04-09-2023, 01:23 PM
Might make a resistance check with a VOM of the two audio transformers, looking for values up to about 300 to 1k on primary and from 1 to 2 k on secondary. If the coil(s) are open check the internal leads, sometimes a repair can be made.
The coils can be replaced with windings from ARBE-III, these have the high resistance required to properly load the driving plate circuit. If low resistance windings are used results may be problematic.
Polarity of the coils is important in a reflex, so if using replacement windings with a tap start of the winding needs to be found so the set will not oscillate. If there is an oscillation from transformer replacement re-open one of the transformers and reverse a pair of connections.
If the detector grid capacitor is leaking so long as it is higher than 10 megs the cap can still be used as the sum of the grid leak resistor would apply. FWIS it is a Dublier 601 with leak clips and lugs.
Fair warning, almost ALL of the insulating parts in this Crosley are made of a "MUD" material. This is a thermoforming compound of coal, barytes and shellac. It will melt and flow at soldering temperature. Its surface can be marred by cleaning with thinners, alcohol, and detergents. It is brittle, the key in the tube sockets is known to break away...
I would use the "C" supply from the ARBE..
Do not starve the tubes! The "A" battery is 6 volts not 5 volts...
GL
Chas
The coils can be replaced with windings from ARBE-III, these have the high resistance required to properly load the driving plate circuit. If low resistance windings are used results may be problematic.
Polarity of the coils is important in a reflex, so if using replacement windings with a tap start of the winding needs to be found so the set will not oscillate. If there is an oscillation from transformer replacement re-open one of the transformers and reverse a pair of connections.
If the detector grid capacitor is leaking so long as it is higher than 10 megs the cap can still be used as the sum of the grid leak resistor would apply. FWIS it is a Dublier 601 with leak clips and lugs.
Fair warning, almost ALL of the insulating parts in this Crosley are made of a "MUD" material. This is a thermoforming compound of coal, barytes and shellac. It will melt and flow at soldering temperature. Its surface can be marred by cleaning with thinners, alcohol, and detergents. It is brittle, the key in the tube sockets is known to break away...
I would use the "C" supply from the ARBE..
Do not starve the tubes! The "A" battery is 6 volts not 5 volts...
GL
Chas
Pliny the younger
“nihil novum nihil varium nihil quod non semel spectasse sufficiat”
