Date   
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

Re: Any interest in uBITX Net

Mick
 

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

Re: RX sensitivity #v6

Curt
 

Thomas

Asshar does quote a perceived sensitivity somewhere, I am not recalling it. On HF its effectiveness in sensitivity should rival other rigs, except maybe at 24 and 28 MHz where is does not offer preamp. This analysis does assume a full sized antenna is available. If the antenna would he quite small, the design of a preamp could matter. Your matter could he complicated by the antenna and particular frequency.

Curt

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

 

I decided that I would go another direction for my low audio problem, instead of trying to insert a preamp I just am using the uBitx's audio amp as the preamp to a TDA2030 module, it works so much better. See picture attached as to how I mounted it. I screwed the chip to the side of the cabinet to keep the chip cool.

Joel
N6ALT

Re: RX sensitivity #v6

_Dave_ AD0B
 

A number I don't have. But that said it is comparable to my other radios. The big advantage that it has over the sdr receivers is that it can transmit, also you don't need a computer to make it work. It doesn't have FM or real narrow filter for cw. Can receive AM on either side band. 
73
Dave
AD0B
Raduino bracket and Ham_Made_Keys

Re: RX sensitivity #v6

Richard
 

I do not have exact figures, however, the article in the description page says there is a usable signal at .1 uv .


On Sunday, March 1, 2020, 01:27:04 PM CST, publique@... <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

RX sensitivity #v6

publique@...
 

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: Efficient speaker for low volume #audiocircuit #ubitx

Jack, W8TEE
 

FWIW, I find Parts-Express to be a really good and responsive company. I've purchased quite a few items from them, including a cheap solder station (<$15.00) and cheap speakers and have been happy with the products and their service.

Jack, W8TEE


On Sunday, March 1, 2020, 10:09:26 AM EST, Mark Muller <markvmuller@...> wrote:


Great idea, Don. If you're looking for a smaller speaker with high sensitivity in the audio frequency region, you might give this one a try.

https://www.parts-express.com/2-mylar-cone-full-range-waterproof-speaker-d0050008nm14bar--289-204

Looking at the sensitivity graph, it might sound pretty "bright" - you won't get much bass, but it cuts off fairly sharply after 6 kHz, so maybe that will be OK?

Can't beat the price!

73's de N5KNG (Mark)

--
Jack, W8TEE

Re: Setup mode #v6

Reed N
 

Holding the tuner button down when powering on goes into the three cal serial mode, not into the menu. Might still do what you need, but isn't necessarily the same.


Reed

Re: Only noise when connected to the antenna #v6

Jonathan Kayne, KM4CFT
 

I have published a YouTube video that goes through my findings. I was also trying to explain how the circuitry works. I show spectrum analyzer readings as I explain it so it might help.
https://youtu.be/pQb-sM8slCg

Curt, I did indeed check each oscillator and they were all working as expected. In fact that was the first thing I checked when I started troubleshooting. I also observed that the LO would appear at the output of the mixer due to nonlinearities of the mixer. 

Evan, I have tested up to the product detector stage. It is of course possible that one of the transformers isn't working properly, but I will say that I checked the product detector by inserting a 1 kHz -50 dBm (that's the lowest the function generator could do as the Agilent I was using for testing is 100 kHz minimum and had to switch to the lower frequency SG) into the audio side and it mixed the baseband up to 11 MHz. The weird thing about that was that the signal appeared to be amplified and not attenuated (by about +28 dBm if I remember correctly) maybe that signal generator wasn't as accurate as the Agilent...

-Jonathan, KM4CFT

Re: Signal pathway highlighted on schematic

Joe Puma
 

Thanks for providing this. 



On Mar 1, 2020, at 10:55 AM, _Dave_ AD0B <davesters@...> wrote:

Here is the signal pathway for a V3 uBITX
--
73
Dave
AD0B
Raduino bracket and Ham_Made_Keys
<ubitxv3s.pdf>

Re: Efficient speaker for low volume #audiocircuit #ubitx

Don - KM4UDX
 

I've always had a thing for clear speakers...I mean how cool is that...hahaha.

There is a price to be paid for that great small form factor...the efficiency is 84 dB 2.83V/1m.

The bigger non-transparent speaker with large magnet efficiency is 96 db...so the difference between the two (84-96) is 12 db gain going from smaller to larger.

But the Mylar speaker is the small bomb.

Re: Signal pathway highlighted on schematic

_Dave_ AD0B
 

Here is the signal pathway for a V3 uBITX
--
73
Dave
AD0B
Raduino bracket and Ham_Made_Keys

Signal pathway highlighted on schematic

_Dave_ AD0B
 

This one is for a uBITX V6

--
73
Dave
AD0B
Raduino bracket and Ham_Made_Keys

RTC07S Si531 DDS VFO

e78cb@...
 

Dear friends, I need help..

I accidentaly burned out Si5351 chip on Raduino on my BITX 40 kit TRX. So I removed Arduino and I decided to use RTC07S DDS VFO from hambuilder.com instead.
It all turned on and I set up IF to 12MHz and it is on frequency BUT there emerged two problems:

1. My BITX is on USB modulation at all times! As you know BITX 40 shoud run on LSB as it was before with Raduino DDS.. I do not know how to correct this.. I tried to switch DDS contacts opposite to get opposite V from DDS in my thinking logic but I got too low gain to hear it.. What do you suggest?
RTC07S has a LSB and USB BFO outputs, but I switched only VFO outputs to DDS on BITX as it only gives some signal.. Does BITX has BFO outputs and can I connect RTC07S to it..I dont know..

2. I get annoying buzz signall at all times in speakers, when DDS runnig.. Hopefully this is more easy to reslove, but I had no idea at the moment...

Thanks for any solution or guidance..

Vule, E78CB




Efficient speaker for low volume #audiocircuit #ubitx

Mark Muller
 

Great idea, Don. If you're looking for a smaller speaker with high sensitivity in the audio frequency region, you might give this one a try.

https://www.parts-express.com/2-mylar-cone-full-range-waterproof-speaker-d0050008nm14bar--289-204

Looking at the sensitivity graph, it might sound pretty "bright" - you won't get much bass, but it cuts off fairly sharply after 6 kHz, so maybe that will be OK?

Can't beat the price!

73's de N5KNG (Mark)

Re: #v6 software #v6

Juha Lindfors
 


Here is link to the Reeds site.

Juha oh8cw

su 1. maalisk. 2020 klo 16.20 Mark Spohr (mhspohr@...) kirjoitti:

Here's the thread on Reed's code.
The forum search function works pretty well.

https://groups.io/g/BITX20/message/75230

Re: #v6 software #v6

Juha Lindfors
 

That's Ashhar's github site?

Juha oh8cw

su 1. maalisk. 2020 klo 16.20 Mark Spohr (mhspohr@...) kirjoitti:

Here's the thread on Reed's code.
The forum search function works pretty well.

https://groups.io/g/BITX20/message/75230

Re: #v6 software #v6

Andy_501 <andrew.webb.501.ve4per@...>
 

I find if I am looking for a link someone quoted in these group.io posts that I can usually find it in the archived messages. I use an email client program and save an archive in it that is specific to my version of uBITx. The advanced search allows searching through actual text as well as header/subjects etc. If I accidentally delete something from my email client program I can find it by searching the online archives also. In these cases I usually use a web browser to search online archives but only go back to a date that coincides with the initial release of my version of UBITx.

Sometimes it is a bit of extra effort to find that elusive link or message but usually I have found it in one of those two searches for what it might be worth wrt "gone forever" comment.

cheers 73 & gud dx

Andy ve4per

On 2020-03-01 8:15 a.m., Juha Lindfors wrote:
Tried to find it by myself also but no
luck. Anyway I downloaded the code and changed it a little bit. the link is on my pc and come back when beside it again.

73 Juha oh8cw

su 1. maaliskuuta 2020 klo 16.07 David R. Hassall WA5DJJ <dhassall@...> kirjoitti:
Dear Juha,
Thanks for the hint where Reed's code might be.   I took a quick look  But didn't find it right off.   But will try again later.
It seems that if a person misses a message on this website where something is..... It is gone forever.  

Take care and have fun.
73 Dave WA5DJJ

Re: #v6 software #v6

Mark Spohr
 

Here's the thread on Reed's code.
The forum search function works pretty well.

https://groups.io/g/BITX20/message/75230