Date   

Re: Question about power output #v5 #ubitx

Jerry Gaffke
 

Firmware for a v3 or v4 board mistakenly installed on a v5 or v6
would seriously attenuate 80 and 40 meters, but 10 and 20 meters should be unaffected.
Operation on 80 and 40 would be as if the antenna was disconnected, might damage the IRF510's.

Firmware for v5 or v6 on a v3 or v4 board would allow harmonics out on 80 and 40 meters
since only the 30m filter would be getting used, but again 20 and 10 meters are unaffected

Here's what the routine setTXFilters() does in the firmware for v3,v4 and v5,v6 boards:
                        30m   20m   40m   80m
ver 3,4:   abc = 000    100    110    111        (a=0 for 30m, else b=0 for 20m,  else c selects 80m not 40m)
ver 5,6:   abc = 000    100    010    001       (1 to engage each filter for 20m,40m,80m,  but 30m is always inline)
 
To get the symptoms reported (particularly an attenuated 20m) would require two different problems
out in the LPF's.   Possible, but seems more likely to be trouble further back in the power amp somewhere.

He reports that CW transmissions are also affected, so not an issue of anything prior to the first mixer at D1,D2.

Jerry, KE7ER


On Wed, Jan 15, 2020 at 06:38 AM, Gary Anderson wrote:
Simple question:
Are you using the factory V5 firmware?  Confirmed that your board is a V5?

With board changes from V3/4 to V5 the BFO and filter circuits changed.
I haven't gone through the logic mapping of what exactly would happen on the LPF circuits if the wrong version of firmware is used, but it will be problematic.


Re: extra nano board

Evan Hand
 

If you are referring to the KD8CEC stand alone s meter and spectrum analyzer, it is on the Hams Key Blog. the latest is here:

http://www.hamskey.com/2018/08/standalone-signal-analyzer-i2c-type.html

Otherwise you can search Hamyskey blog, the messages section in this group, or ubitx.net for other sources.

73
Evan
AC9TU


sotabeams filter installation

dave <dgclifford@...>
 

going to fit a sotabeams  cw filter to my ubitx v5 ,where can i insert this on the board (before lm386 amp) if any one has done this what tracks will i need to break into as i would ike to fit inside the case   many thanks dave c


bitx 40 pcb

dave <dgclifford@...>
 

anyone got a bix40 pcb bare or (partially) populated they want to part with  dave c  gw0nvf


Re: #uBitx #v4 and #sdr panadapter #ubitx #v4 #sdr

Mike McGuigan <w6thw@...>
 

I have the same question did you ever get a answer?

Mike


Re: No XMIT, No Recv #v6

k7ome@...
 

Thanks for the reply Jerry and I think you're basically correct.  It's working again.  The problem was the calibration value that was stored in the EEPROM (where ever that thing may be).  I was implementing a change to the Setup code that would show the stored value when you went back to Setup.  Somehow - and I still don't see how it happened - the calibration value that got stored at some point included the entire frequency plus the calibration value! That made the calibration way out of range and shut everything down.  Even after reloading the original code the problem persisted because the EEPROM values stayed the same.  Once I had that figured out I forced the EEPROM value back to 875 and the radio started working again.  Now I can re-calibrate and see the stored values when I do. 

Well, I guess you have to expect that kind of stuff to happen when you go messing around with the code....


Re: Question about power output #v5 #ubitx

Gary Anderson
 

Simple question:
Are you using the factory V5 firmware?  Confirmed that your board is a V5?

With board changes from V3/4 to V5 the BFO and filter circuits changed.
I haven't gone through the logic mapping of what exactly would happen on the LPF circuits if the wrong version of firmware is used, but it will be problematic.


#ubitx #ubitx-help #v5 Where to buy power socket #ubitx #ubitx-help #v5

Przemek
 

My power socket does not provide a good connection. Where can I buy new ones (preferably on aliexpress). What is the socket model


extra nano board

David Alexander
 

where can i find the lashup for the extra board.  i had not been following that thread and now i would like to add these features to the radio.

dave k7da


Notes from the Dominican Republic on uBITX mods

Bill Meara
 


Re: Question about power output #v5 #ubitx

Evan Hand
 

I would also check that there is not an issue with one of the relays/LPFs.  Without power connected to the PA (brown power wire), check each band for continuity from the antenna jack to TP7.  You should have a connection for all of the bands.  

The above reasoning is that all of the relays are de-energized for 10 meters (28 MHz).  Not sure why all of the other bands have low output, however it is worth a try.

Just a thought.
73
Evan
AC9TU


Re: No XMIT, No Recv #v6

Jerry Gaffke
 

Try sending CW, do you get any power out?

If not, my best guess is that the Si5351 is not working for some reason.
You can verify this by bringing a shortwave receiver near your uBitx
(or bringing your uBItx over to a friend's shortwave reciever)
and listening for a carrier within 10khz of 11.059 mhz, being radiated from CLK0.
The uBitx can be in receive mode for this test, doesn't matter what frequency it is trying to receive.

CLK0 is the uBitx BFO signal, the 11.059mhz BFO beats with any incoming signal
that makes it through the 11.059mhz crystal filter.

Jerry, KE7ER


On Tue, Jan 14, 2020 at 08:20 PM, <k7ome@...> wrote:
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: 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 <jmarco1955@...>
 

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 <john@...>
 

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 <jmarco1955@...>
 

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