 |
| Complete MDF-3 set. (Image courtesy Laval Desbiens via Spectralumni ) |
MDF-3 DF Receiver SPECIFICATIONS
Frequency Range: 273 to 667 KHz
Use: Marine D/F receiver
Circa: 1935
Comment: The receiver does not have a BFO and speaker like the MDF-5
Variant: MDF-3B but the manual doesn't indicate the difference.
GENERAL
The MDF-3 is essentially a radio Pelorus, that is, it may be used to measure or determine the bearing of a fixed point relative to the ship's heading.
The pedestal assembly houses the receiver proper, the quadrantal error corrector, the goniometer and the batteries. Bearing indication is accomplished by reading a dial.
New at the time was the "Zinc Air Cell" filament battery which could power up the filaments for 6 to 8 months on average use before having to be replaced. This battery did not use a charger. One advantage of the air cell battery was the indefinite storage time. This meant it could be carried as a spare and stored dry. To activate it , the operator would simply break the seal and fill it with plain water. The D/F set used the Eveready type 600 air cell.
The Loop antenna consisted of two shielded fixed loops at right angles to each other similar to the MDF-5 antenna.
|
| Complete MDF-3 set. (Image courtesy Laval Desbiens via Spectralumni ) |
 |
 |
| The top portion contained the receiver electronics. | With front panel swung open. |
| (Images courtesy Laval Desbiens via Spectralumni ) | |
| MDF-3 Operators Manual - PDF (Courtesy Laval Desbiens via Spectralumni) |
Contributors and Credits:1) Spectralumni http://www.spectralumni.ca
2) Laval Desbiens <desbiens.laval(at)videotron.ca>
May 16/08