You don't have to worry about IRF510 itself because it has a good heat sink of the bottom case. It is the saturation of the final transformer T3 that causes the problem if the transmit

Hey gang, In looking over the characteristics of the new weak signal FT8 digital mode, I noticed it has a sustained TX time of only 15 seconds (versus nearly 50 seconds for JT9 and JT65). Presumably

THANK YOU Junichi! Wow! This is an excellent resource and very informative. 73, John AA7US ---In CHINA_QRP@..., <mx6s@...> wrote : John, See the following page. You may need translation site. An

John, See the following page. You may need translation site. An builder in JA modified his KN-Q7A+digital VFO to JT65 machine. He uses a larger core and cooling fan. Without them he blown

John, Yes. It is for all bands. It is a wide band transformer. Thanks, Adam 在 2017年8月8日，下午11:13，landrjoh@... [CHINA_QRP] <CHINA_QRP@...> 写道：

Hi Adam, Is the substitution of an FT50-43 toroid for T3 a recommended upgrade for any frequency band of KN-Q7A / CS-series transceiver if we want to try digital modes (long transmission times)? Thank

Thank you for the reply Adam. I don't have a CS-series transceiver working on 20M (or higher) yet. I'm still building. Now I do already have a 10W amplifier for 40M, 30M, and 20M which I use with

Hi Larry, I think you already know that I want at least one! :) John AA7US ---In CHINA_QRP@..., <larry.lovell@...> wrote : If there is sufficient demand, a kit or partial kit will be made available

After experimenting with several options, I have come up with a simple method to add an LCD display to the Sandwich. I use an I2C buss LCD display. I need to add only two wires to the sandwich. I

John, It is not a good idea to reduce power by reducing IRF510's bias because it will make it work in poor situation. How much power can you get so far? If you can get 5 watt or more, adding a power

Does anyone know if there's a safe way to REDUCE the transmit power of a CS-series transceiver using the existing circuitry? Would simply reducing the IRF510's bias current do the trick or would that

Thank you for the suggestions gents. I removed the coax shield ground connections at the Sandwich VFO and left them at the main PCB so only one end of the coax is grounded. Unfortunately there was no

Ground just one side of the coax. You have probably created what is called a ground loop.

Try grounding just one side of the coax.

I recently completed building a CS-40. Everything works great. The Sandwich VFO was connected to the main PCB via two bare 0.1uF (104) capacitors and a separate insulated ground wire just as shown in

Beautiful work Adam! John AA7US

Gang, A photo is more than thousands of words. Thanks, Adam

That's exactly how I plan to wire up a power switch for mine. 73, John AA7US ---In CHINA_QRP@..., <johncronhelm@...> wrote : I could perhaps could cut the axial lead after the large diode connected

Thanks,At last I have got it now. I have no fused power cable from my gel cell. I could perhaps could cut the axial lead after the large diode connected to the power supply and connect a power lead

Hi All thanks for your comments and help . To John AA7US a very concise description. Thank you John Bob Hudson vk2aor@...