[Milsurplus] UHF (& BC-357)

[Mike Morrow]

jeff wrote of the AN/ARC-51BX:

>Would you recommend this as a first milsurplus radio?

It would be fine as a first UHF-AM radio, because of the common availability of major components and service manuals on CD-ROM at low cost.  All of this is best found on ebay, by searching for "ARC* radio" or "aircraft radio*" or just "arc-51*".  The RT-742(*)/ARC-51BX is a 3500 channel set.  The RT-unit is nearly all transistorized, with a few RF tubes in places.  Make sure you get one with the HD-???/ARC-51X cooling blower and the ID-1003/AR SWR meter attached.  The set needs only 28 vdc power...no 400 Hz AC power is needed as is required for many other sets.

>If not, which?

The ARC-55 or -55B is a non-pressurized version of the classic ARC-27 1750 channel set.  It's thus lighter and less bulky than the ARC-27, and a lot easier to pop off the covers and admire the works therein.  It's fun to watch the auto-tune mechanisms work when the channel is changed, plus it uses vacuum tubes (except some late unit power supplies are transistorized).  Manuals (original paper versions) aren't too hard to find...an ARC-27 manual will serve if a ARC-27/55 manual can't be found.

The technical documentation for any set is important, since rarely will you find a set with everything hooked up and ready for antenna and power.  You'll have to find connectors, wire them, etc.  You may also have some significant troubleshooting to do.  All these tunable UHF-AM sets are electrically and mechanically complex, have likely seen a lot of use, and are likely at least 40 years old.  It can be an education.

By the way, I've found most UHF-AM band scanner radios to have considerably better sensitivity than these old radios, but the scanner isn't as much fun.

73,
Mike / KK5F