Re: 'Beat Note' interference on a Roberts R200
I double checked to ensure that I had the transistors connected the correct way around, Geof, especially as I fitted them on the print side of the PCB to avoid the fiddly job of inserting them between the IF cans. I used AF139s because AF127s seem hard to come by and pricey these days-in fact I think Cricklewood Electronics, for one, sells AF139s as substitutes for 127s(don't quote me on that!!)though an old Mullard data book does specify the 139 as 'a mixer/osc. for use up to 860Mhz'
Howard, thanks for the offer-this particular radio is now back with it's owner, but I may PM you re the AF126s-they'll come in handy for other things.
Point taken about the use of 'Q' code terms, folks
|