Topics

ubitx compared to Elecraft or Xiegu for spurs #ubitx

 

Has anyone run tests on the popular Elecraft KX3 or the Xiegu 5105 for spurs and harmonics?  How do they compare to the uBITX?
Thanks,
Jim W0CHL

VE3MIC
 

Has anyone looked at the Yaesu FT-991 for spectral purity? :)


On Sun, Aug 12, 2018 at 5:07 PM, Jim Reagan
<jimreagans@...> wrote:
Has anyone run tests on the popular Elecraft KX3 or the Xiegu 5105 for spurs and harmonics?  How do they compare to the uBITX?
Thanks,
Jim W0CHL

ajparent1/KB1GMX
 

My .02 on testing everything in sight...

Send me one of each and a pot load of money I'll write a report. 
You can read the manual as the specs called out are accurate.
That will save a lot on currency.

Why is this in the Bitx at all?

Allison

 

Hey, I'm just curious how all the other portable radio compare....
Are they :"clean"? Specs can be that "special" radio, just for testing.
Your mileage may vary,
Jim W0CHL

lkorahul
 

Put decent RF devices in uBitx and then we compare for sure...

Rahul VU3WJM

Gordon Gibby
 

​Hi Jim,   Allison already did that for a motley crew of raidos, including a Heathkit HW-100 and they all were good to go except I think one reallly clunky design.   The general thing was that most radios are pretty well engineered.   


Gordon



From: BITX20@groups.io <BITX20@groups.io> on behalf of Jim Reagan <jimreagans@...>
Sent: Sunday, August 12, 2018 11:22 PM
To: BITX20@groups.io
Subject: Re: [BITX20] ubitx compared to Elecraft or Xiegu for spurs #ubitx
 
Hey, I'm just curious how all the other portable radio compare....
Are they :"clean"? Specs can be that "special" radio, just for testing.
Your mileage may vary,
Jim W0CHL

iz oos
 

You means spectral purity around the fundamental or the harmonics? Listening to a few hams on VHF, having an SDR receiver, my impression is that around the fundamental they were not very clean. I have to say that many that have that rig have done a simple mod around the mic input to have plenty of punch. Also that radio have also a arsenal of possible equalization. Do the users of these NASA rigs always check for their spectral purity or maybe they take for granted they are clean whatever the mods and equalization?


Il 13/ago/2018 01:28, "VE3MIC via Groups.Io" <ve3mic=yahoo.com@groups.io> ha scritto:
Has anyone looked at the Yaesu FT-991 for spectral purity? :)


On Sun, Aug 12, 2018 at 5:07 PM, Jim Reagan
Has anyone run tests on the popular Elecraft KX3 or the Xiegu 5105 for spurs and harmonics?  How do they compare to the uBITX?
Thanks,
Jim W0CHL

ajparent1/KB1GMX
 

Hey, I'm just curious how all the other portable radio compare....
Are they :"clean"? Specs can be that "special" radio, just for testing.
Your mileage may vary,
Jim W0CHL

Read the specs.  If they don't have them don't buy it.

As a random comment Elecraft anything tends to be very good.
Some of the new imports are largely unknown.
However my CRkits KNQ7A is good.

Allison

ajparent1/KB1GMX
 

Put decent RF devices in uBitx and then we compare for sure...
Rahul VU3WJM

No, better devices made it more noticeable.   There are issues tied to board
layout and lacking filters.  Fix them and we have a competition.

Allison

ajparent1/KB1GMX
 

Iz oos,

>>Do the users of these NASA rigs always check for their spectral purity or maybe they take for granted they are clean whatever the mods and equalization?<<

Some do some never even thought of it.  The Anan users tend to be very fastidious and 
a lot of them use the adaptive feedback (distortion error correction).  Very clean as an
example of what technology can do for transmitters.

Allison

 

Dennis Yancey
 

Seems there are some that don’t realize that “the law was made for man, not man for the law.” There are those that won’t solder a mic connector or PL-259 without permission of the FCC. On the other side, some could care less about the rules or their impact on others. Then there is the masses in between that see a unique toy that is a lot of fun to get into and will teach you a ton about radio. I guess each of us must answer for ourselves what this hobby is all about. 

If Marconi had been under the FCC, he would have never gotten on the air in the first place.
--
72 and God bless
KD4EPG

Jerry Gaffke
 

That -43dB rule is generous, should be easy enough to meet.
And with thousands of QRP devices out there, the cumulative effect s significant.

Warren's spectrum analyzer screenshots show trouble, though to some not just too alarming.
They were taken with gain adjusted for 2W out to the antenna port.
Crank up the audio to where you get 10 or 15 Watts, and the emissions are much worse.
Having over 10x the unwanted emissions of those prescribed in the regs is not an option.

Going 10x the speed limit through a school zone is not an option either.

Jerry


On Mon, Aug 13, 2018 at 08:30 AM, Dennis Yancey wrote:
Seems there are some that don’t realize that “the law was made for man, not man for the law.

Adrian Waiblinger
 

I had a quick look at my KX3 on the specan and its really clean.  Will have to do better test when I get some  time :)
73's VK5ZBR

On 13 August 2018 at 23:54, ajparent1/KB1GMX <kb1gmx@...> wrote:
Hey, I'm just curious how all the other portable radio compare....
Are they :"clean"? Specs can be that "special" radio, just for testing.
Your mileage may vary,
Jim W0CHL

Read the specs.  If they don't have them don't buy it.

As a random comment Elecraft anything tends to be very good.
Some of the new imports are largely unknown.
However my CRkits KNQ7A is good.

Allison




--
Regards 
Adrian

Sunil Sankaranarayanan
 

Allison,
            i have been an early adopter of an ANAN100D .Still  run it daily with Predistortion and CFC etc.
i aslo run the UBitx v3 harmonics spurs and all. Have seen the harmonics and spurs on the Ubitx on my SDR panadpter screen. The price ratio of the ANAN100D to the Ubitx here is greater than 25:1.

Perhaps a future Ubitx ver.XX will feature Predistortion ad CFC tools etc and still be 25 times cheaper than the ANAN XXXX .
73
Sunil VU2MTM

ajparent1/KB1GMX
 

Sunil,

It takes a lot of hardware to get predistortion and CFC to go.
Basic clean is not that hard though even if the Anan is easily 10 to 100X better.
But you have to start with a good design and then take out the easy flaws,
the harder ones are then better isolated.

Allison

ajparent1/KB1GMX
 

>>>I had a quick look at my KX3 on the specan and its really clean.  Will have to do better test when I get some  time :)
73's VK5ZBR

Over the years I have had the chance to check out most all of the Elecraft lineup.
For pit FD site the are the preferred radio for being clean (all models).  The look
good on bandscopes.  The acid test is two of them on the same band running
phone and CW and not having mutual interference.

That and look at the specs.

Allison

Jim Myers <kd7eir@...>
 

Comparing a multi-thousand dollar commercial radio product to the uBITX is silly.

lkorahul
 

Allison, Sunil and others,

I was involved in  design  of Anan transceivers. Getting the filters right did involve lot of work. Isolation, trace impedance and via size all contributed to filter response. PCB layout also had some impact on gain of PA chain across the HF bands to 6 mtrs. First production run boards came out after 3 iterations.
Another issue was getting a low and straight line on the noise floor upto 6 mtrs but that is another story.
 
Capt Sunil was first VU customer and he ended up paying more than the Dx cost for the radio.. the local VAT.  

Farhan visited me and was witness to LDMOS PA development.

Rahul VU3WJM