Special Topics relevant to Project Pages
On my project pages reference is made to more general topics considered important in the context of the work described. To avoid repeating e.g. thoughts on solid tantalum capacitors, such comments are summarized under this heading "Restorer's Notes".
This note describes the problems encountered in equipment using these components and indicates solutions.
- Care of Series-Parallel Filament Circuits→ Part 1: Indirectly heated tubes→ Part 2: Directly heated tubes
These notes describe the checks and measurements required when servicing or modifying radios that utilize series-parallel heater circuits for indirectly or directly heated tubes and dial lamps such as found e.g. in many military or aircraft radios or Collins or Heathkit ham gear.
A lot of damage has been caused by inserting transmitter tubes stored as spares or bought as NOS directly into the transmitter sets without first passing a much needed reactivation process. Various authors have added helpful explanations and practical tips to solve this problem.
All too often drop type tantalum capacitors used in military and commercial equipment fail, usually shorting the supply voltage. Here an explanation for the cause is given and potential solutions for replacing them are proposed.
Many a set or power transformer has been damaged by old electrolytic capacitors presenting a very low impedance or a short to the power source. Long storage alters the chemistry inside these units causing this effect. The capacitors therefore have to be replaced by new units (best solution), by reformed NOS units or carefully reformed - if possible. An internet search will provide many interesting links covering this matter - A selection is shown on the left: "Special Links".
The Small Print
Before using any of this information in your work please refer to the "The Small Print" page. Kindly note that these are opinions offered only and any resposibility is declined.