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Warren, Excellent information! Thanks! Jerry

I have been following the work everyone is putting in to solve the various issues with the ubitx.? The threads addressing the harmonic and spur issues are getting really long and trying to get a

Warren, Thank you for that precise explanation, I now understand where the IMD is coming from. So at this point do you recommend the I/O transformers on the additional 45Mhz filter replacing R27? If

You can do that but the first mixer is adding no IMD and the second only 5 dB. Between the two bidirectional amps there is at least 15 and perhaps 20 dB of IMD added. The amplifiers are the primary

What about buffering the three S15351 outputs on the Raduino board with three 74LVC1G04GW's as suggested earlier by Jerry and Allison (and add ferrite choke power filters) ? 73 Kees K5BCQ

I used the PD5DJ 4.3 Nextion Screen with KD5CEC firmware version 1.095 on my uBitix. It works very well. His .files can be downloaded at http://ubitx.net/2018/07/23/2831/. You can see my uBitx with

The generally accepted limit for SSB intermodulation products is a minimum of 24 dB between the lowest of the twin tones and the highest of either the third order (products immediately adjacent to the

Yes, I know, on the shematic above in the left corner you can see the drawing for this pins... but the differce is the shematic that you must look for, *i have the Version 3 Ubitx*.. so please look

Jerry, Would you suggest mounting those three 74LVC1G04GW parts on the Raduino board, close to the Si5351? ? 73 Kees K5BCQ

I suspect it is more critical that we have sufficient drive into the mixer LO port than to have that 6dB 50 ohm pad. This sort of thing is best evaluated by somebody with a spectrum analyzer. A series

There are 3 different screens out there. 1 is the original by ian KD8CEC his is not a tru 3.5 it is a 2.8 that has been compiled for 3.5. It will not fill the screen just the left top part. The other

Nick, Would also like to order 4 of the filter boards. Let me know how - PayPal can be on the way THanks -- KG5UMH Michael - DM93am

Thank you very much Ian for all of your hard work on this. Kevin Rea K6REA

Version 1.1 is the first major release since 1.097,?I released it after a 50-day beta test. (Version 1.08 also had a beta test period of about 50 days) Version 1.1 includes all additions or

Hello Nick, I would to order several of those boards. How would I do so? Ripley KD8UYQ The words are mine but this iPad does what it will with them.

So what is the impedance the mixer is seeing for the clock from the si5351? The only claim I saw for the si5351 was an output resistance of 85 ohms if the drive is set to 8MA. Assuming it doesn't have

Diode ring mixers are messy. The port driven by the local oscillator will have unwanted mixer products coming out of it. Using a 6dB attenuator, most of that junk coming back out will get absorbed by

What's the reason to? set-up the Si5351 to maximum drive @ "8 mA" ,3.3 V (Output Driver close to 50 Ohms at 1.65V per IBIS models ) just to send through a? series resistor, then to a? 50 ohm 6 dB

David and Dan, I steered you to the wrong MFJ SWR meter. I mentioned the MFJ-818, but in fact MFJ manufactures a different model SWR meter, the model MFJ-822, that is cheaper at $60, but curiously

When transmitting in CW mode, the uBitx disables clk0 and clk1, Clk2 into the D1,D2 mixer is at the operating frequency.? There is nothing for clk2 to intermodulate with, so CW transmissions are