UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post

G6Tanuki · 13th Oct 2020, 6:46 pm

I'm coming to the conclusion that without some serious-tech-which-I-do-not-have-access-to, shifting a 4.9MHz HC6/U rock 400KHz HF is really not practical. My really-techie books-on-quartz-crystal-resonance-modes all date from the late-1930s!

Now, let's step forward to the 1970s and engineer a 'vintage' series-tuned-Colpitts [a.k.a. Clapp] coil-and-capacitor arrangement to plug into that crystal-socket. Some seriously-pricey mil-spec ceramic coil-formers are on order from the US of A.

13th Oct 2020, 6:46 pm	#5
G6Tanuki Dekatron Join Date: Apr 2012 Location: Wiltshire, UK. Posts: 14,007	Re: Grinding crystals I'm coming to the conclusion that without some serious-tech-which-I-do-not-have-access-to, shifting a 4.9MHz HC6/U rock 400KHz HF is really not practical. My really-techie books-on-quartz-crystal-resonance-modes all date from the late-1930s! Now, let's step forward to the 1970s and engineer a 'vintage' series-tuned-Colpitts [a.k.a. Clapp] coil-and-capacitor arrangement to plug into that crystal-socket. Some seriously-pricey mil-spec ceramic coil-formers are on order from the US of A.