Date   

Re: One question only...

davedt1e@...
 

To the best of my knowledge, the Ubitx is legal if built stock without mods.  In particular ... mods boosting Mic gain on frequencies above 20 meters may cause spurs.  So even with mods, you've still got a legal 20, 40 and 80 meter radio.  Still one heck of a deal for the price.


Re: Harmonic performance - SSB vs CW

James Lynes
 

For now kit up and offer an external filter add-on capable of handling the output of the finals being powered from up to 24v.

Fix the problem on a v5, v6,... board.

James


Re: uBITX: new build #ubitx

hirosmb <hirosmb@...>
 

Cool! I like it.

// hiro, JJ1FXF



2018/08/05 4:05、Jim Reagan <jimreagans@...>のメール:

Oops, the photo!!!
JR
<uBITXv3.jpg>


Re: Harmonic performance - SSB vs CW

John KC9OJV
 

Allison,

If there are pin compatible Omron relays would it make sense to solder a set into a stock board that has been already characterized on a spectrum analyzer and see what effect the better relays have? It seems a reasonable expense for an experiment that may tell us things.

John
KC9OJV


Re: Bitx40v3 CAT Control firmware?

Bill Cromwell
 

Hi =Vic=

It's much the same as VOX or semi-break-in or full QSK. It's a personal requirement driven by personal preferences. In my experience each and every ham is at least a little bit different from every other. Some of the differences are quite a contrast! I don't use CAT because none of my radios have ever cooperated with a computer but now I have one that will. I will eventually get around to trying it. Maybe I will discover that I can't live without CAT :) I tried FT-8 and rejected it out of hand. But I also tried CW and I still like it:) I even enjoy SSB and PSK-31 of all strange things. Have =you= tried CAT? If you did then you will be able to tell us why you do or do not like it:) The rest of us are on our recognizance.

73,

Bill KU8H

On 08/05/2018 06:17 AM, Vic WA4THR via Groups.Io wrote:
Just curious why CAT control is seen as a requirement, When I started
with PSK31 I was using an older rig and the only connection to a
computer was via a SignaLink that provided audio in/out and PTT derived
from a VOX circuit in the SignaLink. Others keyed the rig with some
other output line from the computer off a serial port. Almost all the
digital modes (save RTTY) were on "fixed" frequencies with tuning done
by just varying the tones supplied/received in the audio passband of
that frequency. Logging was easy since the frequency never changed. So
what is the value of CAT control?

=Vic=
WA4THR
--
bark less - wag more


Re: Bitx40v3 CAT Control firmware?

Vic WA4THR
 

Just curious why CAT control is seen as a requirement, When I started with PSK31 I was using an older rig and the only connection to a computer was via a SignaLink that provided audio in/out and PTT derived from a VOX circuit in the SignaLink. Others keyed the rig with some other output line from the computer off a serial port. Almost all the digital modes (save RTTY) were on "fixed" frequencies with tuning done by just varying the tones supplied/received in the audio passband of that frequency. Logging was easy since the frequency never changed. So what is the value of CAT control?

=Vic=
WA4THR


Re: Harmonic performance - SSB vs CW

Warren Allgyer <allgyer@...>
 

Ashar Farhan

I am not sure if you are soliciting my opinion specifically but I will respond as if that is the case.

First, I suspect the four filters will suffice in this case. Because you are using the push-pull amplifiers the pesky second harmonic issue is effectively dealt with. The first harmonic that we have to really worry about is the third and, as can be seen in my photos, it is really the 5th 7th and 9th that are the issues on the lower bands. These are so widely space from the carrier frequency that the suppression can be derived from just 4. I think! :-)

In order to maintain backward compatibility I would design a daughter card that could press fit onto a pattern of posts on the existing main card. The posts should be existing holes that allow picking up input, several grounds, and output. Retrofit would involve removal of two or three strategic components on the existing motherboard, installation of the pins, and plugging the daughter card onto them. I would then supply a “y” jumper cable to pick up power and filter selection signals from the existing connector.

In designing the daughter card it is critical that the input to output isolation be measured carefully with the board unpopulated. If it is not sufficient in this condition it is only going to get worse. Then populate the prototype and measure it again. Finally, install the working model and check it again.

Finally, I think we can likely rely on the software community for this radio to come up with a means of keying and injecting a low level tone that is processed through the filters as SSB in order to remove the discrepancy in harmonic content between SSB and CW.

The modifications should be optional. You have created an incredible product with a crucial price point and its popularity is proof of just that. Many amateurs will turn a pragmatic eye away from the currently non-compliant harmonics and operate the radio as it is. At these levels it is very likely that no one will ever be the wiser and I highly doubt anyone is going to get cited for it.

But, in providing the option, you have given hams who wish to operated according to the letter of the law a pathway to doing exactly that in a fashion that maintains software compatibility across either version.

That is my opinion. Thank you for asking!

WA8TOD


Re: Harmonic performance - SSB vs CW

Mike Woods
 

I would suggest a single relay per LPF (latching relays would be better for QRP use and these could be in circuit on RX as well). In the QRP-Labs approach the relays are midway between the endpoints of the filters (mounted underneath the filter).  This may not be feasible in the uBITx as it would require connectors, etc.  Extra data lines can readily be sourced using i2c for the display (frees up 6 I/O ports). The difference in price between the parallel and i2c versions of the 1602 displays is minimal ... I am not sure why an i2c display wasn't used in the Raduino in the first place?

As Alison will point out, improving isolation in the LPFs will not sort  the problem of flattened response in the TX power line up, and nor will it fix the spurs created in the 45MHz mixer stage.  I am not surprised that constructors may be feeling a bit despondent at this point.... particularly as most of us don't have a 'scope to check up on our own by-products...  It would be great to see some experimentation by someone with the time and knowledge to rework the relay configuration - perhaps using a daughter board in an add-on "second story" to replace the filtering stage.   I would be up to testing  somebody's design ... and I have a few spare data lines, since I am using the Nextion screen :-)

73 Mike ZL1AXG

On 5/08/18 7:40 PM, Raj vu2zap wrote:
Just checked a couple of relays I had new.

Between the coil and contacts it was 0.5-1 (Panasonic) and 1-2pf with another make.

Raj

At 05-08-18, you wrote:
Trying to imaging what the capacitance between the relay contact and the coil connections must be.
--
Mike Woods
mhwoods@...


Re: ubitx and case for sale

Timothy Fidler
 

sorry forgotten your  name .. RIck I think - 

NB I have done some calcs on that coil that A Farhan describes (Many years back) and it comes in at 10.4 uH which is way off where he/you  wants to be for a VFO for a 2.8 to 3 Mhz VFO for 7 Mhz for a 10 Meg IF.  Bear in mind you need to plan on 12 Meg IF filter for the uBitx

If you wish to pursue the option of an analogue Oscillator  to reduce the complexity to start with please contact me but for starters  if you want to do any experimentation you HAVE to have a frequency meter good for at least 10 Mhz and better good to 30 MHz. as per one I gave you vendor and price on.  There are better Air variables still available than the one he called up.  I know where they are advertised in US -  I had a look with respect to buying some for a 100W Z match tuner. You are far better of with an air variable than a voltage tuned varicap diode  which will move around with temperature and self heating,  so dial markings will mean nothing...


Re: One question only...

Marc Jones
 

I think a lot of you are missing the point with the BITX radios , They are basically a kit radio, And are sold as such , They are for experimentation and hack-ability and as such , Experimentation and Modifications are part of the Bitx Experiance .... They are never going to match any of the major radios by the well known manufacturers ... If people are after such performance then there are plenty of top end radios out there .... I person like the challenge of modding  the little BITX radios ,  For the price of these little Radios you'd be hard pressed to buy a decent  commercial power supply ... Let alone a full HF radio such as the Micro-Bitx , Yes it has issues, Yes it's never going to be a TS-990 or IC-7800 etc.
.... But it's a radio you can get inside, Modify, Tweak, Butcher if need be, All in an attempt to make it more personal to you , And challenging to try to get the best from it ........... It's Fun to use, And cheap as Apple pie .

Regards de

Gw0wvl


On Sun, 5 Aug 2018 at 5:48, Brian L. Davis
<brianldavis@...> wrote:
The bottom line question is simply, is this a legal radio or not!
Yes or No?
Which is it?
I appreciate all the technical and intellectual discourse but the bottom line is, IS IT LEGAL OR NOT?
The average HAM wants to buy the unit and put it on the air.  Can that be done without major modifications?
If it can, then nothing is changed and we go on trying to modify or improve.
If it can't, then we need to abandon the project and move on.
So, which is it?
Can I use this radio or not?


Re: Harmonic performance - SSB vs CW

 

Just checked a couple of relays I had new.

Between the coil and contacts it was 0.5-1 (Panasonic) and 1-2pf with another make.

Raj

At 05-08-18, you wrote:
Trying to imaging what the capacitance between the relay contact and the coil connections must be.


Re: One question only...

Christopher Miller
 

What I get out of this is sad. I was one of the last hams in the US to actually have to learn Morse code to be able to have HF privileges. 

To me it seems the hobby is so dumbed down that if you expect to buy an unfinished kit and want to treat it like a Kenwood you probably are in over your head.

This from my understanding was grown out of a desire to in fact provide people in places and economic situations to be able to use hf. 

Find a spectrum analyzer or a person who can if you want to build your own rig. 

KF4FTR


Re: None supprest carrier in TX

George
 

Thanks, I think the same but it still looks all ok with mods but what is under question - wide band amplifiers. If you are interested 4-pole 45 MHz filter with in and out transformes gives 12 kHz/-6dB with 2 dB isertion losses! trans-binocular FT 43-2402 3t/10t.


Re: Harmonic performance - SSB vs CW

Tom, wb6b
 

Hi Gordon,

I agree, it would be nice if someone had some spare relays and could pop one apart and take a picture for us.

In searching around for a picture I did see a SPST miniature relay of the similar outward appearance (just narrower). The design of that relay was terrible. The center contact was electrically connected to the frame and relied in what little insulation that was placed between the coil and the center post the coil was wound around. Trying to imaging what the capacitance between the relay contact and the coil connections must be.

As discussed in other posts there are likely multiple sources of the leakage; capacitive, ground plane impedance, traces routed problematically and whatnot.
 
My modest suggestion would reduce the RF coupling between the two relay pole circuits to that of one relay rather than upwards of three relays (plus PCB traces), as in the current design. Likely, if it is near spec with coupling through three relays, one would be an improvement.  I know many of the suggestion are technically more perfected, but, as the UBITX seems to be close to spec, it may only, as you pointed out, need moderate pushes in the right direction. And solving the issue without increasing the cost of the radio would be important.

Tom, wb6b


Re: One question only...

Warren Allgyer <allgyer@...>
 

Brian

One condition of your license is it is your responsibility to assure your transmissions meet FCC (assuming you live in the United States) requirements. 

My uBitx does not meet those requirement on most bands and modes below 17 meters. While that does mean yours is the same, it would give a reasonable person reason to expect so. 

In the end it is on you to be sure before you put it on the air. 

WA8TOD


Re: One question only...

Gordon Gibby <ggibby@...>
 

Brian,  although I might eventually spring for $700 to get a Rigol, until i do, I'm  "quite certain" that the unit(s) I have are quite legal!    And possibly better in some respects than the vacuum tube SB-102 that I'm hoping to bring back on line, and the homebrew linear I built about 50 years ago.


Ashar might have a different issue as a manufacturer but he's a very bright fellow & I'm sure he'll find a few dB here and there if he decides it has to be done.   And we all might slowly make any changes he suggests...


No one who hears my little 5-10 watt signal can figure out exactly what model radio it comes from and I doubt seriously that anyone will be upset by any tiny signals elsewhere.   I have icom's heathkits, and lots of rigs to use.   


Enjoy ham radio, and keep improving yourself and your gear as you go along!!!


Cheers,


gordon 


From: BITX20@groups.io <BITX20@groups.io> on behalf of Jerry Gaffke via Groups.Io <jgaffke@...>
Sent: Sunday, August 5, 2018 1:12 AM
To: BITX20@groups.io
Subject: Re: [BITX20] One question only...
 
Depends in part on stuff like how much gain the 2n3904's in the 45mhz IF have,
where RV1 is set, how sensitive the mike is.
Those that don't meet spec on some bands and/or modes don't miss it by all that much.
Some users will note that at 5 or 10 watts, it's got weaker obnoxious emissions
than rigs with 100 watts or more that meet spec. 

It should be better.

Jerry

On Sat, Aug 4, 2018 at 09:47 PM, Brian L. Davis wrote:
The bottom line question is simply, is this a legal radio or not!
Yes or No?
Which is it?
I appreciate all the technical and intellectual discourse but the bottom line is, IS IT LEGAL OR NOT?
The average HAM wants to buy the unit and put it on the air.  Can that be done without major modifications?
If it can, then nothing is changed and we go on trying to modify or improve.
If it can't, then we need to abandon the project and move on.
So, which is it?
Can I use this radio or not?


Re: any tips for debugging RFI issue? #ubitx-help

Timothy Fidler
 

Mike , which all goes to prove you are working at the cutting edge of RF technology and should be so grateful to be there :-) 

Timothy E. Fidler : Engineer BE Mech(1) Auckland , NDT specialist AINDT UT /RT3 , MT2 CB #2885, 
Telephone Whangarei   022  691 8405
e: Engstr@...



----- Original Message -----
From:
BITX20@groups.io

To:
<BITX20@groups.io>
Cc:

Sent:
Sat, 04 Aug 2018 22:09:18 -0700
Subject:
Re: [BITX20] any tips for debugging RFI issue? #ubitx-help


I shortened the counterpoise and things got worse.  But after hiding the counterpoise in the rain gutter, things got better.  :-)  Go figure.


73 Mike KK7ER


Re: One question only...

Jerry Gaffke
 

Depends in part on stuff like how much gain the 2n3904's in the 45mhz IF have,
where RV1 is set, how sensitive the mike is.
Those that don't meet spec on some bands and/or modes don't miss it by all that much.
Some users will note that at 5 or 10 watts, it's got weaker obnoxious emissions
than rigs with 100 watts or more that meet spec. 

It should be better.

Jerry


On Sat, Aug 4, 2018 at 09:47 PM, Brian L. Davis wrote:
The bottom line question is simply, is this a legal radio or not!
Yes or No?
Which is it?
I appreciate all the technical and intellectual discourse but the bottom line is, IS IT LEGAL OR NOT?
The average HAM wants to buy the unit and put it on the air.  Can that be done without major modifications?
If it can, then nothing is changed and we go on trying to modify or improve.
If it can't, then we need to abandon the project and move on.
So, which is it?
Can I use this radio or not?


Re: any tips for debugging RFI issue? #ubitx-help

Mike KK7ER
 

I shortened the counterpoise and things got worse.  But after hiding the counterpoise in the rain gutter, things got better.  :-)  Go figure.


73 Mike KK7ER


Re: Bitx40v3 CAT Control firmware?

AA9GG
 

Just take the uBitX software and hack it up accordingly into the BitX40.....


On Sat, Aug 4, 2018 at 12:34 PM, Sean W7SKD <sean.jrdalys@...> wrote:
I have a Bitx40v3 that hasnt been getting much use since I got my ubitx.  I have been thinking about using it for digital modes, but before I do, I need to get firmware on it that will support CAT control.

The ideal situation would be if there was firmware to be found that supported CAT on the USB interface the same way as Ian Lee's CEC firmware for the ubitx.  I have poked around and read through a few of the versions on github and havent found it, so....is there a version of Bitx40v3 firmware out there that supports CAT on the USB interface?

I am a programmer, so I COULD hack together something of a mashup of the bitx40 and ubitx (cec) if it came to it, but looking to see if someone has already done so

Thanks!

Sean




--
Paul Mateer, AA9GG
Elan Engineering Corp.
www.elanengr.com
NAQCC 3123, SKCC 4628