Date   
Re: Question about power output #v5 #ubitx

Jerry Gaffke
 

F4huy,

My best guess is a broken or shorted wire in one of the transformers: T8,9,10,11

The fact that you get 2 Watts of SSB at 30mhz is good news,
that shows that everything from the mike to the first mixer at D1,D2 is working fine.

When transmitting CW, CLK#2 is a square wave at the operating frequency.
Mixer D1,D2 is unbalanced by CW-KEY to allow that signal right on through to the final amp.
So this is not an issue with the BFO offset as previously suggested,
this would affect only SSB transmissions, and attenuate all bands equally.

If the receiver works at 3.5mhz, then the low pass filter at L1,2,3,4 should be working fine.
The problem is somewhere between Q90 and the antenna jack.

The signal going into Q90 should be around 0.1 volts pk-pk,
and the voltage increases by roughly a factor of four as it passes through each stage.
Since there are four stages of amplification between Q90 and the IRF510's,
the output from the IRF510's should be roughly 0.1*4*4*4*4 = 25.6 volts pk-pk.

If you have access to a good oscilloscope capable of seeing at least 3.5mhz,
probe the collector (or drain) of each of the four amplification stages.
See if the AC voltage increases with each stage when operating at 3.5mhz.
Compare that to what you see when operating at 30mhz.

If you don't have a scope, I suggest you build a diode RF probe.
Use either one of the first two circuits shown here, they should give equivalent results:
    http://www.techlib.com/electronics/detect.htm
The first circuit shown is the one most commonly described elsewhere.
The second circuit is easier for most of us to understand.
Note that the smallest AC voltage either circuit can sense will be around 0.3 volts rms,
so it probably will see no signal if you look at the base of Q90.

Many webpages on diode RF probes recommend using a germanium diode,
but those are getting hard to find.  A schottky diode such as the 1n5711 will do fine.
Many dishonest vendors of 1n34 germanium diodes will actually ship a schottky diode instead.
A true 1n34 will be able to see slightly lower level signals than an 1n5711.

When output varies more than it should between bands, my first suspicion
would be the output low pass filters selected by relays KT1, KT2, KT3.
However, all of those output filters are low pass, so all of them should pass
a 3.5mhz signal unmolested even if they got swapped around somehow.

If you do suspect trouble between the IRF510's and the antenna connector,
a good test would be to cut the trace between transformer T11 pin 5 and relay KT1 pin 12,
Then put your wattmeter directly between T11 pin 5 and ground.
The wattmeter will see the raw power coming out of the IRF510's, harmonics and all.
So readings will be a little high, but 3.5mhz should definitely be stronger than 30mhz
since each of the 4 amplifier stages will have more gain at lower frequencies.

Verify that your BNC antenna connector is working with an ohmmeter, 
perhaps go around it by soldering a wire to the PC board till you find this problem.
There have been reports of some BNC connector center pins not making proper contact.


Best Regards,
Jerry Gaffke, KE7ER




On Tue, Jan 14, 2020 at 01:30 PM, <f4huy.ham@...> wrote:
Hello,
got my ubitx v5 one month ago, almost finished ...

it's sell with "More than 10 watts up to 10 MHz, 7 watts up to 21 MHz, 2 watts on 28 MHz" ,
i get 2w between 21 an 30Mhz, then the power drastically decrease under 2w under 21mhz, around 800mw at 7.1mhz, and close to zero on 3.5mhz

what's happen ? it's should be the opposite.

i have already checked and re*tuned rv2/rv3, my microphone is a baofeng, test with cw give same result

i want to operate mainly on 20meters, hope 5watts, should be nice.

any idea ???
73'

Re: Two BitX40's For Sale

Jim WB2LHP in MI
 

Assembled BitX40 is sold. Unbuilt BitX40 v3 with Universal Maroon Case II still available. $100 shipped. CONUS only. PayPal preferred. Thanks for looking...Jim WB2LHP

No XMIT, No Recv #v6

k7ome@...
 

My V6 suddenly decided not to transmit or receive.  I did do a frequency and BFO adjustment a few days ago and had it dead on frequency.  It is possible that I may now have wiped out the settings on the EEPROM but nothing I have tried to correct that situation makes any difference.  The factory software is installed. The software operates as it should but there is no power going out and no audio coming in even when I transmit on my Kenwood (from previous tests I know that this should be working). There is no burning electronics smell and no visible damage inside the radio (I have made no hardware mods). The speaker still produces the 'live air' sound but there does seem to be an extra 'whistle' in it.  It is very cold and dry here so maybe a static charge problem?  Is the EEPROM onboard the Nano? I don't see any I can recognize on the main board. I can replace the Nano if you think that might be a solution.

Summary: worked fine but stopped suddenly.  No power out at all, no reception even from a nearby transmitter. 

Ideas?

Re: Documentation question

Curt
 

John

Honestly, no.

Visit ubitx.com which is coordinated by amateurradiokits.in. last I looked there are instructions and video on assembly there. I had to correlate this with ubitx instruction.

Those rear panel ports aren't used with a stock ubitx, but can later be applied. Lay them aside for now, mine aren't in use yet.

Do note the bicolor led gets wired to the bottom of the board prior to attachment into the enclosure.

Curt

Documentation question

John Kalotai
 

Hi All,



I am a newbie with a v3 board that I just got around to assembling. I have the Universal Case from amateurradiokits.in


Is there a good single source for assembly and tune up instructions for the radio? For instance, What is the digital board with the USB port/DB9, etc for? I mean besides the obvious answer, there were no suggested hook up instructions. Is there a published manual available somewhere?



73



John N1OLO

Re: Two BitX40's For Sale

George P Linehan III
 

Ok tell me how I can pay I’m in...

 linehangp@...
WA6YCA

On Jan 14, 2020, at 6:16 PM, Jim WB2LHP in MI <jmarco1955@...> wrote:


Hi Paul...Yes the built rig is still available...

On Tue, Jan 14, 2020 at 7:20 PM George P Linehan III via Groups.Io <linehangp=icloud.com@groups.io> wrote:
Hi Jim .. is the built rig still available and if not can you build and sell the other?? Thanks, Paul WA6YCA

> On Jan 14, 2020, at 1:34 PM, Jim WB2LHP in MI <jmarco1955@...> wrote:
>
> BitX40's




Re: Two BitX40's For Sale

Jim WB2LHP in MI
 

Hi Paul...Yes the built rig is still available...

On Tue, Jan 14, 2020 at 7:20 PM George P Linehan III via Groups.Io <linehangp=icloud.com@groups.io> wrote:
Hi Jim .. is the built rig still available and if not can you build and sell the other?? Thanks, Paul WA6YCA

> On Jan 14, 2020, at 1:34 PM, Jim WB2LHP in MI <jmarco1955@...> wrote:
>
> BitX40's




Re: New ham, Ubitx issues #ubitx

dwhacks
 

Dear Jerry, KE7ER
You are exactly the kind of person I hoped to encounter in Ham radio. I love DIY, and I love the sharing of knowledge. This is was brought me to the uBitx. Also, your post was the PERFECT step by step guide to finding my problem, and solution!

So, I don't know if anyone has noticed on the V4 boards, but RV3 is crooked from the factory to clear the heatsink. Well, somehow, over time, one of the legs on that trimmer broke so it was now feeding Q94 with around 5v! no bias adjustment possible! All I had to do was swap it out for another one and we are back in business! set the finals to 100mA each and all seems good! Thanks again from everyone who chimed in. I have asked the Ham that did my exam and he said, as far as he reads it, the ubitx falls under "assembly of commercially available transmitter kits of professional design". I will get him to check it over anyway, but I'm not about to stay in bed afraid of the world. I will also be studying towards my advanced, as homebrew QRP is what I am most interested in.

Thanks again,
Dayne, VE7DNT

Re: Two BitX40's For Sale

George P Linehan III
 

Hi Jim .. is the built rig still available and if not can you build and sell the other?? Thanks, Paul WA6YCA

On Jan 14, 2020, at 1:34 PM, Jim WB2LHP in MI <jmarco1955@...> wrote:

BitX40's

Re: Question about power output #v5 #ubitx

Ted
 


Bonjour,

The proper setting of the BFO is very important for output power as well as for receiving, it seems.

I would suggest setting this to 11,056400 and see how the output power is on the bands.  I have one V5 set for 11,056560 and another V5 set for 11,056210, so my suggestion here is about the middle of those.

After this, if the output has improved, one might find an audio spectrum graph application (or the HF Signals web page tool for the purpose) and find your specific BFO value that performs the very best on TX and RX alike.  



Bon chance,


Ted
K3RTA

Re: uBitx microphone wire up

Mike WA0YCN
 

It’s not an idiots guide, it’s a learning process. We’re all going through it, some have just started earlier. I went through this exact issue about a month ago. 


Best of luck. Enjoy!

I hope we get to talk on the air.

Mike

Re: Ubitx V6 Nextion 2.8" Display Modification

bill richardson
 

I used this guide to get started but off from this site I was able to find the later releases:




On Jan 14, 2020, at 12:36 PM, Evan Hand <elhandjr@...> wrote:

Bill,

Thank-you again.  i see that it is a "basic" 2.8" unit.  I know where to get the KD8CEC firmware for the Nano, are you saying that the source on Git hub had the tft file for the Nextion as well?  When I downloaded what was there I could not get it to work with my 2.8" Enhanced display.  I also could not get the source to compile, as it said that there was not enough memory.

I am new to the Nextion editor, so it may be something simple on the settings that I do not know about.  I have built 3 units, a 2.4", 3.2" and now a 3.5", however all have been from tft files.  I did not have the issues that are happening for me now.

73
Evan
AC9TU

Two BitX40's For Sale

Jim WB2LHP in MI
 

Greetings to all. I have two BitX40's in Universal cases for sale. The first is built and ready to go in the Universal Case DA Grey I and the other is unbuilt with the Universal Maroon Case II. Both BitX40's are stock and unmodified...I have loaded Allard's v1.29 firmware on them but can also load v2.04 if you prefer...$100 each shipped. CONUS only. PayPal preferred. Thanks for looking. Jim WB2LHP

Question about power output #v5 #ubitx

Anthony F4HUY
 

Hello,
got my ubitx v5 one month ago, almost finished ...

it's sell with "More than 10 watts up to 10 MHz, 7 watts up to 21 MHz, 2 watts on 28 MHz" ,
i get 2w between 21 an 30Mhz, then the power drastically decrease under 2w under 21mhz, around 800mw at 7.1mhz, and close to zero on 3.5mhz

what's happen ? it's should be the opposite.

i have already checked and re*tuned rv2/rv3, my microphone is a baofeng, test with cw give same result

i want to operate mainly on 20meters, hope 5watts, should be nice.

any idea ???
73'

Re: uBitx microphone wire up

Brad, K7NNR
 

Fantastic! Thank you Mike!

Sorry for needing the idiots guide.

Re: KD8CEC ‘s SWR senser

Vic WA4THR
 

Whoops! My error, now discovered. Nothing like making a post for help to dicover the problem on you own!

I assumed I had the latest DSPMeter sketch (v1) but it appears by looking at the upload dates that (v0.8) is a later version by about 11 days. I guess I didn’t understand the naming convention. I have now installed v.08 and I am getting good SWR indication.

=Vic=

Re: uBitX on CW #v6

Jim
 

Would the (now discontinued) CW Conditioning Board (here) help fix this?  Seems easy enough to home brew this circuit.  Still waiting on my V6 to arrive, but I'm a CW-only kind of op and keenly interested in this.

73, Jim KK0U

Re: KD8CEC ‘s SWR senser

Vic WA4THR
 

I read your post that you have the SWR function working on your uBitX. I have a V4 that I built a year ago and added the Nextion display, then added the second I2C Arduino and I am able to do all functions with that including CW decoding, audio spectrum, S-meter and so forth. All has worked well for many months. In order to eliminate taking a separate SWR bridge for use with my loop antenna when going portable, I decided to add the SWR bridge in KD8CEC’s website. I built up a Stockton bridge and I am measuring good results with itI, with FWD power in the 1.7v range and maybe around 0.5v in the REV pad in a typical check. SWR caculations by hand match actual SWR pretty well. I wired the FWD and REV pads  to pins A2 and A3 on the second, I2C Arduino and on transmit I see nothing…no deflection of the S-meter graph at all.

Did you have to do something different that just connecting the 2 wires? I didn’t run a ground wire as the SWR bridge is already connected to ground through the antenna connector, and the second Arduino is connected to its own ground as well. Is there a switch in software?  I am using version "UBITX_CEC_V1.100_NX_S" of the KD8CEC sketch and “dspmeterv1” dated 4/1/2019 on the second Arduino. Thanks for your help.

=Vic=

Re: VK4PP Ultimate uBitx Daughter Board. #ubitx #filters #parts

wnpauls
 

I would like one or two of these boards when they become available.

thanks, Paul K0ZYV



From: BITX20@groups.io <BITX20@groups.io> on behalf of Richard Perry via Groups.Io <perryrt@...>
Sent: Tuesday, January 14, 2020 12:51 PM
To: BITX20@groups.io <BITX20@groups.io>
Subject: Re: [BITX20] VK4PP Ultimate uBitx Daughter Board. #ubitx #filters #parts
 
I too would like one of these boards.

Re: VK4PP Ultimate uBitx Daughter Board. #ubitx #filters #parts

Richard Perry
 

I too would like one of these boards.