[Milsurplus] ARC-38/618S1

[Ray Fantini]

A while back, the Thursday before Dayton I bought a Collins 618S1 at
Fair Radio. They had plenty of ARC-38A sets but that was the last
complete 618 they had. Before you start wondering why I would buy the
oldest of the series let me start out by saying that I wanted an AM
version and had no interest in the SSB and AME sets. Do all my HF
operating on AM and wanted to build the "Cold War" thing. Anyway
this is the question; The 618 has what appears to be the same chassis as
an ARC-38. The 618 I have has a crystal oscillator 506-6495-004 crystal
pack that determines what channel the radio is on. Stamped on the
chassis is the statement that you can use the crystal oscillator or the
stabilized oscillator 506-6884-006, along with 500Kc oscillator
506-6885-005 and the servo unit stabilized master oscillator
506-6886-006 so to me it appears that the 618 can be converted to an
ARC-38 by inserting those three modules. When the crystal oscillator
module is installed it covers all the connectors for the other three
modules. And the radio works as a 618, if you remove the massive crystal
oscillator pack with its one hundred twenty crystals and install the
three above modules you then have an ARC-38? I am going to speculate
that the SSB part of the 38A had nothing to do with the oscillator
assemblies. And the next question is should I order all the above
modules from Fair at a high cost or just buy a dozen crystals and what
would be cheaper? If you are interested I posted some pictures on my web
site www.ka3ekh.net under project of the week.
Ray Fantini KA3EKH