09-02-2014, 04:36 PM
Here's something you could try with the other coil. Looks like a typical 455kc transformer and they typically resonate with around 100 pf of capacitance. Only one side of your Philco coil is resonant and that simplifies things. Add about 200-300pf (not critical, we are guesstimating here) in parallel with the trimmer for the resonant side. Leave the other side as is. If you can shove the two windings closer together that could help as well.
With the proper test gear this would be duck soup. Otherwise its trial and error.
There are ways to circumvent an IF xfmr with some resistors and a capacitor but you lose a lot of gain and selectivity that way. Plus the 89/19 is a rather persnickety radio to start with and might not work.
With the proper test gear this would be duck soup. Otherwise its trial and error.
There are ways to circumvent an IF xfmr with some resistors and a capacitor but you lose a lot of gain and selectivity that way. Plus the 89/19 is a rather persnickety radio to start with and might not work.
