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Thanks Warren, That is exactly what I was looking for. It just so happens I have all the parts and will make the mod asap and wait to see what else will be recommended. Joel N6ALT

hi i am still waiting for the delivery of my bitx40 but while waiting i am pondering i have 40 and 20 using my trio ft520 and dipoles. but i do not have enough room for an 80 m dipole so i have built

I've always used an ADA-4789 for DDS buffering. 50 ohm in and out, single supply and good to 2.5 GHz. Vince - K8ZW.

Reasonable people can disagree. At -12 dB IMD distortion products become audible within the signal itself.? IMD is one component of the Total Harmonic Distortion spec that we see for our audio

Daniel- I've been studying and building antenna's for 52 years.. Here's some things I've concluded: With regard to uBITX (under 300 watts) operation: #1. The guy that tells you, you need a balun for a

Hello Armin nice to see you! Ok thank you! I have a little bit wondering about that and the voltmeter test between both pins says that they are shorted circuit..? but then it should be ok when yours

Warren did us a service by showing that IMD on the uBitx is worse than it should be and where that is coming from.? I agree it should be fixed. However,? some IMD and some residual carrier are

Hi Jerry, The simple voltage divider you suggest in the linked message could provide a simple solution. No reason that the drive to the mixers needs to be set with a pad, as the Si5351 is not a lab

Published on the IMD thread but wanted to include here for continuity: ? Here is what I did. I did not try with a second transformer because the results were good enough. After the IMD measurements I

WHOOPS!!!! Forgot a critical component. You need a capacitor in the low impedance output of the transformer. WA8TOD

Joel Here is what I did. I did not try with a second transformer because the results were good enough. After the IMD measurements I would be even more concerned about adding a second transformer

Jeff et al: There are multiple proposed fixes for the multitude of issues. For example, for the harmonics on CW I have redesigned the filters so that the existing artwork can be used. Others have

Indeed it shows some mess on the SSB mode. It is not a K3. I am curious how the MFJ SSB hf transceivers, like the 9420 which have a powerful average power, behave on this respect (IMD). And also how

All of the recent orders of 25 boards have now been mailed. If I do this again I’ll be a little smarter, and list them as order of one, or order of pair of 2; I was able to find enough dollar bills

Putting them on the Raduino would allow an easy way to upgrade a current radio. Though the additional signal and ground currents across the Raduino-to-uBitx connector? might give more trouble than

Jeff, I don’t know quite how to do what you are asking and I’m not sure who is appropriate to do so? For the little simple right hand side external relay board that I came up with, I have now

I agree. David A Posthuma, WD8PUO 1 (616) 283-7703 Sent: Wednesday, September 12, 2018 11:24 AM To: [email protected] Subject: [BITX20] Ubitx evolving fixes updated to wiki? #ubitx #ubitx-help I have

Possibly the gain of the transistors at 45 MHz is insufficient, and thus there is much less effective negative feedback. Better transistors might allow the negative feedback to reduce the IMD. Cheers,

Hi Fabian, As Jerry already pointed out, please don't worry about this. I have a V3 board and the connection looks like yours. Armin

Very helpful information, thank you!