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Openqrp radio question please

bruce williams All Messages By This Member #10406 This may sound crazy, but probably 10 years ago I bought a openqrp kit. The pcb says REV D. I am just NOW building it. ? I am in the vfo section and I see that I am missing CT3. Can you please assist? What are my options here? ? Thanks ?? Bruce
Guy Mengel N1GMM All Messages By This Member #10411 Hi Bruce. There is a note the CT3is not needed and it is not. You can get the freq adjusted but it will take some time. On me second unit I installed a ceramic variable cap, a green mica one will work but not quite as stable. the makes the adjustment much easier and it is stable. Let me know and I will look to see if I have a variable ceramic. 72 / 73. Guy N1gmm
bruce williams All Messages By This Member #10412 Thanks for your reply Guy!? It was actually your recent post about this kit, that finally motivated me to build mine.?? ? I assume if I dont use CT3, that just means more tweaking of the 37 turns on the torroid L5? ? And really I should be able to get the vfo calibrated to about 7000-7070 without ct3, just by adjusting L5? ? Would replacing ct3 with a small value NP0 cap aid the process at all? ? Thanks for your time! Bruce
Steve K1EL All Messages By This Member #10413 开云体育 CT3 really isn’t required, the part that I used in the original kits was very difficult to adjust and it was easier to just get the windings close and squeeze or spread windings to get it closer. Keep in mind that it doesn’t need to be exact a little low is preferable. In digging through the parts bins I found a couple of kits U had assembled years ago and they were missing the trimmer. Steve K1EL? toggle quoted message Show quoted text On Feb 2, 2025, at 12:59?PM, bruce williams via groups.io <n9jcv@...> wrote: ? Thanks for your reply Guy!? It was actually your recent post about this kit, that finally motivated me to build mine.?? ? I assume if I dont use CT3, that just means more tweaking of the 37 turns on the torroid L5? ? And really I should be able to get the vfo calibrated to about 7000-7070 without ct3, just by adjusting L5? ? Would replacing ct3 with a small value NP0 cap aid the process at all? ? Thanks for your time! Bruce
bruce williams All Messages By This Member #10414 Thanks Steve and all for your feedback.? I will just build without CT3 and adjust the torroid. ? Once I get the VFO built, I will report back here with my results.? Thanks again for the help! Bruce
Dennis_G6YBC All Messages By This Member #10415 Hi Bruce, I have sent you a email regarding the CT3 type used in the U.K. version, which will work in the USA version equally well.? It is an Orange range Murata variable capacitor, 5-60pf? Dennis G6YBC?

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