Eico 720 Transmitter
September, 2007 - Purchased this EICO 720 transmitter on eBay for $51.00. The rig did not put out any high power. Although the oscillator worked, the cw note was "raspy".
Installed new filter caps and bypass caps. Also found that a "jumper" plug was missing. The jumper must be used when the modulator is not plugged in. Without the jumper, there's no high voltage to the final.
Did a good cleaning job on chassis and cabinet. Also repainted the cabinet with correct factory color. Rig works like new now, and looks pretty good!
Recently bought an old Hallicrafters SX-25 receiver in great condition to complete my early station!
Symptoms:
- Radio does not put out full power
- Signal sounds “raspy”
- All components present
- All voltages normal/present
- Cabinet and panel in fair shape
Mechanical Repair:
- Cleaned all cabinet and chassis surfaces
- Cleaned all switches and knobs
- Sprayed contacts/switches with clean & lube
- Painted cabinet with correct black paint
Electrical Repair:
- Replaced power supply filter capacitors
- Found 2 bad bypass capacitors; replaced
- Dial lights & fuse bad; replaced
- Jumper on accessory socket missing; replaced
- 6AQ5 driver tube, replaced
Notes:
- Radio was purchased for $51.01 eBay
| 
