Re: BITX QSO Afternoon/Night, Sunday, March 11, 3PM/7PM Local Time, 7277 kHz in North America, 7177 kHz elsewhere

_Dave_ AD0B

Was able to work Nx2U and one other operator. Hearing carrier from 7.25mhz.  7.29mhz is better

Re: #uBITX Firmware KD8CEC - IF-Shift etc. #ubitx

Tim Gorman


Diddling with the BFO to make it a clarifier is not good. I agree it is a bad idea today. It worked back in the 50's and 60's because there wasn't much of any other choice and the filters weren't as sharp as they are today. It's why on the old RME 4350 it was always recommended to reset the bfo dial to zero. If you didn't your transmitted frequency wouldn't necessarily jive with your received frequency. Of course back then, a 1kc resolution was considered good and most people had separate receivers and transmitters so it didn't matter as much.

If you want a true clarifier it should be done with the vfo frequency and the offset from the transmitted carrier frequency should be indicated somewhere on the display.

Based on the message Allard left earlier, he *did* implement a true PBT by adjusting the vfo and the bfo so the suppressed carrier frequency is not changed but the relationship to the SSB filter changes. Again, it just goes to show how advanced this little rig actually is!

Re: #uBITX Firmware KD8CEC - IF-Shift etc. #ubitx

Tim Gorman

I think we finally have everything defined correctly. You and I agree.

The design of this radio is impressive. I've had several home built receivers where switching between usb and lsb involved changing the if frequency to move from one side of the filter to the other. Since most simple filters are asymmetric (the slope on the high side and the low side are not the same, the two never sounded quite the same going from usb to lsb.

This design seems to eliminate this problem in the if chain so the bfo remains constant and the filter response is the same on both usb and lsb.


tim ab0wr

ubitx case mount question regarding micro USB connector raduino

Tom Christian

I'm looking for ideas on what others are doing regarding mounting a micro USB connector to the ubitx case.  I'm finishing the case customization and would like to be able to connect the raduino USB to my laptop (or a raspberry pi) for CAT and digital communication.  It would also be used for upgrading the firmware and debugging with the IDE.  I would like to be able to do this without having to open the case.  I haven't seen this anywhere on the blog yet (but I may have missed it).  The panel mount USB micro connectors I've see so far are pretty long (over a foot in length).  I may have to cut s cable and recrimp for a solution.  I'm curious what others have done.  A picture of my case is in another post:  Thanks for any help you could give.

Re: RD16HHF1 power curve flattening...some



I bought the MPSH10's about 5-6years ago. Perhaps less of an issue with fakes then.


Re: RD16HHF1 power curve flattening...some


Hi John

Totally out of the box uBITX, (ie no mods)  I checked power out in CW mode


Checked using CW key at 12.5v dc in. VR1 at ~60% anti-clockwise. (factory setting)


·         80M = 12w

·         40M = 8.5W

·         20M = 4.8W

·         10M = 1.2W

Turning up VR1 to full rotation.

80M = 15w
40M = 12w
20M = 7.8w
10M = 2w


Re: Raduino oscilators. 33mhz and 57mhz " . Documentation says one thing, but this is what I measured.

Michael Shreeve

Also,  there is a site and you may have seen it because the owner of the site, Don, ND6T is active here. What he does is put a little code in the Raduino and tell it to go directly to 25 mhz. He had to use code because I believe he wrote this piece before raduino was installed in a uBitx, it was I believe BITX40. So, you measure the raduino when its at 25, noting the actual freq. Then you change the code with the L at the end, I believe similar to this line     if (prev_freq <= 10000000l && frequency > 10000000l)  (but uses 25000l) until the 25mhz sig is actually on frequency. However, actually having a knob to adjust receiver freqs as your discussing in the other thread on IF Shift, would be great.  ND6Ts,,, Its here ...

Re: ubitx mount question regarding lcd display and bezel

Tom Christian

Thanks to all for the great input!  Now, I've got some good direction on what to do next.  Very helpful!

Bert, I got the tuning knob idea from a vintage Swan 270B I have torn apart for repair.  I found a place on ebay which had new knobs:

        Swan Fluted Tuning Knob for Amplifiers & Tuners

I actually made a mistake on this part.  They have 2 models: one with a white marker on the dial (above) and one with no markings on it.  The seller was great and corrected the order for me before shipment when I reached out to him.  Look for ke9pq on ebay.  I think the actual part he corrected for me was:  "Swan Fluted VFO Tuning Knob with 2" Skirt & Alum Inlay".  Shipping was free and super fast (only took a few days).


Re: Please play well together

Bill Bates

Here here & Amen 😊, I have always advertised ham radio as a "gentleman's hobby" (ladies too of course 😊) let's not get caught out and bring this thing we share & enjoy into disrepute!  Bill  G6ATO.

From: Arv Evans
Sent: ‎11/‎03/‎2018 16:36
Subject: [BITX20] Please play well together


Recently there have been several incidents of group members not playing nicely together. 
Please take a look at what you are about to post to the group before you post it.  If the
content would be objectionable, obnoxious, or annoying to others it might be best to either
modify the wording or just not send it. 

The BITX20 discussion group includes 6000 members from all over the world.  This group
includes many different nationalities and cultures.  When you post to the group you are an
example of your own personality and a representative of your country as seen by others.

Thank you,


Re: uBITx For Sale #ubitx

Tim Young

Hi Marty:

If available I will take it. Paypal to ????



On 2018-03-11 14:46, Marty Squicciarini wrote:

I ordered the uBITx (ordered on 2-Jan) but things have changed and I don't have time for the project.

uBITx  unopened except for photos   $109


Re: RD16HHF1 power curve flattening...some

John <passionfruit88@...>

Hello Glen,

Very interesting. Do you have measurements of you final's power across the bands by any chance?

All the best,

73, John  (vk2eta)

Re: #uBITX Firmware KD8CEC - IF-Shift etc. #ubitx

Jerry Gaffke

Well, that was another thing that got pruned out the original document
before posting as 44182.

All that 44182 has to say is:
  When adjusting the BFO, we should move the VFO to get us back to the displayed frequency.
Doesn't say anything about what the original uBitx code does.
Sorry for any confusion.


On Sun, Mar 11, 2018 at 09:40 am, Jerry Gaffke wrote:
As I stated in post 44182, the original uBitx code only moves the BFO when doing a BFO Adjust,
and you agree that this is not ideal.



I copied N5KYD @ 20:10 and W0OIC @ 20:41. I am in Western Kentucky. Using my bits40 for receive, can not transmit at this time.

Denis, WB8SKP

Re: Complaint Department

Lawrence Galea

Very good advice

On Sun, Mar 11, 2018 at 6:58 PM, ekelley <ekelley828@...> wrote:
Guys & Gals,
I didn't want to leave anyone out. I just thought I should remind everyone that this is a forum for the BitX (all BitX's). It is made up with thousands of radio amateurs who want to expand and enjoy their hobby. I have been licensed for 64 years now. I am a Technician (not an Engineer). I fix things, build them, troubleshoot them, analyze them, I read schematics, what I don't do is design things! Farhan has done an excellent job with the BitX and has made many improvements to his designs. He has put out a quality product that thousands have enjoyed using. Basically the BitX is a great entry level transceiver that is affordable for all. It is not a perfect transceiver, but that is what this forum is for, to share modifications, improvements, and new ideas with each other. We do have outstanding Engineers on this forum. No matter what your background is, there is help for you on this forum. If it doesn't work, someone will help you troubleshoot and find the answer. There is no warranty on the BitX. It is being offered that way to keep the costs down. I have one of the first uBitX's shipped. I put it together in a small chassis, I found a few mistakes and I fixed them. My output power with 12.6 volts applied is about 8 watts on 40 meteres. My first contact was 1500 miles away with a S9 report. I'm almost afraid to add any mods to it since it works sooo good. For beginners, when you get your uBitX, I have a few suggestions, First, follow the instructions, do not try to read the schematic, use the pictures in the instructions for placement of the colored wires. For the 3.5 mm speaker jack, do not jumper the tip to the ring, this will prevent shorting audio out when a mono plug is inserted. Last suggestion - It is a QRP transceiver, don't try to get more power out of it! If you need more power, use an external amplifier, there is a file on this forum on how to do this. Most power supplies run up to 13.8 volts, don't go over that, I chose 12.6 volts and nothing gets hot and I can use digital. Lastly, respect everyone on this group, we are from all over the world and we are all friends in our hobby.

uBITx For Sale #ubitx

Marty Squicciarini <skitch@...>

I ordered the uBITx (ordered on 2-Jan) but things have changed and I don't have time for the project.

uBITx  unopened except for photos   $109


Re: #uBITX Firmware KD8CEC - IF-Shift etc. #ubitx

Jerry Gaffke

One more complication,

Post 44182 puts clk1 at 57995000 for USB and 32997000 for LSB.
They can both be adjusted up and down by some equal number of hz 
to compensate for differences in where the center of the 45mhz passband is.
But this all assumes that the center of the sideband of interest is 1500 hz
from the carrier.  

We may need to move the USB and LSB values for clk1 independently
when the PBT function changes that figure of 1500 hz by a few hundred Hz.
But the effect of a few hundred Hz should be far less noticeable
than the current difference of around 4khz. 

Good thing the math here is all just addition and subtraction, 
nothing complicated.  ;-)

Jerry, KE7ER

On Sun, Mar 11, 2018 at 12:16 pm, Jerry Gaffke wrote:
Yes, the passband of the 12mhz filter can vary by rig.
The fix is using a PBT function within the configuration menu
to get the best audio on an LSB signal.

Could be that the 45mhz passband varies significantly by rig as well, making USB sound different than LSB.
So symptoms like what Gerald's original post to this thread describes.
If so, we need another configuration menu item to scoot around clk1 an equal amount for USB and LSB
as described in post 44182:
> If the 45mhz crystal filter sweeps out to be somewhere else, then add the difference to those two figures.
> For example, if the center is found to be at 44.997mhz (so 2khz higher) then the two figures for clk1
> should be 56995000 hz and 32999000 hz.
Should be able to do this all by ear if stuff is working but just off a bit in frequency.
If not working, then might need a diode RF probe or Nik's AD8307.
Plotting from the Raduino onto the USB host could be done as per post 32630.

Jerry, KE7ER

Re: [uBiTx] last frequency memory?

Mike Woods

Upgrade to the KD8CEC firmware (requires no hardware mods) as this remembers your last tuned frequency ...


On 12/03/18 1:36 AM, sulu82@... wrote:
I have the same problem.Mine defaults at 7.350.

Mike Woods

Re: The issues of the TDA2822

Marko Pavlicevic


That is ok, but can you answer my question?
"I placed an order few days ago... Does that mean that I will have normal chip that doesn't need any mods? Maybe just lowering voltage with 78L09?"

Thank you in advance.

Re: BITX QSO Afternoon/Night, Sunday, March 11, 3PM/7PM Local Time, 7277 kHz in North America, 7177 kHz elsewhere

Richie Chambless

I am KM4TLR. That may be the second station you were trying to identify.

Re: BITX QSO Afternoon/Night, Sunday, March 11, 3PM/7PM Local Time, 7277 kHz in North America, 7177 kHz elsewhere


only just heard WA4THR and xxxDLR???  very weak sigs so far.