31-10-2018, 05:28 PM
(This post was last modified: 31-10-2018, 05:35 PM by Murphyv310.)
Hi.
P series valves are very useful and many have ideal characteristics for both Audio and RF applications. PL82's and PL84 are good audio valves and contrary to what Jeffrey says the PL84 and the EL84 bar the differing heater characteristics are the same valve. Although they seem different the PL84 have de-rated characteristics for AC/DC TV applications where HT of 250-300v is not available so the specs in the books are for the lower HT not the higher values, misleading but perfect common sense. Do your own load lines etc and you'll see it performs just like the EL84, see here: http://www.r-type.org/exhib/aaa0371.htm and can be run at the HT the EL84 is rated at, In fact I tried a PL84 in another Mullard 3-3 project some time ago and it was 100%
Don't throw out "P" valve pulls as they are the ones that will die a death before the likes of ECC81/2/3, EF86, EL84 which are still made. Valves like the ECL86 are now hard to find and expensive and again the PCL86 is the 300ma version of the hard to find ECL86 so again good reason the keep these valves.
P series valves are very useful and many have ideal characteristics for both Audio and RF applications. PL82's and PL84 are good audio valves and contrary to what Jeffrey says the PL84 and the EL84 bar the differing heater characteristics are the same valve. Although they seem different the PL84 have de-rated characteristics for AC/DC TV applications where HT of 250-300v is not available so the specs in the books are for the lower HT not the higher values, misleading but perfect common sense. Do your own load lines etc and you'll see it performs just like the EL84, see here: http://www.r-type.org/exhib/aaa0371.htm and can be run at the HT the EL84 is rated at, In fact I tried a PL84 in another Mullard 3-3 project some time ago and it was 100%
Don't throw out "P" valve pulls as they are the ones that will die a death before the likes of ECC81/2/3, EF86, EL84 which are still made. Valves like the ECL86 are now hard to find and expensive and again the PCL86 is the 300ma version of the hard to find ECL86 so again good reason the keep these valves.
