because the 618 was an ARC-38 without the SMO but have learned later that the ARC-38 chassis is way different then the 618S. Over time I have owned and operated the 618S-1 with the crystal pack and later I built a SMO assembly from an ARC-38A chassis that allowed you to QSY, an ARC-38 non "A" that’s a great radio for AM and CW and the ARC-38A that’s a SSB nightmare compared to the simple versions produced before. 
>Have seen these radios a time or two and do not believe that there were any 618S with SMO produced, but that’s just my opinion and I had also thought the non A version of the ARC-38 was extinct, but then saw pictures of one in Australia and have come to own one myself so there at least two out there.
>Trivia the PA, Slug rack, and servo amplifiers are all the same although the last series had "Modified for SSB" stamped all over them and the audio output amplifier system for the receiver is the same in all three radios and the ARR-41 too.
>
>Ray F
>
>
>-----Original Message-----
>From: antqradio at sbcglobal.net
>Pardon the double post.
>Does anyone have a copy of the preliminary instruction manual for the 618S?  The manual on the web, which is for the 618S-1/-4, has a pub date of 15 October 1957 while the preliminary manual I have for the AN/ARC-38 has a pub date of 1 June 1956. So if the ARC-38 is indeed a 618S with a SMO, (why else would you need a code book to set frequency?) then the 618S must be a bit older then June 1956.  Does anyone know for sure when the 618S first entered commercial service?
>Any help appreciated, Jim