[ARC5] BC-AS-230 Transmitter, part 1 - tube adapters, general clean-up, quest for a dummy load

[Mike Hanz]

On 12/21/2014 5:48 PM, Ben Hall wrote:
> Which brings up a question - when I test it, I want to terminate it 
> into a dummy load.  I know a 50 ohm unit is not appropriate...and the 
> SCR-183 manual mentions an A-55 dummy antenna but I can't find any 
> data on what the internals of an A-55 dummy antenna may be.

Hi Ben,

Most of the SCR-183 manuals contain this excerpt:

(a) Antenna A-55. This is a small phantom
antenna having a capacity of 100 mmfd. with a
resistance of 5 ohms. If the unit is not available
a substitute may be used, for approximate measurements,
consisting of a small mica condenser
and a wire resistance, connected in series between
the Transmitter antenna and ground binding
posts. The condenser should be of standard
make, rated capacity 100 mmfd. and the resistor
should have a d-c resistance of 3.5 to 4 ohms.
Antenna A-55 is suitable for bench testing
throughout the range 4000-7700 kc. The capacity
of 100 mmfd. is too small for use throughout
the entire range of 2500 to 4000 kc, and if tests
are desired in these bands a substitute unit
should be used having a higher capacity: A unit
having a capacity of 200 mmfd. with a resistance
of 5 ohms is suitable for testing throughout the
whole of this lower frequency range.

73,
Mike  KC4TOS