May well be. The audio is too low for the speaker to be of any use. I recently was able to pick K6MYC from CA who usually comes booming in at 10 or 20 over S9, using headphones. I will be using powere

Thanks Dave and John. Yes I think the BFO was the issue. Actually got onto that a few days ago. Also found if I turned on the attenuator and it went away. Reset the BFO and seems ok now. I do notice t

Thanks John, it is rev 4, 2018 vintage. It receives on 80 and 40 but the whine in the background is very irritating. Tried to find any relevant posts by you as noted but without success. I suspect it

G'day Ian, can confirm the whine exists when using a 12 volt battery as well. :( Cheers Jeff

Appreciate the feedback. I am was running it from a linear power supply. Tried a wall wart as I read that thread and it was the same...only 80 and 40 m. It should not be there though with a linear pow

Hi tried to search for this issue on the forum but without success. My microbitx works on all bands, transmit and receive but I experience a high pitched wine on 80 and 40 meters. It isn't present on

Hi Junior, Not sure exactly what you did. I have the same symptoms. I can hear signals provided the antenna tuner is spot on but there should be substantially more audio. Reading your note I am not su

I am with Robert, a decent dvm is the first cab off the rank. I sold my oscilloscope on ebay as I found that while useful when needed, it wasn't needed very often and a digital one could do the job. I

Sounds good, please me me on the list as well. Good onya. Jeff VK3GMO

#ubitx #filters #parts

Thanks Allison, haven't checked the coils yet. Finally got the rig back on line and operating. I put in an inline fuse and blew four of them adjusting the bias and rv1. The VERY best advise I have see

Thanks Allison, I will check those coils. I Learned the hard way that one pass is a turn when I built my K2. :) Cheers jeff VK3GMO

Yes Allison, thanks. It had been working fine but a bit low on output only about 4 watts on 40 meters but 8 to 10 watts on 20 meters. So I am sure my connectors are all wired correctly. My issue has t

Progress I think. Replaced the 1-AM smd with a 2n3904 and have side tone back (thanks Conrad) but the display has gone off showing black boxes across the top and gibberish when I key. It had been work

Thank you Marco, I worked that out by using a USB microscope to see the number stamped on the component and found out it was a version of the 2n3904. I have some spare 2n3904s and might give it a try

Can I get a copy of that component list as well please. Thanks Jeff VK3GMO ex WA2GMO

Conrad, according to the schematic q90 is a 2n3904. What is installed on the board is a flush mounted transistor....if it is a 2n3904 no reason not to replace it with a t0-92 form is there? Am I readi

Thanks Conrad; Adrian and Tim. Yep I can see the inline fuse is a must. Was also thinking about a master heatsink so the warning about the heatsinks needing to be isolated from each other was timely.

My uBITX was working for cw and ssb but the irf510s were running too hot. All output dropped to zero, no smoke or dramas and I was sure the IRF510s were fried and I just happened to have four more aro

I have a current version of the BITX which I just finished assembling in the case. It works after some debugging....replacing the code in the Arduino due to a cw fault per another discussion. It is no

#ubitx

Thanks for jumping in Tom. Yes as I noted above the bias resistors are adjusted for maximum output. I felt pretty good about 8 watts on 20 but not too happy with the 4 on 40m. :(. Any other suggestion