[jshorva65]

Since all of the frequencies of the "old" IF band (at least for RCA sets and RCA clones) are EXACTLY 20 MHz below the B&K 415's built-in markers (21.25 MHz Sound vs. 41.25 MHz Sound, 25.75 Pix vs. 45.75 MHz Pix, 24 MHz Sweep Center vs. 44 MHz Sweep Center), it follows that perhaps an "add-on board" containing a single 20.000 MHz crystal-controlled Master Oscillator and a set of buffer/mixer stages could be constructed as a means of modifying a B&K 415 for 24 MHz IF. I'm a little rusty with Transistor/IC Circuit Design and PC Board Design/Fabrication, so I'll ask for expert input on that aspect. It's been YEARS since I designed/built any multi-stage "solid state" circuits. At least theoretically, though, a "board" wired in for pick-off and beating of the Sweep and each Marker individually against a 20 MHz reference and accomplishing re-insertion of the "new" frequencies into the appropriate Output circuits of the 415 seems most logical. This is, of course, based on the assumption that there are many great new IC's available featuring small size, low power drain, excellent performance at the frequencies required, and requiring very few support components other than ordinary Vcc decoupling. Am I over-complicating, or perhaps over-simplifying, the goal of creating a 24 MHz version of the B&K 415?

It seems like a reasonably straightforward POOGE project (Progressive Optimization Of Generic Equipment) at least from my viewpoint. Perhaps even providing some means to switch the Master Oscillator from 20.00 MHz to 19.35 MHz (RCA's 21.25 MHz and 25.75 MHz or Dumont's 21.9 MHz and 26.4 MHz) or an In/Out switch could be incorporated? Perhaps even a combination of all those features (RCA B/W / Delta-F=20.00 MHz, Dumont B/W / Delta-F=19.35 MHz, Standard Color / Delta-F=0.00 MHz) with a three-position selector?