Re: Ubitx V5.1 frequencies below 3MHz down to 500KHz


Because the ubitx does not have a LPF for 160 meters, the stock firmware does not hop down there in the band menu. No worries just tune fast. There is nothing to inhibit low frequency receiving. You should hear signals on 160m, and down lower hear broadcast stations by tuning in one of their sidebands.

Make sure all is okay before adjusting frequency dial calibration.  BFO much more important, see that you can tune in ssb signals, otherwise time for BFO adjustment.

Curt wb8yyy

Re: Ubitx V5.1 frequencies below 3MHz down to 500KHz


FYI: AM broadcasts occur in the HF range as well.  try evening on 7.200 or
there about.

Try 5, 10 or 15 mhz for WWV or CHU at 7.885..h thee are many other s to pick from.
you can for SW AM broadcast look up their frequency on the the 'net.

Am using USB or LSB will sound normal without any beats when correctly tuned in.

Filter do not kill below SW frequencies, the firmware in use may not work right
depending on what version.  No I've not kept track.


Ubitx V5.1 frequencies below 3MHz down to 500KHz

David Forrest

I was working through the "Tune Up" page at with a bad antenna, and may have screwed up the settings.  I know that my v5 has a BFO of 11.059MHz versus the 11.996MHz in the earlier models per ( )

My questions come from the "Tune to an AM broadcast signal with known frequency." on the tune up page and unexpected tuning behavior.

On the specs say the receiver has "Continuous coverage from 500 KHz to 30 MHz"

How do you tune and read AM stations conveniently?  On my newly received, stock "uBITX v5.1", the "Band Select" slewing doesn't seem to step below 2.9MHz.

I can do fine-tuning down below 3MHz, but the MHz, KHz separation decimal separators start looking confusing below 1MHz with readings like: "LSB A: 9.490.50 " . Would this be 949.050 KHz?  

I can also seem to fine tune to "LSB A: 5.432.50_" (where '_' is a space) and then continue below past "LSB A: 4.000.50_", "LSB A: 1.998.50_" and  "LSB A: 9.995.0__" and "LSB A: 5.850.___" and down into "LSB A: 4.50.____"  The step below "LSB A: 5.0._____" rolls through "LSB A: 0..______"  back around to "USB A:42.949.672" where "Band Select" will slew down slowly, but not back up.

What's happening in these out-of-normal-range areas?  Do the filters kill off stuff below 500kHz?  What causes the tone I hear at "LSB A: 4.50"

Can I tune to frequencies in the Region 2 530-1700 kHz AM band per the clock config as on  What should LSB decoding of AM sound like?

Is there a v5 or v5.1-specific manual somewhere? 

(I just noticed that the V5.1 firmware is on github at which is a bit ahead of the webpage at

Re: Awaiting for µBITX #ubitx-help

Dennis Beverage

Hello Przemek,

and welcome to the Bitx community.  It is good to see that you want reading material on the ubitx.  If you will note that at the top of the every page in this forum is a link to the  Click on the link and it will take you to a page where you will find a huge mass of communications discussing just about everything you could imagine about all of the Bitx radios.  It will take you weeks to review all of it, but anytime you have a question start by logging in and going to this page and use it to look up the subject you need help with.  

Secondly, read/review this group email daily.  There is so much stuff discussed in these daily reports it will keep your head spinning, AND provide you with a great deal of direction in assembling your Bitx.  I don’t spend a lot of time talking with other users here, but I read everything every day, and believe me, if you do likewise you will become a fountain of information on your radio and and also learn a lot about amateur radio in general.

73’s to you and just have fun.


Re: NXP Homebrew RF Design Contest

Jack, W8TEE

Did I miss what the kit will sell for?

Jack, W8TEE

On Monday, November 4, 2019, 10:40:47 AM EST, Razvan (M0HZH) <razvanfatu@...> wrote:

I made some improvements to the design and I am preparing to make a small limited run for the kit in the next few weeks. I will post future updates on this page, where you can also sign up to be notified via email:

Jack, W8TEE

Re: NXP Homebrew RF Design Contest

Razvan (M0HZH)

I made some improvements to the design and I am preparing to make a small limited run for the kit in the next few weeks. I will post future updates on this page, where you can also sign up to be notified via email:



hello men has anyone fitted the Sotabeams Laserbeam digital filter (cw) to the ubitx  v5 as an integral part, rather than used as a stand alone filter   many thanks   Dave c

Re: Downloading firmware


That email direct would be 

Re: Downloading firmware


Your email in group is not highlighted and doesn't work at least for me.

Can you email step by step to me.   
or yrralguthrie@...

Re: CW/SSB Quarz filter with tunable bandwidth #ubitxcw #cw filter #ssb filter #ubitxcw #cw #ssb


Here is the implementation of the TenTec variable filter in my TenTec Rebel.  Looks easy and works great.


Re: New file uploaded to, Audio AGC Circuit

Dean Souleles

Time to give something back to the group.

I was looking for a an audio AGC that did not require a mod to the ubitx bored (because I am a solder wimp and scared of cutting traces!).   The very informative Alan Wolke, W2AE designed a stand alone audio leveler circuit for a SWL friend a few years back.  You can see it on hackaday and youtube.  I built it to go between my ubitx V5 and a West Mountain Radio ClearSpeech, DSP ClrSpkr.  I found I needed a little more drive for the speaker so I added a simple single transistor common emitter preamp.  Even on the breadboard it sounds great and works as advertised.  Strong signals which previously made me jump out of my chair are now under control with no loss of weak signals.  I also modeled it in LtSpice and amazingly enough I think I understand how it works.

I love this little radio.  Thanks to Farhan and the group of homebrewers who brought this to us.



New file uploaded to Notification <BITX20+notification@...>


This email message is a notification to let you know that the following files have been uploaded to the Files area of the group.

Uploaded By: Dean Souleles <dsouleles@...>

Audio leveler / AGC with preamp. External, connect between phone output and an amplified speaker. Attenuates strong signals while letting weak ones through.

The Team

Re: Veron's Day of the Amateur in the Netherlands

Allard PE1NWL

On Sun, November 3, 2019 12:48, Cor Beijersbergen wrote:
Yesterday at the Day of the Amateur I spotted two beautifully executed
samples of the Ubitx.

Yeah I saw those radios too at the event yesterday.
Those guys did indeed a nice job. Truly fine piece of work!

On Sun, November 3, 2019 20:01, Curt via Groups.Io wrote:
Is this a national ham radio convention
there, and is it an easy journey for many hams in the Netherlands?
It's a yearly event oganised by the Dutch radio society VERON.
The Netherlands is only a small country so it's an easy journey for most
hams in the Netherlands.

73 Allard PE1NWL

Re: uBITX Securing radiuno after Nextion install #raduino #ubitx

Justin Phillips K5AXL

Nice, thanks.. this looks perfect. On a completely unrelated newbie note, where can one get a nice tuner knob? The one that came with is ok, but I'm a little spoiled with rubberized grip and all.

Re: uBITX Securing radiuno after Nextion install #raduino #ubitx



If you know someone with a 3d printer. If not I sell them for 5$



Shop is open!

uBITX Securing radiuno after Nextion install #raduino #ubitx

Justin Phillips K5AXL

I'm assembling an Inkits 5" Nextion case and after making connections to the raduino, I'm realizing its kind of haphazardly sitting there on its pins. Does anyone have any suggestions on how to secure it so it's not flopping about or leaning?

Re: Veron's Day of the Amateur in the Netherlands



Thanks for the nice pictures. Is this a national ham radio convention there, and is it an easy journey for many hams in the Netherlands?

Curt wb8yyy

Re: bitx40, sk

Jerry Gaffke


You totally nailed it when creating firmware for the Bitx40.
Anyone with a Bitx40 should try it out:
I'm glad to have been of help.

Jerry, KE7ER    Flora OR, USA

On Tue, Oct 29, 2019 at 10:58 AM, Allard PE1NWL wrote:

Many thanks from us all for the wonderful effort you , arv, rahul and many others put into this project.
Yes many others contributed to the firmware.
I want to specifically thank Jerry Gaffke, KE7ER, for his "minimalist standalone si5351bx routines".
This not only made the firmware independant from the standard external SI5351 library, but it greatly reduced the memory usage as well.
The reclaimed program space was used for features that would otherwise not fit in a Nano.

73 Allard PE1NWL

Re: uBitx V3 low power continues


You're welcome Ted,

Good luck and I think short stints is a good idea too.  Take written or audio notes as you go, so you can note measurements and remember what you did and where you left off.

You might check the compressor too.  Perhaps it has a power problem or a level control or compression control got changed?

Regardless of the SSB and CW difference, it seems you still need to sort the overall lower power output.  So investigation of the PA power chain seems a good thing to do.  If it would help, I could dig out my rig (just moved) and do some 'scope and RF probe measurements of it.

Someone here may have already done that and made a list of measurements or taken 'scope pictures?



Re: ubitx v5 receive problem

howard winwood G4GPF

many thanks to all who replied, setting BFO did the trick (as I should have known!!!!).
background noise much suppressed and can pick u/tune into stations with ease and with good audio.
can now start on the various mods, age, cw filter, s meter etc.
Oh! and a decent antenna of course :-)
cheers everyone

On 2 Nov 2019, at 16:53, pd0zz@... wrote:

My 2 cents... Do you have a real strong MW radiostation near you? In that case it would be advisable to install a special filter onto the motherboard. Look at this small BCI-filter...

Furthermore a BFO tune-up as described by VK3YE is very advisable...

Happy ubitx-ing!

Op 2-11-2019 om 15:40 schreef howard winwood:
just completed my ubitx v5 built into a ready made case, everything went together as expected, on switch on, nothing from speaker but headphones ok. found a short across the speaker terminals on the front panel circuit board (my fault!).
receive sounds very noisy, when a long wire is connected (not a proper antenna yet....) I get a massive increase in noise, very hard to distinguish stations even with volume control turned down. Also find it difficult to tune into a ssb contact.
I have an old home made tx/rx (about 40 years old) that picks up signals much better with almost no noise on same piece of wire than ubitx and tunes into ssb signal very easily on its analogue vfo, compared to ubitx.
is this normal for ubitx or do I have a problem?
Ubitx is supposed to have a sensitive receiver but due to the high noise level does not seem as sensitive as my old rig who's arial input goes straight into a diode ring mixer.
anyone have any ideas please?