[Milsurplus] I-70-B Meter(BC-31)

[Mike Morrow]

Jeff wrote:

> After looking for an S-Meter for one of my low End National Receivers
>(an outboard accessory) and never finding one I decided to use a Type
>I-70-B Tuning Meter from a BC-311.  I ordered one form Fair Radio and it
>arrived today.

Jeff,

Did they have the whole BC-311-A control box, or just the meter?  Their
on-line catalog lists just the meter, but William Donzelli indicated some
time ago that they had the whole BC-311-A.  I've been trying to find a
BC-311-A to go with my 1937 BC-310-A RDF.  Multiple requests to Fair for one
have received the response that they didn't think they had any, or at least
they didn't know where to find them in their warehouse if they did.  I've
been in their new warehouse, so I guess I can understand how hard it would
be to find some of the odd items.

>My question is does anyone know what the Illumination Lamp
>number is and what voltage does it operate at? The one that is in the
>meter seems to be very bright at only 3 VDC, and I do not what to hook it
>up till I am sure of what voltage should be used

The SCR-269-G ADF uses the same I-70-B meter (2 mA produces zero right
reading, 5 mA produces full scale left reading, 5 ohm DC resistance).  The
lamp is shown in the manual parts list as type LM-32, rated at 3 volts, 0.18
amps.   The bulb is permanently cemented into the little screw cap that
forms the base and screws into the meter.  I doubt that these are easy to
find today unless a place like Fair Radio just happened to have a bunch.

These lamps in my BC-434-A control boxes do NOT light very brightly when I
apply the specified 3 volts to the control box lamp circuit.

73,
Mike / KK5F