Ahh, mhhhh, aha..... four bands, four crystals and a 250kHz wide VFO.
Lets have a look at the combination for 80m:
The converter-crystal is mentioned to be 12.395MHz. That would determine the VFO oscillating at 8.895MHz at its maximum frequency.
Hmm, 8.645MHz to 8.895MHz, that rings a bell! Yes, you guessed it, there is a widely available standard crystal at 8.86724MHz, resulting a very interesting operating frequency at about 3.528MHz... Interesting, a super-VXO at 8.867MHz, will get us 28kHz off from the lower edges of the four bands.
Now lets see how well a 8.867 super-VXO will do with other standard crystals...
- 8.867 - 9.000 = (-) 0.133
- 8.867 - 7.000 = 1.867
- 8.867 - 12.406 = (-) 3.539
- 8.867 - 1.843 = 7.024
- 8.867 + 5.185 = 14.052
- 8.867 + 9.216 = 18.083
- 8.867 + (5.000/4) = 8.867 + 1.25 = 10.117
- 8.867 - (38.000/2) = 8.867 - 19.000 = (-) 10.133
I leave it to the reader to find more, in particular for the bands 15m and higher...