Advance E2

• Circa 1949
• Covers 100Kc/s to 100Mc/s in six ranges
• Internal or external AF modulation
• 3 Valves (ECC91, 6SN7GT and 6X5GT)
• Size 13.5" by 10.25" by 8.25"

Band A : 100 - 300Kc/s
Band B : 300 - 1000Kc/s
Band C : 1 - 3 Mc/s
Band D : 3 - 10 Mc/s
Band E : 10 - 30 Mc/s
Band F : 30 - 100 Mc/s

Period advertisement from June 1951 [123K]

A little scratched and grimey.

Inside there is some discolouration around the mains input presumably from a previous problem and there has been some messing about with the mains wiring.

The rubber mains lead was in a dangerous condition, and inside the electrical tape round some of the mains wiring looks a little suspicious .....

With the HT rectifier removed, a variable D.C. supply was used to reform the main electrolytic smoothing. At ~200V, leakage was ~600uA which, in the absence of the manual, doesn't seem too unreasonable.

A mains lead was wired direct to the mains transformer which, at the same time, was disconnected from the mains circuitry.

With mains supplying power for the valve heaters and the HT rectifier still removed, the HT was gradually wound up to 200V and the outputs connected to a 'scope. The reward was a nice modulated RF signal and only about 10mA HT current.

The DC power supply was removed and the 6X5GT HT rectifier refitted. The mains variac was gently wound up, and all seems well.

Just need to rebuild the mains input components. As far as I can make out, the circuit is as shown opposite, which definately isn't right.

The two caps are 0.005uF and looks like those 'orrible 'unts types. These wil be replaced with appropriate modern 'Y' rated capacitors in due course, or maybe by a complete modern mains filter assembly (one with a built-in fuse would be nice).