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Old 27th Dec 2016, 3:24 pm   #97
GeoffK
Heptode
 
Join Date: Mar 2016
Location: Essex, UK.
Posts: 518
Default Re: My first valve radio project - Philips 462A

Quote:
Originally Posted by indigo.girl View Post
Well, the rectifier heaters light up but very faintly compared to the other valves in the set. The voltage across the heater is only 2V rather than the expected 4V. The continuity of the heater is OK with resistance just 2 OHMS. So, apart from the voltage across the heater being a bit low the rest seem ok.
Quote:
Originally Posted by indigo.girl View Post
With the 200V disc setting giving me valve spec values I checked for HT output from the EBL21 anode (pin 2 to chassis) but ZERO HT DC voltage :-(. The valves are illuminating nicely at this 200V setting - in all cases though the rectifier is much less bright than the other (I guess to be expected because heaters are only powered by 4 not 6 V AC.)
Should be pointed out that the rectifier valve is meant to operate from the separate isolated 4 Volt winding so will light with the same level of brightness at 4 Volts as the other Valves at 6.3 Volts.

With the rectifier removed there will be no D.C. high tension voltage with the 4 Volts A.C. voltage that is there to light the rectifier heater.
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