Adam, Thanks for sharing this. It's interesting and educational. I've learned a lot from VK3YE's videos and books. John AA7US

I figured out why. Inductor is not need. Varactor is the key. Now I can easily get wide enough coverage. It is a great idea to modify with the ceramic resonator. If you are interested

Thanks, I checked it on both of my wattmeters and shows nothing. My little qrp pixie at least shows 300mwatts on these wattmeters but nothing on the rockmite. the q3 collector voltage supposed to

Robert, Just to be safe, I'd recommend you get a "second opinion" using a different wattmeter. I suggest this because a couple months ago I assembled a CS-40 transceiver and was only measuring 2 watts

Hello folks. Building a chinese 51 super rockmite, cant get the wattmeter to move but hear the signal on my other radio. Test voltages with digital volt meter and everything checks out ok according to

Congratulations, John. You did very well. Thanks, Adam 于 2017-8-19 23:23, landrjoh@... [CHINA_QRP] 写道:

I'm pleased to report that yesterday afternoon I was able to get a 20 meter CS-Series transceiver on the air using the new FT8 digital mode. I made 8 contacts in the span of an hour and the CS-20

Gang, I followed VK3YE video to try 4.92 MHz ceramic resonator as the local oscillator for BITX-40 when the IF is 12 MHz. In his video, it seems quite easy to pull even without inductors in series,

I definitely prefer winding bifilar and trifiar toroids using different colored wires. Not only is it easier to keep track of the wires, but it makes the toroid look pretty... and a pretty toroid must

I just need some time to build and test. I will be on business trip next week, so the earliest possible time will be early September. BTW, are you still interested in VXO

Hi John Thanks for the info on the FET , I was probably a bit impatient to get it going and had not considered that aspect. Will get some IFR510’s and replace it. Best Regards Bob Bob

Thanks Adam The instruction text says to twist the the wires together and the photo of the toroids shows them in parallel. I rewound the T3 coil using the method in the photo. Having come from a

Hey Adam, When will a 80m/75m version of the CS-Series transceiver be released? Thank you, John AA7US ---In CHINA_QRP@..., <rongxh@...> wrote : 80m/75m/40m/20m/17m/15m will be supported. 40m/20m is

Hi Bob, I'm surprised that the IRF540 is working as a good replacement for the original IRF510. The IRF540 has a significantly higher input capacitance (1700 pF) compared to the IRF510 (180 pF). From

It is true that the wire gauge has little impact to the performance of the transformer. Heavier gauge will have a bit less loss but harder to wind. Thanks, Adam

Hi John and all While replacing the final FET I forgot to put the insulator under the nut holding it to the heat sink case so it was shorted s soon as power was applied and burn’t out the winding

Adam, Is it acceptable to use a heavier gauge (larger diameter) wire when winding a larger toroid such as the FT50-43? Thank you, John AA7US ---In CHINA_QRP@..., <rongxh@...> wrote : This iswhy our

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