Its not obvious so I'll try to explain. Lets say we have two transformers (any for the moment save for they are the same). Also the transformer have a separated primary and secondary as that makes it

I found that by simply increasing C1 to 2.2 uF (just parallel the existing 0.1 uF cap) the keying shape is greatly improved with about 3 ms attack and 6 ms decay. That is much better than the key

Bob Interesting. Maybe that indicates that the solution by Allison is still best...? Actively pulling the RX power line to ground when switching to transmit mode seems productive. Could solve the

Thanks for your efforts so far. Alan

Bob, Try the ubuitx.net trick I poseted a day back. The two cross coupled 3904s to pull the unused power line to ground. Allison

The cables add common mode inductance. That is an incorrect assumption as a result. We had this conversation before. In this stream. Allison

UPDATE!!!!! I tried my earlier suggestion about putting a diode in series with R66 and it causes another problem. The energy stored in C64 keeps the mic amplifier running for about a half a second

Allison The transformers have a common ground shared by the primary and secondary. The coax pigtails connected to the low impedance side of each transformer were, along with the low side of both high

Also, make sure you are using the latest version of the Arduino compiler.

Mike, good cheat! Me I pulled the connector and the pins and drilled three more holes and use a PC mount SMA so it points straight up. Made testing easier and it looks cool. Allison

Hi Allison, Thanks for your help! That what I thought so I order a replacement encoder from Digi-Key and installed it this morning still the same. I just received my uBITX last week, it seemed to be

Is ubitx_cat.ino in the same directory as the V4.3 code? There should be 7 files: ubitx_si5351.ino ubitx_menu.ino ubitx_keyer.ino ubutx_factory_alignment.ino

Wheck wires/wiring and then check the encoder for possible failure. The fact that you get some indications of activity suggests it is broken. Allison

Warren, Did you ground coax at the transformer to the the other in the back to back test? For clarity a piece of heavy wire from the coax connector of one to the coax connector of the other

Did the other participants grant permission to post that? As that would be my first question. I see no such permission granted. As such if they ask the mods to take it down I'd not be

hi i loaded ubitx-v4.3-code into aduino iide and clicked on compile/verify the error message " checkCAT() not declared in this scope what has gone wrong note - i have no trouble in compiling the

Yes, the AGC mini-kit works with the Ver-4 uBITX board. Ordering info and a lot more is in the "Files" section of this reflector under my call. 73 Kees K5BCQ

Bob Agreed. That sounds good. Arv

Hi Arv, It is probably a good idea to have some series resistance in the circuit (over and above that of the diodes) to limit the peak current to the 47 uF capacitors during RX-TX-RX transitions and

Bob N1KW I'm a bit short on time right now, but when finished with a current project I will revisit a few older pre-uBITX transceivers (BITX17A, and a BITX40A) to see if the diode idea will work on