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Jerry, A resistive bridge SWR meter should not work if this statement is true. Am I missing something here? 73 Evan AC9TU

Good to hear! If so, then all should ignore my previous post: /g/BITX20/message/94334 Jerry, KE7ER

I would tune up any antenna matching network (if you have one) at low power, that should be close.? Then increase power and tune again. Alternantely, use something like an Antuino or nanoVNA to do

If it works well, it's good. This does not strike me as all that odd. I wouldn't worry unless it somehow caused significant distortion in the transmitted signal. Jerry, KE7ER

There is room for doubt here. An SWR meter assumes the transmitter wants to see a 50 ohm resistive load. A uBitx/sBitx might work a bit better into a load that is somewhat different than assumed.

David, Here is the explanation as I see it. First, the impedance. It is the ratio of voltage to current. Let's skip RF and only consider DC, then we will expand this to DC. Ex 1: Consider a 12 supply

Correct David. How come so many still believe the myth that a bunch of passive elements ( antenna system) actually changes with power level? simple, they have a crappy SWR meter. It either has poor

This is not correct.? The output impedance of the PA does not change the SWR and resistance/reactance of the tuner/antenna combination. What one is really doing is tuning out the reactance of the

Please forgive my ignorance but I've never understood statements like this.? "That is because at lower power, the output impedance of the PA will be different." Since SSB is all about audio (no

If the receiver goes down to 10kHz you can try to catch the sendings from the Grimeton transmitter at 17.2 kHz. https://grimeton.org/en/ ( https://grimeton.org/en/ ) or

Got it "turned ON" just for a moment before heading out to my teacher pre=planning day, today. Used a safe 12V wall -based laptop power supply, will need to replace with connectors for a REAL power

Well that's not good!

Same here..and of course I'm back traveling for an extended period starting next week, so its even more torturous that its not here by the weekend so I can at least takea peek. DHL has surprised me

"Many recommend tuning at a lower power. This risky as well. That is because at lower power, the output impedance of the PA will be different. Once you are tuned at QRP level, increasing the power

Go retro and make a collage of the old logos from the past... Collins, Drake, Harmmarlaud, Hallicrafters, etc... be sure to add the builders kits like Heathkit and Eico

You can also get some TO-220 non-inductive resistors of a suitable wattage, and mount those to the heatsink. 10-watt devices should be OK, and 50 ohms is close enough. Those devices aren't cheap, but

You can control it in software, much simpler! The main reason for not putting in an RF sensor is that raspberry pi doesnt have an ADC

decorations: speaking of star war and star trek.... how about a layout of our solar system some where on the radio? Alan w7aln wrote:

I'm wondering if we could add an SWR bridge and use the reverse sense voltage to automatically fold back the RF power? Perhaps control the gain of Q11 to accomplish this? (I have an sBitx on order...)

?Scott, where did you get three legs? If all the resistors are parallel there will be only two legs. Connect one to the ground of your transmitter and one to the antenna pin in your output