[ARC5] RU-** Receiver differences

[Mike Morrow]

>Whist the RU-16 system is designed to operate on 12v, and the RU-17
>system is designed to operate on 24v, am I correct in assuming that
>the differences are confined to the Dynamotor and the Junction Box,
>and the receivers themselves are interchangeable?

Yes, the RU-16 and RU-17 are directly interchangeable, as indicated
by having the same CW-46051A designation.  In the complete RU-16/GF-11
and RU-17/GF-12 system, the antenna relay is also different in the
two systems due to the voltage rating of the antenna relay coil.

>This is supported by the plates on two receivers I have, both
>designated CW-46051-A, but one saying 'a unit of model RU-16'
>and the other 'a model of RU-17'?

That's not unusual in the old USN nomenclature system.  For example,
the CBY-46108 was a unit of model RAT and a unit of model RAV, while
the CBY-46106 was a unit of model RAV and a unit of model ARA.

>The same question applies also to the RU-18 and RU-19 - are the
>differences confined to the Dyno and JB?

Yes.  There's no antenna relay for the RU-18 and RU-19, so that is
not an issue.  Both of these receivers are CW-46048D, but that differs
from the CW-46051A in having its AGC bias resitor located in the
receiver rather than in the dynamotor base.  The RU-18 and -19 were
designed for liaison receiver use (up to two receivers off the same
dynamotor) with GP and GO transmitters.  Their junction boxes and
dynamotors are NOT interchangeable with the equivalent units of the
RU-16/GF-11 and RU-17/GF-12.

  SYSTEM     RECEIVE    TRANSMIT   JUNC. BOX  DYNAMOTOR
RU-16 GF-11  CW-46051A  CW-52063A  CW-62008A  CW-21109A
RU-17 GF-12  CW-46051A  CW-52063A  CW-62018   CW-21454A
RU-18  --    CW-46048D     --      CW-62007A  CW-21215A
RU-19  --    CW-46048D     --      CW-62017   CW-21441

>It seems a fair bet that the coil units for the RU-16 and RU-17 are
>interchangeable, and likewise for the RU-18 and RU-19. But are they
>also interchangeable across all four versions?

Yes.  The RU/GF (command set) and the RU (liaison receiver) were,
when issued new, of all matching serial numbers on all components.
Mixing components of differing serial numbers may mean the cal
plates on the coil may not be as accurate, but I doubt they were
very accurate when serial numbers matched.  It wouldn't matter much
since the frequency would be set accurately using a LM frequency
meter.

Mike / KK5F