Mahogany Twin 1625 Radio

Mahagony Wood Case 1625 Regenerative Radio

This radio has been a trial since day one. I first put it together back in February and had problem after problem with it. I would set it aside for a couple of days hoping for an epistle to arrive showing me the errors of my way. None came. I completely wore out my welcome at Dave Schmarder’s place constantly asking for answers as to why this thing would not work.

The original schematic called for the use of a 24vac 2 amp power supply to be converted to 12vdc with diodes and resistors. These wall wart transformers blew one after another until I ran completely out of money. Occasionally the set would actually work for a few minutes until the transformer went south and week after week of searching for the cause of this dilemma passed without success. This week I decided to try wiring it for a 12vdc transformer that has 2 amps to power both filament requirements but, again, nothing worked. No power was getting even to the switch and the culprit turned out to be a defective power jack. In checking it out I discovered that not only was it shorted out but that I had wired it incorrectly with the (+) going to the ground circuit! That is how you go about burning up transformers boy. Holy Cow! So after wiring it correctly this time I flipped the switch and not a peep was heard through the small amplifier. Scratching my head with enthusiasm did no good but looking again I discovered that I had never even hooked up the speaker to the amp. Holy Cow #2! Enough to make one just stop building altogether.

The truly frustrating issue here is that I have built this schematic from Dave several times with no problems at all. The only difference here is the inclusion of the amp and speaker with this one. This version also features a honeycomb coil that I wound with 175/46 litz wire coupled with a 365pF variable capacitor to complete the tank. The antenna is coupled to the tuning section via a small trimmer capacitor adjusted to 31pF.

I adorned this radio with very nice mahogany from high to low yet every component does has brass cores fitted with appropriate set screws as required. Everything has been sanded to 320 grit, stained, sealed, shaded and finished with several coats of satin nitro cellulose lacquer. This is one of the few radios I have constructed of late that did not entail bending of sides, fronts or anything else. It does at last play although the volume is not much higher than a single tube 1625 set. But something has to be said for the grand look of those two behemoths sitting up there. Handsome is what it is.

Mahagony Wood Case 1625 Regenerative Radio, side view
Mahagony Wood Case 1625 Regenerative Radio, rear view