03-04-2013, 04:25 PM
(03-04-2013, 04:06 PM)Skywave Wrote: Many moons ago, I did do a 're-valve' job on an HRO using 2 6BA6 as the R.F. amps.: no problems, as I recall.
The 6BA6 and the ECH81 are a common choice for several Eddystone receivers: the S.888 / S.888A and the S.750 being two that spring to mind.
Having said that, for a mixer, I would use a 6U8 / ECF82 with cathode-coupled osc. injection: substantially lower e.n.r. as a mixer; excellent osc. / mixer isolation. Shouldn't present any serious problems @ 30 MHz; probably O.K. to 50 MHz.
HTH,
Al.
Thanks Al, it's for that Regenerodyne heap I hope to be working on again, I have decided to go minature glass instead of octal for the receiver, for the osc/mixer I will try both the ECH81 and a ECF82 and see what's what, I am wondering what advantage there would be by going the cascode RF amp route so far as antenna to mixer isolation goes or any other possible advantages, just to re cap the reciever will tune from 1.6 Mhz to 30 Mhz, any thoughts?
Lawrence.
