开云体育

QCX 50W Amplifier

John Baines All Messages By This Member #123770 Hi all, I realise that this is way out of it’s specification, but does anyone have any experience of using this amplifier on 2m? I’m not expecting 50W but will it work at all? 73/72 John M0JBA
Bruce Akhurst All Messages By This Member #123771 They are VHF FETS but the transformers (cores etc )will be way out of their comfort zone, the gain well down from HF levels etc. ? The PCB *might* be a basis for your own ?VHF design but there will be a lot of experimental design to do ?
ajparent1/kb1gmx All Messages By This Member #123772 NO and no. The transformers are completely unsuitable for 2M.? For 2M I've had best result using coaxial Transmission lines of the correct impedance (not 50 ohm!) The IRF510s are untried at 2M.? Highest I've gone with them is 70mhz and then it was pushing a bit. At 2M the input match requires a considerably different approach and mosfets that will work there.? Forget a simple transformer.? There I've used both TLT and stripline matching. For 2M I'd start with RD series for 12V operation or MRF101 or MRF301 at (50V).? Then a much different board and likely switching. -- Allison ------------------ Post online only,? direct email will go to a bit bucket.
John Baines All Messages By This Member #123773 开云体育 Alison, Bruce, Thanks for the info. It’s much as I feared. I may try the 5W PA (now a retired kit) with a RD15VHF1 which I already have. Thanks again for saving me a lot of wasted time, which I can now waste on something else! 73 John M0JBA toggle quoted message Show quoted text On 8 Jun 2024, at 16:10, ajparent1/kb1gmx via <kb1gmx@...> wrote: NO and no. The transformers are completely unsuitable for 2M.? For 2M I've had best result using coaxial Transmission lines of the correct impedance (not 50 ohm!) The IRF510s are untried at 2M.? Highest I've gone with them is 70mhz and then it was pushing a bit. At 2M the input match requires a considerably different approach and mosfets that will work there.? Forget a simple transformer.? There I've used both TLT and stripline matching. For 2M I'd start with RD series for 12V operation or MRF101 or MRF301 at (50V).? Then a much different board and likely switching. -- Allison ------------------ Post online only,? direct email will go to a bit bucket.

Previous Topic Next Topic