CY1 or CY2 in Ekco AD65? - UK Vintage Radio Repair and Restoration Discussion Forum

stevehertz · 27th Feb 2023, 4:57 pm

The Trader sheet (649) for the Ekco AD65 states that either a CY1 or CY2 can be used for V4, the rectifier. The wiring simply straps the two halves in parallel in the case of the CY2. But in both cases the rectification is still 'only' half wave.

Is this simply a case of enabling one to use either type of valve (ie an availability, versatility benefit), or are there any other benefits to be had either way? I guess the CY1 was cheaper back in the day, but apart from that? Would the CY2 in theory last longer due to less current passing between individual cathodes and anodes?

G6Tanuki · 27th Feb 2023, 6:17 pm

I guess it was a case of availability.... some repairers made an effort to reduce the number of different valves they needed to stock.

In theory, there should be low-value [100 Ohms or so] wired in series with each anode when the two halves are strapped, in order to try and equalize the currents taken in each half.

In practice, these were often omitted, seemingly without catastrophic outcomes (though some users of the Mazda U801 four-diodes-in-one-bottle TV rectifier may have different views on this.... see http://www.r-type.org/exhib/aay0008.htm ).

27th Feb 2023, 4:57 pm	#1
stevehertz Dekatron Join Date: Sep 2011 Location: Rugeley, Staffordshire, UK. Posts: 8,835	CY1 or CY2 in Ekco AD65? The Trader sheet (649) for the Ekco AD65 states that either a CY1 or CY2 can be used for V4, the rectifier. The wiring simply straps the two halves in parallel in the case of the CY2. But in both cases the rectification is still 'only' half wave. Is this simply a case of enabling one to use either type of valve (ie an availability, versatility benefit), or are there any other benefits to be had either way? I guess the CY1 was cheaper back in the day, but apart from that? Would the CY2 in theory last longer due to less current passing between individual cathodes and anodes? Attached Thumbnails __________________ A digital radio is the latest thing, but a vintage wireless is forever..

27th Feb 2023, 6:17 pm	#2
G6Tanuki Dekatron Join Date: Apr 2012 Location: Wiltshire, UK. Posts: 14,007	Re: CY1 or CY2 in Ekco AD65? I guess it was a case of availability.... some repairers made an effort to reduce the number of different valves they needed to stock. In theory, there should be low-value [100 Ohms or so] wired in series with each anode when the two halves are strapped, in order to try and equalize the currents taken in each half. In practice, these were often omitted, seemingly without catastrophic outcomes (though some users of the Mazda U801 four-diodes-in-one-bottle TV rectifier may have different views on this.... see http://www.r-type.org/exhib/aay0008.htm ). __________________ I'm the Operator of my Pocket Calculator. -Kraftwerk.