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I ordered a ubitx (V3) last May, wired it up and made one contact on 20 meter SSB. THEN, I started reading about the various issues with the transmitter so stopped using it. I would really like to

Somethign about your assembly is getting RF into the wires going to the Raduino. Hint Keep all wires far away from the heatsinks, lots of RF there.?? This has been seen many times before usually on

Tom, Bitx40 (and bitx20) the additional stage effectively replaces Q90. At lower gain not enough stages.? You have to balance power and gain.? For more power often you can get only so much gain.

Here is more data that I am gathering for my own reference. I am sharing for those interested.? This characterizes the gain and drive requirements of the transmit chain at operating frequency from

The BITX40 has a additional stage of amplification after the final mixer. Maybe that helps reduce the signal level that goes through the final mixer to a more reasonable level.? On the uBITX maybe

Sorry. I said aduino board replacement, my radio came from ubitx $129+10 shipping sorry for any confusion

Karan I just checked Ebay and did not find any uBITX there. Might be interesting to see a picture from the OP to see just what he purchased. Arv _._

I assembled my uBITX as a WSPR transmitter.? I use a SignaLink USB for receive and transmit audio plus PTT.? Everything works as it should on 30 meters and lower.? On 20 meters and higher when,

Thanks, Joel. Anything new happenin' on your bench?? Jack, W8TEE

Henning, For the fist stage (q90) its been tried and 20db to 30mhz with BFR106 (FT4.5ghz) is easy.? Keep in mind we are asking for -1db compression of maximum 5-7db, for that stage its not an issue.

Allison, according to my block diagramme the needed flat gain up to and best a bit above 30 MHz of the first stage i.e. 20 dB makes me a bit nervous.? Clearly 2N3904 transistors are not suitable! May

Looks pretty nice Jack, very professional. Joel N6ALT

Allison, Thank you very much. Very appreciated. Tom, wb6b

Jim, For that inductor the amps I have that perform well use it. All three use different arrangements and all produce 10W and do it well.? One its a Ft50-43 with 8turns, the other its 4 turns on

Henning, Thanks,? One hopes that will help those that haven't a clear idea of whats needed. That will go in the wiki. Allison

Warren, That proves first get the signal to the mixer clean and at a reasonable level.? IT also finds the needed level to the mixer? and that is under -10dbm for the available LO drive (that can

Well ya there's that too ..But I drink coffee so... Jim

I was specifically referring to BIFILAR inductor ....Just like the big guys do it Jim

Thank you first and foremost I apologize to the group. My signal has increased chu 7.85 nice strong my wire feeds off my cable attached to bnc connector got 200 feet 50 ohms type. I'm in apartment

Resonant antenna is not required on receive. I've heard over 40 states and 20 countries with 65ft wire up 10ft in my rafters with my ZZRX-40 DC receiver. Check the BNC connector center pin. It's been