24-08-2013, 12:20 PM
It depends what use the inductor is used for in many cases, my interest at the moment is with high Q single layer inductance pertaining to shortwave reception/tuned circuits etc so home brew wave wound inductors are not a priority with me at the moment, if I need one say for a typical RF choke then I tend to salvage a winding from an old IF transformer as these are generally wave wound and use that for experimenting with.
RF tuning coils in the old broadcast band receivers tend to be wave wound eg: MW and LW coils, also some comms receivers used the high inductance primary trick to even out the overall stage gain as did many broadcast band radios.
It can sometimes be confusing if not familiar with the concept in broadcast band radios ie: a large wave wound winding doesn't always mean that it's the LW tuning coil, in many cases it's the high inductance primary for the MW coil.
The high inductance primary is designed to self resonate just below the lower end of the band being tuned thus making up for the overall gain drop that would be incurred with out it, this technique was often used in radios that were TRF regens, it was also used in comms receivers such as the HRO and some of the early Hallicrafters and possibly in other comms receiver makes.
Lawrence.
RF tuning coils in the old broadcast band receivers tend to be wave wound eg: MW and LW coils, also some comms receivers used the high inductance primary trick to even out the overall stage gain as did many broadcast band radios.
It can sometimes be confusing if not familiar with the concept in broadcast band radios ie: a large wave wound winding doesn't always mean that it's the LW tuning coil, in many cases it's the high inductance primary for the MW coil.
The high inductance primary is designed to self resonate just below the lower end of the band being tuned thus making up for the overall gain drop that would be incurred with out it, this technique was often used in radios that were TRF regens, it was also used in comms receivers such as the HRO and some of the early Hallicrafters and possibly in other comms receiver makes.
Lawrence.
