Date   
Re: RX sensitivity #v6

_Dave_ AD0B
 

Hi Rick Perhaps you might want to cross your eyes and look again at the  2 transistors in the receive circuit.  Most ubitx have 7 transistors and op amp in the receiver. If you can hear a signal at 1/3rd of a microvolt then where does the 1μV come in.

To the OP:
If you are looking for a radio for a boat you might think of something that will work in a rough wet environment. Ask Jeanne Socrates as she knows something about ithttps://www.qrz.com/db/VE0JS  Of course she may have been given that radio for publicity. Caveat emptor.

73
Dave
AD0B
Raduino bracket and Ham_Made_Keys

Re: RX sensitivity #v6

MVS Sarma
 

Technical Specifications

The µBITX is an understandable radio and, hence, can also be a learning experience. The complexity is kept to a minimum so you can always repair and make changes if you so desire. The µBITX has a carefully thought-out operator interface. The tuning knob features many menu options available with a simple push on the tuning knob. From RIT, to dual VFOs, to the keyer, and many other features are all accessible from the tuning knob by simply pushing on it. There are intelligent defaults everywhere (these are easily overridden). Example : below 10 MHz, it auto-selects LSB and vice versa. To operate CW, you just press the morse key. Architecture The µBITX uses upconversion to the first IF of 45 MHz. This eliminates the need for a large number of band pass filters, keeping the design simple and virtually image free. The roofing filter at 45 MHz is 15 KHz wide. The signal is then down-converted to 12 MHz where a low ripple SSB filter with 8 crystals is used to provide a sparkling audio. The transmitter has push-pull PA using two IRF510s for a clean output. The low cost IRF510s are simple and inexpensive to replace should the need ever arise. Receiver :
  • Sensitivity: a 0.2uv signal is clearly audible
  • Selectivity: 2.4 KHz,  low ripple SSB filter with 8 crystals
  • RIT (Receiver Incremental Tuning)
  • Continuous coverage from 500 KHz to 30 MHz
  • Sideband selection
  • Detent-less encoder tuning. Tunes with larger step rates when tuned quickly
This info is there in hfsignals.com


On Mon, Mar 2, 2020 at 12:57 AM <publique@...> wrote:

Hello ! This is a very dummy question, but I can't really find the information... I would like to know what is the RX sensitivity of the ubitx ? I'm planning to use it (among other things) in my sailboat to receive weather forecast, but how good is the reception compared to a SDR (RTL-SDR, or even the more HF-oriented SDRPlay RSPDx), or to a HF transceiver from big brands ?

Many thanks !
73's from French Guyana ;)

Thomas

Re: W8TEE pending software release and port(?) #w8tee

Jack, W8TEE
 

Dave:

Attached is the last version I have for the BITX40.

Jack, W8TEE

On Sunday, March 1, 2020, 6:02:24 PM EST, David R. Hassall WA5DJJ <dhassall@...> wrote:


Dear Jack,
I have your VFO Board built but not tested.   Does the software for it still exist somewhere?   If I does, I would like to have it so I can finish my BTX40 and maybe give it to a new ham just starting out to play with. 

Take care and have fun.
Dave WA5DJJ

--
Jack, W8TEE

Re: No RX LED indication #v5

_Dave_ AD0B
 

The display changes to TX when transmitting. No need for a separate light or led. 
--
73
Dave
AD0B
Raduino bracket and Ham_Made_Keys

Re: No RX LED indication #v5

Brad, K7NNR
 

Thanks for the suggestion Rick. I actually had not checked for continuity on the RX wire, out of frustration I know I am missing silly things.

Sadly though, I did check and the connections are all good but there is still no RX indication.

Any more ideas?

Re: Unbuilt uBITX Ver4 and Blue Cabinet for sale.

Mike WA0YCN
 

Rob, Mike, or anyone,

Have you gotten this to work with the tap board off the 1st IF as SM6MOJ suggests?  I’ve installed the board, but can’t figure out the settings in uBitx Manager and OmniRig.  Ian’s approach off the 2nd IF was to set the offset frequency to 30,000,000 in both Manager and OmniRig, but that doesn’t work for me.  

Ii haven’t understood how the offset works.  Is it adding 30mhz to the IF oscillator(s), or just the difference between 30mhz and 11.097mhz.

Thanks,

Mike

Re: Setup mode #v6

sam
 

thank you to all
I go the menu 
73!

Re: Made Mods to V3 uBitx - no longer transmitting #ubitx-help #v3

_Dave_ AD0B
 

Was trying out Steve's radio this afternoon.

The furthest station I made contact with was from the Slovak Republic on 40m @10w. I think it may be a new country for me. 

Thanks Steve. It is a winner.
73
Dave
AD0B
Raduino bracket and Ham_Made_Keys

Re: RX sensitivity #v6

Rick Tilton <rtilton@...>
 

Sorry but I was a techs home the other day working on some other stuff.  Showed him the ubitx.  He put it on his equipment to check SNR and it came out to 1 microvolt?  VERY high!  At 1/3 microvolt you could hear if someone had GREAT audio.   Yes we checked several times and checked SEVERAL other receivers to make sure we were reading correctly.  Suggestions?  I only see about two transistors or such in the rx section.  However, I did not get anywhere close to .01 microvolt?  I'm not the greatest tech but know enough to be dangerous somewhat.  Suggestions again or am I the only one seeing this? 


On Sun, Mar 1, 2020 at 2:27 PM <publique@...> wrote:

Hello ! This is a very dummy question, but I can't really find the information... I would like to know what is the RX sensitivity of the ubitx ? I'm planning to use it (among other things) in my sailboat to receive weather forecast, but how good is the reception compared to a SDR (RTL-SDR, or even the more HF-oriented SDRPlay RSPDx), or to a HF transceiver from big brands ?

Many thanks !
73's from French Guyana ;)

Thomas



--
73,

Rick WK4R

--
73,

Rick WK4R

Re: RX sensitivity #v6

iz oos
 

I have ver. 3, ver. 6 should be even more sensitive. Ubitx is sensitive like other rigs. The difference between expensive and the least expensive radios is not on sensitivity. Even my portables, tecsun PL660 or Sargeant 909 are as sensitive as expensive rigs. Consider even portables with SSB like the Tecsun PL660 or the PL680. As receivers they work absolutely fine. I have used portables like these to decode FAX weather maps years ago and I found them nice.


Il 01/mar/2020 21:47, "David Nelson" <kc2ipx@...> ha scritto:
just received new xiegu g90  and it is a very nice well made radio but I find it considerably  noisier than my ubitx v3.
That is on the same antenna. A vertical multi band. I am going to look into some audio filtering. I would love to try 
a nescaf if neqrp ever sells more kits. Just my experience.  Dave  kc2ipx

On Sun, Mar 1, 2020 at 3:34 PM Evan Hand <elhandjr@...> wrote:
Thomas,

I would caution that the ubitx, while a good radio, that in my opinion it is really designed for two markets; the just starting out ham that cost is a large factor, and the tinkerer (like myself) that uses it to both learn and sharpen skills.

Reading between the lines of your message, I believe that a little bit higher end might be a better choice for the sailboat.  The one that comes to mind is the new MFJ G90 that is a Chinese import of the Xiegu G90.  I do not own one, so am only going by reviews that I have read and the specs.  The three that caught my eye were the 20 watts out, the built in antenna tuner, and the SDR based design.

With the above said, I concur with the others that have commented so far; receive compares favorably with my main go to rig (An IC-7300), and better than the Hermes HL2 (
that I have started to play with) for sensitivity.  The uBitx has nowhere near the number of modes and features as either the HL2 or the IC-7300.  I need to also say that I have not got consistent results from the different boards that I have bought at different times.  The last v5 board is by far the best, so would expect the v6 to be comparable.  The messages on this site do indicate the there may be variability between units within the same model, as some state having low receive volume and others great results.

The above are my personal views.  Others may be different, and that is OK.
73
Evan
AC9TU

Re: W8TEE pending software release and port(?) #w8tee

David R. Hassall WA5DJJ
 

Dear Jack,
I have your VFO Board built but not tested.   Does the software for it still exist somewhere?   If I does, I would like to have it so I can finish my BTX40 and maybe give it to a new ham just starting out to play with. 

Take care and have fun.
Dave WA5DJJ

Re: Good spot to insert audio preamp on V6 #v6

 

If any desire to add a amp as I did you might want to remove C75, a 1mfd cap across pins 1 and 8 of the LM386 chip, this will lower the gain of that chip from 200 to 20 which makes the audio noise floor go down considerably.

Joel
N6ALT

Re: Any interest in uBITX Net

_Dave_ AD0B
 

I have been calling cq bitx the last few  minutes .It is 22:10 z
--
73
Dave
AD0B
Raduino bracket and Ham_Made_Keys

Re: Any interest in uBITX Net

Bob Fischer, Fischer Technical Services
 


I listened & called CQ BITX on 7.277 MHz from 3:05 PM to 3:10 PM EST.  Running 40W mobile.  From Daytona Beach, FL.
Nothing heard except some adjacent frequency QRM. 
Note:  20M was open coast-to-coast from Florida this afternoon. 
Bob
WB8BEL/4


From: "Mick" <Mgsebele@...>
To: BITX20@groups.io
Sent: Sunday, March 1, 2020 3:13:06 PM
Subject: Re: [BITX20] Any interest in uBITX Net

Anybody on 40m ssb 7277? @20:12 itch

Re: RX sensitivity #v6

David Nelson
 

just received new xiegu g90  and it is a very nice well made radio but I find it considerably  noisier than my ubitx v3.
That is on the same antenna. A vertical multi band. I am going to look into some audio filtering. I would love to try 
a nescaf if neqrp ever sells more kits. Just my experience.  Dave  kc2ipx

On Sun, Mar 1, 2020 at 3:34 PM Evan Hand <elhandjr@...> wrote:
Thomas,

I would caution that the ubitx, while a good radio, that in my opinion it is really designed for two markets; the just starting out ham that cost is a large factor, and the tinkerer (like myself) that uses it to both learn and sharpen skills.

Reading between the lines of your message, I believe that a little bit higher end might be a better choice for the sailboat.  The one that comes to mind is the new MFJ G90 that is a Chinese import of the Xiegu G90.  I do not own one, so am only going by reviews that I have read and the specs.  The three that caught my eye were the 20 watts out, the built in antenna tuner, and the SDR based design.

With the above said, I concur with the others that have commented so far; receive compares favorably with my main go to rig (An IC-7300), and better than the Hermes HL2 (
that I have started to play with) for sensitivity.  The uBitx has nowhere near the number of modes and features as either the HL2 or the IC-7300.  I need to also say that I have not got consistent results from the different boards that I have bought at different times.  The last v5 board is by far the best, so would expect the v6 to be comparable.  The messages on this site do indicate the there may be variability between units within the same model, as some state having low receive volume and others great results.

The above are my personal views.  Others may be different, and that is OK.
73
Evan
AC9TU

Re: Any interest in uBITX Net

Evan Hand
 

I called CQ earlier (around 2:05 PM Central and 2:10).  No response.

I left my rig on and have been listening while responding to other emails, Have not heard anything.

I also tuned in two different web based SDRs, and only found contestants at 7.278.  NOt sure what contest is going this weekend.

The above has been my experience for the past year.  No one seems to be on Sundays.

73
Evan
AC9TU

Re: Only noise when connected to the antenna #v6

Jonathan Kayne, KM4CFT
 

I think I might have the reason that the display is causing this issue. In the code the touch control CS pin is pulled high after initializing the TFT portion. That pin is probably low on startup so the touch controller probably thinks the TFT commands are for it resulting in both touch and TFT to respond simultaneously and effectively jumbling up the SPI line. Might be something to fix in the code as it is a good idea to make sure all SPI CS lines are high before sending anything!

-Jonathan, KM4CFT

Re: RX sensitivity #v6

Evan Hand
 

Thomas,

I would caution that the ubitx, while a good radio, that in my opinion it is really designed for two markets; the just starting out ham that cost is a large factor, and the tinkerer (like myself) that uses it to both learn and sharpen skills.

Reading between the lines of your message, I believe that a little bit higher end might be a better choice for the sailboat.  The one that comes to mind is the new MFJ G90 that is a Chinese import of the Xiegu G90.  I do not own one, so am only going by reviews that I have read and the specs.  The three that caught my eye were the 20 watts out, the built in antenna tuner, and the SDR based design.

With the above said, I concur with the others that have commented so far; receive compares favorably with my main go to rig (An IC-7300), and better than the Hermes HL2 (
that I have started to play with) for sensitivity.  The uBitx has nowhere near the number of modes and features as either the HL2 or the IC-7300.  I need to also say that I have not got consistent results from the different boards that I have bought at different times.  The last v5 board is by far the best, so would expect the v6 to be comparable.  The messages on this site do indicate the there may be variability between units within the same model, as some state having low receive volume and others great results.

The above are my personal views.  Others may be different, and that is OK.
73
Evan
AC9TU

Re: Any interest in uBITX Net

Martin Potter <ve3oat@...>
 

Maybe it's propagation of I am too far away from everyone, but I heard no one. Lots of adjacent activity (7278) and I called CQ BITX once on 7277 but there were no replies. I also called twice on 7275, which seemed clear at the time, but heard no response there either.

I recently changed the mic element in my cheap Baofeng microphone, replacing it with the element from the QRP-Kits mic kit. Wonder if it has improved the audio quality at all.

73,
... Martin VE3OAT

Re: Any interest in uBITX Net

David Nelson
 

got contesters on 277  kc2ipx


On Sun, Mar 1, 2020 at 3:13 PM Mick <Mgsebele@...> wrote:
Anybody on 40m ssb 7277? @20:12 itch